: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;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #fbbf24;
}

* {
    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: 1100px;
    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);
}

.card {
    background-color: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.4);
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.form-group input,
input[type="number"] {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    padding: 8px 12px;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.form-group input:focus,
input[type="number"]:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

input[type="number"].input-sm {
    width: 3rem;
    text-align: center;
    padding: 6px 8px;
}

button {
    background: linear-gradient(to bottom right, var(--accent-color), var(--secondary-accent));
    border: none;
    border-radius: 8px;
    color: white;
    padding: 10px 20px;
    font-size: 0.9375rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.1s, opacity 0.2s;
}

button:hover {
    opacity: 0.9;
}

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

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

button.btn-sm {
    padding: 8px 14px;
    font-size: 0.8125rem;
}

button.btn-success {
    background: linear-gradient(to bottom right, #059669, #10b981);
}

button.btn-danger {
    background: linear-gradient(to bottom right, #dc2626, #ef4444);
}

button.btn-secondary {
    background: linear-gradient(to bottom right, #7c3aed, #8b5cf6);
}

button.btn-worker-1 {
    background: linear-gradient(to bottom right, #059669, #10b981);
}

button.btn-worker-2 {
    background: linear-gradient(to bottom right, #7c3aed, #a78bfa);
}

button.btn-running {
    background: linear-gradient(to bottom right, #dc2626, #ef4444);
}

.formula-display {
    margin-top: 20px;
    padding: 15px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 8px;
    font-size: 0.9rem;
    color: #e5e7eb;
}

.formula-display strong {
    color: var(--text-color);
}

footer {
    text-align: center;
    margin-top: 50px;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* GridWorld demos (w-nn, wout-nn) */
.demo-layout {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.demo-layout .canvas-panel {
    flex: 0 1 auto;
}

.demo-layout .log-panel {
    flex: 1;
    min-width: 300px;
}

.demo-layout h3 {
    margin-top: 0;
    color: var(--text-color);
    font-size: 1.1rem;
}

.stat-box {
    margin: 16px 0 8px;
    font-weight: 600;
    color: var(--secondary-accent);
}

#logArea {
    width: 100%;
    height: 400px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.8125rem;
    background-color: #1e1e1e;
    color: #10b981;
    border: 1px solid var(--border-color);
    padding: 12px;
    resize: none;
    border-radius: 8px;
    margin-bottom: 12px;
}

canvas {
    border: 1px solid var(--border-color);
    background-color: #f3f4f6;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    border-radius: 8px;
}

/* A3C layout */
.section-card {
    margin-bottom: 24px;
}

.section-card.global-section {
    border-top: 3px solid var(--accent-color);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 16px;
}

.section-header h2 {
    margin: 0;
    font-size: 1.25rem;
    color: var(--accent-color);
}

.section-header h2.worker-1 {
    color: var(--success-color);
}

.section-header h2.worker-2 {
    color: var(--secondary-accent);
}

.btn-group {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
}

.section-body {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

@media (min-width: 768px) {
    .section-body {
        flex-direction: row;
    }
}

.canvas-wrap {
    flex: none;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.canvas-wrap canvas {
    cursor: pointer;
}

.canvas-hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 8px;
    font-style: italic;
}

.console-section {
    flex: 1;
    min-width: 0;
}

.console-section h3 {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-muted);
    margin: 0 0 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.console-log {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.75rem;
    white-space: pre-wrap;
    background-color: #1e1e1e;
    color: var(--success-color);
    overflow-y: auto;
    height: 200px;
    padding: 12px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.console-log.global {
    color: #60a5fa;
    border-color: var(--accent-color);
}

.console-log.worker-2 {
    color: #c4b5fd;
}

.workers-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
}

@media (min-width: 768px) {
    .workers-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.worker-card {
    border-top: 3px solid var(--success-color);
}

.worker-card.worker-2 {
    border-top-color: var(--secondary-accent);
}

.worker-body {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

/* Network modal */
#network-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    z-index: 50;
    justify-content: center;
    align-items: center;
}

#network-modal.active {
    display: flex;
}

.modal-content {
    background-color: var(--panel-bg);
    border: 1px solid var(--border-color);
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
    max-width: 960px;
    width: calc(100% - 32px);
    max-height: 90vh;
    overflow: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 20px;
    gap: 16px;
}

.modal-header h2 {
    margin: 0 0 4px;
    font-size: 1.5rem;
}

.modal-header p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.75rem;
    padding: 0 8px;
    line-height: 1;
    cursor: pointer;
}

.modal-close:hover {
    color: var(--text-color);
    opacity: 1;
}

.modal-viz {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
    overflow: auto;
}

.viz-panel {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.viz-panel h3 {
    margin: 0 0 12px;
    font-size: 1rem;
}

.viz-panel h3.actor-title {
    color: var(--success-color);
}

.viz-panel h3.critic-title {
    color: var(--accent-color);
}

.network-canvas {
    background: #111;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
}

.highlight {
    color: var(--warning-color);
    font-family: 'Courier New', Courier, monospace;
}