/* ============================================
   AI Explorer — Main Stylesheet
   ============================================ */

/* ----- CSS Variables / Design Tokens ----- */
:root {
    --bg-primary: #0d0a0a;
    --bg-secondary: #151010;
    --bg-card: #1e1416;
    --bg-card-hover: #2a1a1d;
    --text-primary: #f5e8e8;
    --text-secondary: #c4a0a4;
    --text-muted: #9a6b72;
    --accent-blue: #ff4d4d;
    --accent-purple: #ff6b8a;
    --accent-cyan: #ff8a65;
    --accent-green: #00e676;
    --accent-orange: #ff9100;
    --accent-pink: #ff4081;
    --accent-red: #ff5252;
    --gradient-primary: linear-gradient(135deg, #ff4d4d, #ff6b8a);
    --gradient-hero: linear-gradient(135deg, #0d0a0a 0%, #2a0f15 50%, #0d0a0a 100%);
    --border-color: rgba(255, 77, 77, 0.15);
    --border-glow: rgba(255, 77, 77, 0.3);
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(255, 77, 77, 0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 16px;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-blue); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-cyan); }

img { max-width: 100%; height: auto; }

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ----- Navbar ----- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
    height: 64px;
    background: rgba(10, 11, 26, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(10, 11, 26, 0.95);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
}

.brand-icon { font-size: 1.5rem; }
.brand-text { background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

.nav-links {
    display: flex;
    list-style: none;
    gap: 4px;
}

.nav-link {
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
    color: var(--text-primary);
    background: rgba(255, 77, 77, 0.1);
}

.nav-link.active {
    color: var(--accent-blue);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 5px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* ----- Hero Section ----- */
.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 100px 24px 60px;
    background: var(--gradient-hero);
    overflow: hidden;
}

.hero-particles {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 900;
    line-height: 1.15;
    margin-bottom: 24px;
}

.hero-line { display: block; }

.gradient-text {
    background: linear-gradient(135deg, #ff4d4d, #ff6b8a, #ff8a65);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 4.5rem;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 650px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 60px;
}

.btn {
    display: inline-flex;
    align-items: center;
    padding: 14px 32px;
    border-radius: var(--radius-xl);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-family: var(--font-main);
}

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
    box-shadow: 0 4px 20px rgba(255, 77, 77, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(255, 77, 77, 0.6);
    color: #fff;
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-glow);
}

.btn-secondary:hover {
    background: rgba(255, 77, 77, 0.1);
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

.hero-stats {
    display: flex;
    gap: 48px;
    justify-content: center;
}

.stat { text-align: center; }

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #ff4d4d, #ff6b8a);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-size: 0.8rem;
    animation: scrollBounce 2s infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid var(--text-muted);
    border-bottom: 2px solid var(--text-muted);
    transform: rotate(45deg);
}

@keyframes scrollBounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(10px); }
}

/* ----- Sections ----- */
.section {
    padding: 100px 0;
}

.section-alt {
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-badge {
    display: inline-block;
    padding: 6px 16px;
    border-radius: 50px;
    background: rgba(255, 77, 77, 0.1);
    border: 1px solid var(--border-color);
    color: var(--accent-blue);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 12px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ----- Cards ----- */
.content-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 36px;
    margin-bottom: 32px;
    transition: var(--transition);
}

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

.content-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.card-intro {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.card-note {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
}

.highlight-card {
    position: relative;
    background: linear-gradient(135deg, rgba(255, 77, 77, 0.08), rgba(255, 107, 138, 0.08));
    border-color: rgba(255, 77, 77, 0.25);
    overflow: hidden;
}

.card-glow {
    position: absolute;
    top: -50%;
    right: -20%;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(255, 77, 77, 0.1) 0%, transparent 70%);
    pointer-events: none;
}

/* ----- Learning Path / Roadmap ----- */
.roadmap {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    align-items: center;
}

