/* ======================================
   AIR POLLUTION — INFORMATIONAL WEBPAGE
   Professional Design System
   ====================================== */

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

:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-card: #16161f;
    --bg-card-hover: #1c1c28;
    --text-primary: #f0f0f5;
    --text-secondary: #a0a0b0;
    --text-muted: #6a6a7a;
    --accent: #4da6ff;
    --accent-dim: #2d6aa0;
    --danger: #ff4d4d;
    --warning: #ffa726;
    --success: #66bb6a;
    --border: rgba(255, 255, 255, 0.06);
    --border-light: rgba(255, 255, 255, 0.1);
    --glow: rgba(77, 166, 255, 0.15);
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 20px;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --max-width: 1200px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: #7dc0ff; }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

strong { color: var(--text-primary); font-weight: 600; }

/* --- Navigation --- */
.nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    padding: 16px 0;
    transition: all var(--transition);
    background: transparent;
}

.nav.scrolled {
    background: rgba(10, 10, 15, 0.92);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 10px 0;
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 0.85rem;
    letter-spacing: 2px;
    color: var(--text-primary);
    flex-shrink: 0;
}

.nav-icon { width: 28px; height: 28px; color: var(--accent); }

.nav-links { display: flex; gap: 32px; }
.nav-links a {
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text-secondary);
    letter-spacing: 0.5px;
    transition: color var(--transition);
}
.nav-links a:hover { color: var(--text-primary); }

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}
.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: 999;
    background: rgba(10, 10, 15, 0.98);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 28px;
}
.mobile-menu.active { display: flex; }
.mobile-menu a {
    font-size: 1.3rem;
    font-weight: 500;
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    .nav-links { display: none; }
    .nav-toggle { display: flex; }
}

/* --- Hero --- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    background: linear-gradient(180deg, #0a0a0f 0%, #0f1420 40%, #1a1020 70%, #0a0a0f 100%);
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 50% 40%, rgba(255, 77, 77, 0.06) 0%, transparent 70%),
        radial-gradient(ellipse 60% 50% at 30% 60%, rgba(77, 166, 255, 0.04) 0%, transparent 70%);
    pointer-events: none;
}

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

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 0 24px;
}

.hero-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 24px;
    padding: 8px 20px;
    border: 1px solid var(--accent-dim);
    border-radius: 100px;
    word-break: break-word;
    max-width: 100%;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: -1px;
}

.hero-highlight {
    background: linear-gradient(135deg, #ff4d4d, #ff8c42, #ff4d4d);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 48px;
    line-height: 1.7;
}

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

.hero-stat { text-align: center; }

.hero-stat-number {
    font-size: 3rem;
    font-weight: 800;
    font-family: var(--font-mono);
    color: var(--text-primary);
    letter-spacing: -2px;
}

.hero-stat-suffix {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent);
    margin-left: 2px;
}

.hero-stat-label {
    display: block;
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-top: 4px;
    letter-spacing: 0.5px;
}

.hero-cta {
    display: inline-block;
    padding: 14px 36px;
    background: var(--accent);
    color: #000;
    font-weight: 600;
    font-size: 0.9rem;
    border-radius: 100px;
    letter-spacing: 0.5px;
    transition: all var(--transition);
}
.hero-cta:hover {
    background: #7dc0ff;
    color: #000;
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(77, 166, 255, 0.3);
}

.hero-scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    z-index: 2;
}
.hero-scroll-indicator span {
    font-size: 0.7rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--text-muted);
}
.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, var(--accent), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
    0%, 100% { opacity: 0.3; transform: scaleY(0.6); }
    50% { opacity: 1; transform: scaleY(1); }
}

/* --- Sections --- */
.section {
    padding: 120px 0;
}

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

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 72px;
}

.section-tag {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    font-weight: 800;
    letter-spacing: -0.5px;
    margin-bottom: 16px;
}

.section-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* --- Overview --- */
.overview-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 72px;
}

.overview-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 36px 28px;
    transition: all var(--transition);
}
.overview-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-light);
    transform: translateY(-4px);
}

