/* CSS Variables for theming */
:root {
    --bg-primary: #e8e8e8;
    --bg-secondary: #f5f5f5;
    --text-primary: #2c2c2c;
    --text-secondary: #555555;
    --border-color: #cccccc;
    --border-strong: #b5b5b5;
    --shadow: rgba(0, 0, 0, 0.1);
    /* Terminal-green identity. --brand is the exact logo phosphor green (used
       for brand moments); --accent is a slightly deeper green kept legible for
       buttons / links / borders on a light ground. */
    --brand: #52dc3f;
    --accent: #2ea043;
    --accent-hover: #24913a;
    --canvas-bg: #ffffff;
    --paper-bg: #fdf6e3;
    --panel-surface: #f9f9f9;
    --panel-surface-strong: #ededed;
    --panel-glow: rgba(255, 255, 255, 0.45);
    --panel-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2c2c2c;
    --text-primary: #cccccc;
    --text-secondary: #888888;
    --border-color: #3a3a3a;
    --border-strong: #4a4a4a;
    --shadow: rgba(0, 0, 0, 0.3);
    /* On the dark theme the phosphor green reads well as the accent itself. */
    --brand: #52dc3f;
    --accent: #3fb950;
    --accent-hover: #52dc3f;
    --canvas-bg: #ffffff;
    --paper-bg: #fdf6e3;
    --panel-surface: #262626;
    --panel-surface-strong: #2f2f2f;
    --panel-glow: rgba(255, 255, 255, 0.05);
    --panel-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    overscroll-behavior: none;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    -webkit-tap-highlight-color: transparent;
}

/* Walkthrough Modal */
.walkthrough-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 15, 18, 0.96);
    backdrop-filter: blur(8px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 32px;
    opacity: 1;
    animation: fadeIn 0.3s ease-out;
}

.walkthrough-modal.hidden {
    display: none;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.walkthrough-content {
    background: #1a1c20;
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
    padding: 32px;
    width: min(720px, calc(100% - 32px));
    max-width: 720px;
    max-height: calc(100vh - 80px);
    overflow-y: auto;
    box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55);
    animation: slideUp 0.4s ease-out;
    position: relative;
}

.walkthrough-content > * {
    position: relative;
    z-index: 1;
}

/* Dim the background photo (Gran's garden) down to a faint watermark so the
   text reads clearly on top of it. Sits above the image, below the content. */
.walkthrough-content::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: rgba(16, 18, 22, 0.8);
    z-index: 0;
    pointer-events: none;
}

@keyframes slideUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes dropdownSlideUp {
    from {
        transform: translateY(60px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.walkthrough-close {
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    font-size: 28px;
    color: rgba(255, 255, 255, 0.75);
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background 0.2s ease, color 0.2s ease;
    z-index: 2;
}

.walkthrough-close:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #ffffff;
}

.walkthrough-slide {
    display: none;
    animation: slideIn 0.4s ease-out;
}

.walkthrough-slide.active {
    display: block;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.walkthrough-header {
    text-align: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 2px solid rgba(255, 255, 255, 0.25);
}

.walkthrough-logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 16px;
    display: block;
    border-radius: 12px;
}

.walkthrough-header h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.walkthrough-subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

.walkthrough-body {
    min-height: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.walkthrough-image {
    width: 100%;
    max-width: 400px;
    margin-bottom: 20px;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.walkthrough-image img {
    width: 100%;
    height: auto;
    display: block;
}

.walkthrough-body h2 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 14px;
    color: #ffffff;
    text-align: left;
}

.walkthrough-body p {
    font-size: 15px;
    line-height: 1.55;
    color: #d6d8de;
    margin-bottom: 12px;
    text-align: left;
}

.walkthrough-body ul {
    align-self: stretch;
    margin: 2px 0 14px;
    padding-left: 20px;
    list-style: disc;
    text-align: left;
    color: #d6d8de;
}
.walkthrough-body ul li {
    font-size: 15px;
    line-height: 1.55;
    margin-bottom: 8px;
}
.walkthrough-body ul li strong,
.walkthrough-body p strong {
    color: #ffffff;
    font-weight: 600;
}

/* Walkthrough welcome slide text contrast */
.walkthrough-content .walkthrough-header h1,
.walkthrough-content .walkthrough-subtitle,
.walkthrough-content .walkthrough-body h2,
.walkthrough-content .walkthrough-body p,
.walkthrough-content .walkthrough-body ul {
    color: #ffffff;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.85), 0 2px 12px rgba(0, 0, 0, 0.55);
}

.walkthrough-navigation {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 24px;
    padding-top: 16px;
    border-top: 2px solid rgba(255, 255, 255, 0.25);
}

.walkthrough-nav-btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    background: var(--accent);
    color: white;
    transition: all 0.2s ease;
}

.walkthrough-nav-btn:hover {
    background: var(--accent-hover);
}

.walkthrough-nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.walkthrough-nav-btn.primary {
    background: #5a8dee;
}

.walkthrough-nav-btn.primary:hover {
    background: #4a7dde;
}

.walkthrough-dots {
    display: flex;
    gap: 8px;
    align-items: center;
}

.walkthrough-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border-color);
    cursor: pointer;
    transition: all 0.2s ease;
}

.walkthrough-dot:hover {
    background: var(--accent);
}

.walkthrough-dot.active {
    background: #5a8dee;
    width: 12px;
    height: 12px;
}

.walkthrough-footer {
    margin-top: 16px;
    text-align: center;
}

/* Bigger, centered tap target for "Do not show again" so it's easy to hit. */
.walkthrough-footer .checkbox-label {
    display: inline-flex;
    padding: 10px 8px;
}

/* Mobile responsiveness */
@media (max-width: 600px) {
    .walkthrough-modal {
        padding: 12px;
    }

    .walkthrough-content {
        /* Reserve the iOS safe-area insets so the last element (the
           "Do not show again" checkbox) is never hidden behind the notch or the
           home indicator in an installed PWA - which made it un-tappable. dvh
           tracks the real visible height on iOS better than vh. */
        padding: calc(18px + env(safe-area-inset-top)) 18px calc(12px + env(safe-area-inset-bottom));
        max-height: calc(100dvh - 24px);
        max-width: 100%;
        width: 100%;
    }

    .walkthrough-header h1 {
        font-size: 22px;
    }

    .walkthrough-body h2 {
        font-size: 19px;
        margin-bottom: 10px;
    }