.roadmap-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    width: 200px;
    text-align: center;
    transition: var(--transition);
    cursor: default;
}

.roadmap-item:hover {
    transform: translateY(-4px);
    border-color: var(--accent-blue);
    box-shadow: var(--shadow-glow);
}

.roadmap-icon { font-size: 2rem; margin-bottom: 8px; }
.roadmap-item h3 { font-size: 1rem; margin-bottom: 6px; }
.roadmap-item p { font-size: 0.8rem; color: var(--text-secondary); margin-bottom: 8px; }

.roadmap-link {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent-blue);
}

.roadmap-connector {
    width: 30px;
    height: 2px;
    background: var(--border-glow);
}

.learning-path-section {
    padding: 60px 0;
    background: var(--bg-secondary);
}

/* ----- Timeline ----- */
.timeline {
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gradient-primary);
}

.timeline-item {
    position: relative;
    margin-bottom: 32px;
    padding-left: 24px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -32px;
    top: 6px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--accent-blue);
    border: 3px solid var(--bg-card);
    box-shadow: 0 0 10px rgba(79, 140, 255, 0.5);
}

.timeline-date {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent-cyan);
    margin-bottom: 4px;
}

.timeline-content h4 {
    font-size: 1.05rem;
    margin-bottom: 4px;
}

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

/* ----- AI Types Grid ----- */
.ai-types-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.ai-type-card {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    padding: 24px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.ai-type-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
}

.ai-type-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.ai-type-header h4 { font-size: 1.1rem; }

.ai-type-badge {
    font-size: 0.7rem;
    padding: 3px 10px;
    border-radius: 50px;
    font-weight: 600;
}

.ai-type-badge.current { background: rgba(0, 230, 118, 0.15); color: var(--accent-green); }
.ai-type-badge.future { background: rgba(255, 145, 0, 0.15); color: var(--accent-orange); }
.ai-type-badge.hypothetical { background: rgba(255, 82, 82, 0.15); color: var(--accent-red); }

.examples-list {
    list-style: none;
    margin-top: 12px;
}

.examples-list li {
    padding: 6px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.examples-list li:last-child { border-bottom: none; }

/* ----- Nested Circles (AI/ML/DL/GenAI) ----- */
.nested-circles-diagram {
    display: flex;
    align-items: center;
    gap: 48px;
    flex-wrap: wrap;
    justify-content: center;
}

.circle-outer {
    width: 400px;
    height: 400px;
    border-radius: 50%;
    border: 3px solid rgba(255, 77, 77, 0.3);
    background: rgba(255, 77, 77, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    position: relative;
}

.circle-mid {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    border: 3px solid rgba(0, 230, 118, 0.3);
    background: rgba(0, 230, 118, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    position: relative;
}

.circle-inner {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    border: 3px solid rgba(157, 92, 255, 0.3);
    background: rgba(157, 92, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    position: relative;
}

.circle-core {
    width: 110px;
    height: 110px;
    border-radius: 50%;
    border: 3px solid rgba(255, 64, 129, 0.3);
    background: rgba(255, 64, 129, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
}

.circle-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-align: center;
    color: var(--text-secondary);
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    white-space: nowrap;
}

.circle-core .circle-label {
    position: static;
    transform: none;
    font-size: 0.7rem;
}

.circles-legend {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
}

.legend-dot {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    flex-shrink: 0;
}

.legend-dot.ai { background: #ff4d4d; }
.legend-dot.ml { background: var(--accent-green); }
.legend-dot.dl { background: #ff6b8a; }
.legend-dot.genai { background: var(--accent-pink); }

/* ----- Tabs ----- */
.tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    font-family: var(--font-main);
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

.tab-btn:hover {
    background: rgba(255, 77, 77, 0.1);
    color: var(--text-primary);
}

.tab-btn.active {
    background: rgba(255, 77, 77, 0.15);
    border-color: var(--accent-blue);
    color: var(--accent-blue);
}

