/* ========================================================
   CMSHub — Design System
   Dark theme with glassmorphism, premium aesthetics
   ======================================================== */

/* --- CSS Custom Properties --- */
:root {
    /* Colors */
    --bg-primary: #0a0e17;
    --bg-secondary: #111827;
    --bg-card: rgba(17, 24, 39, 0.85);
    --bg-card-hover: rgba(30, 41, 59, 0.9);
    --bg-sidebar: rgba(15, 23, 42, 0.95);
    --bg-input: rgba(30, 41, 59, 0.7);

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --accent-blue: #3b82f6;
    --accent-cyan: #06b6d4;
    --accent-purple: #8b5cf6;
    --accent-green: #10b981;
    --accent-amber: #f59e0b;
    --accent-rose: #f43f5e;

    --gradient-primary: linear-gradient(135deg, #3b82f6, #8b5cf6);
    --gradient-accent: linear-gradient(135deg, #06b6d4, #3b82f6);
    --gradient-warm: linear-gradient(135deg, #f59e0b, #f43f5e);

    --border-color: rgba(148, 163, 184, 0.12);
    --border-glow: rgba(59, 130, 246, 0.3);

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.15);

    /* Spacing */
    --sidebar-width: 260px;
    --header-height: 80px;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Border radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 20px;
}

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

html {
    font-size: 15px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    display: flex;
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Animated background gradient */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(ellipse at 20% 20%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(139, 92, 246, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(6, 182, 212, 0.04) 0%, transparent 60%);
    pointer-events: none;
    z-index: 0;
}

/* --- Sidebar --- */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 100;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    padding-bottom: 2rem;
}

.sidebar-header {
    padding: 1.6rem 1.4rem 1.2rem;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.logo-icon {
    font-size: 1.8rem;
    filter: drop-shadow(0 0 8px rgba(59, 130, 246, 0.5));
}

.logo h1 {
    font-size: 1.4rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
}

.logo-subtitle {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.3rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.nav-section {
    padding: 1rem 0.8rem 0;
}

.nav-section-title {
    font-size: 0.65rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    padding: 0 0.6rem;
    margin-bottom: 0.5rem;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    padding: 0.6rem 0.8rem;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 400;
    transition: all var(--transition-fast);
    position: relative;
    cursor: pointer;
}

.nav-item:hover:not(.disabled) {
    color: var(--text-primary);
    background: rgba(59, 130, 246, 0.08);
}

.nav-item.active {
    color: var(--text-primary);
    background: rgba(59, 130, 246, 0.12);
    font-weight: 500;
}

.nav-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    background: var(--gradient-primary);
    border-radius: 0 3px 3px 0;
}

.nav-item.disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.nav-icon {
    font-size: 1rem;
    width: 1.3rem;
    text-align: center;
    flex-shrink: 0;
}

.nav-label {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.badge {
    font-size: 0.55rem;
    padding: 0.15rem 0.45rem;
    border-radius: 100px;
    background: var(--gradient-primary);
    color: white;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-left: auto;
}

/* --- Main Content --- */
.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 2rem 2.5rem;
    position: relative;
    z-index: 1;
    min-height: 100vh;
}

/* --- Pages --- */
.page {
    display: none;
    animation: fadeIn 0.3s ease;
}

.page.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.page-header {
    margin-bottom: 1.8rem;
}

.page-header h2 {
    font-size: 1.7rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    margin-bottom: 0.4rem;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.page-desc {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* --- Controls Bar --- */
.controls-bar {
    display: flex;
    align-items: flex-end;
    gap: 1.2rem;
    padding: 1rem 1.2rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.control-group label {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.control-group select,
.control-group input[type="number"] {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: 0.5rem 0.8rem;
    font-size: 0.85rem;
    font-family: var(--font-sans);
    outline: none;
    transition: border-color var(--transition-fast);
    min-width: 140px;
    cursor: pointer;
}

.control-group select:focus,
.control-group input:focus {
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.15);
}

