:root {
    --r: 0px;
    --font-display: "Syne", sans-serif;
    --font-body: "Plus Jakarta Sans", sans-serif;

    --paper: #f2efe8;
    --panel: #e8e4db;
    --panel-2: #ddd9cf;
    --ink: #0f0e0d;
    --ink-muted: #5a5650;
    --ink-faint: #9a958e;
    --wall: #b0aba0;
    --wall-soft: #c8c3b8;
    --accent: #e8380d;
    --go: #1a7a4a;
    --stop: #c0321a;
    --trace: #d97706;
    --final-path: #2563eb;
    --btn-shadow: rgba(15, 14, 13, 0.75);
}

body.dark {
    --paper: #131210;
    --panel: #1c1a17;
    --panel-2: #252320;
    --ink: #f0ece4;
    --ink-muted: #8a8680;
    --ink-faint: #504d49;
    --wall: #3d3a35;
    --wall-soft: #3d3a35;
    --accent: #ff5533;
    --go: #22c55e;
    --stop: #ef4444;
    --trace: #fbbf24;
    --final-path: #3b82f6;
    --btn-shadow: rgba(0, 0, 0, 0.8);
}

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

body {
    font-family: var(--font-body);
    background: var(--paper);
    color: var(--ink);
    height: 100vh;
    overflow: hidden;
}

.app-container {
    display: flex;
    height: 100vh;
    padding: 16px;
    gap: 14px;
}

.left-pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

header {
    position: relative;
    margin-bottom: 10px;
    padding: 14px;
    flex-shrink: 0;
    background: var(--ink);
    color: var(--paper);
    border: 2px solid var(--ink);
    overflow: hidden;
}

header::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    opacity: 0.13;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220' viewBox='0 0 220 220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.95' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='220' height='220' filter='url(%23n)'/%3E%3C/svg%3E");
}

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

header h1,
.right-pane h2 {
    font-family: var(--font-display);
    font-weight: 800;
    letter-spacing: 0.03em;
    text-transform: uppercase;
}

header h1 { font-size: 1.55rem; }

header p {
    margin-top: 6px;
    color: color-mix(in oklab, var(--paper) 74%, transparent);
    font-size: 0.9rem;
}

.pulse-dot {
    width: 10px;
    height: 10px;
    background: var(--accent);
    display: inline-block;
    border: 2px solid var(--paper);
    animation: pulse-dot 3s ease-in-out infinite;
}

.theme-toggle {
    margin-top: 8px;
    padding: 6px 10px;
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    background: transparent;
    color: var(--paper);
    border-color: color-mix(in oklab, var(--paper) 66%, transparent);
}

.grid-container {
    flex: 1;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    grid-template-rows: repeat(2, minmax(0, 1fr));
    gap: 12px;
    margin-bottom: 15px;
    min-height: 0;
}

.algo-card,
.controls-container,
.right-pane,
.leaderboard-item {
    border: 2px solid var(--wall);
    border-radius: var(--r);
}

.algo-card {
    background: var(--panel);
    padding: 10px;
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.algo-title {
    font-family: var(--font-display);
    font-size: 1.02rem;
    font-weight: 700;
    letter-spacing: 0.015em;
    text-transform: uppercase;
}

.algo-status {
    font-size: 0.8rem;
    color: var(--ink-muted);
    margin: 4px 0 8px;
    display: flex;
    justify-content: space-between;
}

.canvas-wrapper {
    flex: 1;
    position: relative;
    overflow: hidden;
    background: var(--panel-2);
    min-height: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--wall-soft);
}

canvas {
    width: 100%;
    height: 100%;
    object-fit: contain;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
}

.controls-container {
    flex-shrink: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--panel);
    padding: 12px 16px;
}

.speed-control {
    display: flex;
    align-items: center;
    gap: 15px;
    color: var(--ink);
    font-size: 0.86rem;
    font-weight: 700;
}

.speed-control input[type="range"] {
    width: 200px;
    accent-color: var(--accent);
    cursor: pointer;
}

