/**
 * IntuitionLab - Dark Glassmorphism Design System
 * Background: #070a12
 * Frosted Glass Cards: backdrop-filter: blur(16px)
 * Neon Tokens: Cyan (#06b6d4), Rose (#f43f5e), Emerald (#10b981), Amber (#f59e0b), Violet (#8b5cf6)
 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
    --bg-dark: #070a12;
    --bg-darker: #04060a;
    --card-bg: rgba(15, 23, 42, 0.65);
    --card-bg-hover: rgba(24, 34, 58, 0.75);
    --card-border: rgba(255, 255, 255, 0.08);
    --card-border-glow: rgba(6, 182, 212, 0.35);

    --cyan: #06b6d4;
    --cyan-glow: rgba(6, 182, 212, 0.4);
    --rose: #f43f5e;
    --rose-glow: rgba(244, 63, 94, 0.4);
    --emerald: #10b981;
    --emerald-glow: rgba(16, 185, 129, 0.4);
    --amber: #f59e0b;
    --amber-glow: rgba(245, 158, 11, 0.4);
    --violet: #8b5cf6;
    --violet-glow: rgba(139, 92, 246, 0.4);
    --blue: #3b82f6;

    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-dim: #64748b;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 22px;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    overflow-x: hidden;
    background-image: 
        radial-gradient(circle at 15% 20%, rgba(6, 182, 212, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 85% 75%, rgba(139, 92, 246, 0.08) 0%, transparent 45%),
        radial-gradient(circle at 50% 50%, rgba(244, 63, 94, 0.04) 0%, transparent 50%);
    background-attachment: fixed;
}

/* =========================================================================
 * HEADER & TOP NAVIGATION
 * ========================================================================= */
.topbar {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1.5rem;
    background: rgba(7, 10, 18, 0.75);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--card-border);
}

.topbar-left {
    display: flex;
    align-items: center;
    gap: 1.25rem;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
}

.brand-icon {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--cyan), var(--violet));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 16px var(--cyan-glow);
    font-size: 1.1rem;
    font-weight: 700;
}

.brand-text {
    display: flex;
    flex-direction: column;
}

.brand-title {
    font-size: 1.05rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    background: linear-gradient(to right, #ffffff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.brand-sub {
    font-size: 0.68rem;
    font-weight: 600;
    color: var(--cyan);
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.subject-tabs {
    display: flex;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 3px;
    gap: 4px;
}

.subject-tab {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.5rem 1.1rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.subject-tab:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.subject-tab.active {
    color: #ffffff;
    background: rgba(6, 182, 212, 0.18);
    border: 1px solid rgba(6, 182, 212, 0.4);
    box-shadow: 0 0 12px rgba(6, 182, 212, 0.25);
}

.subject-tab[data-subject-tab="physics"].active {
    background: rgba(245, 158, 11, 0.18);
    border-color: rgba(245, 158, 11, 0.4);
    box-shadow: 0 0 12px rgba(245, 158, 11, 0.25);
}

.subject-tab[data-subject-tab="algebra"].active {
    background: rgba(244, 63, 94, 0.18);
    border-color: rgba(244, 63, 94, 0.4);
    box-shadow: 0 0 12px rgba(244, 63, 94, 0.25);
}

.topbar-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.icon-btn {
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
    padding: 0.45rem 0.85rem;
    border-radius: var(--radius-md);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    transition: all 0.2s ease;
}

.icon-btn:hover {
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.25);
    background: rgba(255, 255, 255, 0.08);
}

.search-trigger-btn {
    border-color: rgba(6, 182, 212, 0.3);
    color: var(--cyan);
}

/* =========================================================================
 * SUB NAVIGATION BAR
 * ========================================================================= */
.sub-nav {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding: 0.65rem 1.5rem;
    gap: 0.65rem;
    overflow-x: auto;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    background: rgba(7, 10, 18, 0.4);
}

.sub-pill {
    background: rgba(15, 23, 42, 0.5);
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
    padding: 0.4rem 0.9rem;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.18s ease;
}

