/* 
    PULSE Simulator Documentation Styles V4
    Theme: Antigravity (Google Material 3 Dark)
*/

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

:root {
    /* 
       Color Palette: Antigravity / Material 3 Dark
       Backgrounds: Deep matte grays, not pure black. 
    */
    --bg-base: #131314;       /* Main background */
    --bg-surface: #1E1F20;    /* Cards, Sidebar */
    --bg-surface-high: #2D2E31; /* Hover states, inputs */

    --primary-accent: #A8C7FA; /* Google Blue Pastel */
    --primary-hover: #D3E3FD;
    
    --secondary-accent: #6DD58C; /* Success/Go Greenish */
    --nlos-accent: #F2B8B5;      /* Error/Stop Reddish */

    --text-primary: #E3E3E3;
    --text-secondary: #C4C7C5;
    --text-tertiary: #8E918F;

    --border-subtle: #444746;
    --border-contrast: #5E5E5E;

    --code-bg: #1B1C1D;
    
    /* Variable additions for proper theming */
    --nav-active-bg: #394457;
    --logo-filter: invert(1) brightness(2);

    /* Layout */
    --sidebar-width: 260px;
    --content-max-width: 1200px;
    --border-radius-lg: 16px;
    --border-radius-md: 12px;
    --border-radius-sm: 8px;
}

/* Light Mode Override */
[data-theme="light"] {
    --bg-base: #FFFFFF;
    --bg-surface: #F8F9FA;
    --bg-surface-high: #E8EAED;
    --primary-accent: #0B57D0;
    --primary-hover: #174EA6;
    --text-primary: #1F1F1F;
    --text-secondary: #444746;
    --border-subtle: #E0E2E0;
    --border-contrast: #C4C7C5;
    --code-bg: #F1F3F4;
    
    /* Light Mode Specifics */
    --nav-active-bg: #D3E3FD; /* Lighter Blue */
    --logo-filter: none;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-base);
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    min-height: 100vh;
    font-feature-settings: "ss01", "cv01"; /* Cleaner functional look */
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* ===========================
   Sidebar Navigation (Explorer Style)
   =========================== */
.sidebar {
    width: var(--sidebar-width);
    height: 100vh;
    position: fixed;
    top: 0;
    left: 0;
    background-color: var(--bg-base); /* Seamless with body in this theme */
    border-right: 1px solid var(--border-subtle);
    display: flex;
    flex-direction: column;
    z-index: 1000;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.sidebar-header {
    padding: 2rem 1.5rem; /* Increased padding for breathing room */
    display: flex;
    flex-direction: column;
    gap: 1rem;
    border-bottom: 1px solid var(--border-subtle); 
    background: linear-gradient(180deg, var(--bg-surface) 0%, var(--bg-base) 100%); /* Subtle gradient */
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo-icon {
    height: 48px; 
    width: auto;
    filter: var(--logo-filter);
    transition: all 0.3s ease;
}
.logo-icon:hover {
    transform: rotate(-5deg) scale(1.05); /* Playful interaction */
}

.logo-text {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--primary-accent) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Version Badge Style */
.subtitle {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary-accent);
    background-color: rgba(168, 199, 250, 0.1); /* Subtle blue tint */
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    align-self: flex-start;
    border: 1px solid rgba(168, 199, 250, 0.2);
    margin-top: -0.5rem; /* Pull closer to logo */
    margin-bottom: 0.5rem;
}

/* Theme Switcher - Modern Toggle */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--bg-surface-high);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--border-subtle);
}

.theme-switch-wrapper em {
    font-style: normal;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.theme-switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
}
.theme-switch input { display: none; }

.slider {
    position: absolute; cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--border-subtle);
    transition: .3s;
    border-radius: 34px;
}
.slider:before {
    position: absolute; content: "";
    height: 18px; width: 18px;
    left: 3px; bottom: 3px;
    background-color: #fff;
    transition: .3s cubic-bezier(0.4, 0.0, 0.2, 1);
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}
/* Icons inside toggle */
.slider:after {
    content: "🌙"; 
    position: absolute;
    right: 6px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 12px;
    opacity: 0.6;
}

input:checked + .slider { background-color: var(--primary-accent); }
input:checked + .slider:before { transform: translateX(20px); background-color: #fff; }
input:checked + .slider:after {
    content: "☀️";
    left: 6px;
    right: auto;
    color: #fff;
    opacity: 1;
}