.overview-card-icon {
    width: 48px; height: 48px;
    display: flex; align-items: center; justify-content: center;
    margin-bottom: 20px;
    color: var(--accent);
}
.overview-card-icon svg { width: 36px; height: 36px; }

.overview-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.overview-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.65;
}

/* --- AQI Scale --- */
.aqi-scale {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 48px 40px;
}

.aqi-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.aqi-subtitle {
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.aqi-bar {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 4px;
    border-radius: var(--radius);
    overflow: hidden;
}

.aqi-segment {
    background: var(--color);
    padding: 16px 12px;
    text-align: center;
    transition: transform var(--transition);
}
.aqi-segment:hover { transform: scaleY(1.08); }

.aqi-range {
    display: block;
    font-size: 0.85rem;
    font-weight: 700;
    color: #000;
    margin-bottom: 4px;
}

.aqi-label {
    display: block;
    font-size: 0.68rem;
    font-weight: 600;
    color: rgba(0,0,0,0.7);
}

/* --- Pollutants --- */
.pollutants-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.pollutant-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 28px;
    transition: all var(--transition);
}
.pollutant-card:hover {
    border-color: var(--border-light);
    transform: translateY(-3px);
}

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

.pollutant-formula {
    font-family: var(--font-mono);
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--accent);
}

.pollutant-badge {
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 1px;
    text-transform: uppercase;
    padding: 4px 10px;
    border-radius: 100px;
}
.pollutant-badge-critical {
    background: rgba(255, 77, 77, 0.15);
    color: #ff6b6b;
    border: 1px solid rgba(255, 77, 77, 0.3);
}

.pollutant-card h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.pollutant-card > p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
}

.pollutant-details {
    border-top: 1px solid var(--border);
    padding-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.pollutant-detail {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 12px;
}

.pollutant-detail-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    flex-shrink: 0;
}

.pollutant-detail-value {
    font-size: 0.8rem;
    font-weight: 600;
    text-align: right;
    color: var(--text-secondary);
}

.highlight-red { color: #ff6b6b !important; }

/* --- Health --- */
.health-body-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    margin-bottom: 72px;
}

.health-organ-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.health-organ {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: default;
    transition: all var(--transition);
}
.health-organ:hover, .health-organ.active {
    border-color: var(--accent-dim);
    background: var(--bg-card-hover);
}

.health-organ-icon {
    width: 48px; height: 48px;
    flex-shrink: 0;
    color: var(--accent);
}
.health-organ-icon svg { width: 48px; height: 48px; }

.health-organ h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 6px;
}

.health-organ p {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.health-stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.health-stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    transition: border-color var(--transition);
}
.health-stat-card:hover { border-color: var(--border-light); }

.health-stat-number {
    font-size: 1.8rem;
    font-weight: 800;
    font-family: var(--font-mono);
    color: var(--danger);
    letter-spacing: -1px;
}

.health-stat-label {
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-top: 4px;
    line-height: 1.4;
}

.health-stat-source {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 8px;
}

/* Vulnerable */
.health-vulnerable {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 48px 40px;
}

.health-vulnerable h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 32px;
    text-align: center;
}

.vulnerable-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.vulnerable-card {
    text-align: center;
    padding: 24px 16px;
}

.vulnerable-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 12px;
    color: var(--accent);
}
.vulnerable-icon svg {
    width: 100%;
    height: 100%;
}

.vulnerable-card h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.vulnerable-card p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* --- Sources --- */
.sources-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
}

.sources-chart h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 32px;
}

.donut-chart {
    position: relative;
    width: 260px;
    height: 260px;
    margin: 0 auto 32px;
}

.donut-chart svg { width: 100%; height: 100%; }

.donut-center {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.donut-total {
    display: block;
    font-size: 1.5rem;
    font-weight: 800;
    font-family: var(--font-mono);
}

.donut-label {
    display: block;
    font-size: 0.72rem;
    color: var(--text-muted);
}

.donut-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 12px 20px;
    justify-content: center;
}

.donut-legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.donut-legend-dot {
    width: 10px; height: 10px;
    border-radius: 50%;
    flex-shrink: 0;
}

.sources-details {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.source-detail-card {
    display: flex;
    gap: 20px;
    padding: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: all var(--transition);
}
.source-detail-card:hover {
    border-color: var(--border-light);
}

.source-percent {
    font-size: 1.5rem;
    font-weight: 800;
    font-family: var(--font-mono);
    color: var(--accent);
    flex-shrink: 0;
    min-width: 56px;
}

.source-detail-card h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 6px;
}

.source-detail-card p {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* --- Regional --- */
.regional-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 72px;
}

.region-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: all var(--transition);
}
.region-card:hover {
    border-color: var(--border-light);
    transform: translateY(-3px);
}

.region-header {
    padding: 24px 24px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.region-header h3 { font-size: 1rem; font-weight: 700; }

.region-pm25 { text-align: right; }
.region-pm25-value {
    font-size: 1.4rem;
    font-weight: 800;
    font-family: var(--font-mono);
}
.region-pm25-unit {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-left: 2px;
}

.region-south-asia .region-pm25-value { color: #ff4d4d; }
.region-middle-east .region-pm25-value { color: #c060cf; }
.region-east-asia .region-pm25-value { color: #ff6b6b; }
.region-africa .region-pm25-value { color: #ffa726; }
.region-latam .region-pm25-value { color: #ffd54f; }
.region-europe .region-pm25-value { color: #66bb6a; }

.region-bar-container {
    padding: 0 24px;
    margin-bottom: 16px;
}

.region-bar {
    height: 6px;
    border-radius: 3px;
    background: var(--color);
    width: var(--width);
    transition: width 1s ease-out;
}

.region-facts {
    padding: 0 24px 24px;
    list-style: none;
}
.region-facts li {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.5;
    padding: 6px 0;
    border-top: 1px solid var(--border);
    padding-left: 12px;
    position: relative;
}
.region-facts li::before {
    content: '';
    position: absolute;
    left: 0; top: 13px;
    width: 4px; height: 4px;
    border-radius: 50%;
    background: var(--text-muted);
}

/* Most Polluted Cities */
.most-polluted {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 48px 40px;
}

.most-polluted h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.most-polluted-source {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 32px;
}

.city-bars { display: flex; flex-direction: column; gap: 12px; }

.city-bar-row {
    display: flex;
    align-items: center;
    gap: 16px;
}

.city-name {
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text-secondary);
    min-width: 160px;
    text-align: right;
    flex-shrink: 0;
}

.city-bar-track {
    flex: 1;
    height: 28px;
    background: rgba(255,255,255,0.03);
    border-radius: 4px;
    overflow: hidden;
}

.city-bar-fill {
    height: 100%;
    width: var(--width);
    background: var(--color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 10px;
    transition: width 1.2s ease-out;
}

.city-bar-fill span {
    font-size: 0.72rem;
    font-weight: 700;
    color: #fff;
    text-shadow: 0 1px 3px rgba(0,0,0,0.5);
}

/* --- Economic --- */
.econ-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.econ-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 36px 28px;
    text-align: center;
    transition: all var(--transition);
}
.econ-card:hover {
    border-color: var(--border-light);
    transform: translateY(-3px);
}

.econ-number {
    font-size: 2.2rem;
    font-weight: 800;
    font-family: var(--font-mono);
    color: var(--warning);
    letter-spacing: -1px;
    margin-bottom: 12px;
}

.econ-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.econ-source {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 12px;
}

/* --- Action --- */
.action-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-bottom: 72px;
}

.action-column {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 36px 28px;
}

.action-level {
    font-size: 1rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.action-list { list-style: none; }
.action-list li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
    padding: 10px 0 10px 20px;
    position: relative;
    border-bottom: 1px solid var(--border);
}
.action-list li:last-child { border-bottom: none; }
.action-list li::before {
    content: '';
    position: absolute;
    left: 0; top: 16px;
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--accent);
}

/* Success Stories */
.success-stories {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 48px 40px;
}

.success-stories h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 32px;
    text-align: center;
}

.story-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.story-card {
    padding: 24px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: border-color var(--transition);
}
.story-card:hover { border-color: var(--success); }

.story-location {
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--success);
    margin-bottom: 6px;
}

.story-stat {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.story-card p {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* --- Footer --- */
.footer {
    border-top: 1px solid var(--border);
    padding: 72px 0 32px;
    background: var(--bg-primary);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-main h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.footer-main p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.footer-sources h4 {
    font-size: 0.85rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-muted);
    letter-spacing: 1px;
    text-transform: uppercase;
}

.footer-sources ul { list-style: none; }
.footer-sources li {
    font-size: 0.82rem;
    color: var(--text-secondary);
    padding: 4px 0;
}

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 24px;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* --- Animations --- */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    .overview-grid { grid-template-columns: 1fr; }
    .pollutants-grid { grid-template-columns: repeat(2, 1fr); }
    .health-body-section { grid-template-columns: 1fr; }
    .sources-layout { grid-template-columns: 1fr; }
    .regional-grid { grid-template-columns: repeat(2, 1fr); }
    .econ-grid { grid-template-columns: repeat(2, 1fr); }
    .action-grid { grid-template-columns: 1fr; }
    .story-grid { grid-template-columns: 1fr; }
    .vulnerable-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-content { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .section { padding: 80px 0; }
    .pollutants-grid { grid-template-columns: 1fr; }
    .regional-grid { grid-template-columns: 1fr; }
    .econ-grid { grid-template-columns: 1fr; }
    .hero-stats { gap: 24px; }
    .aqi-bar { grid-template-columns: repeat(3, 1fr); }
    .health-stats-grid { grid-template-columns: 1fr; }
    .vulnerable-grid { grid-template-columns: 1fr; }
    .city-name { min-width: 100px; font-size: 0.72rem; }
    .most-polluted { padding: 32px 20px; }
    .success-stories { padding: 32px 20px; }
    .health-vulnerable { padding: 32px 20px; }
    .aqi-scale { padding: 32px 20px; }

    /* Nav mobile fixes */
    .nav { padding: 12px 0; }
    .nav.scrolled { padding: 8px 0; }
    .nav-inner { padding: 0 16px; }

    /* Hero mobile fixes */
    .hero { min-height: 100svh; }
    .hero-content { padding: 80px 20px 0; }
    .hero-label {
        font-size: 0.6rem;
        letter-spacing: 1.5px;
        padding: 6px 14px;
    }
    .hero-title { font-size: 2.2rem; margin-bottom: 20px; }
    .hero-subtitle { font-size: 0.95rem; margin-bottom: 36px; }
    .hero-stats { gap: 20px; margin-bottom: 36px; }
    .hero-stat-number { font-size: 2.4rem; }
    .hero-stat-suffix { font-size: 1.2rem; }
    .hero-stat-label { font-size: 0.7rem; }
    .hero-scroll-indicator { bottom: 24px; }

    /* Section headers */
    .section-header { margin-bottom: 48px; }
    .section-title { font-size: 1.6rem; }
    .section-desc { font-size: 0.9rem; }

    /* Source detail cards */
    .source-detail-card { flex-direction: column; gap: 12px; }
    .source-percent { min-width: auto; }

    /* City bars */
    .city-bar-row { flex-direction: column; align-items: stretch; gap: 6px; }
    .city-name { text-align: left; min-width: auto; }
}

@media (max-width: 480px) {
    .aqi-bar { grid-template-columns: repeat(2, 1fr); }
    .hero-stat-number { font-size: 2rem; }
    .hero-title { font-size: 1.8rem; }
    .hero-label {
        font-size: 0.55rem;
        letter-spacing: 1px;
        padding: 5px 12px;
    }
    .hero-content { padding: 70px 16px 0; }
    .container { padding: 0 16px; }
    .econ-number { font-size: 1.6rem; }
    .econ-card { padding: 24px 20px; }
}