/* ============ Reset & Base ============ */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --bg-primary: #001633;
    --bg-secondary: #0A2540;
    --bg-card: #0E2A47;
    --text-primary: #FFFFFF;
    --text-secondary: #78909C;
    --accent: #FFAB40;
    --accent-glow: rgba(255, 171, 64, 0.25);
    --accent2: #85D5E6;
    --success: #0097A7;
    --border: #1A3A5C;
}

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

/* ============ Header ============ */
.back-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}
.back-link:hover { color: var(--accent); }

header {
    display: flex;
    align-items: center;
    padding: 12px 24px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    gap: 20px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-logo {
    width: 32px;
    height: 32px;
    object-fit: contain;
}

header h1 {
    font-size: 1.2rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    flex: 1;
}

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

.controls button {
    padding: 6px 16px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.controls button:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--bg-primary);
}

#btn-start {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--bg-primary);
    font-weight: 700;
}

.speed-group {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-left: 8px;
}

.speed-group label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-right: 4px;
}

.speed-btn {
    padding: 4px 10px !important;
    font-size: 0.75rem !important;
}

.speed-btn.active {
    background: var(--accent) !important;
    border-color: var(--accent) !important;
    color: var(--bg-primary) !important;
}

/* ============ Main Layout ============ */
main {
    display: grid;
    grid-template-columns: auto 1fr;
    height: calc(100vh - 53px);
}

/* ============ Game Panel ============ */
.game-panel {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
}

#game-canvas {
    border-radius: 8px;
    max-height: calc(100vh - 77px);
    width: auto;
}

/* ============ Info Panel ============ */
.info-panel {
    padding: 20px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.info-panel h2 {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 12px;
}

/* ============ Stats ============ */
.stats {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    padding: 6px 0;
    border-bottom: 1px solid var(--border);
}

.stat-row:last-child { border-bottom: none; }

.stat-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.stat-value {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
}

/* ============ NN Visualization ============ */
.nn-viz {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px;
}

#nn-svg {
    width: 100%;
    height: 180px;
    background: var(--bg-card);
    border-radius: 6px;
}

.nn-node {
    stroke: var(--border);
    stroke-width: 1;
}

.nn-conn {
    stroke-width: 1.5;
}

.nn-label {
    fill: var(--text-secondary);
    font-size: 8px;
    font-family: Arial, 'Segoe UI', system-ui, sans-serif;
    text-anchor: middle;
}

/* ============ Info Text ============ */
.info-text {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px;
}

.info-text p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 6px;
}

.info-text p:last-child { margin-bottom: 0; }

/* ============ Parameter Panels ============ */
.param-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px;
}

.param-section summary {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    cursor: pointer;
    user-select: none;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 6px;
}

.param-section summary::before {
    content: "\25B6";
    font-size: 0.6rem;
    transition: transform 0.2s;
}

.param-section[open] summary::before {
    transform: rotate(90deg);
}

.param-section summary::-webkit-details-marker {
    display: none;
}

.param-section summary:hover {
    color: var(--accent);
}

.param-grid {
    margin-top: 10px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.param-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
}

.param-row label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

.param-row input[type="number"] {
    width: 72px;
    padding: 4px 6px;
    border: 1px solid var(--border);
    border-radius: 4px;
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 0.8rem;
    text-align: right;
    -moz-appearance: textfield;
}

.param-row input[type="number"]::-webkit-inner-spin-button,
.param-row input[type="number"]::-webkit-outer-spin-button {
    opacity: 1;
}

.param-row input[type="number"]:focus {
    outline: none;
    border-color: var(--accent);
}

.hint {
    opacity: 0.6;
    font-style: italic;
}

/* ============ NN Input Toggles ============ */
.nn-input-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.82rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 0;
}

.nn-input-toggle input[type="checkbox"] {
    accent-color: var(--accent);
    cursor: pointer;
    width: 15px;
    height: 15px;
}

/* ============ Responsive ============ */
@media (max-width: 900px) {
    main {
        grid-template-columns: 1fr;
        grid-template-rows: auto 1fr;
    }
    .game-panel { border-right: none; border-bottom: 1px solid var(--border); }
    #game-canvas { max-height: 50vh; }
}