/* Navigation Links */
.nav-links {
    list-style: none;
    padding: 1rem 0.75rem;
    flex-grow: 1;
    overflow-y: auto;
}

.nav-links li {
    margin-bottom: 4px; /* Slightly more space */
}

.nav-links a {
    display: flex;
    align-items: center;
    padding: 0.6rem 1rem; /* More comfortable touch target */
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem; /* Improved readability */
    font-weight: 500;
    border-radius: 50px; /* Pill shape */
    transition: all 0.2s cubic-bezier(0.2, 0.0, 0, 1.0);
}

.nav-links a:hover {
    background-color: var(--bg-surface-high);
    color: var(--text-primary);
    transform: translateX(4px); /* Subtle movement on hover */
}

.nav-links a.active {
    background-color: var(--nav-active-bg);
    color: var(--primary-accent);
    font-weight: 600;
}

/* Sidebar Footer */
.sidebar-footer {
    padding: 1.5rem;
    color: var(--text-tertiary);
    font-size: 0.75rem;
    border-top: 1px solid var(--border-subtle);
}

/* ===========================
   Main Content Area 
   =========================== */
.content-wrapper {
    margin-left: var(--sidebar-width);
    width: calc(100% - var(--sidebar-width));
    padding: 4rem 3rem;
    display: flex;
    justify-content: center;
    transition: margin-left 0.3s ease;
}

.content {
    width: 100%;
    max-width: var(--content-max-width);
}

/* Typography */
h1, h2, h3, h4 {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 1rem;
    letter-spacing: -0.01em;
}

h1 {
    font-size: 2.25rem;
    font-weight: 500; /* Google style is often lighter for large text */
    margin-bottom: 0.5rem;
}

h2 {
    font-size: 1.5rem;
    margin-top: 3rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-subtle);
}

h3 {
    font-size: 1.25rem;
    margin-top: 2rem;
    color: var(--primary-accent);
}

h4 {
    font-size: 1rem;
    margin-top: 1.5rem;
    font-weight: 600;
}

p {
    margin-bottom: 1.25rem;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
}

.lead {
    font-size: 1.15rem;
    color: var(--text-tertiary);
    margin-bottom: 2rem;
}

a {
    color: var(--primary-accent);
    text-decoration: none;
    transition: color 0.2s;
}
a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

ul, ol {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
    color: var(--text-secondary);
}
li { margin-bottom: 0.5rem; }

hr {
    border: none;
    height: 1px;
    background-color: var(--border-subtle);
    margin: 3rem 0;
}

/* Images & Figures */
figure {
    margin: 2rem 0;
    background-color: var(--bg-surface);
    padding: 1rem;
    border-radius: var(--border-radius-md);
    border: 1px solid var(--border-subtle);
}

img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius-sm);
    display: block;
    margin: 0 auto;
}

figcaption {
    margin-top: 1rem;
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-tertiary);
}

/* Code Blocks (IDE Style) */
pre {
    background-color: var(--code-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    overflow-x: auto;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-subtle);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.5;
}

code {
    font-family: 'JetBrains Mono', monospace;
    color: var(--primary-accent);
}

p code, li code {
    background-color: var(--bg-surface-high);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    border: 1px solid var(--border-subtle);
    font-size: 0.85em;
    color: var(--text-primary);
}

/* Tables (Material Style) */
table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 2rem 0;
    border: 1px solid var(--border-subtle);
    border-radius: var(--border-radius-md);
    overflow: hidden;
}

th {
    background-color: var(--bg-surface);
    color: var(--text-primary);
    font-weight: 600;
    text-align: left;
    padding: 1rem;
    border-bottom: 1px solid var(--border-subtle);
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-subtle);
    color: var(--text-secondary);
}

tr:last-child td { border-bottom: none; }
tr:hover td { background-color: var(--bg-surface-high); }

/* Components: Concept Grid & Cards */
.concept-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--border-radius-lg);
    padding: 1.5rem;
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-4px);
    background-color: var(--bg-surface-high);
    border-color: var(--primary-accent);
    box-shadow: 0 8px 24px rgba(0,0,0,0.2);
}

.card h4 {
    margin-top: 0;
    color: var(--primary-accent);
    font-size: 1.1rem;
}

