:root {
    --bd-primary-color: #6366f1;
    --bd-secondary-color: #1e293b;
    --bd-accent-color: #ef4444;
    --bd-bg-color: #f8fafc;
    --bd-card-bg: #ffffff;
    --bd-text-color: #334155;
    --bd-border-radius: 12px;
}

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

.bifurcation-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bd-bg-color);
    color: var(--bd-text-color);
    line-height: 1.6;
}

.bifurcation-container header {
    text-align: center;
    margin-bottom: 30px;
}

.bifurcation-container h1 {
    font-size: 2.5rem;
    color: var(--bd-secondary-color);
    margin-bottom: 10px;
}

.bifurcation-container .subtitle {
    font-size: 1.1rem;
    color: #64748b;
}

.bifurcation-container .math {
    font-family: 'Times New Roman', Times, serif;
    font-style: italic;
    background: #eef2ff;
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: bold;
}

/* ===== MAIN CONTENT ===== */
.bifurcation-container main {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 20px;
    margin-bottom: 40px;
}

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

/* ===== CANVAS ===== */
.bifurcation-container .canvas-wrapper {
    position: relative;
}

.bifurcation-container .canvas-container {
    background: var(--bd-card-bg);
    padding: 20px;
    border-radius: var(--bd-border-radius);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 500px;
    cursor: crosshair;
}

.bifurcation-container canvas {
    max-width: 100%;
    border: 1px solid #e2e8f0;
    border-radius: 4px;
    background: #0f172a;
}

.bifurcation-container .zoom-hint {
    text-align: center;
    font-size: 0.85rem;
    color: #94a3b8;
    margin-top: 8px;
}

/* ===== CONTROLS ===== */
.bifurcation-container .controls-panel {
    background: var(--bd-card-bg);
    padding: 25px;
    border-radius: var(--bd-border-radius);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    height: fit-content;
}

.bifurcation-container .control-group {
    margin-bottom: 20px;
}

.bifurcation-container .control-group label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--bd-secondary-color);
    font-size: 0.95rem;
}

.bifurcation-container .control-group input[type="range"] {
    width: 100%;
    height: 6px;
    background: #e2e8f0;
    border-radius: 5px;
    outline: none;
    cursor: pointer;
    -webkit-appearance: none;
}

.bifurcation-container .control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: var(--bd-primary-color);
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s ease;
}

.bifurcation-container .control-group input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background: var(--bd-accent-color);
}

.bifurcation-container .control-group input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--bd-primary-color);
    border: none;
    border-radius: 50%;
    cursor: pointer;
}

.bifurcation-container .param-info {
    font-size: 0.8rem;
    color: #64748b;
    margin-top: 6px;
    padding: 6px 10px;
    background: #f1f5f9;
    border-radius: 4px;
    border-left: 3px solid var(--bd-primary-color);
}

.bifurcation-container .checkbox-group {
    margin-bottom: 15px;
}

.bifurcation-container .checkbox-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: var(--bd-secondary-color);
    cursor: pointer;
}

.bifurcation-container .checkbox-group input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--bd-primary-color);
}

/* ===== BUTTONS ===== */
.bifurcation-container .button-group {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

.bifurcation-container .btn {
    flex: 1;
    padding: 10px 16px;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.bifurcation-container .btn-primary {
    background: var(--bd-primary-color);
    color: white;
}

.bifurcation-container .btn-primary:hover {
    background: #4f46e5;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.bifurcation-container .btn-secondary {
    background: #64748b;
    color: white;
}

.bifurcation-container .btn-secondary:hover {
    background: #475569;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(100, 116, 139, 0.4);
}

.bifurcation-container .btn:active {
    transform: translateY(0);
}

/* ===== STATUS PANEL ===== */
.bifurcation-container .status-panel {
    margin-top: 20px;
    padding: 16px;
    background: #f1f5f9;
    border-radius: 8px;
    border-left: 4px solid var(--bd-accent-color);
}

.bifurcation-container .status-panel h3 {
    color: var(--bd-secondary-color);
    margin-bottom: 12px;
    font-size: 1rem;
    border-bottom: 2px solid #e2e8f0;
    padding-bottom: 6px;
}

.bifurcation-container .status-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.bifurcation-container .status-item span:first-child {
    font-weight: 600;
    color: var(--bd-secondary-color);
}

.bifurcation-container .status-item span:last-child {
    color: var(--bd-primary-color);
    font-weight: 700;
    font-family: 'Courier New', monospace;
}

/* ===== EXPLANATION ===== */
.bifurcation-container .explanation {
    background: var(--bd-card-bg);
    padding: 30px;
    border-radius: var(--bd-border-radius);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.bifurcation-container .explanation h2 {
    color: var(--bd-secondary-color);
    margin-bottom: 20px;
    font-size: 1.8rem;
    border-bottom: 3px solid var(--bd-primary-color);
    padding-bottom: 10px;
}

.bifurcation-container .explanation h3 {
    color: var(--bd-secondary-color);
    margin-top: 25px;
    margin-bottom: 15px;
    font-size: 1.4rem;
}

.bifurcation-container .explanation p {
    margin-bottom: 15px;
    text-align: justify;
    line-height: 1.8;
}

.bifurcation-container .formula-box {
    background: #f1f5f9;
    border: 2px solid var(--bd-primary-color);
    border-radius: 8px;
    padding: 20px;
    text-align: center;
    font-size: 1.5rem;
    font-family: 'Times New Roman', Times, serif;
    color: var(--bd-accent-color);
    margin: 20px 0;
    font-weight: bold;
}

.bifurcation-container .reading-list {
    list-style: none;
    padding-left: 0;
}

.bifurcation-container .reading-list li {
    padding: 12px 15px;
    margin-bottom: 10px;
    background: #f8fafc;
    border-left: 4px solid var(--bd-primary-color);
    border-radius: 4px;
    transition: all 0.3s ease;
}

.bifurcation-container .reading-list li:hover {
    background: #eef2ff;
    transform: translateX(5px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.bifurcation-container .reading-list strong {
    color: var(--bd-accent-color);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .bifurcation-container {
        padding: 15px;
    }

    .bifurcation-container h1 {
        font-size: 1.8rem;
    }

    .bifurcation-container .subtitle {
        font-size: 0.95rem;
    }

    .bifurcation-container .controls-panel {
        padding: 20px;
    }

    .bifurcation-container .button-group {
        flex-direction: column;
    }

    .bifurcation-container .canvas-container {
        min-height: 350px;
        padding: 15px;
    }
}

@media (max-width: 480px) {
    .bifurcation-container h1 {
        font-size: 1.5rem;
    }

    .bifurcation-container .canvas-container {
        min-height: 280px;
    }
}