:root {
    /* Beige Palette Backgrounds */
    --bg-dark: #fbf9f6;            /* Primary elegant light beige background */
    --bg-surface: #f3efe6;         /* Slightly deeper beige for structural sectioning */
    --bg-card: #ffffff;            /* Clean white card backgrounds for high contrast */
    --border-color: #e3ded5;       /* Soft warm tint for borders and dividers */
    
    /* Green Palette Accents & Typography */
    --text-primary: #1b2a22;       /* Rich charcoal-forest green for main titles and text */
    --text-secondary: #526359;     /* Muted olive-gray for paragraphs and metadata */
    --accent-green: #16423c;       /* Primary deep forest green accent color */
    --accent-green-hover: #0f302b;  /* Darker green variant for hover states */
    --accent-sage: #6b8a7a;        /* Secondary soft sage green for subtle callouts */
    --accent-glow: rgba(22, 66, 60, 0.08);
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Global link accent to match theme */
a {
    color: var(--accent-green);
    text-decoration: none;
    transition: color 0.15s ease;
}

a:hover, a:focus {
    color: var(--accent-green-hover);
    text-decoration: underline;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 5rem 2rem 3rem;
}

.grid {
    display: grid;
    gap: 2rem;
}

/* Navbar Layout */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 3rem;
    background-color: rgba(251, 249, 246, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo-icon {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 3px;
}

.logo-icon .sq {
    width: 10px;
    height: 10px;
    background-color: var(--text-secondary);
    border-radius: 2px;
}

.logo-icon .sq2 { background-color: var(--accent-sage); }
.logo-icon .sq3 { background-color: var(--accent-green); }

.logo-text {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-primary);
}

.highlight { color: var(--accent-green); }

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    margin-right: 1.75rem;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover { color: var(--accent-green); }

.lang-switch {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-switch button {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-weight: 600;
    cursor: pointer;
    font-size: 0.85rem;
    transition: color 0.2s;
}

.lang-switch button.active { color: var(--accent-green); }
.lang-switch .divider { color: var(--border-color); }

/* Hero Presentation Section */
.hero {
    text-align: center;
    padding: 8rem 2rem 6rem;
    background: linear-gradient(180deg, var(--bg-surface) 0%, var(--bg-dark) 100%);
    border-bottom: 1px solid var(--border-color);
}

.hero-badge {
    display: inline-block;
    padding: 0.4rem 1rem;
    background-color: rgba(22, 66, 60, 0.05);
    border: 1px solid rgba(22, 66, 60, 0.12);
    color: var(--accent-green);
    border-radius: 9999px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 3.2rem;
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.03em;
    max-width: 900px;
    margin: 0 auto 1.5rem;
    color: var(--text-primary);
}

.hero p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 750px;
    margin: 0 auto 3rem;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

/* Button Refinement */
.btn {
    padding: 0.85rem 2rem;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.2s;
}

.btn-primary {
    background-color: var(--accent-green);
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(22, 66, 60, 0.15);
}

.btn-primary:hover {
    transform: translateY(-2px);
    background-color: var(--accent-green-hover);
    box-shadow: 0 6px 20px rgba(22, 66, 60, 0.25);
}

.btn-secondary {
    border: 1px solid var(--accent-green);
    color: var(--accent-green);
    background-color: transparent;
}

.btn-secondary:hover {
    background-color: rgba(22, 66, 60, 0.04);
}

/* Structural Components */
.section-title {
    font-size: 2.1rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
    color: var(--accent-green);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3.5rem;
    font-size: 1.05rem;
}

.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.02), 0 2px 4px -1px rgba(0, 0, 0, 0.02);
}

/* Profile Details */
.about-grid { grid-template-columns: 1fr 1fr; }

.supervisors {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.supervisors span {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.supervisors p {
    font-size: 0.95rem;
    color: var(--accent-green);
    font-weight: 500;
}

.supervisors .email {
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 400;
}

.features-grid { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }

.feature-box {
    transition: transform 0.2s, border-color 0.2s;
}

.feature-box:hover {
    transform: translateY(-3px);
    border-color: var(--accent-green);
}

