:root {
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --primary-color: #bb86fc;
    --primary-hover: #9965f4;
    --secondary-color: #03dac6;
    --border-color: #333;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    min-height: 100vh;
    padding: 1rem;
}

#app {
    width: 100%;
    max-width: 480px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    padding-top: 2rem;
}

header {
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    letter-spacing: -0.5px;
}

#home-link {
    text-decoration: none;
}

#home-link:hover h1 {
    opacity: 0.8;
}

header p {
    color: #888;
    font-size: 0.9rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 1rem 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    max-width: 480px;
    margin: 0 auto;
}

footer a {
    text-decoration: none;
    transition: opacity 0.2s;
}

footer a:hover {
    opacity: 0.7;
}

.footer-github {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    color: #888;
    font-size: 0.8rem;
}

.footer-icon {
    width: 18px;
    height: 18px;
    opacity: 0.7;
    filter: invert(1);
}

.footer-credit {
    color: #666;
    font-size: 0.75rem;
}

.footer-clear-btn {
    background: none;
    border: none;
    color: #444;
    font-size: 0.7rem;
    cursor: pointer;
    padding: 0.3rem 0.6rem;
    border-radius: 6px;
    transition: color 0.2s, background 0.2s;
    margin-top: 0.5rem;
}

.footer-clear-btn:hover {
    color: #e57373;
    background: rgba(229, 115, 115, 0.08);
}

.card {
    background-color: var(--card-bg);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Form controls */
label {
    font-size: 0.85rem;
    color: #aaa;
    font-weight: 500;
    display: block;
    margin-bottom: 0.3rem;
}

select {
    width: 100%;
    padding: 0.65rem 0.9rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: #252525;
    color: var(--text-color);
    font-size: 0.9rem;
    font-family: inherit;
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23888' d='M6 8.5L1 3.5h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 12px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

select:hover {
    border-color: #555;
}

select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(187, 134, 252, 0.15);
}

/* Palette selector */
.palette-selector {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.palette-selector .palette-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.palette-selector .palette-header label {
    margin-bottom: 0;
}

.palette-toggle-group {
    display: flex;
    background: #1e1e1e;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    overflow: hidden;
}

.palette-toggle {
    background: transparent;
    color: #666;
    border: none;
    padding: 0.25rem 0.6rem;
    font-size: 0.7rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
}

.palette-toggle.active {
    background: var(--primary-color);
    color: #fff;
}

.palette-swatches {
    display: flex;
    gap: 3px;
    height: 28px;
    border-radius: 6px;
    overflow: hidden;
    cursor: pointer;
    border: 2px solid var(--border-color);
    transition: border-color 0.2s;
}

.palette-swatches:hover {
    border-color: #555;
}

.palette-swatches.active {
    border-color: var(--primary-color);
    box-shadow: 0 0 8px rgba(187, 134, 252, 0.2);
}

.palette-swatch {
    flex: 1;
    height: 100%;
}

.palette-nav {
    display: flex;
    gap: 0.4rem;
    align-items: center;
}

.palette-nav button {
    background-color: #252525;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.3rem 0.7rem;
    font-size: 0.8rem;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: 600;
}

.palette-nav button:hover {
    border-color: #555;
    background-color: #2a2a2a;
}

.palette-mode-label {
    font-size: 0.7rem;
    color: #666;
    text-align: center;
    flex: 1;
}

/* ── Expandable Section ──────────────────────────── */
.expandable-section {
    border: 1px solid var(--border-color);
    border-radius: 10px;
    overflow: hidden;
    transition: border-color 0.2s;
}

.expandable-section:hover {
    border-color: #444;
}

.expandable-header {
    width: 100%;
    background: #1a1a1a;
    border: none;
    cursor: pointer;
    padding: 0.7rem 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-color);
    font-family: inherit;
    font-size: 0.88rem;
    font-weight: 500;
    transition: background 0.2s;
    text-align: left;
}

