:root {
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --bg-tertiary: #252525;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --border-color: #333;
    --accent: #0d9488;
    --accent-light: #14b8a6;
    --success: #059669;
    --warning: #d97706;
    --error: #dc2626;
    --board-light: #d9c39a;
    --board-dark: #8a6a44;
    --board-highlight: rgba(13, 148, 136, 0.35);
    --board-selected: rgba(255, 255, 255, 0.18);
    --board-target: rgba(13, 148, 136, 0.45);
}

[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --accent: #0d9488;
    --accent-light: #14b8a6;
    --board-light: #f1e3c2;
    --board-dark: #c2965a;
    --board-highlight: rgba(13, 148, 136, 0.28);
    --board-selected: rgba(0, 0, 0, 0.1);
    --board-target: rgba(13, 148, 136, 0.32);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: none;
    margin: 0 auto;
    padding: 1rem 1.5rem;
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover {
    color: var(--accent-light);
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 600;
}

.logo span {
    color: var(--accent);
}

.controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.accent-selector {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.color-dropdown {
    padding: 0.25rem 0.5rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-primary);
    cursor: pointer;
}

/* Main Layout */
.main-grid {
    display: block;
    min-height: calc(100vh - 120px);
}

/* Sidebar */
.sidebar {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 1rem;
    height: fit-content;
    position: sticky;
    top: 1rem;
}

.search-box {
    margin-bottom: 1.5rem;
}

.search-box input {
    width: 100%;
    padding: 0.5rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-primary);
}

.categories {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.category {
    padding: 0.75rem;
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.2s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.category:hover {
    background: var(--bg-tertiary);
}

.category.active {
    background: var(--accent);
    color: white;
}

.recent-tools {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.recent-tools h4 {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.tool-chip {
    display: inline-block;
    background: var(--bg-tertiary);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    margin: 0.125rem;
    font-size: 0.75rem;
    cursor: pointer;
}

/* Tool Container */
.tool-container {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 1.5rem;
}

.tool-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.tool-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
}

.tool-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.tool-actions {
    display: flex;
    gap: 0.5rem;
}

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    transition: all 0.2s;
}

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

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

/* Tool I/O */
.io-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
}

@media (max-width: 768px) {
    .io-container {
        grid-template-columns: 1fr;
    }

    .board-shell {
        width: 100%;
    }
}

.io-panel {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.io-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.stats {
    font-size: 0.75rem;
}

textarea {
    width: 100%;
    min-height: 300px;
    padding: 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-primary);
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.875rem;
    line-height: 1.4;
    resize: vertical;
}

textarea:focus {
    outline: none;
    border-color: var(--accent);
}

.output {
    background: var(--bg-primary);
}

/* Options Panel */
.options-panel {
    background: var(--bg-tertiary);
    border-radius: 4px;
    padding: 1rem;
    margin-bottom: 1rem;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}

.option-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.option-group label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

select, input[type="range"], input[type="checkbox"], input[type="radio"] {
    padding: 0.25rem 0.5rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-primary);
}

input[type="checkbox"], input[type="radio"] {
    width: auto;
    cursor: pointer;
}

/* Status Bar */
.status-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Tool Cards (for homepage) */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.tool-card {
    display: block;
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 1.5rem;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
    color: inherit;
    text-decoration: none;
}

.tool-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}

.tool-icon {
    width: 40px;
    height: 40px;
    background: var(--accent);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    color: white;
}

.tool-card h3 {
    margin-bottom: 0.5rem;
}

.tool-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.site-footer {
    margin-top: 2rem;
    padding: 1.5rem 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
    line-height: 1.5;
    font-size: 0.95rem;
}

.site-footer p {
    margin: 0;
}

.engine-grid {
    grid-template-columns: minmax(440px, 1.3fr) minmax(260px, 0.9fr);
    align-items: start;
}

.board-wrapper {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.board-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.board-buttons {
    display: flex;
    gap: 0.35rem;
    flex-wrap: wrap;
}

.board-buttons.compact .btn {
    padding: 0.3rem 0.45rem;
}

.puzzle-top {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.puzzle-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.puzzle-metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 0.4rem;
}

.puzzle-metrics.textual {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem 1rem;
    align-items: center;
}

.puzzle-metrics.textual span {
    font-size: 0.95rem;
}

.puzzle-metrics.textual .muted {
    color: var(--text-secondary);
}

.puzzle-metrics.textual .accent {
    color: var(--accent);
}

.puzzle-moves {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.io-label.tight {
    margin: 0;
}

.puzzle-header-panel {
    padding: 0.75rem 0.85rem;
}

.move-list.slim {
    padding: 0.5rem;
    gap: 0.25rem;
}

.puzzle-info {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.puzzle-info-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.puzzle-info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 0.5rem;
}

.pill {
    padding: 0.35rem 0.75rem;
    border-radius: 999px;
    border: 1px solid var(--accent);
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.pill.engine {
    border-color: var(--accent);
    color: var(--accent);
}