/* Feature Card (Flush Image) */
.card-feature {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.card-feature:hover {
    transform: translateY(-4px);
    border-color: var(--primary-accent);
    box-shadow: 0 12px 32px rgba(0,0,0,0.3);
}

.card-feature img {
    width: 100%;
    height: 180px; 
    object-fit: cover;
    object-position: top;
    border-radius: 0;
    border: none;
    border-bottom: 1px solid var(--border-subtle);
    margin: 0;
}

.card-feature-content {
    padding: 1.5rem;
}

.card-feature h4 {
    margin-top: 0;
    color: var(--primary-accent);
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.card-feature p {
    margin-bottom: 0;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* Feature/Info Boxes */
.info-box, .mission-box, .feature-block {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-left: 4px solid var(--primary-accent);
    padding: 1.5rem;
    border-radius: 4px var(--border-radius-md) var(--border-radius-md) 4px;
    margin-bottom: 1.5rem;
}

/* Math Blocks */
.math-block {
    background-color: var(--bg-surface);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    text-align: center;
    margin: 1.5rem 0;
    border: 1px solid var(--border-subtle);
    font-family: 'Inter', serif; /* Or keep default serif for math */
    font-size: 1.1rem;
}

@media (max-width: 768px) {
    body { flex-direction: column; }
    .sidebar { width: 100%; height: auto; position: relative; border-right: none; border-bottom: 1px solid var(--border-subtle); }
    .nav-links { display: flex; overflow-x: auto; padding: 0.5rem; }
    .nav-links a { white-space: nowrap; margin-right: 0.5rem; }
    .content-wrapper { margin-left: 0; width: 100%; padding: 2rem 1.5rem; }
}

/* Researcher Cards */
.researcher-card {
    display: flex;
    flex-direction: column;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.2s, box-shadow 0.2s;
}

.researcher-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 12px rgba(0,0,0,0.1);
}

.researcher-img {
    width: 150px;
    height: 150px;
    object-fit: cover;
    border-radius: 50%;
    border: 3px solid var(--primary-accent);
    margin: 0 auto 1.5rem auto;
    display: block;
}

.researcher-info h2 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    color: var(--primary-accent);
    text-align: center;
}

.researcher-info p {
    line-height: 1.6;
    margin-bottom: 1rem;
    text-align: justify;
}

/* ===========================
   Hero Section 
   =========================== */
/* ===========================
   Hero Section 
   =========================== */
.hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 3rem;
    padding: 3rem 0 5rem 0;
    animation: fadeIn 0.8s ease-out;
}

.hero-content {
    flex: 1;
    max-width: 550px;
}

.hero-media {
    flex: 1.4;
    max-width: 800px;
    position: relative;
    display: flex;
    justify-content: center;
}

.hero-media video {
    width: 100%;
    border-radius: var(--border-radius-lg);
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.4);
    border: 1px solid var(--border-subtle);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-media video:hover {
    transform: scale(1.02);
    box-shadow: 0 30px 60px -12px rgba(0,0,0,0.5);
}

/* Hero badge */
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--secondary-accent);
    background-color: rgba(109, 213, 140, 0.08);
    border: 1px solid rgba(109, 213, 140, 0.2);
    padding: 0.35rem 0.85rem;
    border-radius: 50px;
    margin-bottom: 1.5rem;
}

.hero-badge-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background-color: var(--secondary-accent);
    box-shadow: 0 0 0 0 rgba(109, 213, 140, 0.4);
    animation: badgePulse 2s infinite;
    flex-shrink: 0;
}

@keyframes badgePulse {
    0%   { box-shadow: 0 0 0 0 rgba(109, 213, 140, 0.4); }
    70%  { box-shadow: 0 0 0 8px rgba(109, 213, 140, 0); }
    100% { box-shadow: 0 0 0 0 rgba(109, 213, 140, 0); }
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.05;
    margin-bottom: 1.25rem;
    background: linear-gradient(160deg, var(--text-primary) 0%, var(--primary-accent) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.03em;
}

.hero-title-alt {
    background: linear-gradient(135deg, var(--primary-accent) 0%, #93c5fd 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 300;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 1.25rem;
    line-height: 1.6;
    border-left: 3px solid var(--primary-accent);
    padding-left: 1rem;
}

.hero-description {
    font-size: 1rem;
    color: var(--text-tertiary);
    margin-bottom: 2.5rem;
    line-height: 1.75;
}