.expandable-header:hover {
    background: #222;
}

.expandable-header[aria-expanded="true"] {
    border-bottom: 1px solid var(--border-color);
}

.expandable-title {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 0.45rem;
}

.expandable-icon {
    font-size: 1rem;
}

.expandable-badge {
    font-size: 0.68rem;
    color: var(--secondary-color);
    background: rgba(3, 218, 198, 0.1);
    padding: 0.1rem 0.45rem;
    border-radius: 4px;
    font-weight: 600;
    transition: all 0.2s;
}

.expandable-badge.active {
    color: var(--primary-color);
    background: rgba(187, 134, 252, 0.12);
}

.expandable-chevron {
    font-size: 0.65rem;
    color: #666;
    transition: transform 0.25s ease;
}

.expandable-header[aria-expanded="true"] .expandable-chevron {
    transform: rotate(90deg);
}

.expandable-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 0.9rem;
    background: rgba(0, 0, 0, 0.15);
}

.expandable-body.open {
    max-height: 600px;
    padding: 0.75rem 0.9rem;
}

/* ── Adjustment Rows ─────────────────────────────── */
.adj-row {
    margin-bottom: 0.75rem;
}

.adj-row:last-of-type {
    margin-bottom: 0.5rem;
}

.adj-label-row {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    margin-bottom: 0.3rem;
}

.adj-label {
    flex: 1;
    font-size: 0.78rem;
    color: #aaa;
    font-weight: 500;
    margin-bottom: 0;
}

.adj-value {
    font-size: 0.72rem;
    color: var(--primary-color);
    font-weight: 600;
    min-width: 2.5rem;
    text-align: right;
    font-variant-numeric: tabular-nums;
}

.adj-reset {
    background: none;
    border: 1px solid transparent;
    color: #555;
    cursor: pointer;
    font-size: 0.85rem;
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
    transition: color 0.2s, border-color 0.2s;
    line-height: 1;
}

.adj-reset:hover {
    color: var(--primary-color);
    border-color: rgba(187, 134, 252, 0.3);
}

/* Range input — styled to match dark theme */
.adj-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    border-radius: 2px;
    background: linear-gradient(to right, var(--primary-color) var(--pct, 50%), #333 var(--pct, 50%));
    outline: none;
    cursor: pointer;
    border: none;
    margin: 0;
}

.adj-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--primary-color);
    box-shadow: 0 0 6px rgba(187, 134, 252, 0.5);
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s;
}

.adj-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 10px rgba(187, 134, 252, 0.7);
}

.adj-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border: none;
    border-radius: 50%;
    background: var(--primary-color);
    box-shadow: 0 0 6px rgba(187, 134, 252, 0.5);
    cursor: pointer;
}

.adj-reset-all {
    width: 100%;
    padding: 0.5rem;
    font-size: 0.8rem;
    margin-top: 0.25rem;
}

.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 3rem 1rem;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s, background-color 0.2s;
}

.drop-zone:hover,
.drop-zone.dragover {
    border-color: var(--primary-color);
    background-color: rgba(187, 134, 252, 0.05);
}

.drop-zone p {
    color: #aaa;
    font-weight: 500;
}

#preview-container {
    width: 100%;
    border-radius: 8px;
    overflow: hidden;
    background-color: #000;
    display: flex;
    justify-content: center;
}

#image-preview {
    max-width: 100%;
    object-fit: contain;
}

#palette-preview-canvas {
    image-rendering: pixelated;
    width: 100%;
    max-width: 800px;
    height: auto;
    display: block;
    border-radius: 8px;
}

.message-box {
    margin-top: 0.6rem;
    padding: 0.65rem 0.9rem;
    border-radius: 8px;
    font-size: 0.82rem;
    line-height: 1.5;
    animation: fadeIn 0.2s ease;
}