    .walkthrough-body p {
        font-size: 14px;
        line-height: 1.5;
        margin-bottom: 10px;
    }

    .walkthrough-body ul {
        padding-left: 18px;
    }

    .walkthrough-body ul li {
        font-size: 14px;
        line-height: 1.5;
        margin-bottom: 6px;
    }

    .walkthrough-body {
        min-height: auto;
        align-items: stretch;
    }

    .walkthrough-nav-btn {
        padding: 8px 14px;
        font-size: 13px;
    }

    .walkthrough-image {
        max-width: 100%;
    }
}

/* Advanced Color Panel */
.advanced-backdrop {
    display: none;
}

.advanced-panel {
    position: fixed;
    top: 0;
    left: 0;
    width: 380px;
    max-width: 100%;
    height: 100%;
    background: linear-gradient(165deg, var(--bg-secondary) 0%, var(--panel-surface) 55%, var(--bg-secondary) 100%);
    box-shadow: 12px 0 30px rgba(0, 0, 0, 0.3);
    border-right: 1px solid var(--border-strong);
    z-index: 1000;
    padding: 20px 20px 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    min-height: 0;
    overflow: hidden;
    transform: translateX(-100%);
    transition: transform 0.3s ease, opacity 0.3s ease, box-shadow 0.3s ease;
    opacity: 0;
}

.advanced-panel.show {
    transform: translateX(0);
    opacity: 1;
}

@media (min-width: 1200px) {
    .advanced-panel {
        width: 420px;
    }

    .inspector-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.advanced-panel.hidden,
.advanced-backdrop.hidden {
    display: none;
}

.advanced-panel-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
}

.panel-kicker {
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.advanced-panel-header h3 {
    font-size: 20px;
    color: var(--text-primary);
}

.advanced-panel-body {
    display: flex;
    flex-direction: column;
    gap: 16px;
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    padding-right: 4px;
}

.advanced-panel-body > .wheel-section,
.advanced-panel-body > .slider-group,
.advanced-panel-body > .palette-section,
.advanced-panel-body > .inspector-section,
.advanced-panel-body > .harmony-section,
.advanced-panel-body > .palette-manager,
.advanced-panel-body > .gradient-builder,
.advanced-panel-body > .image-extract,
.advanced-panel-body > .current-color-row {
    background: var(--panel-surface);
    border: 1px solid var(--border-strong);
    border-radius: 12px;
    box-shadow: var(--panel-shadow);
    padding: 12px 12px 14px;
}

/* When the wheel + lightness + artist palettes are wrapped in .wheel-section,
   the inner blocks no longer need their own card backgrounds (the wrapper
   provides one). Keep them visually grouped instead. */
.wheel-section {
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.wheel-section > .slider-group,
.wheel-section > .palette-section,
.wheel-section > .current-color-row {
    background: transparent;
    border: none;
    box-shadow: none;
    padding: 0;
}
.wheel-section > .current-color-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.advanced-panel-body > .current-color-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.color-wheel-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 1 / 1;
    max-width: 280px;
    align-self: center;
}

#color-wheel-canvas {
    width: 100%;
    height: 100%;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 18px var(--shadow);
}

.color-wheel-indicator {
    position: absolute;
    width: 16px;
    height: 16px;
    border: 2px solid #fff;
    border-radius: 50%;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.35);
    transform: translate(-50%, -50%);
    pointer-events: none;
}

.slider-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text-primary);
}

.slider-row {
    display: flex;
    align-items: center;
    gap: 10px;
}

#lightness-slider {
    flex: 1;
}

.slider-value {
    min-width: 40px;
    text-align: right;
    color: var(--text-secondary);
}

.palette-section {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.palette-manager {
    display: flex;
    flex-direction: column;
    gap: 10px;
    position: sticky;
    top: 8px;
    z-index: 2;
    order: -1;
}

.palette-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 8px;
}

.palette-header h4 {
    font-size: 15px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--text-primary);
}

.palette-note {
    font-size: 12px;
    color: var(--text-secondary);
}

.gradient-swatches {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: 10px;
}

.gradient-swatch {
    height: 40px;
    border-radius: 10px;
    border: 1px solid var(--border-strong);
    box-shadow: 0 6px 12px var(--shadow);
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.gradient-swatch:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 18px var(--shadow);
    border-color: var(--accent);
}

.current-color-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: var(--bg-primary);
}

.color-chip {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    border: 2px solid var(--border-strong);
    box-shadow: inset 0 0 0 1px rgba(0,0,0,0.15), 0 6px 12px var(--shadow);
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.inspector-actions {
    display: flex;
    gap: 8px;
}

.section-header h4 {
    font-size: 14px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-primary);
    cursor: pointer;
    user-select: none;
    -webkit-tap-highlight-color: rgba(90, 141, 238, 0.18);
}

/* Chevron indicator prefixed to the h4 text. Bigger and accent-colored so
   it reads as an interactive affordance, not decoration. */
.section-header h4::before {
    content: '\25BE';
    display: inline-block;
    color: var(--accent);
    font-size: 16px;
    line-height: 1;
    transition: transform 0.2s ease;
    transform-origin: 50% 55%;
    margin-right: 8px;
    vertical-align: -1px;
}
.collapsed > .section-header h4::before {
    transform: rotate(-90deg);
}
.section-header h4:hover {
    color: var(--accent);
}

/* Collapse hides everything in the section except the header itself. Works
   for any Color Lab section that uses .section-header. */
.advanced-panel-body .collapsed > *:not(.section-header) {
    display: none;
}
.advanced-panel-body .collapsed > .section-header {
    border-bottom: none;
    padding-bottom: 0;
}

.inspector-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
}

.inspector-grid label {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding: 10px 10px 9px;
    border: 1px solid var(--border-strong);
    border-radius: 10px;
    background: var(--panel-surface-strong);
    color: var(--text-primary);
    font-size: 12px;
    box-shadow: 0 4px 12px var(--shadow);
}

.inspector-grid input {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-weight: 600;
}

.mini-btn {
    padding: 6px 10px;
    border-radius: 8px;
    border: 1px solid var(--border-strong);
    background: linear-gradient(180deg, var(--panel-surface) 0%, var(--bg-primary) 100%);
    color: var(--text-primary);
    cursor: pointer;
    font-weight: 700;
    letter-spacing: 0.01em;
    transition: all 0.2s ease;
    box-shadow: 0 4px 10px var(--shadow);
}