.tab-pane { display: none; }
.tab-pane.active { display: block; animation: fadeIn 0.3s ease; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.tab-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
    align-items: start;
}

.tab-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Mini Diagrams */
.mini-diagram {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.mini-box {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    text-align: center;
    font-size: 0.85rem;
    font-weight: 600;
}

.mini-box.input { background: rgba(255, 77, 77, 0.15); border: 1px solid rgba(255, 77, 77, 0.3); }
.mini-box.model { background: rgba(255, 107, 138, 0.15); border: 1px solid rgba(255, 107, 138, 0.3); }
.mini-box.output { background: rgba(0, 230, 118, 0.15); border: 1px solid rgba(0, 230, 118, 0.3); }
.mini-box.labels { background: rgba(255, 145, 0, 0.15); border: 1px solid rgba(255, 145, 0, 0.3); font-size: 0.75rem; margin-top: 8px; }

.mini-arrow {
    color: var(--text-muted);
    font-size: 1.2rem;
    font-weight: bold;
}

.mini-feedback {
    width: 100%;
    text-align: center;
}

/* ----- Transformer Visual ----- */
.transformer-diagram {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}

.transformer-component {
    display: flex;
    gap: 16px;
    padding: 16px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.2);
    margin-bottom: 12px;
}

.comp-icon { font-size: 1.5rem; }
.transformer-component strong { display: block; margin-bottom: 4px; }
.transformer-component p { font-size: 0.85rem; color: var(--text-secondary); }

.transformer-visual {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.tv-block {
    padding: 14px 24px;
    border-radius: var(--radius-sm);
    text-align: center;
    font-size: 0.85rem;
    font-weight: 600;
    width: 100%;
    max-width: 300px;
}

.tv-input { background: rgba(255, 77, 77, 0.15); border: 1px solid rgba(255, 77, 77, 0.3); }
.tv-embed { background: rgba(255, 138, 101, 0.15); border: 1px solid rgba(255, 138, 101, 0.3); }
.tv-attention { background: rgba(255, 107, 138, 0.15); border: 1px solid rgba(255, 107, 138, 0.3); }
.tv-ffn { background: rgba(255, 145, 0, 0.15); border: 1px solid rgba(255, 145, 0, 0.3); }
.tv-output { background: rgba(0, 230, 118, 0.15); border: 1px solid rgba(0, 230, 118, 0.3); }

.tv-arrow { color: var(--text-muted); font-size: 1.2rem; }

.tv-block-group {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    width: 100%;
    max-width: 300px;
}

.tv-repeat {
    font-size: 0.75rem;
    color: var(--accent-cyan);
    font-weight: 600;
    margin-top: 4px;
}

/* ----- Attention Demo ----- */
.attention-demo { text-align: center; }

.attention-sentence {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.attention-word {
    padding: 10px 16px;
    border-radius: var(--radius-sm);
    background: rgba(255, 77, 77, 0.1);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.attention-word:hover, .attention-word.selected {
    background: rgba(255, 77, 77, 0.25);
    border-color: var(--accent-blue);
    box-shadow: 0 0 15px rgba(255, 77, 77, 0.3);
}

.attention-word.high-attention {
    background: rgba(0, 230, 118, 0.3);
    border-color: var(--accent-green);
}

.attention-word.medium-attention {
    background: rgba(255, 145, 0, 0.2);
    border-color: var(--accent-orange);
}

.attention-word.low-attention {
    background: rgba(255, 255, 255, 0.05);
    border-color: transparent;
}

.attention-hint {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.attention-result {
    margin-top: 16px;
    padding: 16px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.2);
    font-size: 0.9rem;
    min-height: 40px;
}

/* ----- Tokenizer Demo ----- */
.tokenizer-demo {
    margin-top: 16px;
}

.token-input {
    width: 100%;
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.3);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 1rem;
    margin: 12px 0;
    transition: var(--transition);
}

.token-input:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 15px rgba(255, 77, 77, 0.2);
}

