/* ============================================================
   ChurnSense AI - Portfolio Dark Theme
   ============================================================ */

/* --- CSS Variables --- */
:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-card: #1a1f35;
    --bg-card-hover: #242b45;
    --bg-input: #151b2e;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-blue: #3b82f6;
    --accent-purple: #8b5cf6;
    --accent-green: #10b981;
    --accent-red: #ef4444;
    --accent-amber: #f59e0b;
    --accent-cyan: #06b6d4;
    --border-color: #1e293b;
    --border-light: #334155;
    --gradient-start: #667eea;
    --gradient-end: #764ba2;
    --gradient-text: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.5);
    --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --nav-height: 72px;
    --transition: all 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: var(--nav-height); }
body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}
a { color: var(--accent-blue); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-purple); }
img { max-width: 100%; height: auto; }
strong { color: var(--text-primary); font-weight: 600; }

/* --- Background Effects --- */
.bg-grid {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background-image:
        linear-gradient(rgba(102,126,234,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(102,126,234,0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    pointer-events: none; z-index: 0;
}
.bg-glow {
    position: fixed; border-radius: 50%; filter: blur(120px);
    pointer-events: none; z-index: 0; opacity: 0.4;
}
.bg-glow-1 { top: -200px; right: -100px; width: 600px; height: 600px; background: rgba(102,126,234,0.12); }
.bg-glow-2 { bottom: -200px; left: -100px; width: 500px; height: 500px; background: rgba(118,75,162,0.10); }

/* --- Container --- */
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; position: relative; z-index: 1; }

/* ============================================================
   NAVIGATION
   ============================================================ */
.nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: rgba(10, 14, 26, 0.85);
    backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    height: var(--nav-height);
    transition: var(--transition);
}
.nav.scrolled { background: rgba(10, 14, 26, 0.95); box-shadow: var(--shadow-md); }
.nav-inner {
    max-width: 1280px; margin: 0 auto; padding: 0 24px;
    display: flex; align-items: center; justify-content: space-between;
    height: 100%;
}
.nav-logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.15rem; color: var(--text-primary); }
.nav-logo-icon {
    width: 36px; height: 36px; border-radius: 10px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    display: flex; align-items: center; justify-content: center;
    font-size: 0.9rem; color: white;
}
.nav-logo .accent { color: var(--accent-blue); }
.nav-links { display: flex; gap: 4px; }
.nav-link {
    padding: 8px 16px; border-radius: var(--radius-sm);
    font-size: 0.875rem; font-weight: 500; color: var(--text-secondary);
    transition: var(--transition);
}
.nav-link:hover { color: var(--text-primary); background: rgba(255,255,255,0.05); }
.nav-link.active { color: var(--accent-blue); background: rgba(59,130,246,0.1); }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.btn-chat {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 18px; border-radius: var(--radius-sm);
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white; border: none; cursor: pointer; font-size: 0.875rem;
    font-weight: 600; transition: var(--transition);
}
.btn-chat:hover { transform: translateY(-1px); box-shadow: 0 4px 20px rgba(102,126,234,0.4); }
.nav-hamburger {
    display: none; flex-direction: column; gap: 5px;
    background: none; border: none; cursor: pointer; padding: 4px;
}
.nav-hamburger span { width: 22px; height: 2px; background: var(--text-secondary); border-radius: 2px; transition: var(--transition); }

/* ============================================================
   SECTIONS
   ============================================================ */
.section { padding: 100px 0; position: relative; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-tag {
    display: inline-block; padding: 6px 16px; border-radius: 20px;
    background: rgba(102,126,234,0.1); border: 1px solid rgba(102,126,234,0.2);
    color: var(--accent-blue); font-size: 0.8rem; font-weight: 600;
    letter-spacing: 0.05em; text-transform: uppercase; margin-bottom: 16px;
}
.section-title { font-family: 'Space Grotesk', sans-serif; font-size: 2.5rem; font-weight: 700; margin-bottom: 12px; }
.section-subtitle { color: var(--text-secondary); font-size: 1.1rem; max-width: 640px; margin: 0 auto; }