.mini-btn:hover {
    background: var(--panel-surface-strong);
    border-color: var(--accent);
    transform: translateY(-1px);
}

.swatch-row {
    display: flex;
    flex-wrap: nowrap;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 4px;
}

.swatch-row .swatch,
.swatch-list .swatch {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    border: 2px solid var(--border-color);
    cursor: pointer;
    box-shadow: 0 2px 6px var(--shadow);
}

.palette-manager .swatch-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    overflow: visible;
    padding-bottom: 6px;
}

.palette-swatch-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 8px 10px;
    border: 1px solid var(--border-strong);
    border-radius: 10px;
    background: linear-gradient(180deg, var(--panel-surface) 0%, var(--bg-primary) 100%);
    min-width: 88px;
    box-shadow: 0 6px 14px var(--shadow);
}

.palette-swatch-controls {
    display: flex;
    gap: 4px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.15s ease;
}

.palette-swatch-item:hover .palette-swatch-controls,
.palette-swatch-item:focus-within .palette-swatch-controls {
    opacity: 1;
    pointer-events: auto;
}

.palette-save-row,
.palette-load-row,
.palette-io-row {
    display: flex;
    gap: 8px;
    align-items: center;
}

.palette-save-row input,
.palette-load-row select {
    flex: 1;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-primary);
    color: var(--text-primary);
}

.recent-row h5 {
    margin-bottom: 6px;
    color: var(--text-primary);
}

.gradient-builder {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.gradient-stop-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.gradient-stop-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border: 1px solid var(--border-strong);
    border-radius: 10px;
    background: var(--panel-surface);
    box-shadow: 0 6px 14px var(--shadow);
}

.gradient-stop-item input[type="range"] {
    flex: 1;
    pointer-events: auto;
    -webkit-appearance: none;
    appearance: none;
    height: 10px;
    background: transparent;
}

.gradient-stop-item input[type="range"]::-webkit-slider-runnable-track {
    height: 4px;
    background: var(--border-strong);
    border-radius: 999px;
}

.gradient-stop-item input[type="range"]::-moz-range-track {
    height: 4px;
    background: var(--border-strong);
    border-radius: 999px;
}

.gradient-stop-item input[type="range"]::-webkit-slider-thumb,
.gradient-stop-item input[type="range"]::-moz-range-thumb {
    pointer-events: auto;
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--text-primary);
    border: 2px solid var(--bg-primary);
    box-shadow: 0 2px 6px var(--shadow);
    margin-top: -6px;
}

.gradient-stop-color {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    border: 2px solid var(--border-color);
    box-shadow: 0 2px 6px var(--shadow);
}

.gradient-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.image-extract .extract-controls {
    display: flex;
    align-items: center;
    gap: 8px;
}

.image-extract select,
.harmony-section select,
.gradient-builder select {
    padding: 8px 10px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--text-primary);
}

.swatch-list .swatch-button {
    width: 32px;
    height: 32px;
    border: 2px solid var(--border-strong);
    border-radius: 8px;
    cursor: pointer;
    box-shadow: 0 6px 12px var(--shadow);
    transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.swatch-list .swatch-button:hover,
.swatch-row .swatch-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 18px var(--shadow);
    border-color: var(--accent);
}

@media (max-width: 720px) {
    .advanced-panel {
        width: 100%;
        max-width: 100vw;
        padding: 16px 14px 20px;
        box-sizing: border-box;
        overflow-x: hidden;
    }

    .advanced-panel-body {
        padding-right: 0;
        gap: 12px;
    }

    .advanced-panel-body > .slider-group,
    .advanced-panel-body > .palette-section,
    .advanced-panel-body > .inspector-section,
    .advanced-panel-body > .harmony-section,
    .advanced-panel-body > .palette-manager,
    .advanced-panel-body > .gradient-builder,
    .advanced-panel-body > .image-extract,
    .advanced-panel-body > .current-color-row {
        padding: 10px;
    }

    .palette-swatch-item {
        min-width: 64px;
        padding: 6px 8px;
    }

    #gradient-preview,
    #color-wheel-canvas {
        max-width: 100%;
    }

    /* Mobile-friendly Advanced tab improvements */
    .inspector-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .inspector-grid label {
        padding: 10px;
        font-size: 14px;
    }

    .inspector-grid input {
        width: 100%;
        padding: 8px;
        font-size: 14px;
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .section-header h4 {
        font-size: 16px;
    }

    .inspector-actions,
    .palette-actions {
        width: 100%;
        justify-content: stretch;
    }

    .inspector-actions .mini-btn,
    .palette-actions .mini-btn {
        flex: 1;
        padding: 10px;
        font-size: 14px;
        min-height: 44px;
    }

    .mini-btn {
        padding: 10px 12px;
        font-size: 14px;
        min-height: 44px;
    }

    .harmony-section select,
    .gradient-builder select,
    .image-extract select {
        padding: 10px;
        font-size: 14px;
        min-height: 44px;
    }

    .palette-save-row input,
    .palette-load-row select {
        padding: 10px;
        font-size: 14px;
        min-height: 44px;
    }

    .gradient-actions {
        flex-direction: column;
    }

    .gradient-actions .mini-btn,
    .gradient-actions .secondary-btn {
        width: 100%;
        padding: 12px;
        font-size: 14px;
    }

    .image-extract .extract-controls {
        flex-wrap: wrap;
    }

    .image-extract .extract-controls label,
    .image-extract .extract-controls select {
        font-size: 14px;
    }

    .palette-io-row {
        flex-direction: column;
    }

    .palette-io-row .mini-btn {
        width: 100%;
    }
}

.primary-btn, .secondary-btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: 48px;
}

.primary-btn {
    background: var(--accent);
    color: white;
}

.primary-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(90, 141, 238, 0.3);
}

.secondary-btn {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.secondary-btn:hover {
    background: var(--border-color);
    transform: translateY(-1px);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #555555;
    cursor: pointer;
    user-select: none;
}

[data-theme="dark"] .checkbox-label {
    color: #888888;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

/* Main App */
#app {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* Menu Toggle Button (Hamburger) */
.menu-toggle {
    position: fixed;
    top: max(env(safe-area-inset-top, 0px) + 12px, 12px);
    left: max(env(safe-area-inset-left, 0px) + 12px, 12px);
    width: 44px;
    height: 44px;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    z-index: 100;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    padding: 8px;
    box-shadow: 0 2px 8px var(--shadow);
    transition: background 0.3s ease, transform 0.2s ease;
}