.sub-pill:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.2);
}

.sub-pill.active {
    color: #ffffff;
    background: rgba(6, 182, 212, 0.2);
    border-color: var(--cyan);
    box-shadow: 0 0 10px rgba(6, 182, 212, 0.3);
}

/* =========================================================================
 * MAIN WORKSPACE & SIMULATION CARDS
 * ========================================================================= */
.main-container {
    max-width: 98%;
    margin: 0 auto;
    padding: 1.5rem;
}

[hidden] {
    display: none !important;
}

[data-subject-section][hidden] {
    display: none !important;
}

.sub-pill[hidden] {
    display: none !important;
}

.sim-panel {
    display: none;
    flex-direction: column;
    gap: 1.25rem;
    animation: fadeIn 0.25s ease-out;
}

.sim-panel.active:not([hidden]) {
    display: flex;
}

.sim-panel[hidden] {
    display: none !important;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to { opacity: 1; transform: translateY(0); }
}

.sim-panel-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 1rem;
}

.sim-header-text h2 {
    font-size: 1.45rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: #ffffff;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sim-header-text p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.sim-formula-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 0.75rem 1.25rem;
    display: flex;
    align-items: center;
    font-size: 0.95rem;
    color: var(--cyan);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

/* Dual Canvas Layout or Single Canvas with Controls */
.sim-grid-split {
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 1.25rem;
}

.sim-grid-split > * {
    min-width: 0;
}

@media (max-width: 1080px) {
    .sim-grid-split {
        grid-template-columns: 1fr;
    }
}

.canvases-column {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.canvas-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    position: relative;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
    display: flex;
    flex-direction: column;
}

.canvas-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.6rem 1rem;
    background: rgba(255, 255, 255, 0.03);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.canvas-wrap {
    width: 100%;
    position: relative;
    background: #070a12;
}

.canvas-wrap canvas {
    display: block;
    width: 100%;
    height: 100%;
    touch-action: none;
}

.dual-horizontal-canvases {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.dual-horizontal-canvases > * {
    min-width: 0;
}

@media (max-width: 860px) {
    .dual-horizontal-canvases {
        grid-template-columns: 1fr;
    }
}

/* =========================================================================
 * CONTROL PANEL SIDEBAR CARDS
 * ========================================================================= */
.controls-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.control-header span:last-child {
    font-family: var(--font-mono);
    color: var(--cyan);
}

.select-input {
    background: rgba(7, 10, 18, 0.7);
    border: 1px solid var(--card-border);
    color: var(--text-primary);
    padding: 0.55rem 0.85rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-family: inherit;
    cursor: pointer;
    outline: none;
    transition: all 0.2s ease;
}

.select-input:focus {
    border-color: var(--cyan);
    box-shadow: 0 0 10px var(--cyan-glow);
}

.range-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.12);
    border-radius: 3px;
    outline: none;
    cursor: pointer;
    transition: background 0.2s ease;
}

.range-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #ffffff;
    border: 2px solid var(--cyan);
    box-shadow: 0 0 8px var(--cyan-glow);
    cursor: grab;
    transition: transform 0.15s ease, background 0.15s ease;
}

.range-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background: var(--cyan);
}

.btn-row {
    display: flex;
    gap: 0.5rem;
}

.btn-primary {
    flex: 1;
    background: linear-gradient(135deg, rgba(6, 182, 212, 0.25), rgba(59, 130, 246, 0.25));
    border: 1px solid var(--cyan);
    color: #ffffff;
    padding: 0.65rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    box-shadow: 0 0 14px rgba(6, 182, 212, 0.25);
    transition: all 0.2s ease;
}

.btn-primary:hover {
    background: linear-gradient(135deg, rgba(6, 182, 212, 0.4), rgba(59, 130, 246, 0.4));
    box-shadow: 0 0 20px rgba(6, 182, 212, 0.45);
    transform: translateY(-1px);
}