.hero-description strong {
    color: var(--text-secondary);
    font-weight: 600;
}

.hero-actions {
    display: flex;
    flex-direction: row;
    gap: 1.5rem;
    align-items: center;
    width: 100%;
    margin-top: 3rem;
}

/* Premium Download Button */
.btn-download {
    display: inline-flex;
    flex: 1;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    padding: 0.85rem 1.5rem;
    border-radius: var(--border-radius-md);
    text-decoration: none;
    transition: all 0.25s cubic-bezier(0.2, 0.0, 0, 1.0);
    background: linear-gradient(135deg, var(--primary-accent) 0%, #7aadff 100%);
    color: #0d1117;
    font-weight: 600;
    border: none;
    box-shadow: 0 0 0 1px rgba(168, 199, 250, 0.3), 0 8px 24px rgba(168, 199, 250, 0.15);
    position: relative;
    overflow: hidden;
}

.btn-download::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.15) 0%, transparent 60%);
    pointer-events: none;
}

.btn-download:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 0 1px rgba(168, 199, 250, 0.5), 0 12px 32px rgba(168, 199, 250, 0.3);
    text-decoration: none;
    color: #0d1117;
}

[data-theme="light"] .btn-download {
    background: linear-gradient(135deg, #0B57D0 0%, #1a6fe8 100%);
    color: #ffffff;
    box-shadow: 0 0 0 1px rgba(11, 87, 208, 0.3), 0 8px 24px rgba(11, 87, 208, 0.2);
}

[data-theme="light"] .btn-download:hover {
    box-shadow: 0 0 0 1px rgba(11, 87, 208, 0.5), 0 12px 32px rgba(11, 87, 208, 0.3);
    color: #ffffff;
}

.btn-download-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: rgba(0,0,0,0.15);
    border-radius: var(--border-radius-sm);
    flex-shrink: 0;
}

.btn-download-text {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
    text-align: left;
}

.btn-download-label {
    font-size: 0.95rem;
    font-weight: 700;
    line-height: 1;
    letter-spacing: -0.01em;
}

.btn-download-sub {
    font-size: 0.72rem;
    font-weight: 500;
    opacity: 0.7;
    letter-spacing: 0.02em;
    line-height: 1;
}

/* Secondary Buttons */
.btn-secondary {
    display: inline-flex;
    flex: 1;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 0.85rem 1.5rem;
    border-radius: var(--border-radius-md);
    text-decoration: none;
    transition: all 0.25s cubic-bezier(0.2, 0.0, 0, 1.0);
    background-color: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.95rem;
}

.btn-secondary:hover {
    transform: translateY(-3px);
    border-color: var(--primary-accent);
    box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    color: var(--primary-accent);
    background-color: var(--bg-surface-high);
    text-decoration: none;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s cubic-bezier(0.2, 0.0, 0, 1.0);
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary-accent);
    color: var(--bg-base); /* Using bg-base for contrast on light blue */
}

[data-theme="light"] .btn-primary {
    color: #FFFFFF;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(168, 199, 250, 0.3);
    text-decoration: none;
}

.btn-secondary {
    background-color: var(--bg-surface);
    color: var(--text-primary);
    border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
    background-color: var(--bg-surface-high);
    border-color: var(--text-secondary);
    transform: translateY(-2px);
    text-decoration: none;
    color: var(--text-primary);
}

/* ===========================
   New Sections & Layouts 
   =========================== */
.section-divider {
    border: none;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-subtle), transparent);
    margin: 4rem 0;
}

.features-section h3 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.info-layout {
    display: flex;
    align-items: center;
    gap: 4rem;
}

.info-text {
    flex: 1;
}

.info-image {
    flex: 1;
}

.shadow-lg {
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
    border: 1px solid var(--border-subtle);
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 900px) {
    .hero {
        flex-direction: column-reverse;
        text-align: center;
        gap: 2rem;
    }

    .hero-content, .hero-media {
        max-width: 100%;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero-actions {
        align-items: center;
    }

    .info-layout {
        flex-direction: column;
    }
}

@media (min-width: 768px) {
    .researcher-card {
        flex-direction: row;
        align-items: flex-start;
        gap: 2rem;
    }

    .researcher-img {
        margin: 0;
        flex-shrink: 0;
    }
    
    .researcher-info h2 {
        text-align: left;
    }
    
    .researcher-info p {
        text-align: left;
    }
}