/* ============================================================
   HERO
   ============================================================ */
.hero-section { padding-top: calc(var(--nav-height) + 80px); padding-bottom: 80px; }
.hero-content { text-align: center; max-width: 800px; margin: 0 auto 60px; }
.hero-badges { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-bottom: 28px; }
.badge {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 6px 14px; border-radius: 20px; font-size: 0.78rem;
    font-weight: 600; letter-spacing: 0.02em;
}
.badge-blue { background: rgba(59,130,246,0.12); color: var(--accent-blue); border: 1px solid rgba(59,130,246,0.25); }
.badge-purple { background: rgba(139,92,246,0.12); color: var(--accent-purple); border: 1px solid rgba(139,92,246,0.25); }
.badge-green { background: rgba(16,185,129,0.12); color: var(--accent-green); border: 1px solid rgba(16,185,129,0.25); }
.badge-amber { background: rgba(245,158,11,0.12); color: var(--accent-amber); border: 1px solid rgba(245,158,11,0.25); }
.hero-title { font-family: 'Space Grotesk', sans-serif; font-size: 3.5rem; font-weight: 800; line-height: 1.15; margin-bottom: 20px; }
.gradient-text {
    background: var(--gradient-text); -webkit-background-clip: text;
    background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-author {
    font-size: 0.95rem; color: var(--text-muted); margin: -8px auto 20px;
    letter-spacing: 0.3px;
}
.hero-author a {
    color: var(--accent-blue); text-decoration: none; font-weight: 500;
    transition: var(--transition);
}
.hero-author a:hover { color: var(--accent-purple); text-decoration: underline; }
.hero-subtitle { color: var(--text-secondary); font-size: 1.2rem; line-height: 1.8; max-width: 620px; margin: 0 auto 32px; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* Buttons */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 14px 28px; border-radius: var(--radius-sm); font-size: 0.95rem;
    font-weight: 600; cursor: pointer; transition: var(--transition); border: none;
}
.btn-primary {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(102,126,234,0.35); color: white; }
.btn-outline {
    background: transparent; color: var(--text-secondary);
    border: 1px solid var(--border-light);
}
.btn-outline:hover { border-color: var(--accent-blue); color: var(--accent-blue); transform: translateY(-2px); }

/* KPI Grid */
.kpi-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.kpi-card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 28px 24px; text-align: center;
    transition: var(--transition); position: relative; overflow: hidden;
}
.kpi-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    opacity: 0; transition: var(--transition);
}
.kpi-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-glow); border-color: rgba(102,126,234,0.3); }
.kpi-card:hover::before { opacity: 1; }
.kpi-icon { font-size: 1.5rem; color: var(--accent-blue); margin-bottom: 12px; }
.kpi-value { font-family: 'Space Grotesk', sans-serif; font-size: 2.8rem; font-weight: 800; line-height: 1; margin-bottom: 8px; }
.kpi-label { font-size: 0.9rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 4px; }
.kpi-detail { font-size: 0.78rem; color: var(--text-muted); }

/* ============================================================
   PROBLEM / SOLUTION
   ============================================================ */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.col-card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 36px; transition: var(--transition);
}
.col-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-glow); }
.col-card-header { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; }
.col-card-header h3 { font-family: 'Space Grotesk', sans-serif; font-size: 1.35rem; }
.col-card-icon {
    width: 44px; height: 44px; border-radius: 12px;
    display: flex; align-items: center; justify-content: center; font-size: 1.1rem;
}
.col-card-icon.red { background: rgba(239,68,68,0.12); color: var(--accent-red); }
.col-card-icon.green { background: rgba(16,185,129,0.12); color: var(--accent-green); }
.col-card p { color: var(--text-secondary); margin-bottom: 18px; line-height: 1.7; }
.feature-list { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.feature-list li { display: flex; align-items: flex-start; gap: 10px; font-size: 0.92rem; color: var(--text-secondary); }
.red-icon { color: var(--accent-red); margin-top: 3px; flex-shrink: 0; }
.green-icon { color: var(--accent-green); margin-top: 3px; flex-shrink: 0; }