.token-output {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    margin: 16px 0;
    padding: 16px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.3);
    min-height: 50px;
}

.token {
    padding: 6px 12px;
    border-radius: 6px;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    background: hsl(var(--hue, 200), 60%, 20%);
    border: 1px solid hsl(var(--hue, 200), 60%, 40%);
    color: hsl(var(--hue, 200), 80%, 80%);
}

.token-stats {
    display: flex;
    gap: 24px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ----- Training Stages ----- */
.training-stages {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.stage {
    display: flex;
    gap: 24px;
    padding: 24px;
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--accent-blue);
}

.stage:nth-child(2) { border-left-color: var(--accent-purple); }
.stage:nth-child(3) { border-left-color: var(--accent-green); }

.stage-number {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 800;
    flex-shrink: 0;
}

.stage-content h4 { margin-bottom: 8px; }
.stage-content p { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 12px; }

.stage-stats {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.stage-stats span {
    padding: 4px 10px;
    border-radius: 50px;
    background: rgba(255, 77, 77, 0.08);
}

/* ----- Charts ----- */
.chart-container {
    position: relative;
    height: 400px;
    width: 100%;
}

/* ----- Concept Cards (Flip) ----- */
.concepts-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.concept-card {
    perspective: 800px;
    cursor: pointer;
    height: 180px;
}

.concept-front, .concept-back {
    position: absolute;
    inset: 0;
    padding: 24px;
    border-radius: var(--radius-md);
    backface-visibility: hidden;
    transition: transform 0.6s ease;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.concept-front {
    background: var(--gradient-primary);
    text-align: center;
}

.concept-front h4 { font-size: 1.2rem; margin-bottom: 8px; }
.concept-front p { font-size: 0.8rem; opacity: 0.8; }

.concept-back {
    background: var(--bg-card);
    border: 1px solid var(--border-glow);
    transform: rotateY(180deg);
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.concept-card {
    position: relative;
}

.concept-card.flipped .concept-front { transform: rotateY(180deg); }
.concept-card.flipped .concept-back { transform: rotateY(0deg); }

/* ----- Comparison Table ----- */
.comparison-table {
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.comp-header {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    background: rgba(0, 0, 0, 0.3);
    font-weight: 700;
}

.comp-col-header {
    padding: 16px 20px;
    text-align: center;
    font-size: 0.95rem;
}

.comp-col-header.open { color: var(--accent-green); }
.comp-col-header.closed { color: var(--accent-orange); }
.comp-col-header.feature { color: var(--text-muted); min-width: 140px; }

.comp-row {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.comp-row:hover { background: rgba(79, 140, 255, 0.05); }

.comp-cell {
    padding: 14px 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.comp-cell.feature {
    text-align: center;
    font-weight: 600;
    color: var(--text-primary);
    min-width: 140px;
    background: rgba(0, 0, 0, 0.15);
}

/* ----- Model Landscape ----- */
.model-category {
    margin-bottom: 32px;
}

.model-cat-title {
    font-size: 1.2rem;
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.open-title { border-color: rgba(0, 230, 118, 0.3); }
.closed-title { border-color: rgba(255, 145, 0, 0.3); }

.model-cards-row {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
}

.model-card-small {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    transition: var(--transition);
}

.model-card-small:hover {
    transform: translateY(-3px);
    border-color: var(--border-glow);
    box-shadow: var(--shadow-glow);
}

.model-logo { font-size: 1.5rem; margin-bottom: 8px; }
.model-card-small h5 { font-size: 1rem; margin-bottom: 4px; }
.model-org { font-size: 0.75rem; color: var(--accent-blue); display: block; margin-bottom: 2px; }
.model-size { font-size: 0.7rem; color: var(--text-muted); display: block; margin-bottom: 8px; }
.model-card-small p { font-size: 0.8rem; color: var(--text-secondary); }

/* ----- Decision Tree ----- */
.decision-tree {
    max-width: 600px;
    margin: 0 auto;
}

.dt-question, .dt-result {
    display: none;
    animation: fadeIn 0.4s ease;
}

.dt-question.active, .dt-result.active { display: block; }

.dt-question p, .dt-result p {
    font-size: 1.1rem;
    margin-bottom: 20px;
    text-align: center;
}

.dt-result {
    padding: 24px;
    background: rgba(0, 230, 118, 0.08);
    border: 1px solid rgba(0, 230, 118, 0.3);
    border-radius: var(--radius-md);
    text-align: center;
}

.dt-result h4 {
    color: var(--accent-green);
    margin-bottom: 12px;
}

.dt-btn {
    display: block;
    width: 100%;
    padding: 14px 20px;
    margin-bottom: 8px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.2);
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.dt-btn:hover {
    background: rgba(255, 77, 77, 0.15);
    border-color: var(--accent-blue);
}

.dt-back {
    color: var(--text-muted);
    font-size: 0.85rem;
    text-align: center;
    border-style: dashed;
}

/* ----- Agent Architecture ----- */
.agent-arch-diagram {
    display: flex;
    justify-content: center;
}

.agent-core {
    max-width: 700px;
    width: 100%;
}

.agent-brain {
    text-align: center;
    padding: 24px;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    margin-bottom: 24px;
}

.agent-brain h4 { font-size: 1.3rem; margin-bottom: 4px; }
.agent-brain p { opacity: 0.9; font-size: 0.9rem; }

.agent-components {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
}

.agent-comp {
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: center;
    transition: var(--transition);
}

.agent-comp:hover {
    border-color: var(--accent-purple);
    transform: translateY(-3px);
}

.agent-comp-icon { font-size: 1.5rem; margin-bottom: 8px; }
.agent-comp h5 { font-size: 0.95rem; margin-bottom: 6px; }
.agent-comp p { font-size: 0.8rem; color: var(--text-secondary); }

/* ----- Agent Loop ----- */
.loop-visual {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.loop-step {
    padding: 24px;
    border-radius: var(--radius-md);
    background: rgba(0, 0, 0, 0.3);
    border: 2px solid var(--border-color);
    text-align: center;
    width: 180px;
    transition: var(--transition);
}

.loop-step.active {
    border-color: var(--accent-blue);
    box-shadow: 0 0 20px rgba(255, 77, 77, 0.3);
    background: rgba(255, 77, 77, 0.1);
}

.loop-step[data-loop="act"].active {
    border-color: var(--accent-green);
    box-shadow: 0 0 20px rgba(0, 230, 118, 0.3);
    background: rgba(0, 230, 118, 0.1);
}

.loop-step[data-loop="observe"].active {
    border-color: var(--accent-purple);
    box-shadow: 0 0 20px rgba(255, 107, 138, 0.3);
    background: rgba(255, 107, 138, 0.1);
}

.loop-icon { font-size: 2rem; margin-bottom: 8px; }
.loop-step h4 { font-size: 1rem; margin-bottom: 6px; }
.loop-step p { font-size: 0.75rem; color: var(--text-secondary); }

.loop-arrow { font-size: 1.5rem; color: var(--text-muted); }
.loop-back { color: var(--accent-cyan); }

.loop-example {
    margin-top: 20px;
    padding: 20px;
    border-radius: var(--radius-md);
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
}

.loop-trace {
    max-height: 300px;
    overflow-y: auto;
}

.trace-step {
    padding: 10px 16px;
    margin-bottom: 8px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    background: rgba(0, 0, 0, 0.2);
    border-left: 3px solid var(--accent-blue);
    animation: fadeIn 0.5s ease;
}

.trace-step.think { border-left-color: var(--accent-blue); }
.trace-step.act { border-left-color: var(--accent-green); }
.trace-step.observe { border-left-color: var(--accent-purple); }

/* ----- Agent Types Grid ----- */
.agent-types-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.agent-type {
    padding: 24px;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.agent-type:hover {
    border-color: var(--border-glow);
    transform: translateY(-3px);
}

.agent-type h4 { margin-bottom: 8px; }
.agent-type > p { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 12px; }

.agent-example {
    padding: 12px;
    background: rgba(79, 140, 255, 0.05);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.agent-tools-list {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-style: italic;
}

/* ----- Frameworks Grid ----- */
.frameworks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 16px;
}

.framework-card {
    padding: 24px;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

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

.framework-card h4 { margin-bottom: 8px; font-size: 1rem; }
.framework-card p { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 12px; }
.framework-card a { font-size: 0.85rem; font-weight: 600; }

/* ----- Fine-Tuning Spectrum ----- */
.finetune-spectrum {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.spectrum-item {
    padding: 20px 24px;
    border-radius: var(--radius-md);
    background: rgba(0, 0, 0, 0.2);
    border-left: 4px solid;
}

.spectrum-item.easy { border-left-color: var(--accent-green); }
.spectrum-item.medium { border-left-color: var(--accent-blue); }
.spectrum-item.hard { border-left-color: var(--accent-orange); }
.spectrum-item.extreme { border-left-color: var(--accent-red); }

.spectrum-item h4 { margin-bottom: 6px; }
.spectrum-item > p { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 12px; }

.spectrum-bar {
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
    margin-bottom: 8px;
}

.spectrum-fill {
    height: 100%;
    border-radius: 3px;
    transition: width 1s ease;
}

.easy .spectrum-fill { background: var(--accent-green); }
.medium .spectrum-fill { background: var(--accent-blue); }
.hard .spectrum-fill { background: var(--accent-orange); }
.extreme .spectrum-fill { background: var(--accent-red); }

.spectrum-label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ----- Code Blocks ----- */
.code-block {
    border-radius: var(--radius-md);
    overflow: hidden;
    margin: 16px 0;
    border: 1px solid var(--border-color);
}

.code-header {
    padding: 10px 16px;
    background: rgba(0, 0, 0, 0.4);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.code-block pre {
    margin: 0;
    padding: 20px;
    background: rgba(0, 0, 0, 0.3);
    overflow-x: auto;
}

.code-block code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* ----- Process Steps ----- */
.process-steps {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.process-step {
    display: flex;
    gap: 20px;
}

.process-num {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    flex-shrink: 0;
}

.process-content h4 { margin-bottom: 6px; }
.process-content p { font-size: 0.9rem; color: var(--text-secondary); }

/* ----- RAG Pipeline ----- */
.rag-pipeline {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.rag-stage {
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.rag-stage-header {
    padding: 12px 20px;
    font-weight: 700;
    font-size: 0.95rem;
}

.rag-stage-header.ingestion { background: rgba(255, 77, 77, 0.15); color: var(--accent-blue); }
.rag-stage-header.retrieval { background: rgba(157, 92, 255, 0.15); color: var(--accent-purple); }
.rag-stage-header.generation { background: rgba(0, 230, 118, 0.15); color: var(--accent-green); }

.rag-flow {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 20px;
    overflow-x: auto;
    flex-wrap: wrap;
    justify-content: center;
}

.rag-node {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.85rem;
    min-width: 150px;
}

.rag-node small {
    display: block;
    color: var(--text-muted);
    font-size: 0.75rem;
    margin-top: 4px;
}

.rag-arrow {
    color: var(--text-muted);
    font-size: 1.2rem;
    font-weight: bold;
    flex-shrink: 0;
}

/* ----- Embeddings Visual ----- */
.embeddings-visual {
    position: relative;
    height: 350px;
    background: rgba(0, 0, 0, 0.3);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.embed-point {
    position: absolute;
    left: var(--x);
    top: var(--y);
    font-size: 0.8rem;
    padding: 4px 8px;
    background: rgba(0, 0, 0, 0.5);
    border-radius: 4px;
    white-space: nowrap;
    animation: float 3s ease-in-out infinite;
}

.embed-point:nth-child(odd) { animation-delay: -1.5s; }

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.embed-label {
    position: absolute;
    left: var(--x);
    top: var(--y);
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ----- Advanced RAG Grid ----- */
.advanced-rag-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.advanced-rag-item {
    padding: 20px;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.advanced-rag-item:hover {
    border-color: var(--border-glow);
    transform: translateY(-2px);
}

.advanced-rag-item h4 { margin-bottom: 8px; font-size: 1rem; }
.advanced-rag-item p { font-size: 0.85rem; color: var(--text-secondary); }

/* ----- Lab Playground ----- */
.lab-playground {
    margin-top: 16px;
}

.lab-control {
    margin-bottom: 16px;
}

.lab-control label {
    display: block;
    font-size: 0.9rem;
    margin-bottom: 8px;
    font-weight: 600;
}

input[type="range"] {
    width: 100%;
    -webkit-appearance: none;
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.1);
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-blue);
    cursor: pointer;
    box-shadow: 0 0 10px rgba(79, 140, 255, 0.5);
}

.temp-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.lab-output {
    margin-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.lab-output .completion {
    padding: 16px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.3);
    border-left: 3px solid;
    font-size: 0.9rem;
    animation: fadeIn 0.5s ease;
}

.lab-output .completion:nth-child(1) { border-left-color: var(--accent-blue); }
.lab-output .completion:nth-child(2) { border-left-color: var(--accent-purple); }
.lab-output .completion:nth-child(3) { border-left-color: var(--accent-green); }

/* ----- Prompt Lab ----- */
.prompt-techniques {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.prompt-technique h4 {
    font-size: 1.1rem;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.prompt-result {
    padding: 16px;
    border-radius: var(--radius-sm);
    background: rgba(0, 230, 118, 0.05);
    border: 1px solid rgba(0, 230, 118, 0.2);
    margin-top: 12px;
    font-size: 0.9rem;
}

.prompt-quality {
    margin-top: 8px;
    font-size: 0.85rem;
    color: var(--accent-orange);
    font-weight: 600;
}

/* ----- Quiz ----- */
.quiz-question { display: none; animation: fadeIn 0.3s ease; }
.quiz-question.active { display: block; }

.quiz-q {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.quiz-opt {
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.2);
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.quiz-opt:hover:not(.answered) {
    background: rgba(255, 77, 77, 0.15);
    border-color: var(--accent-blue);
}

.quiz-opt.correct {
    background: rgba(0, 230, 118, 0.15);
    border-color: var(--accent-green);
    color: var(--accent-green);
}

.quiz-opt.incorrect {
    background: rgba(255, 82, 82, 0.15);
    border-color: var(--accent-red);
    color: var(--accent-red);
}

.quiz-feedback {
    margin-top: 12px;
    padding: 12px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    min-height: 20px;
}

.quiz-score {
    text-align: center;
    padding: 24px;
    font-size: 1.3rem;
    font-weight: 700;
}

/* ----- Glossary ----- */
.glossary-list {
    margin-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 500px;
    overflow-y: auto;
}

.glossary-item {
    padding: 16px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition);
}

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

.glossary-term {
    font-weight: 700;
    color: var(--accent-blue);
    margin-bottom: 4px;
}

.glossary-def {
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: none;
}

.glossary-item.open .glossary-def { display: block; animation: fadeIn 0.3s ease; }

/* ----- References ----- */
.references-card {
    background: linear-gradient(135deg, rgba(255, 138, 101, 0.05), rgba(255, 77, 77, 0.05));
}

.references-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 12px;
}

.ref-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.85rem;
    transition: var(--transition);
}

.ref-link:hover {
    background: rgba(255, 77, 77, 0.1);
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

.ref-icon { font-size: 1.2rem; flex-shrink: 0; }

/* ----- Footer ----- */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr repeat(3, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h4 { margin-bottom: 16px; font-size: 1rem; }
.footer-col p { font-size: 0.85rem; color: var(--text-secondary); }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a { font-size: 0.85rem; color: var(--text-secondary); }
.footer-col a:hover { color: var(--accent-blue); }

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.footer-bottom p { margin-bottom: 4px; }

/* ----- Responsive ----- */
@media (max-width: 1024px) {
    .ai-types-grid { grid-template-columns: 1fr; }
    .concepts-grid { grid-template-columns: repeat(2, 1fr); }
    .transformer-diagram { grid-template-columns: 1fr; }
    .tab-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .nav-toggle { display: flex; }

    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: rgba(10, 11, 26, 0.97);
        padding: 16px;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.open { display: flex; }

    .hero-title { font-size: 2.2rem; }
    .gradient-text { font-size: 3rem; }
    .hero-stats { gap: 24px; }
    .section-title { font-size: 1.8rem; }

    .roadmap { flex-direction: column; align-items: stretch; }
    .roadmap-connector { width: 2px; height: 20px; align-self: center; }
    .roadmap-item { width: 100%; }

    .concepts-grid { grid-template-columns: 1fr; }
    .nested-circles-diagram { flex-direction: column; }
    .circle-outer { width: 300px; height: 300px; }
    .circle-mid { width: 220px; height: 220px; }
    .circle-inner { width: 150px; height: 150px; }
    .circle-core { width: 80px; height: 80px; }

    .agent-types-grid { grid-template-columns: 1fr; }
    .comp-header, .comp-row { grid-template-columns: 1fr; }
    .comp-col-header.feature, .comp-cell.feature { display: none; }

    .content-card { padding: 20px; }
    .footer-grid { grid-template-columns: 1fr; }

    .loop-visual { flex-direction: column; }
    .loop-arrow { transform: rotate(90deg); }
    .loop-back { transform: rotate(0); }
}

@media (max-width: 480px) {
    .hero-title { font-size: 1.8rem; }
    .gradient-text { font-size: 2.3rem; }
    .section-title { font-size: 1.5rem; }
    .hero-cta { flex-direction: column; align-items: center; }
}

/* ----- Neural Network Visualizer ----- */
.nn-visualizer {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
}

.nn-visualizer canvas {
    background: rgba(0, 0, 0, 0.3);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    max-width: 100%;
}

.nn-controls {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: center;
}

.nn-info {
    width: 100%;
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 8px;
    min-height: 20px;
}

/* ----- Similarity Calculator ----- */
.similarity-lab {
    margin-top: 16px;
}

.sim-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}

.sim-input-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.sim-result {
    margin-top: 20px;
    padding: 20px;
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
}

.sim-bar-container {
    height: 24px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 12px;
}

.sim-bar {
    height: 100%;
    border-radius: 12px;
    background: var(--gradient-primary);
    transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
    min-width: 0;
}

.sim-score {
    text-align: center;
    font-size: 1.8rem;
    font-weight: 800;
    margin-bottom: 8px;
}

.sim-explanation {
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ----- Cost Calculator ----- */
.cost-lab { margin-top: 16px; }

.cost-controls {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-bottom: 20px;
}

.cost-control label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.cost-control select {
    width: 100%;
    padding: 12px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.3);
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 0.9rem;
}

.cost-control select:focus {
    outline: none;
    border-color: var(--accent-blue);
}

.cost-result {
    padding: 20px;
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.cost-breakdown {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.cost-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.cost-item:last-child { border-bottom: none; }

.cost-label { font-size: 0.9rem; color: var(--text-secondary); }
.cost-value { font-size: 1rem; font-weight: 700; }

.cost-total {
    padding-top: 14px;
    margin-top: 4px;
    border-top: 2px solid var(--border-color);
    border-bottom: none;
}

.cost-total .cost-value {
    font-size: 1.5rem;
    color: var(--accent-blue);
}

@media (max-width: 768px) {
    .sim-inputs { grid-template-columns: 1fr; }
}