.feature-box .icon {
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.feature-box h3 {
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.feature-box p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* System Specifications */
.req-tables {
    grid-template-columns: 1fr 1fr;
    margin-top: 3rem;
}

.req-list h3 {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.accent-blue { border-color: var(--accent-green) !important; color: var(--accent-green); }
.accent-green { border-color: var(--accent-sage) !important; color: var(--accent-sage); }

.req-list ul { list-style: none; }

.req-list li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.req-list li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--accent-sage);
    font-size: 1.2rem;
    top: -2px;
}

/* Architecture Framework Blocks */
.arch-flow {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    margin-top: 2rem;
}

.arch-block {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    width: 29%;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.01);
}

.arch-block h4 {
    margin-bottom: 1rem;
    font-size: 1rem;
    color: var(--text-primary);
}

.sub-block {
    background-color: var(--bg-dark);
    border: 1px solid var(--border-color);
    padding: 0.6rem;
    margin-top: 0.5rem;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
}

.text-accent-blue { color: var(--accent-green); }
.text-accent-green { color: var(--accent-sage); }
.secure-llm { color: #9a3412; background-color: #fff7ed; border-color: #ffedd5; }

.arch-arrow {
    font-size: 1.3rem;
    color: var(--text-secondary);
    font-weight: 700;
}

.db-group {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

/* Simple figure for the architecture image */
.arch-figure {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 2rem;
}

.arch-img {
    width: 100%;
    max-width: 1000px;
    height: auto;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: 0 8px 30px rgba(11, 22, 17, 0.06);
    background-color: var(--bg-card);
    display: block;
}

/* Presentation Video Area */
.video-card {
    padding: 1rem;
    overflow: hidden;
}

.video-frame {
    position: relative;
    min-height: 420px;
    border-radius: 18px;
    border: 1px solid var(--border-color);
    background:
        radial-gradient(circle at top left, rgba(34, 197, 94, 0.15), transparent 32%),
        linear-gradient(135deg, #0f172a, #111827 45%, #1f2937);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.08);
    overflow: hidden;
}

.video-frame::before {
    content: "";
    position: absolute;
    inset: 20px;
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 14px;
}

.video-frame::after {
    content: "";
    position: absolute;
    inset: 0;
    background-image: linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
    background-size: 36px 36px;
    opacity: 0.35;
    pointer-events: none;
}

.video-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 2rem;
    color: #f8fafc;
    text-align: left;
    z-index: 1;
}

.video-play {
    width: 72px;
    height: 72px;
    border-radius: 999px;
    background: rgba(255,255,255,0.14);
    border: 1px solid rgba(255,255,255,0.2);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    box-shadow: 0 18px 30px rgba(15, 23, 42, 0.35);
    flex: 0 0 auto;
}

.video-overlay strong {
    display: block;
    margin-bottom: 0.35rem;
    font-size: 1.1rem;
}

.video-overlay p {
    max-width: 520px;
    color: rgba(248, 250, 252, 0.82);
    margin: 0;
    line-height: 1.55;
}

/* App Simulator Engine Area */
.sim-wrapper { grid-template-columns: 300px 1fr; }

.sim-controls {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.sim-btn {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    text-align: left;
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.2s;
    box-shadow: 0 1px 3px rgba(0,0,0,0.01);
}

.sim-btn.active, .sim-btn:hover {
    background-color: var(--bg-surface);
    border-color: var(--accent-green);
    color: var(--accent-green);
}

.sim-display {
    padding: 0;
    overflow: hidden;
    background-color: #fafaf9;
    border-color: var(--border-color);
}

.sim-header {
    background-color: var(--bg-surface);
    padding: 0.8rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sim-header .dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.sim-header .dot:nth-child(1) { background-color: #e11d48; }
.sim-header .dot:nth-child(2) { background-color: #ca8a04; }
.sim-header .dot:nth-child(3) { background-color: #16a34a; }

.sim-app-title {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-left: 1rem;
    font-weight: 600;
}