.pill.muted {
    color: var(--text-secondary);
}

.engine-chip {
    padding: 0.35rem 0.75rem;
    border-radius: 999px;
    border: 1px solid var(--accent);
    background: var(--bg-secondary);
    font-size: 0.85rem;
    color: var(--accent);
}

.engine-chip.ready {
    color: var(--success);
    border-color: var(--success);
}

.engine-chip.busy {
    color: var(--warning);
    border-color: var(--warning);
}

.btn-compact {
    padding: 0.35rem 0.75rem;
    font-size: 0.85rem;
}

.chess-board {
    position: relative;
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    aspect-ratio: 1 / 1;
    width: 100%;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    overflow: hidden;
    background: var(--bg-primary);
    user-select: none;
}

.square {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0;
    cursor: pointer;
    transition: background 0.15s, box-shadow 0.15s;
}

.light-square {
    background: var(--board-light);
}

.dark-square {
    background: var(--board-dark);
}

.piece {
    width: 90%;
    height: 90%;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    pointer-events: none;
}

.square.highlight {
    box-shadow: inset 0 0 0 3px var(--board-highlight);
}

.square.selected {
    outline: 2px solid var(--accent);
    outline-offset: -2px;
    background: linear-gradient(135deg, var(--board-selected), transparent);
}

.square.target {
    box-shadow: inset 0 0 0 3px var(--board-target);
    background: linear-gradient(135deg, var(--board-highlight), transparent);
}

.chess-board.game-over {
    filter: brightness(0.75);
    position: relative;
}

.square.mated {
    box-shadow:
        inset 0 0 0 3px rgba(220, 38, 38, 0.75),
        0 0 12px 5px rgba(220, 38, 38, 0.45);
    background: linear-gradient(135deg, rgba(220, 38, 38, 0.25), transparent);
}

.board-footer {
    display: flex;
    justify-content: space-between;
    gap: 0.5rem;
    flex-wrap: wrap;
    font-size: 0.9rem;
}

.color-pill {
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
}

.color-pill.engine {
    border-color: var(--accent);
    color: var(--accent);
}

.move-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
    padding: 0.75rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    min-height: 64px;
}

.move-tag {
    padding: 0.25rem 0.6rem;
    background: var(--bg-secondary);
    border: 1px solid var(--accent);
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: border 0.2s, transform 0.2s;
    color: var(--accent);
}

.move-tag:hover {
    border-color: var(--accent-light);
    background: var(--bg-tertiary);
    color: var(--accent-light);
    transform: translateY(-1px);
}

.move-tag.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #ffffff;
}

.pgn-panel {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.pgn-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.engine-log {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.75rem;
    min-height: 80px;
    max-height: 200px;
    overflow-y: auto;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.85rem;
}

.engine-log-entry {
    margin-bottom: 0.35rem;
    color: var(--text-secondary);
}

.engine-log-entry:last-child {
    margin-bottom: 0;
}

.piece[data-piece="wP"] { background-image: url('../img/merida/wP.svg'); }
.piece[data-piece="wN"] { background-image: url('../img/merida/wN.svg'); }
.piece[data-piece="wB"] { background-image: url('../img/merida/wB.svg'); }
.piece[data-piece="wR"] { background-image: url('../img/merida/wR.svg'); }
.piece[data-piece="wQ"] { background-image: url('../img/merida/wQ.svg'); }
.piece[data-piece="wK"] { background-image: url('../img/merida/wK.svg'); }
.piece[data-piece="bP"] { background-image: url('../img/merida/bP.svg'); }
.piece[data-piece="bN"] { background-image: url('../img/merida/bN.svg'); }
.piece[data-piece="bB"] { background-image: url('../img/merida/bB.svg'); }
.piece[data-piece="bR"] { background-image: url('../img/merida/bR.svg'); }
.piece[data-piece="bQ"] { background-image: url('../img/merida/bQ.svg'); }
.piece[data-piece="bK"] { background-image: url('../img/merida/bK.svg'); }

.board-shell {
    display: flex;
    flex-direction: column;
    gap: 6px;
    align-items: center;
    width: min(100%, 640px);
    margin: 0 auto;
}

.board-mid {
    display: flex;
    width: 100%;
    gap: 6px;
    align-items: stretch;
}

.board-files {
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    width: 100%;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
    letter-spacing: 0.5px;
}

.board-ranks {
    display: grid;
    grid-template-rows: repeat(8, 1fr);
    gap: 2px;
    width: 26px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.hidden {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.success {
    color: var(--success);
}

.warning {
    color: var(--warning);
}

.error {
    color: var(--error);
}

/* Responsive */
@media (max-width: 768px) {
    .main-grid {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: static;
    }
    
    .tool-header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
}
.io-container.puzzle-grid {
    align-items: flex-start;
}