:root {
    --bg-color: #0b0f19;
    --panel-bg: #111827;
    --accent-color: #3b82f6; /* Blue for ε-Greedy / General */
    --success-color: #22c55e; /* Green for UCB */
    --secondary-accent: #a855f7; /* Purple for Exp3 */
    --text-color: #f3f4f6;
    --text-muted: #9ca3af;
    --border-color: #1f2937;
    --input-bg: #1f2937;
}

* {
    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);
    margin: 0;
    line-height: 1.5;
}

.container {
    max-width: 1400px;
    margin: 40px auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

header h1 {
    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: 10px;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.card {
    background-color: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.4);
}

.config-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.config-section {
    display: flex;
    flex-direction: column;
}

.config-section h3 {
    font-size: 0.875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.section-greedy { color: var(--accent-color); border-color: rgba(59, 130, 246, 0.2); }
.section-ucb { color: var(--success-color); border-color: rgba(34, 197, 94, 0.2); }
.section-exp3 { color: var(--secondary-accent); border-color: rgba(168, 85, 247, 0.2); }

.form-group {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.form-group label {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.form-group input[type="number"], 
.form-group input[type="text"] {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-color);
    padding: 6px 10px;
    font-size: 0.9rem;
    width: 80px;
    transition: all 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 10px;
    padding: 10px;
    background: rgba(239, 68, 68, 0.05);
    border-radius: 8px;
    border: 1px dashed rgba(239, 68, 68, 0.2);
}

.checkbox-group label {
    font-size: 0.9rem;
    font-weight: 600;
    color: #f87171;
}

button {
    width: 100%;
    background: linear-gradient(to bottom right, var(--accent-color), var(--secondary-accent));
    border: none;
    border-radius: 12px;
    color: white;
    padding: 14px;
    font-size: 1rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    cursor: pointer;
    transition: transform 0.1s, opacity 0.2s, box-shadow 0.2s;
    margin-top: 20px;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

button:hover {
    opacity: 0.95;
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.4);
}

button:active {
    transform: scale(0.98);
}

.charts-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

@media (max-width: 1024px) {
    .charts-grid {
        grid-template-columns: 1fr;
    }
}

.chart-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 20px;
    text-align: center;
    color: var(--text-color);
}

.canvas-container {
    position: relative;
    height: 350px;
    width: 100%;
}

.results-summary {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 30px;
}

.result-box {
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
}

.result-box .label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.result-box .value {
    font-size: 2rem;
    font-weight: 800;
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
}

.result-greedy .value { color: var(--accent-color); }
.result-ucb .value { color: var(--success-color); }
.result-exp3 .value { color: var(--secondary-accent); }

footer {
    text-align: center;
    margin-top: 60px;
    padding-bottom: 40px;
    color: var(--text-muted);
    font-size: 0.9rem;
}

@media (max-width: 640px) {
    .results-summary {
        grid-template-columns: 1fr;
    }
}