.sim-body {
    padding: 2rem;
    min-height: 380px;
}

/* Simulator specific styles */
.sim-status-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}
.status-card {
    padding: 0.8rem 1rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background: var(--bg-card);
    text-align: center;
}
.status-card .status-title { font-weight: 700; color: var(--text-primary); margin-bottom: 0.5rem; font-size: 0.95rem; }
.status-card .status-value { font-weight: 700; font-size: 0.88rem; color: var(--text-secondary); }
.status-pending { border-left: 4px solid #f59e0b; }
.status-inprogress { border-left: 4px solid #2563eb; }
.status-complete { border-left: 4px solid #16a34a; }
.status-attention { border-left: 4px solid #ef4444; }

.sim-logs { max-height: 240px; overflow: auto; padding: 1rem; border-radius: 8px; border: 1px dashed var(--border-color); background: linear-gradient(180deg, #fff 0%, #fbfbfb 100%); margin-bottom: 1rem; }
.sim-logs .chat-block { margin-bottom: 0.75rem; }
.chat-user { color: var(--accent-sage); font-weight: 700; }
.chat-ai { color: var(--accent-green); font-weight: 700; }
.chat-text { background-color: var(--bg-card); padding: 0.8rem; border-radius: 6px; border: 1px solid var(--border-color); margin-top: 0.4rem; }

.sim-draft { white-space: pre-wrap; background: var(--bg-card); padding: 1rem; border-radius: 8px; border: 1px solid var(--border-color); margin-bottom: 1rem; }

.sim-controls-row { display: flex; gap: 0.75rem; justify-content: flex-end; align-items: center; margin-top: 1rem; }
.sim-action-row { margin-top: 0.5rem; }

/* Small arch reference */
.arch-ref { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 0.75rem; }

/* Internal Interactive Chat Logs */
.chat-block { margin-bottom: 1.5rem; }
.chat-user { color: var(--accent-sage); font-weight: 700; font-size: 0.9rem; margin-bottom: 0.25rem; }
.chat-ai { color: var(--accent-green); font-weight: 700; font-size: 0.9rem; margin-bottom: 0.25rem; }
.chat-text { background-color: var(--bg-card); padding: 1rem; border-radius: 8px; border: 1px solid var(--border-color); color: var(--text-primary); }

/* Simulation Tables Configuration */
.sim-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
    font-size: 0.85rem;
    background-color: var(--bg-card);
}

.sim-table th, .sim-table td {
    border: 1px solid var(--border-color);
    padding: 0.6rem 0.8rem;
    text-align: left;
    color: var(--text-primary);
}

.sim-table th { background-color: var(--bg-surface); color: var(--text-primary); font-weight: 600; }
.status-badge { padding: 0.2rem 0.5rem; border-radius: 4px; font-weight: 700; font-size: 0.75rem; }
.st-pending { background-color: #fef3c7; color: #d97706; }
.st-partial { background-color: #f0fdf4; color: #16a34a; }
.st-complete { background-color: #e0f2fe; color: #0369a1; }

.summary-flex {
    display: flex;
    gap: 1.5rem;
    margin-top: 1rem;
    background: var(--bg-surface);
    padding: 1rem;
    border-radius: 6px;
    border: 1px dashed var(--accent-green);
    font-size: 0.9rem;
    font-weight: 600;
}

/* Target Stakeholders / Personas */
.personas-grid { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }

.persona-card {
    position: relative;
    text-align: left;
    overflow: hidden;
    padding: 1.8rem;
    border: 1px solid rgba(34, 197, 94, 0.12);
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.05);
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.persona-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(34, 197, 94, 0.08), transparent 55%);
    opacity: 0.9;
    pointer-events: none;
}

.persona-card > * {
    position: relative;
    z-index: 1;
}

.persona-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 22px 46px rgba(15, 23, 42, 0.1);
    border-color: rgba(34, 197, 94, 0.24);
}

.advantage-card--1 { background: linear-gradient(180deg, #ffffff 0%, #f9fff7 100%); }
.advantage-card--2 { background: linear-gradient(180deg, #ffffff 0%, #f7fbff 100%); }
.advantage-card--3 { background: linear-gradient(180deg, #ffffff 0%, #fffaf5 100%); }

.advantage-topline {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.1rem;
}