/* ============================================================
   METRICS & CHARTS
   ============================================================ */
.metrics-strip { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-bottom: 40px; }
.metric-pill {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-md); padding: 16px 20px; text-align: center;
    min-width: 150px; transition: var(--transition);
}
.metric-pill.highlight { border-color: var(--accent-green); background: rgba(16,185,129,0.06); }
.metric-pill-label { display: block; font-size: 0.78rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 4px; }
.metric-pill-value { display: block; font-family: 'Space Grotesk', sans-serif; font-size: 1.5rem; font-weight: 700; }
.metric-pill.highlight .metric-pill-value { color: var(--accent-green); }
.metric-pill-ci { display: block; font-size: 0.72rem; color: var(--text-muted); margin-top: 2px; font-family: 'JetBrains Mono', monospace; }

/* Insight Callout */
.insight-callout {
    display: flex; gap: 16px; align-items: flex-start;
    padding: 20px 24px; border-radius: var(--radius-md);
    background: rgba(245,158,11,0.06); border: 1px solid rgba(245,158,11,0.2);
    margin-bottom: 40px; font-size: 0.92rem; color: var(--text-secondary);
}
.insight-callout i { color: var(--accent-amber); font-size: 1.2rem; margin-top: 2px; flex-shrink: 0; }

/* Chart Cards */
.chart-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-bottom: 24px; }
.chart-card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 24px; transition: var(--transition);
}
.chart-card:hover { border-color: rgba(102,126,234,0.2); }
.chart-card.full-width { margin-bottom: 24px; }
.chart-card-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; flex-wrap: wrap; gap: 12px; }
.chart-card-header h3 { font-family: 'Space Grotesk', sans-serif; font-size: 1.1rem; font-weight: 600; display: flex; align-items: center; gap: 10px; }
.chart-card-header h3 i { color: var(--accent-blue); font-size: 0.95rem; }
.chart-description { font-size: 0.82rem; color: var(--text-muted); }
.chart-container { width: 100%; min-height: 320px; }
.chart-container.tall { min-height: 500px; }

/* Chart Toggle */
.chart-toggle { display: flex; gap: 4px; background: var(--bg-input); border-radius: var(--radius-sm); padding: 3px; }
.toggle-btn {
    padding: 6px 16px; border: none; background: transparent;
    color: var(--text-muted); font-size: 0.82rem; font-weight: 600;
    border-radius: 6px; cursor: pointer; transition: var(--transition);
}
.toggle-btn.active { background: var(--accent-blue); color: white; }

/* ROI Summary */
.roi-summary { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.roi-item { display: flex; justify-content: space-between; align-items: center; padding: 10px 14px; border-radius: var(--radius-sm); background: var(--bg-input); }
.roi-item.big { grid-column: 1 / -1; padding: 16px; background: rgba(16,185,129,0.06); border: 1px solid rgba(16,185,129,0.15); }
.roi-label { font-size: 0.85rem; color: var(--text-secondary); }
.roi-value { font-family: 'Space Grotesk', sans-serif; font-weight: 700; font-size: 1rem; }
.roi-value.highlight-green { color: var(--accent-green); }
.roi-footnote { font-size: 0.75rem; color: var(--text-muted); margin-top: 16px; text-align: center; font-style: italic; }

/* Tables */
.stats-table-card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 24px; margin-bottom: 24px;
}
.table-wrapper { overflow-x: auto; }
.data-table { width: 100%; border-collapse: collapse; font-size: 0.88rem; }
.data-table th {
    text-align: left; padding: 12px 16px; font-weight: 600;
    color: var(--text-muted); text-transform: uppercase; font-size: 0.75rem;
    letter-spacing: 0.05em; border-bottom: 1px solid var(--border-color);
}
.data-table td { padding: 12px 16px; border-bottom: 1px solid var(--border-color); color: var(--text-secondary); }
.data-table tbody tr:hover { background: rgba(255,255,255,0.02); }
.status-badge {
    display: inline-block; padding: 3px 10px; border-radius: 12px;
    font-size: 0.75rem; font-weight: 600;
}
.status-badge.success { background: rgba(16,185,129,0.12); color: var(--accent-green); }
.status-badge.neutral { background: rgba(148,163,184,0.12); color: var(--text-muted); }