.control-group input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100px;
    height: 4px;
    background: var(--bg-input);
    border-radius: 2px;
    outline: none;
    margin-top: 0.5rem;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-blue);
    cursor: pointer;
    box-shadow: 0 0 6px rgba(59, 130, 246, 0.4);
    transition: transform var(--transition-fast);
}

.control-group input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.range-val {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent-cyan);
    font-family: var(--font-mono);
    min-width: 1.2rem;
    text-align: center;
    display: inline-block;
}

/* --- Buttons --- */
.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.55rem 1.3rem;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
    white-space: nowrap;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.4);
}

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

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-icon {
    font-size: 0.75rem;
}

/* --- Cards --- */
.content-grid {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 1.2rem;
}

.content-single {
    display: block;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    overflow: hidden;
    transition: border-color var(--transition-normal);
}

.card:hover {
    border-color: var(--border-glow);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.9rem 1.2rem;
    border-bottom: 1px solid var(--border-color);
}

.card-header h3 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
}

.info-badge {
    font-size: 0.7rem;
    font-family: var(--font-mono);
    color: var(--accent-cyan);
    background: rgba(6, 182, 212, 0.1);
    padding: 0.2rem 0.6rem;
    border-radius: 100px;
}

/* --- 3D Canvas --- */
.canvas-container {
    width: 100%;
    height: 480px;
    position: relative;
    background: radial-gradient(ellipse at center, rgba(15, 23, 42, 1) 0%, rgba(10, 14, 23, 1) 100%);
}

.canvas-container canvas {
    display: block;
    width: 100% !important;
    height: 100% !important;
}

/* --- Charts --- */
.chart-container {
    width: 100%;
    min-height: 420px;
    padding: 0.8rem;
    position: relative;
}

.chart-container .js-plotly-plot,
.chart-container .plot-container {
    width: 100% !important;
}

/* --- Details Panel --- */
.details-panel {
    padding: 1rem 1.2rem;
    font-size: 0.85rem;
    line-height: 1.7;
}

.details-panel .detail-row {
    display: flex;
    justify-content: space-between;
    padding: 0.45rem 0;
    border-bottom: 1px solid var(--border-color);
}

.details-panel .detail-row:last-child {
    border-bottom: none;
}

.details-panel .detail-label {
    color: var(--text-secondary);
    font-size: 0.8rem;
}

.details-panel .detail-value {
    font-weight: 600;
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--accent-cyan);
}

.placeholder-text {
    color: var(--text-muted);
    font-size: 0.85rem;
    text-align: center;
    padding: 2rem;
}

/* --- Theory Box --- */
.theory-box {
    padding: 1.2rem;
    font-size: 0.85rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

.equation {
    background: rgba(59, 130, 246, 0.06);
    border: 1px solid rgba(59, 130, 246, 0.15);
    border-radius: var(--radius-md);
    padding: 1rem 1.4rem;
    margin: 0.8rem 0;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    color: var(--accent-cyan);
    text-align: center;
    letter-spacing: 0.02em;
}

.theory-list {
    list-style: none;
    margin: 0.6rem 0;
}

.theory-list li {
    padding: 0.25rem 0;
    padding-left: 1.2rem;
    position: relative;
}

.theory-list li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: var(--accent-blue);
    font-weight: 700;
}

.theory-note {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-style: italic;
    margin-top: 0.8rem;
    padding-top: 0.6rem;
    border-top: 1px solid var(--border-color);
}

/* --- Loading Spinner --- */
.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(10, 14, 23, 0.7);
    backdrop-filter: blur(4px);
    z-index: 10;
}

.spinner {
    width: 36px;
    height: 36px;
    border: 3px solid rgba(59, 130, 246, 0.2);
    border-top-color: var(--accent-blue);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .content-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform var(--transition-normal);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .main-content {
        margin-left: 0;
        padding: 1.5rem 1rem;
    }

    .controls-bar {
        flex-direction: column;
        align-items: stretch;
    }
}

/* --- Plotly dark theme overrides --- */
.js-plotly-plot .plotly .modebar {
    top: 4px !important;
    right: 4px !important;
}

.js-plotly-plot .plotly .modebar-btn {
    font-size: 14px !important;
}