.advantage-index {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.15rem;
    height: 2.15rem;
    border-radius: 999px;
    background: var(--bg-surface);
    color: var(--accent-green);
    font-size: 0.85rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    border: 1px solid var(--border-color);
}

.advantage-tag {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    color: var(--accent-sage);
    font-weight: 700;
}

.persona-card .avatar {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 4.2rem;
    height: 4.2rem;
    border-radius: 1.2rem;
    font-size: 2rem;
    margin-bottom: 1.1rem;
    background: rgba(34, 197, 94, 0.08);
    border: 1px solid rgba(34, 197, 94, 0.12);
}

.persona-card h3 {
    font-size: 1.28rem;
    margin-bottom: 0.6rem;
    color: var(--text-primary);
    line-height: 1.2;
}

.persona-card p {
    color: var(--text-secondary);
    font-size: 0.97rem;
    line-height: 1.65;
    margin: 0;
}

.persona-card::after {
    content: "";
    position: absolute;
    right: -24px;
    top: -24px;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(34, 197, 94, 0.18), transparent 70%);
    pointer-events: none;
}

/* Core Milestone Roadmap (Timeline) */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding-left: 2rem;
}

.timeline::before {
    content: "";
    position: absolute;
    left: 7px;
    top: 5px;
    bottom: 5px;
    width: 2px;
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
}

.timeline-dot {
    position: absolute;
    left: -2rem;
    top: 6px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: var(--bg-dark);
    border: 3px solid var(--accent-green);
    margin-left: -1px;
}

.timeline-date {
    font-weight: 700;
    color: var(--accent-sage);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.25rem;
}

.timeline h3 { font-size: 1.3 Basin; margin-bottom: 0.5rem; color: var(--text-primary); }
.timeline p { color: var(--text-secondary); font-size: 0.95rem; }

/* Global Institutional 4-Column Footer System */
footer {
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    margin-top: 6rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1.5fr 2fr 1.5fr;
    gap: 2rem;
    padding: 4rem 2rem 3rem;
}

.footer-block h5 {
    font-size: 1.05rem;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
    font-weight: 700;
}

.footer-block p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.academic-label {
    margin-top: 0.5rem;
    font-size: 0.8rem !important;
    color: var(--text-secondary) !important;
    opacity: 0.7;
}

.team-list, .bib-list { list-style: none; }

.team-list li, .bib-list li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.bib-list li {
    font-size: 0.8rem;
    border-left: 2px solid var(--border-color);
    padding-left: 0.75rem;
}

/* Right-Aligned Vertical Logo Column Specifics */
.vertical-logo-stack {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    align-items: flex-start;
    margin-top: 1.2rem;
}

.footer-logos-column .logo-container-placeholder {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    width: 250px;  /* Clean bounding box width constraints */
    height: 60px;  /* Neat height bounds preventing layout shifts */
}

.footer-logos-column .logo-container-placeholder img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    display: block;
}

/* Repurposed Bottom Legal Information Bar */
.logo-footer-bar {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1.5rem 2rem;
    background-color: #eae5da; /* Balanced deeper beige contrast footer bar */
    border-top: 1px solid var(--border-color);
}

.legal-info-container {
    max-width: 900px;
    text-align: center;
}

.legal-info-container p {
    color: var(--text-secondary);
    font-size: 0.8rem;
    line-height: 1.5;
    font-weight: 500;
}

/* Mobile Responsive Optimization Matrix */
@media(max-width: 900px) {
    .about-grid, .req-tables, .sim-wrapper, .footer-content { 
        grid-template-columns: 1fr; 
    }
    .footer-content {
        text-align: center;
    }
    .arch-flow { flex-direction: column; gap: 1.5rem; }
    .arch-block { width: 100%; }
    .hero h1 { font-size: 2.3rem; }
    .navbar { padding: 1.2rem; }
    .nav-links { display: none; }
    
    .vertical-logo-stack {
        align-items: center;
        margin-bottom: 2rem;
    }
    .footer-logos-column .logo-container-placeholder {
        justify-content: center;
    }
    .bib-list li {
        border-left: none;
        padding-left: 0;
    }
}