.color-wheel-toggle {
    position: fixed;
    top: max(env(safe-area-inset-top, 0px) + 12px, 12px);
    left: max(env(safe-area-inset-left, 0px) + 64px, 64px);
    right: auto;
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, #ff8a00, #e52e71, #5a8dee);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    cursor: pointer;
    z-index: 100;
    display: grid;
    place-items: center;
    box-shadow: 0 2px 8px var(--shadow);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.color-wheel-toggle:hover {
    transform: scale(1.06);
    box-shadow: 0 4px 12px var(--shadow);
}

.color-wheel-toggle:active {
    transform: scale(0.95);
}

.color-wheel-icon {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: conic-gradient(#ff5f6d, #ffc371, #00c6ff, #7f5a83, #ff5f6d);
    box-shadow: inset 0 0 0 2px rgba(0, 0, 0, 0.2);
}

.menu-toggle:hover {
    background: var(--border-color);
    transform: scale(1.05);
}

.menu-toggle:active {
    transform: scale(0.95);
}

.hamburger-line {
    width: 24px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* Hamburger animation when menu is collapsed */
.menu-collapsed .menu-toggle .hamburger-line:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.menu-collapsed .menu-toggle .hamburger-line:nth-child(2) {
    opacity: 0;
}

.menu-collapsed .menu-toggle .hamburger-line:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* Navbar */
.navbar {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 12px 16px;
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
    box-shadow: 0 2px 8px var(--shadow);
    z-index: 10;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

/* Navbar collapsed state */
.menu-collapsed .navbar {
    transform: translateY(-200%);
    opacity: 0;
    pointer-events: none;
    display: none;
}

.nav-section {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.nav-section label {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
}

.colors-section {
    flex: 1;
    min-width: 200px;
    margin-left: auto;
    justify-content: flex-end;
}

.colors-section-body {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
}

/* Small chevron button that collapses the palette body to reclaim navbar
   space. Hidden on desktop where there's plenty of room. */
.colors-collapse-btn {
    display: none;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    width: 26px;
    height: 26px;
    font-size: 14px;
    line-height: 1;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0;
    touch-action: manipulation;
    transition: transform 0.2s ease;
}
.colors-collapse-btn:hover {
    color: var(--text-primary);
    border-color: var(--text-secondary);
}
.colors-section.collapsed .colors-collapse-btn {
    transform: rotate(-90deg);
}
.colors-section.collapsed .colors-section-body,
.colors-section.collapsed > label {
    display: none;
}

.color-swatches {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    margin-left: auto;
}

.preset-swatches {
    display: none;
}

.palette-inline-group {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: 8px;
    padding-left: 10px;
    border-left: 1px solid var(--border-color);
}

.palette-inline {
    flex-wrap: wrap;
    gap: 6px;
    margin-left: 0;
}

.palette-inline-label {
    font-size: 12px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-secondary);
}

.hidden-inline {
    display: none;
}

.palette-inline-swatch {
    width: 28px;
    height: 28px;
    border: 2px solid var(--border-strong);
    border-radius: 8px;
    box-shadow: 0 3px 8px var(--shadow);
    cursor: pointer;
    background: var(--bg-primary);
}

.palette-inline-swatch.active {
    box-shadow: 0 0 0 2px var(--bg-secondary), 0 0 0 4px var(--accent), 0 6px 12px var(--shadow);
}

.color-swatch {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease;
}

.color-swatch:hover {
    transform: scale(1.1);
    box-shadow: 0 2px 8px var(--shadow);
}

.color-swatch.active {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--bg-secondary), 0 0 0 4px var(--accent);
}

#custom-color {
    width: 32px;
    height: 32px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    background: none;
}

#pen-size {
    width: 100px;
    cursor: pointer;
}

#pen-size-value {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    min-width: 24px;
    text-align: center;
}

#brush-texture {
    padding: 6px 12px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    min-height: 36px;
}

.actions-section {
    gap: 8px;
}

.settings-section {
    margin-left: auto;
}

.zoom-section {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 8px;
    background: var(--bg-primary);
    border-radius: 6px;
    border: 1px solid var(--border-color);
}

#zoom-level {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    min-width: 45px;
    text-align: center;
}

.tool-btn {
    padding: 8px 16px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: 36px;
    white-space: nowrap;
}

.tool-btn:hover {
    background: var(--border-color);
    transform: translateY(-1px);
}

.tool-btn:active {
    transform: translateY(0);
}

.tool-btn.primary {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

.tool-btn.primary:hover {
    background: var(--accent-hover);
}

.tool-btn.active {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

.checkbox-label.small {
    font-size: 13px;
}

.checkbox-label.small input[type="checkbox"] {
    width: 16px;
    height: 16px;
}

/* Canvas Container */
#canvas-container {
    flex: 1;
    position: relative;
    overflow: hidden;
    background: var(--canvas-bg);
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
}

/* Background canvas - bottom layer */
#bgCanvas {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
    z-index: 1;
}

/* Drawing canvas - middle layer */
#drawCanvas {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    touch-action: none;
    cursor: crosshair;
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
    z-index: 2;
}

/* Overlay canvas - top layer for previews */
#overlay-canvas {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    touch-action: none;
    pointer-events: none;
    user-select: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
    z-index: 5;
}

#canvas-container.paper-mode {
    background: var(--paper-bg);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: 12px 24px;
    border-radius: 8px;
    box-shadow: 0 4px 16px var(--shadow);
    z-index: 999;
    opacity: 0;
    transition: all 0.3s ease;
    font-size: 14px;
    max-width: 90%;
    text-align: center;
    pointer-events: none;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    pointer-events: auto;
}

.toast button {
    margin-left: 12px;
    padding: 4px 12px;
    border: none;
    border-radius: 4px;
    background: var(--accent);
    color: white;
    cursor: pointer;
    font-size: 13px;
}

/* Safe area support for iOS */
@supports (padding: max(0px)) {
    .navbar {
        padding-left: max(16px, env(safe-area-inset-left));
        padding-right: max(16px, env(safe-area-inset-right));
        padding-top: max(12px, env(safe-area-inset-top));
    }
    
    #canvas-container {
        padding-left: env(safe-area-inset-left);
        padding-right: env(safe-area-inset-right);
        padding-bottom: env(safe-area-inset-bottom);
    }
}