.action-buttons {
    display: flex;
    gap: 10px;
    align-items: center;
}

.btn {
    position: relative;
    padding: 8px 13px;
    font-size: 0.83rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.055em;
    font-family: var(--font-body);
    border: 2px solid var(--ink);
    border-radius: var(--r);
    cursor: pointer;
    transition: transform 0.14s ease, box-shadow 0.14s ease, color 0.2s ease;
    overflow: hidden;
}

.btn::after {
    content: "";
    position: absolute;
    inset: 0;
    transform: scaleY(0);
    transform-origin: bottom;
    transition: transform 0.2s ease;
    z-index: 0;
    opacity: 0.16;
}

.btn:hover::after { transform: scaleY(1); }
.btn > * { position: relative; z-index: 1; }
.btn:active { transform: translate(1px, 1px); box-shadow: none; }

.btn.primary {
    background: var(--accent);
    color: #fff;
}
.btn.primary::after { background: #fff; }
.btn.primary:hover {
    transform: translate(-1px, -1px);
    box-shadow: 4px 4px 0 var(--btn-shadow);
}

.btn.secondary {
    background: var(--stop);
    color: #fff;
}
.btn.secondary::after { background: #fff; }

.btn.accent {
    background: var(--go);
    color: #fff;
}
.btn.accent::after { background: #fff; }

.right-pane {
    width: 332px;
    flex-shrink: 0;
    background: var(--panel);
    padding: 18px;
    display: flex;
    flex-direction: column;
}

.right-pane h2 {
    font-size: 1.35rem;
    color: var(--ink);
}

.leaderboard-subtitle {
    color: var(--ink-muted);
    font-size: 0.84rem;
    margin-bottom: 16px;
    padding-bottom: 11px;
    border-bottom: 2px solid var(--wall);
}

.leaderboard-item {
    padding: 12px;
    background: var(--panel-2);
    margin-bottom: 10px;
}

.leaderboard-item.first-place {
    border-color: var(--accent);
}

.leaderboard-item.shortest-route {
    border-left: 6px solid var(--go);
}

.item-header {
    font-weight: 700;
    font-size: 0.98rem;
    margin-bottom: 6px;
    color: var(--ink);
}

.item-stats {
    font-size: 0.84rem;
    color: var(--ink-muted);
}

.item-stats strong { color: var(--ink); }

@keyframes pulse-dot {
    0%, 100% { transform: scale(0.85); opacity: 0.7; }
    50% { transform: scale(1.15); opacity: 1; }
}

.algo-card.fullscreen {
    position: fixed;
    inset: 20px;
    z-index: 9999;
    box-shadow: 0 10px 50px rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
}

body.dark .algo-card.fullscreen {
    box-shadow: 0 10px 50px rgba(0,0,0,0.9);
}

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

.expand-btn {
    background: transparent;
    border: none;
    color: var(--ink-muted);
    font-size: 1.2rem;
    cursor: pointer;
    line-height: 1;
    transition: color 0.2s;
}

.expand-btn:hover {
    color: var(--ink);
}

/* Responsive Mobile Layout */
@media (max-width: 960px) {
    body {
        height: auto;
        overflow-y: auto;
    }
    .app-container {
        flex-direction: column;
        height: auto;
        overflow: visible;
    }
    .left-pane {
        overflow: visible;
    }
    .right-pane {
        width: 100%;
        margin-top: 5px;
    }
    .grid-container {
        grid-template-columns: 1fr 1fr;
        grid-template-rows: auto;
    }
    .canvas-wrapper {
        aspect-ratio: 1 / 1;
    }
    .algo-card.fullscreen {
        inset: 10px;
    }
}

@media (max-width: 650px) {
    .grid-container {
        grid-template-columns: 1fr;
    }
    header h1 {
        font-size: 1.2rem;
    }
    .header-top {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    .back-btn {
        align-self: flex-start;
    }
    .controls-container {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
    }
    .speed-control {
        justify-content: space-between;
    }
    .speed-control input[type="range"] {
        flex: 1;
        margin-left: 10px;
    }
    .action-buttons {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 10px;
        width: 100%;
    }
    #btn-new-maze {
        grid-column: span 2;
    }
}