/* ============================================================
   FEATURE IMPORTANCE
   ============================================================ */
.insight-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 40px; }
.insight-card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 24px; transition: var(--transition);
}
.insight-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-glow); }
.insight-icon {
    width: 48px; height: 48px; border-radius: 14px;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.2rem; margin-bottom: 16px;
}
.insight-icon.red { background: rgba(239,68,68,0.12); color: var(--accent-red); }
.insight-icon.orange { background: rgba(245,158,11,0.12); color: var(--accent-amber); }
.insight-icon.blue { background: rgba(59,130,246,0.12); color: var(--accent-blue); }
.insight-icon.purple { background: rgba(139,92,246,0.12); color: var(--accent-purple); }
.insight-card h4 { font-size: 1rem; margin-bottom: 8px; }
.insight-card p { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.6; margin-bottom: 14px; }
.insight-bar { height: 4px; background: var(--bg-input); border-radius: 2px; overflow: hidden; }
.insight-bar-fill { height: 100%; border-radius: 2px; background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end)); transition: width 1.5s ease; }

/* SHAP Image */
.shap-image-container { text-align: center; padding: 20px; background: rgba(255,255,255,0.02); border-radius: var(--radius-md); }
.shap-image { max-width: 100%; border-radius: var(--radius-sm); }

/* ============================================================
   WHAT-IF SIMULATOR
   ============================================================ */
.scenario-pills { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-bottom: 40px; }
.scenario-pill {
    display: flex; align-items: center; gap: 8px;
    padding: 10px 20px; border: 1px solid var(--border-light);
    border-radius: 24px; background: var(--bg-card);
    color: var(--text-secondary); font-size: 0.88rem; font-weight: 500;
    cursor: pointer; transition: var(--transition);
}
.scenario-pill:hover { border-color: var(--accent-blue); color: var(--accent-blue); }
.scenario-pill.active { background: rgba(59,130,246,0.1); border-color: var(--accent-blue); color: var(--accent-blue); }

.simulator-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.sim-inputs {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 28px;
}
.sim-panel-title { font-family: 'Space Grotesk', sans-serif; font-size: 1.1rem; margin-bottom: 24px; display: flex; align-items: center; gap: 10px; }
.sim-panel-title i { color: var(--accent-blue); }
.sim-group { margin-bottom: 20px; }
.sim-group label { display: block; font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 8px; font-weight: 500; }
.sim-value { color: var(--accent-blue); font-weight: 700; font-family: 'JetBrains Mono', monospace; }

/* Radio Group */
.sim-radio-group { display: flex; gap: 6px; flex-wrap: wrap; }
.sim-radio {
    padding: 8px 16px; border: 1px solid var(--border-light);
    border-radius: var(--radius-sm); background: var(--bg-input);
    color: var(--text-muted); font-size: 0.82rem; font-weight: 500;
    cursor: pointer; transition: var(--transition);
}
.sim-radio:hover { border-color: var(--accent-blue); color: var(--text-secondary); }
.sim-radio.active { background: rgba(59,130,246,0.12); border-color: var(--accent-blue); color: var(--accent-blue); }

/* Slider */
.sim-slider {
    -webkit-appearance: none; appearance: none; width: 100%; height: 6px;
    background: var(--bg-input); border-radius: 3px; outline: none;
    border: 1px solid var(--border-color);
}
.sim-slider::-webkit-slider-thumb {
    -webkit-appearance: none; appearance: none; width: 20px; height: 20px;
    border-radius: 50%; background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    cursor: pointer; border: 3px solid var(--bg-card);
    box-shadow: 0 0 10px rgba(102,126,234,0.4);
}
.sim-slider::-moz-range-thumb {
    width: 20px; height: 20px; border-radius: 50%;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    cursor: pointer; border: 3px solid var(--bg-card);
}
.sim-slider-labels { display: flex; justify-content: space-between; font-size: 0.72rem; color: var(--text-muted); margin-top: 4px; }

/* Select */
.sim-select {
    width: 100%; padding: 10px 14px; border: 1px solid var(--border-light);
    border-radius: var(--radius-sm); background: var(--bg-input);
    color: var(--text-primary); font-size: 0.88rem;
    appearance: none; cursor: pointer;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat; background-position: right 12px center;
}
.sim-select option { background: var(--bg-secondary); color: var(--text-primary); }