.btn-primary.active {
    background: rgba(244, 63, 94, 0.35);
    border-color: var(--rose);
    box-shadow: 0 0 14px var(--rose-glow);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
    padding: 0.65rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-secondary:hover {
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.1);
}

/* =========================================================================
 * STAT READOUT BOXES & ENERGY BARS
 * ========================================================================= */
.stat-box {
    background: rgba(7, 10, 18, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: var(--radius-md);
    padding: 0.75rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    font-size: 0.82rem;
}

.stat-label {
    color: var(--text-dim);
}

.stat-val {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--text-primary);
}

.energy-bar-wrap {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    margin-top: 0.25rem;
}

.energy-track {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 4px;
    overflow: hidden;
    position: relative;
}

.energy-fill {
    height: 100%;
    transition: width 0.08s ease;
}

.energy-fill.ek {
    background: linear-gradient(90deg, var(--rose), #fb7185);
    box-shadow: 0 0 10px var(--rose-glow);
}

.energy-fill.ep {
    background: linear-gradient(90deg, var(--cyan), #38bdf8);
    box-shadow: 0 0 10px var(--cyan-glow);
}

/* =========================================================================
 * SPOTLIGHT SEARCH PALETTE (⌘K)
 * ========================================================================= */
.palette-overlay {
    position: fixed;
    inset: 0;
    z-index: 999;
    background: rgba(4, 6, 10, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 15vh;
}

.palette-overlay[hidden] {
    display: none;
}

.palette-card {
    width: 100%;
    max-width: 620px;
    background: rgba(15, 23, 42, 0.92);
    border: 1px solid rgba(6, 182, 212, 0.3);
    border-radius: var(--radius-xl);
    box-shadow: 0 16px 64px rgba(0, 0, 0, 0.7), 0 0 24px rgba(6, 182, 212, 0.15);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.palette-header {
    display: flex;
    align-items: center;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--card-border);
    gap: 0.75rem;
}

.palette-icon {
    font-size: 1.2rem;
    color: var(--cyan);
}

.palette-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: #ffffff;
    font-size: 1.1rem;
    font-family: inherit;
}

.palette-input::placeholder {
    color: var(--text-dim);
}

.palette-results {
    list-style: none;
    max-height: 380px;
    overflow-y: auto;
    padding: 0.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.search-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.15s ease;
    border: 1px solid transparent;
}

.search-item:hover,
.search-item.selected {
    background: rgba(6, 182, 212, 0.14);
    border-color: rgba(6, 182, 212, 0.4);
    box-shadow: 0 0 12px rgba(6, 182, 212, 0.15);
}

.search-item-info {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.search-item-badge {
    font-size: 0.65rem;
    font-weight: 700;
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px solid;
    width: fit-content;
    letter-spacing: 0.05em;
}

.search-item strong {
    font-size: 0.92rem;
    color: #ffffff;
}

.search-item p {
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.search-item-enter {
    font-size: 0.85rem;
    color: var(--text-dim);
    padding: 3px 6px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.05);
}

.search-empty {
    padding: 2rem;
    text-align: center;
    color: var(--text-dim);
    font-size: 0.88rem;
}

/* =========================================================================
 * VISUAL LEARNING GUIDE MODAL
 * ========================================================================= */
.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 999;
    background: rgba(4, 6, 10, 0.8);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
}

.modal-overlay[hidden] {
    display: none;
}

.modal-card {
    width: 100%;
    max-width: 780px;
    max-height: 85vh;
    background: rgba(15, 23, 42, 0.95);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.8);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.75rem;
    border-bottom: 1px solid var(--card-border);
}

.modal-header h3 {
    font-size: 1.25rem;
    color: #ffffff;
}

.modal-close-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    line-height: 1;
}

.modal-close-btn:hover {
    color: #ffffff;
}

.modal-body {
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.modal-section-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: #ffffff;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.shortcuts-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 0.5rem;
}

.shortcuts-table td {
    padding: 0.5rem 0.75rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.kbd-badge {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    padding: 2px 7px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: #ffffff;
    box-shadow: 0 2px 0 rgba(0,0,0,0.4);
}