.message-box.warning {
    background-color: rgba(255, 193, 7, 0.1);
    border-left: 3px solid #f5a623;
    color: #f5c842;
}

.message-box.warning strong {
    color: #ffd966;
}

.message-box.danger {
    background-color: rgba(244, 67, 54, 0.1);
    border-left: 3px solid #f44336;
    color: #ff8a80;
}

.message-box.danger strong {
    color: #ff5252;
}

.message-box.fatal {
    background-color: rgba(0, 0, 0, 0.4);
    border-left: 3px solid #9c27b0;
    border-right: 1px solid #4a148c;
    border-top: 1px solid #4a148c;
    border-bottom: 1px solid #4a148c;
    color: #ce93d8;
}

.message-box.fatal strong {
    color: #e1bee7;
}

.btn {
    border: none;
    border-radius: 8px;
    padding: 0.8rem 1.2rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.1s;
    width: 100%;
}

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

.btn:active:not(:disabled) {
    transform: scale(0.98);
}

.btn.primary {
    background-color: var(--primary-color);
    color: #000;
}

.btn.secondary {
    background-color: var(--secondary-color);
    color: #000;
}

.btn.outline {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-color);
}

.hidden {
    display: none !important;
}

.url-box {
    background-color: #000;
    padding: 1rem;
    border-radius: 8px;
    font-family: monospace;
    word-break: break-all;
    font-size: 0.85rem;
    color: #aaa;
    max-height: 150px;
    overflow-y: auto;
}

#decoded-container {
    display: flex;
    justify-content: center;
    background-color: transparent;
    min-height: 200px;
    align-items: center;
    /* Break out of max-width to fill full screen width */
    width: 100vw;
    margin-left: calc(-50vw + 50%);
    padding: 0;
}

#decoded-canvas {
    image-rendering: pixelated;
    width: 100%;
    max-width: 800px;
    height: auto;
    display: block;
    padding: 1rem;
}

canvas:not(#decoded-canvas) {
    image-rendering: pixelated;
    max-width: 100%;
    height: auto;
}

/* Chunk buttons */
.chunk-buttons-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.chunk-btn-row {
    display: flex;
    gap: 0.5rem;
}

.chunk-btn-row .btn {
    flex: 1;
    padding: 0.6rem 0.5rem;
    font-size: 0.85rem;
}

/* Platform Selector */
#platform-container label {
    font-size: 0.9rem;
    color: #aaa;
    margin-bottom: 0.25rem;
    display: block;
}

.platform-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.6rem;
}

.platform-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.35rem;
    padding: 0.7rem 0.3rem;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    background-color: rgba(255, 255, 255, 0.03);
    cursor: pointer;
    transition: all 0.25s ease;
    position: relative;
    overflow: hidden;
}

.platform-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 10px;
    opacity: 0;
    transition: opacity 0.25s ease;
}

.platform-btn:hover {
    border-color: #555;
    background-color: rgba(255, 255, 255, 0.06);
    transform: translateY(-2px);
}

.platform-btn.selected {
    border-color: var(--primary-color);
    background-color: rgba(187, 134, 252, 0.1);
    box-shadow: 0 0 12px rgba(187, 134, 252, 0.2);
}

.platform-btn.selected::before {
    opacity: 1;
    background: linear-gradient(135deg, rgba(187, 134, 252, 0.08), transparent);
}

.platform-icon {
    width: 32px;
    height: 32px;
    object-fit: contain;
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.3));
    transition: transform 0.2s ease;
}

.platform-btn:hover .platform-icon {
    transform: scale(1.1);
}

.platform-name {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-color);
    line-height: 1;
}

.platform-limit {
    font-size: 0.6rem;
    color: #666;
    line-height: 1;
}

.platform-btn.selected .platform-name {
    color: var(--primary-color);
}

.platform-btn.selected .platform-limit {
    color: var(--primary-color);
    opacity: 0.7;
}