/* Toggles */
.sim-toggles { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.sim-toggle { display: flex; align-items: center; justify-content: space-between; padding: 10px 14px; background: var(--bg-input); border-radius: var(--radius-sm); }
.sim-toggle label { font-size: 0.82rem; color: var(--text-secondary); margin: 0; }
.toggle-switch {
    width: 44px; height: 24px; border-radius: 12px;
    background: var(--border-light); border: none; cursor: pointer;
    position: relative; transition: var(--transition);
}
.toggle-switch.active { background: var(--accent-blue); }
.toggle-knob {
    position: absolute; top: 3px; left: 3px;
    width: 18px; height: 18px; border-radius: 50%;
    background: white; transition: var(--transition);
}
.toggle-switch.active .toggle-knob { left: 23px; }

/* Sim Results */
.sim-results {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 28px;
}
.sim-gauge-container { margin-bottom: 12px; }
.sim-gauge-container .chart-container { min-height: 240px; }
.sim-risk-label { text-align: center; margin-bottom: 20px; }
.risk-badge {
    display: inline-block; padding: 6px 18px; border-radius: 20px;
    font-size: 0.82rem; font-weight: 700; letter-spacing: 0.08em;
}
.risk-badge.high { background: rgba(239,68,68,0.12); color: var(--accent-red); }
.risk-badge.medium { background: rgba(245,158,11,0.12); color: var(--accent-amber); }
.risk-badge.low { background: rgba(16,185,129,0.12); color: var(--accent-green); }
.sim-factors { margin-bottom: 20px; }
.sim-factors h4 { font-size: 0.92rem; margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.sim-factors h4 i { color: var(--accent-amber); }
.sim-factors .chart-container { min-height: 200px; }
.sim-recommendation {
    padding: 16px; border-radius: var(--radius-md);
    background: rgba(59,130,246,0.06); border: 1px solid rgba(59,130,246,0.15);
}
.rec-header { font-size: 0.85rem; font-weight: 700; color: var(--accent-blue); margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.rec-text { font-size: 0.88rem; color: var(--text-secondary); line-height: 1.6; }

/* ============================================================
   SEGMENTS
   ============================================================ */
.segment-tabs { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; margin-bottom: 40px; }
.segment-tab {
    padding: 10px 22px; border: 1px solid var(--border-light);
    border-radius: var(--radius-sm); background: var(--bg-card);
    color: var(--text-muted); font-size: 0.88rem; font-weight: 500;
    cursor: pointer; transition: var(--transition);
}
.segment-tab:hover { border-color: var(--accent-blue); color: var(--text-secondary); }
.segment-tab.active { background: rgba(59,130,246,0.1); border-color: var(--accent-blue); color: var(--accent-blue); }

/* ============================================================
   TECH GRID
   ============================================================ */
.tech-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 40px; }
.tech-card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 28px; transition: var(--transition);
}
.tech-card:hover { transform: translateY(-4px); border-color: rgba(102,126,234,0.3); }
.tech-icon {
    width: 48px; height: 48px; border-radius: 14px;
    background: linear-gradient(135deg, rgba(102,126,234,0.15), rgba(118,75,162,0.15));
    display: flex; align-items: center; justify-content: center;
    font-size: 1.2rem; color: var(--accent-blue); margin-bottom: 16px;
}
.tech-card h4 { font-size: 1rem; margin-bottom: 12px; }
.tech-card ul { list-style: none; display: flex; flex-direction: column; gap: 6px; }
.tech-card li { font-size: 0.82rem; color: var(--text-secondary); padding-left: 16px; position: relative; }
.tech-card li::before { content: '\2022'; position: absolute; left: 0; color: var(--accent-blue); }

/* Stack Tags */
.stack-tags { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-bottom: 24px; }
.stack-tag {
    padding: 6px 14px; border-radius: 6px; font-size: 0.78rem;
    font-weight: 600; background: var(--bg-card); border: 1px solid var(--border-color);
    color: var(--text-secondary); font-family: 'JetBrains Mono', monospace;
}
.model-version {
    text-align: center; font-size: 0.78rem; color: var(--text-muted);
    padding: 12px; border-radius: var(--radius-sm);
    background: var(--bg-card); border: 1px solid var(--border-color);
}
.model-version i { color: var(--accent-purple); margin-right: 6px; }