/* Mobile optimizations */
@media (max-width: 768px), (max-height: 500px) {
    .navbar {
        padding: 8px 12px;
        gap: 10px;
    }

    .nav-section {
        gap: 6px;
    }

    .nav-section label {
        font-size: 13px;
    }

    .tool-btn {
        padding: 8px 12px;
        font-size: 13px;
        min-height: 40px;
    }

    .color-swatch {
        width: 30px;
        height: 30px;
    }

    #custom-color {
        width: 30px;
        height: 30px;
    }

    .intro-content {
        padding: 24px;
    }

    .intro-header h1 {
        font-size: 28px;
    }
}

/* Phone-specific layout: full mobile app bar at the bottom (wraps so nothing
   gets cut off). The hamburger toggle still hides it entirely for full-screen
   drawing. Fires on both narrow viewports (portrait phones) and short ones
   (landscape phones), since landscape iPhones can be wider than 600px
   (e.g. 844x390). */
@media (max-width: 600px), (max-height: 500px) {
    /* Full mobile app bar pinned to the BOTTOM of the viewport. Items wrap
       onto rows that build UPWARD (wrap-reverse), so the toggles always sit
       on the bottom row beside the first items, with no wasted left-column
       space on the rows above. */
    .navbar {
        position: fixed;
        left: 0;
        right: 0;
        bottom: 0;
        top: auto;
        flex-wrap: wrap-reverse;
        row-gap: 8px;
        column-gap: 10px;
        padding-top: 10px;
        padding-bottom: max(env(safe-area-inset-bottom, 0px) + 10px, 10px);
        padding-left: max(env(safe-area-inset-left, 0px) + 10px, 10px);
        padding-right: max(env(safe-area-inset-right, 0px) + 10px, 10px);
        background: var(--bg-secondary);
        border-top: 1px solid var(--border-color);
        border-bottom: none;
        box-shadow: 0 -2px 12px var(--shadow);
        max-height: 55vh;
        overflow-y: auto;
        z-index: 99;
        align-items: center;
    }

    /* Spacer reserves room on the BOTTOM row for the position:fixed toggles. */
    .navbar::before {
        content: '';
        flex: 0 0 102px;
        height: 44px;
        order: -1;
    }

    .navbar > .nav-section {
        flex: 0 0 auto;
        margin: 0;
        padding: 0;
        border-left: none;
    }

    .colors-section,
    .settings-section,
    .status-section {
        margin-left: 0;
        justify-content: flex-start;
    }

    .colors-section {
        min-width: 0;
    }

    /* Show the palette collapse chevron on phones - the swatches eat too
       much horizontal space otherwise. */
    .colors-collapse-btn {
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .nav-section label {
        display: none; /* labels eat too much room on phones */
    }

    #pen-size {
        width: 80px;
    }

    #brush-texture {
        max-width: 140px;
    }

    .status-section {
        gap: 6px;
    }

    .tool-status {
        font-size: 11px;
        padding: 4px 8px;
    }

    /* Toggles anchor to the bottom-left, inside the navbar's reserved padding. */
    .menu-toggle,
    .color-wheel-toggle {
        top: auto;
        bottom: max(env(safe-area-inset-bottom, 0px) + 12px, 12px);
    }
    .menu-toggle {
        left: max(env(safe-area-inset-left, 0px) + 12px, 12px);
    }
    .color-wheel-toggle {
        left: max(env(safe-area-inset-left, 0px) + 62px, 62px);
    }

    /* Tools dropdown opens UPWARD from the bottom navbar.
       !important + #tools-menu specificity overrides the desktop base rule
       below (`position: absolute; top: 100%`) which would otherwise apply on
       mobile because of CSS source order and push the menu off-screen below. */
    .dropdown-menu,
    #tools-menu {
        position: fixed !important;
        top: auto !important;
        left: 8px !important;
        right: 8px !important;
        bottom: max(env(safe-area-inset-bottom, 0px) + 110px, 110px) !important;
        max-width: calc(100vw - 16px) !important;
        max-height: 60vh !important;
        overflow-y: auto;
        z-index: 9999 !important;
        border-radius: 12px;
        box-shadow: 0 -8px 24px rgba(0, 0, 0, 0.35);
    }
    #tools-menu.show {
        animation: dropdownSlideUp 0.22s ease-out;
    }

    /* Color Lab panel needs to clear the bottom navbar so its content + close
       button remain reachable. */
    .advanced-panel {
        top: max(env(safe-area-inset-top, 0px), 0px);
        height: auto;
        bottom: max(env(safe-area-inset-bottom, 0px) + 130px, 130px);
    }
}

/* Update-available banner. Pinned at the top of the viewport so the user can
   see a new deploy is ready. Stays put until they tap "Update now" or dismiss. */
.update-banner {
    position: fixed;
    /* Banner is flush to the top edge so its background fills behind the iOS
       status bar (looks intentional). The content has its own top padding to
       clear the status bar - see .update-banner-content below. */
    top: 0;
    left: 0;
    right: 0;
    z-index: 300;
    background: linear-gradient(135deg, #4a90e2, #5a8dee);
    color: #ffffff;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
    transform: translateY(-100%);
    transition: transform 0.35s ease;
    pointer-events: auto;
}
.update-banner:not(.hidden) {
    transform: translateY(0);
}
.update-banner.hidden {
    pointer-events: none;
}
.update-banner-content {
    max-width: 720px;
    margin: 0 auto;
    /* Top padding clears the iOS status bar (time / signal / battery overlay).
       Use safe-area-inset-top when it's reported (~44-59px on notch devices /
       PWA standalone), else fall back to a hardcoded 44px minimum so the
       content is never hidden behind the system status bar. */
    padding: max(env(safe-area-inset-top, 0px) + 8px, 44px) 14px 12px;
    display: flex;
    align-items: center;
    gap: 12px;
}
.update-banner-icon {
    font-size: 22px;
    line-height: 1;
    animation: update-spin 2.5s linear infinite;
}
@keyframes update-spin {
    to { transform: rotate(360deg); }
}
.update-banner-text {
    flex: 1;
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}
.update-banner-text strong {
    font-size: 14px;
    font-weight: 600;
}
.update-banner-sub {
    font-size: 12px;
    opacity: 0.85;
}
.update-banner-btn {
    background: rgba(255, 255, 255, 0.95);
    color: #2c5aa0;
    border: none;
    border-radius: 6px;
    padding: 8px 14px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    touch-action: manipulation;
    white-space: nowrap;
}
.update-banner-btn:hover {
    background: #ffffff;
}
.update-banner-btn:active {
    transform: scale(0.96);
}
.update-banner-close {
    background: transparent;
    color: #ffffff;
    border: none;
    font-size: 22px;
    line-height: 1;
    padding: 4px 8px;
    cursor: pointer;
    opacity: 0.8;
    touch-action: manipulation;
}
.update-banner-close:hover {
    opacity: 1;
}

