:root {
    --bg-color: #0b0f19;
    --panel-bg: #111827;
    --accent-color: #3b82f6;
    --secondary-accent: #8b5cf6;
    --text-color: #f3f4f6;
    --text-muted: #9ca3af;
    --border-color: #1f2937;
    --input-bg: #1f2937;
}

/* Base resets and layout preservation */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    padding: 20px;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    background-color: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
}

/* Typography */
h1 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(to right, var(--accent-color), var(--secondary-accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 20px;
}

.map-info {
    text-align: center;
    margin-bottom: 30px;
    padding: 24px;
    background: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.map-info pre {
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color);
    margin: 15px 0;
    letter-spacing: 2px;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    padding: 12px 24px;
    background: var(--input-bg);
    border: none;
    border-top-left-radius: 8px;
    border-top-right-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    color: var(--text-muted);
    transition: all 0.3s;
    position: relative;
    bottom: -2px;
}

.tab-btn:hover {
    background: var(--border-color);
    color: var(--text-color);
}

.tab-btn.active {
    background: var(--panel-bg);
    color: var(--accent-color);
    border-bottom: 3px solid var(--accent-color);
    border-top: 2px solid var(--border-color);
    border-left: 2px solid var(--border-color);
    border-right: 2px solid var(--border-color);
}

/* Tab Panels */
.tab-content {
    margin-bottom: 30px;
}

.tab-panel {
    display: none;
    padding: 20px;
    background: rgba(255, 255, 255, 0.01);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    border-top-left-radius: 0;
}

.tab-panel.active {
    display: block;
}

.method-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}

.method-header h2 {
    color: var(--text-color);
    font-size: 1.5em;
    margin: 0;
}

.episode-counter {
    font-weight: bold;
    color: var(--secondary-accent);
    padding: 8px 16px;
    background: var(--input-bg);
    border-radius: 5px;
    font-size: 14px;
}

/* Content Grid */
.content-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 20px;
}

.left-panel {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.right-panel {
    display: flex;
    flex-direction: column;
}

/* Interactive Elements */
.train-btn {
    width: 100%;
    padding: 12px;
    background: linear-gradient(to bottom right, var(--accent-color), var(--secondary-accent));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: transform 0.1s, opacity 0.2s, box-shadow 0.2s;
    margin-bottom: 15px;
}

.train-btn:hover {
    opacity: 0.9;
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.3);
}

.train-btn:active {
    transform: scale(0.98);
}

.trajectories-container {
    max-height: 200px;
    overflow-y: auto;
    background: var(--input-bg);
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.trajectory-item {
    padding: 8px;
    margin: 5px 0;
    background: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s;
    font-size: 12px;
    color: var(--text-muted);
}

.trajectory-item:hover {
    background: var(--border-color);
    color: var(--text-color);
}

.trajectory-item.selected {
    background: rgba(59, 130, 246, 0.2);
    color: var(--accent-color);
    border-color: var(--accent-color);
}

.visualization-container {
    min-height: 350px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--input-bg);
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

/* Visualization Grid */
.grid-container {
    display: inline-block;
    border: 2px solid var(--text-muted);
    border-radius: 5px;
    overflow: hidden;
    background: var(--panel-bg);
}

.grid-row {
    display: flex;
}

.grid-cell {
    width: 80px;
    height: 80px;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: bold;
    position: relative;
    transition: background 0.3s;
}

.grid-cell.start { background: #059669; color: white; }
.grid-cell.goal { background: #d97706; color: white; }
.grid-cell.penalty { background: #b91c1c; color: white; }
.grid-cell.penalty-high { background: #7f1d1d; color: white; }
.grid-cell.empty { background: transparent; }
.grid-cell.agent { background: var(--accent-color); color: white; }
.grid-cell.agent::after { content: '🤖'; font-size: 32px; }
.grid-cell.visited { background: rgba(59, 130, 246, 0.1); }

.controls {
    margin-top: 15px;
    text-align: center;
}

.control-btn {
    padding: 8px 16px;
    margin: 0 5px;
    background: var(--input-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
}

.control-btn:hover:not(:disabled) {
    background: var(--accent-color);
    border-color: var(--accent-color);
}

.control-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* Data Display */
.calculation-area {
    width: 100%;
    min-height: 500px;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 12px;
    resize: vertical;
    background: var(--input-bg);
    color: var(--text-color);
    line-height: 1.6;
    flex: 1;
}

.theta-display {
    margin-top: 30px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 12px;
}

.theta-display h3 {
    margin-bottom: 15px;
    color: var(--text-muted);
    font-size: 1.1rem;
}

.theta-values {
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 14px;
    background: var(--input-bg);
    padding: 15px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.theta-value {
    margin: 8px 0;
    padding: 8px;
    background: var(--panel-bg);
    border-left: 4px solid var(--accent-color);
    border-radius: 0 4px 4px 0;
}

footer {
    text-align: center;
    margin-top: 50px;
    padding: 20px 0;
    color: var(--text-muted);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
}