/* ============================================================
   ABOUT
   ============================================================ */
.about-layout { display: grid; grid-template-columns: 1.2fr 1fr; gap: 40px; align-items: start; }
.about-text p { color: var(--text-secondary); margin-bottom: 16px; line-height: 1.8; }
.about-links { display: flex; gap: 12px; margin-top: 24px; flex-wrap: wrap; }
.about-outcomes {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 28px;
}
.about-outcomes h4 { margin-bottom: 20px; }
.outcome-item {
    display: flex; align-items: center; gap: 16px;
    padding: 14px 0; border-bottom: 1px solid var(--border-color);
}
.outcome-item:last-of-type { border-bottom: none; }
.outcome-metric {
    font-family: 'Space Grotesk', sans-serif; font-size: 1.6rem; font-weight: 800;
    background: var(--gradient-text); -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent; min-width: 80px;
}
.outcome-text { font-size: 0.9rem; color: var(--text-secondary); }
.outcome-note { font-size: 0.78rem; color: var(--text-muted); margin-top: 16px; font-style: italic; }

/* ============================================================
   FOOTER
   ============================================================ */
.footer { padding: 40px 0; border-top: 1px solid var(--border-color); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; }
.footer-inner p { font-size: 0.85rem; color: var(--text-muted); }
.footer-links { display: flex; gap: 16px; }
.footer-links a { color: var(--text-muted); font-size: 1.2rem; transition: var(--transition); }
.footer-links a:hover { color: var(--accent-blue); }

/* ============================================================
   CHATBOT
   ============================================================ */
.chatbot-panel {
    position: fixed; right: -420px; top: 0; bottom: 0; width: 400px;
    background: var(--bg-secondary); border-left: 1px solid var(--border-color);
    z-index: 200; display: flex; flex-direction: column;
    transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -8px 0 40px rgba(0,0,0,0.3);
}
.chatbot-panel.open { right: 0; }
.chatbot-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 16px 20px; border-bottom: 1px solid var(--border-color);
    background: var(--bg-card);
}
.chatbot-header-left { display: flex; align-items: center; gap: 10px; font-weight: 600; font-size: 0.95rem; }
.chatbot-header-left i { color: var(--accent-blue); }
.chatbot-close { background: none; border: none; color: var(--text-muted); cursor: pointer; font-size: 1.1rem; padding: 4px; transition: var(--transition); }
.chatbot-close:hover { color: var(--text-primary); }
.chatbot-body { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column; gap: 16px; }
.chat-message { display: flex; gap: 10px; max-width: 90%; animation: chatFadeIn 0.3s ease; }
.chat-message.bot { align-self: flex-start; }
.chat-message.user { align-self: flex-end; flex-direction: row-reverse; }
.chat-avatar {
    width: 32px; height: 32px; border-radius: 10px; flex-shrink: 0;
    display: flex; align-items: center; justify-content: center;
    font-size: 0.85rem;
}
.chat-message.bot .chat-avatar { background: rgba(59,130,246,0.12); color: var(--accent-blue); }
.chat-message.user .chat-avatar { background: rgba(139,92,246,0.12); color: var(--accent-purple); }
.chat-bubble {
    padding: 12px 16px; border-radius: 14px; font-size: 0.88rem;
    line-height: 1.6; color: var(--text-secondary);
}
.chat-message.bot .chat-bubble { background: var(--bg-card); border: 1px solid var(--border-color); border-bottom-left-radius: 4px; }
.chat-message.user .chat-bubble { background: rgba(59,130,246,0.12); border: 1px solid rgba(59,130,246,0.2); border-bottom-right-radius: 4px; }
.chatbot-footer { padding: 16px 20px; border-top: 1px solid var(--border-color); }
.chat-suggestions { display: flex; gap: 6px; margin-bottom: 10px; flex-wrap: wrap; }
.chat-suggestion {
    display: inline-flex; align-items: center; gap: 5px;
    padding: 5px 11px; border: 1px solid var(--border-light);
    border-radius: 16px; background: transparent; color: var(--text-muted);
    font-size: 0.72rem; cursor: pointer; transition: var(--transition);
}
.chat-suggestion i { font-size: 0.68rem; opacity: 0.7; }
.chat-suggestion:hover { border-color: var(--accent-blue); color: var(--accent-blue); background: rgba(59,130,246,0.06); }
.chat-input-form { display: flex; gap: 8px; }
.chat-input {
    flex: 1; padding: 12px 16px; border: 1px solid var(--border-light);
    border-radius: var(--radius-sm); background: var(--bg-input);
    color: var(--text-primary); font-size: 0.88rem; outline: none;
    transition: var(--transition);
}
.chat-input:focus { border-color: var(--accent-blue); }
.chat-send {
    width: 44px; height: 44px; border-radius: var(--radius-sm);
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    border: none; color: white; cursor: pointer; font-size: 0.9rem;
    transition: var(--transition);
}
.chat-send:hover { transform: scale(1.05); }
.chat-typing { display: flex; gap: 4px; padding: 12px 16px; }
.chat-typing span {
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--text-muted); animation: typingDot 1.4s infinite;
}
.chat-typing span:nth-child(2) { animation-delay: 0.2s; }
.chat-typing span:nth-child(3) { animation-delay: 0.4s; }