/* Auto-generated version footer. Sits at the bottom-right of the viewport on
   desktop; on phones the bottom navbar is fixed at bottom: 0 so the footer
   floats just above it. Empty until JS populates it on first paint. */
.app-footer {
    position: fixed;
    right: max(env(safe-area-inset-right, 0px) + 10px, 10px);
    bottom: max(env(safe-area-inset-bottom, 0px) + 6px, 6px);
    z-index: 200;
    pointer-events: none;
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 11px;
    line-height: 1;
    opacity: 0.7;
    user-select: none;
    -webkit-user-select: none;
}

.app-footer:empty,
.app-footer:has(.app-version-link:empty) {
    display: none;
}

.app-version-link {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 3px 7px;
    border-radius: 8px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    pointer-events: auto;
    white-space: nowrap;
}

.app-version-link:hover {
    opacity: 1;
    color: var(--text-primary);
}

@media (max-width: 600px), (max-height: 500px) {
    /* On phones, the version chip is HIDDEN whenever the bottom navbar (design
       bar) is open - it would otherwise sit on top of toolbar buttons and
       block taps on Tools / Help / etc. The chip only appears when the menu
       is collapsed (no bottom bar). #app.menu-collapsed ~ .app-footer uses the
       general sibling combinator because .app-footer is a sibling of #app,
       not a child. */
    .app-footer {
        display: none;
    }
    #app.menu-collapsed ~ .app-footer {
        display: block;
        right: max(env(safe-area-inset-right, 0px) + 8px, 8px);
        bottom: max(env(safe-area-inset-bottom, 0px) + 4px, 4px);
    }
}

/* Interactive elements should never trigger pinch-zoom / double-tap-zoom on
   touch devices - these gestures fight with the drawing UI. */
.tool-btn,
.color-swatch,
.gradient-swatch,
.menu-toggle,
.color-wheel-toggle,
.palette-inline-swatch,
.shape-btn,
.dropdown-item,
.walkthrough-nav-btn,
.walkthrough-dot,
.primary-btn,
.secondary-btn,
.mini-btn,
.close-btn,
#custom-color {
    touch-action: manipulation;
}

/* Status pills */
.status-section {
    margin-left: auto;
    gap: 12px;
}

.tool-status {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    background: var(--bg-primary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    white-space: nowrap;
}

/* Modal Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    opacity: 1;
    animation: fadeIn 0.3s ease-out;
}

.modal-overlay.hidden {
    display: none;
}

.modal-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-top: 3px solid var(--accent);
    border-radius: 14px;
    max-width: 600px;
    width: 100%;
    max-height: min(90vh, 90dvh);
    overflow-y: auto;
    box-shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
    animation: slideUp 0.4s ease-out;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 22px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    font-size: 21px;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
    letter-spacing: 0.01em;
}

/* Terminal-brand cue: a green ">_" before every modal title. */
.modal-header h2::before {
    content: ">_ ";
    color: var(--brand);
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-weight: 700;
}

.close-btn {
    background: none;
    border: none;
    font-size: 32px;
    line-height: 1;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    transition: all 0.2s ease;
}

.close-btn:hover {
    background: var(--bg-primary);
    color: var(--text-primary);
}


.info-box {
    background: var(--bg-primary);
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    border-left: 4px solid var(--accent);
}

.info-box p {
    margin: 0 0 8px 0;
    font-size: 14px;
    color: var(--text-primary);
}

.info-box ol {
    margin: 8px 0 0 20px;
    padding: 0;
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.info-box li {
    margin-bottom: 4px;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input[type="password"],
.form-group textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 14px;
    font-family: inherit;
    resize: vertical;
}

.form-group input[type="password"]:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(90, 141, 238, 0.1);
}

.output-section,
.input-section {
    margin-top: 20px;
    padding: 16px;
    background: var(--bg-primary);
    border-radius: 8px;
}

.output-section.hidden,
.input-section.hidden {
    display: none;
}

.output-section label,
.input-section label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.output-section textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 12px;
    font-family: 'Courier New', monospace;
    resize: vertical;
    margin-bottom: 8px;
}

.modal-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.error-message {
    padding: 12px 16px;
    background: #cccccc;
    color: #2c2c2c;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 500;
    flex: 1;
}

.error-message.hidden {
    display: none;
}

[data-theme="dark"] .error-message {
    background: #3a3a3a;
    color: #cccccc;
}

.modal-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: center;
    gap: 10px;
}

/* High contrast improvements for accessibility */
@media (prefers-contrast: high) {
    :root {
        --border-color: #999999;
    }
    
    [data-theme="dark"] {
        --border-color: #888888;
    }
}

/* Tools Dropdown */
.tools-dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    margin-top: 4px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    box-shadow: 0 4px 16px var(--shadow);
    z-index: 100;
    min-width: 150px;
}

.dropdown-menu.show {
    display: block;
}

.dropdown-item {
    display: block;
    width: 100%;
    padding: 10px 16px;
    border: none;
    background: none;
    color: var(--text-primary);
    font-size: 14px;
    text-align: left;
    cursor: pointer;
    transition: background 0.2s ease;
}

.dropdown-item:hover {
    background: var(--bg-primary);
}

.dropdown-item:first-child {
    border-radius: 6px 6px 0 0;
}

.dropdown-item:last-child {
    border-radius: 0 0 6px 6px;
}

/* Shapes Panel */
.shapes-panel {
    position: absolute;
    top: 20px;
    right: 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 16px;
    box-shadow: 0 4px 16px var(--shadow);
    z-index: 50;
    min-width: 200px;
}

.shapes-panel.hidden {
    display: none;
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.panel-header h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 20px;
    cursor: pointer;
    padding: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    transition: all 0.2s ease;
}

.close-btn:hover {
    background: var(--bg-primary);
    color: var(--text-primary);
}

.shapes-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    margin-bottom: 12px;
}

.shape-btn {
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 24px;
    cursor: pointer;
    transition: all 0.2s ease;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.shape-btn:hover {
    background: var(--border-color);
    transform: translateY(-2px);
}

.shape-btn.active {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

.shape-controls {
    padding-top: 8px;
    border-top: 1px solid var(--border-color);
}

.shape-controls label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: var(--text-primary);
    cursor: pointer;
}

.shape-controls input[type="checkbox"] {
    cursor: pointer;
}

/* Ruler Overlay */
.ruler-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 40;
}

.ruler-overlay.hidden {
    display: none;
}

.ruler-container {
    width: 100%;
    height: 100%;
    position: relative;
}

.ruler {
    position: absolute;
    background: rgba(100, 100, 100, 0.8);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    pointer-events: auto;
    cursor: move;
    user-select: none;
}

.horizontal-ruler {
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 40px;
    border-radius: 4px;
}

.vertical-ruler {
    top: 50%;
    left: 20px;
    transform: translateY(-50%);
    width: 40px;
    height: 600px;
    border-radius: 4px;
}

.ruler-measurements {
    width: 100%;
    height: 100%;
    position: relative;
}

.horizontal-ruler .ruler-measurements {
    display: flex;
    align-items: center;
    padding: 0 10px;
}

.vertical-ruler .ruler-measurements {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 10px 0;
}

.close-ruler-btn {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    padding: 10px 20px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    pointer-events: auto;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    transition: all 0.2s ease;
}

.close-ruler-btn:hover {
    background: var(--accent-hover);
    transform: translateX(-50%) translateY(-2px);
}

/* Ruler measurement marks */
.ruler-mark {
    position: absolute;
    background: white;
}

.horizontal-ruler .ruler-mark {
    width: 2px;
    top: 0;
}

.horizontal-ruler .ruler-mark.major {
    height: 30px;
}

.horizontal-ruler .ruler-mark.minor {
    height: 20px;
}

.vertical-ruler .ruler-mark {
    height: 2px;
    left: 0;
}

.vertical-ruler .ruler-mark.major {
    width: 30px;
}

.vertical-ruler .ruler-mark.minor {
    width: 20px;
}

.ruler-label {
    position: absolute;
    color: white;
    font-size: 11px;
    font-weight: bold;
}

.horizontal-ruler .ruler-label {
    top: 5px;
}

.vertical-ruler .ruler-label {
    left: 5px;
    writing-mode: vertical-rl;
}

/* Ruler resize handles */
.resize-handle {
    position: absolute;
    background: rgba(255, 255, 255, 0.6);
    cursor: pointer;
    z-index: 10;
    transition: background 0.2s ease;
}

.resize-handle:hover {
    background: rgba(255, 255, 255, 0.9);
}

.resize-handle-h {
    right: 0;
    top: 0;
    width: 20px;
    height: 100%;
    cursor: ew-resize;
    border-top-right-radius: 4px;
    border-bottom-right-radius: 4px;
}

.resize-handle-v {
    bottom: 0;
    left: 0;
    width: 100%;
    height: 20px;
    cursor: ns-resize;
    border-bottom-left-radius: 4px;
    border-bottom-right-radius: 4px;
}

/* Ruler controls */
.ruler-controls {
    position: absolute;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-secondary);
    padding: 15px 20px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    display: flex;
    gap: 20px;
    align-items: center;
    pointer-events: auto;
    z-index: 45;
}

.ruler-control-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.ruler-control-group label {
    font-size: 13px;
    font-weight: 500;
    color: var(--text);
    white-space: nowrap;
}

.ruler-control-group input[type="range"] {
    width: 150px;
}

.ruler-control-group span {
    font-size: 13px;
    font-weight: bold;
    color: var(--accent);
    min-width: 40px;
}

.ruler-controls .secondary-btn {
    padding: 8px 16px;
    font-size: 13px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.ruler-controls .secondary-btn:hover {
    background: var(--accent-hover);
}

/* Mobile adjustments for new features */
@media (max-width: 768px) {
    .shapes-panel {
        right: 10px;
        top: 10px;
        min-width: 180px;
    }
    
    .horizontal-ruler {
        width: 90%;
        max-width: 400px;
    }
    
    .vertical-ruler {
        height: 90%;
        max-height: 400px;
    }
    
    .ruler-controls {
        flex-direction: column;
        gap: 10px;
        bottom: 70px;
        padding: 12px 15px;
    }
    
    .ruler-control-group input[type="range"] {
        width: 120px;
    }
}

/* Text Dialog */
.text-dialog {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 8px 32px var(--shadow);
    z-index: 100;
    min-width: 300px;
    max-width: 500px;
}

.text-dialog.hidden {
    display: none;
}

.text-dialog-content textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 16px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    resize: vertical;
    margin-bottom: 16px;
}

.text-dialog-content textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(90, 141, 238, 0.1);
}

.text-dialog-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
}

.text-dialog-actions button {
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

/* Selection highlight */
.selection-box {
    position: absolute;
    border: 2px dashed var(--accent);
    background: rgba(90, 141, 238, 0.1);
    pointer-events: none;
    z-index: 20;
}

/* Object handles */
.object-handle {
    position: absolute;
    width: 10px;
    height: 10px;
    background: white;
    border: 2px solid var(--accent);
    border-radius: 50%;
    cursor: pointer;
    z-index: 21;
}

/* ============================================================
   Opening splash — terminal logo that fades into the intro.
   Pure-CSS timing (auto-dismisses without JS); app.js only adds
   .splash-skip for tap-to-skip. z-index sits above the walkthrough.
   ============================================================ */
#splash {
    position: fixed;
    inset: 0;
    z-index: 100000;
    display: flex;
    align-items: center;
    justify-content: center;
    background:
        radial-gradient(60% 60% at 50% 42%, rgba(82, 220, 63, 0.12), transparent 70%),
        #0d1017;
    animation: splashOut 0.65s ease 1.7s forwards;
}
#splash .splash-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 18px;
    padding: 24px;
    animation: splashIn 0.8s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}
#splash .splash-logo {
    width: min(46vw, 300px);
    height: auto;
    filter: drop-shadow(0 0 26px rgba(82, 220, 63, 0.35));
}
#splash .splash-wordmark {
    font-family: Georgia, "Iowan Old Style", "Times New Roman", serif;
    font-size: clamp(2.4rem, 9vw, 4rem);
    font-weight: 700;
    letter-spacing: -0.01em;
    color: #eef4ef;
    line-height: 1;
}
#splash .splash-wordmark span { color: #52dc3f; }
#splash .splash-tag {
    font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
    font-size: clamp(0.72rem, 2.6vw, 0.95rem);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: #52dc3f;
    opacity: 0.9;
    display: inline-flex;
    align-items: center;
}
#splash .splash-cursor {
    display: inline-block;
    width: 0.62em;
    height: 1.05em;
    margin-left: 0.35em;
    background: #52dc3f;
    animation: splashBlink 1s steps(1) infinite;
}
#splash.splash-skip { animation: splashOut 0.35s ease forwards; }

@keyframes splashIn {
    from { opacity: 0; transform: translateY(10px) scale(0.965); }
    to   { opacity: 1; transform: none; }
}
@keyframes splashOut {
    to { opacity: 0; visibility: hidden; pointer-events: none; }
}
@keyframes splashBlink { 50% { opacity: 0; } }

@media (prefers-reduced-motion: reduce) {
    #splash { animation: splashOut 0.3s ease 0.9s forwards; }
    #splash .splash-inner { animation: none; }
    #splash .splash-cursor { animation: none; }
}

/* Links inside the walkthrough (e.g. the support email) — on-brand + readable
   on the dark panel instead of default browser blue. */
.walkthrough-body a {
    color: var(--accent);
    text-decoration: underline;
    text-underline-offset: 2px;
    font-weight: 600;
}
.walkthrough-body a:hover { color: var(--accent-hover); }

/* ---- My Drawings gallery ---- */
.gallery-toolbar {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 18px;
}
.mini-btn.primary {
    border-color: var(--accent);
    background: var(--accent);
    color: #ffffff;
    box-shadow: none;
}
.mini-btn.primary:hover {
    background: var(--accent-hover, var(--accent));
    border-color: var(--accent-hover, var(--accent));
    color: #ffffff;
}
.mini-btn.danger:hover {
    border-color: #e5534b;
    color: #e5534b;
}
.gallery-empty {
    color: var(--text-secondary);
    text-align: center;
    padding: 28px 12px;
    margin: 0 auto 8px;
    max-width: 320px;
    line-height: 1.5;
}
/* Fixed-width cards centered as a group, so one drawing or ten both look
   intentional (no lonely half-width card). */
.gallery-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
}
.gallery-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
    width: 150px;
    background: var(--panel-surface, var(--bg-primary));
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 10px;
}
.gallery-thumb {
    display: block;
    width: 100%;
    aspect-ratio: 3 / 4;
    padding: 0;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: #ffffff;
    cursor: pointer;
    overflow: hidden;
}
.gallery-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.gallery-thumb:hover { border-color: var(--accent); }
.gallery-name {
    font-weight: 700;
    color: var(--text-primary);
    font-size: 0.9rem;
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.gallery-actions {
    display: flex;
    gap: 6px;
}
.gallery-actions .mini-btn {
    flex: 1;
    padding: 6px 4px;
    font-size: 0.8rem;
    box-shadow: none;
}
.gallery-note {
    color: var(--text-secondary);
    font-size: 0.8rem;
    text-align: center;
    margin: 20px 0 0;
}

/* ---- Brush size cursor (DOM ring, never touches the canvas) ---- */
.brush-cursor {
    position: fixed;
    top: 0;
    left: 0;
    width: 0;
    height: 0;
    border-radius: 50%;
    border: 1.5px solid rgba(0, 0, 0, 0.75);
    box-shadow: 0 0 0 1.5px rgba(255, 255, 255, 0.7);
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: 900;
    opacity: 0;
    transition: opacity 0.12s ease;
    will-change: transform, width, height;
}
.brush-cursor.visible {
    opacity: 1;
}
:root[data-theme="dark"] .brush-cursor {
    border-color: rgba(255, 255, 255, 0.85);
    box-shadow: 0 0 0 1.5px rgba(0, 0, 0, 0.6);
}

/* ---- Focus mode: hide the toolbar for a full-bleed canvas ---- */
.focus-mode .navbar { display: none !important; }
.focus-exit {
    position: fixed;
    top: calc(10px + env(safe-area-inset-top));
    right: calc(10px + env(safe-area-inset-right));
    z-index: 950;
    display: none;
    padding: 8px 14px;
    border-radius: 999px;
    border: 1px solid var(--accent);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 14px var(--shadow);
    opacity: 0.85;
}
.focus-exit:hover { opacity: 1; }
.focus-mode .focus-exit { display: block; }

/* ---- In-app dialog (replaces native prompt/confirm for installed PWAs) ---- */
.modal-content.app-dialog { max-width: 380px; }
.app-dialog-title {
    color: var(--text-primary);
    font-size: 1.05rem;
    line-height: 1.5;
    margin: 4px 0 16px;
    text-align: center;
}
.app-dialog-input {
    width: 100%;
    box-sizing: border-box;
    padding: 10px 12px;
    margin-bottom: 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
}
.app-dialog-actions {
    display: flex;
    justify-content: center;
    gap: 10px;
}
.app-dialog-actions .mini-btn { min-width: 88px; }

/* ---- Layer composite canvases (stacked around drawCanvas) ---- */
.layer-composite {
    position: absolute;
    top: 0;
    left: 0;
    pointer-events: none;
}

/* ---- Layers panel ---- */
.layers-list { display: flex; flex-direction: column; gap: 8px; }
.layer-row {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: var(--bg-primary);
}
.layer-row.active { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.layer-row .layer-name {
    flex: 1;
    font-weight: 700;
    color: var(--text-primary);
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.layer-row .layer-eye,
.layer-row .layer-move,
.layer-row .layer-del {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    cursor: pointer;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.layer-row .layer-del:hover { border-color: #e5534b; color: #e5534b; }
.layer-row input[type="range"].layer-opacity { width: 74px; }

/* ---- The in-app dialog opens from inside other modals (gallery / layers), so
   it must stack ABOVE them. Same z-index + earlier DOM order was leaving it
   hidden behind the gallery modal (Save "did nothing"). ---- */
#app-dialog { z-index: 1100; }

/* ---- Press feedback: every button visibly depresses when tapped ---- */
button { -webkit-tap-highlight-color: transparent; }
button:active:not(:disabled) {
    transform: scale(0.95);
    filter: brightness(0.9);
    transition: transform 0.04s ease, filter 0.04s ease;
}