/* Chatbot Follow-up Chips */
.chat-followups {
    display: flex; flex-wrap: wrap; gap: 6px;
    padding: 4px 0 4px 42px;
    animation: chatFadeIn 0.3s ease;
}
.chat-followup-btn {
    padding: 5px 12px; border: 1px solid rgba(102,126,234,0.25);
    border-radius: 14px; background: rgba(102,126,234,0.06);
    color: var(--accent-blue); font-size: 0.73rem; font-weight: 500;
    cursor: pointer; transition: var(--transition);
}
.chat-followup-btn:hover {
    background: rgba(102,126,234,0.15); border-color: var(--accent-blue);
    transform: translateY(-1px);
}

/* Chatbot Author Credit */
.chatbot-author {
    display: flex; align-items: center; justify-content: space-between;
    padding: 10px 0 0; margin-top: 10px;
    border-top: 1px solid var(--border-color);
    font-size: 0.72rem; color: var(--text-muted);
}
.chatbot-author strong { color: var(--text-secondary); font-weight: 600; }
.chatbot-author-links { display: flex; gap: 10px; }
.chatbot-author-links a {
    color: var(--text-muted); font-size: 0.85rem;
    transition: var(--transition);
}
.chatbot-author-links a:hover { color: var(--accent-blue); }

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes chatFadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes typingDot {
    0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
    30% { transform: translateY(-6px); opacity: 1; }
}

/* Scroll animations */
[data-animate] { opacity: 0; transform: translateY(30px); transition: all 0.7s cubic-bezier(0.4, 0, 0.2, 1); }
[data-animate].visible { opacity: 1; transform: translateY(0); }

.section { opacity: 0; transform: translateY(40px); transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1); }
.section.visible { opacity: 1; transform: translateY(0); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
    .kpi-grid { grid-template-columns: repeat(2, 1fr); }
    .chart-grid-2 { grid-template-columns: 1fr; }
    .insight-grid { grid-template-columns: repeat(2, 1fr); }
    .tech-grid { grid-template-columns: repeat(2, 1fr); }
    .simulator-layout { grid-template-columns: 1fr; }
    .about-layout { grid-template-columns: 1fr; }
    .hero-title { font-size: 2.8rem; }
}

@media (max-width: 768px) {
    .nav-links { display: none; position: absolute; top: var(--nav-height); left: 0; right: 0; background: var(--bg-secondary); border-bottom: 1px solid var(--border-color); flex-direction: column; padding: 12px; }
    .nav-links.open { display: flex; }
    .nav-hamburger { display: flex; }
    .hero-title { font-size: 2.2rem; }
    .section { padding: 60px 0; }
    .two-col { grid-template-columns: 1fr; }
    .insight-grid { grid-template-columns: 1fr; }
    .tech-grid { grid-template-columns: 1fr; }
    .kpi-grid { grid-template-columns: 1fr; }
    .metrics-strip { flex-direction: column; align-items: stretch; }
    .chatbot-panel { width: 100%; right: -100%; }
    .sim-toggles { grid-template-columns: 1fr; }
    .btn-chat span { display: none; }
    .section-title { font-size: 2rem; }
    .about-layout { grid-template-columns: 1fr; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border-light); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }