/* ==========================================
    MyApp APK Website Styles
    ========================================== */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
    --color-co2: #FF6B6B; --color-temp: #4ECDC4; --color-humidity: #45B7D1; --color-pressure: #96CEB4;
    --text-primary: #2D3436; --text-secondary: #636E72; --text-tertiary: #B2BEC3;
    --bg-light: #F8F9FA; --bg-white: #FFFFFF; --bg-dark: #1A1A1A; --bg-card: #FFFFFF; --border-color: #E0E0E0;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1); --shadow-md: 0 4px 12px rgba(0,0,0,0.15); --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);
    --radius: 12px; --transition: all 0.3s ease; --transition-fast: all 0.15s ease; --transition-slow: all 0.5s ease;
    --easing-standard: cubic-bezier(0.4,0,0.2,1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --text-primary: #F0F0F0; --text-secondary: #B2BEC3; --text-tertiary: #888888;
        --bg-light: #121212; --bg-white: #1E1E1E; --bg-dark: #0A0A0A; --bg-card: #252525; --border-color: #333333;
        --shadow-sm: 0 2px 4px rgba(0,0,0,0.3); --shadow-md: 0 4px 12px rgba(0,0,0,0.4); --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
    }
}

body { font-family: 'Open Sans', 'Roboto', sans-serif; line-height: 1.6; color: var(--text-primary); background-color: var(--bg-light); scroll-behavior: smooth; transition: background-color 0.3s ease, color 0.3s ease; }
a:focus-visible, button:focus-visible, .btn:focus-visible { outline: 2px solid var(--color-co2); outline-offset: 2px; }
@media (prefers-reduced-motion: reduce) { *,*::before,*::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; } .gradient-bg { animation: none !important; } }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
h1,h2,h3,h4 { font-family: 'Roboto', sans-serif; font-weight: 700; line-height: 1.2; }
h1 { font-size: 3rem; } h2 { font-size: 2.2rem; } h3 { font-size: 1.5rem; } h4 { font-size: 1.1rem; }
a { color: var(--color-co2); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--color-temp); text-decoration: underline; }

/* Navigation */
.navbar { background: var(--bg-white); box-shadow: var(--shadow-sm); position: sticky; top: 0; z-index: 1000; border-bottom: 1px solid var(--border-color); transition: background-color 0.3s ease, box-shadow 0.3s ease; }
.nav-container { display: flex; justify-content: space-between; align-items: center; padding: 15px 20px; position: relative; }
.logo { display: flex; align-items: center; gap: 10px; font-size: 1.5rem; font-weight: 700; color: var(--text-primary); text-decoration: none; transition: color 0.3s ease; }
.logo:hover { text-decoration: none; color: var(--color-co2); }
.nav-links { display: flex; list-style: none; gap: 30px; }
.nav-links a { color: var(--text-secondary); font-weight: 500; text-decoration: none; padding: 8px 0; border-bottom: 2px solid transparent; transition: var(--transition); position: relative; }
.nav-links a:hover, .nav-links a.active { color: var(--color-co2); text-decoration: none; border-bottom-color: var(--color-co2); }
.mobile-menu-btn { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--text-primary); transition: color 0.3s ease; padding: 4px; }
.mobile-menu-btn:hover { color: var(--color-co2); }

/* Buttons */
.btn { display: inline-block; padding: 12px 28px; border-radius: 30px; font-weight: 600; font-size: 1rem; text-decoration: none; transition: var(--transition); cursor: pointer; border: 2px solid transparent; text-align: center; }
.btn-primary { background: linear-gradient(135deg, var(--color-co2), var(--color-temp)); color: white; box-shadow: 0 4px 12px rgba(255,107,107,0.3); border: 2px solid var(--color-co2); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(255,107,107,0.4); color: white; text-decoration: none; }
.btn-secondary { background: var(--bg-white); color: var(--text-primary); border: 2px solid var(--color-co2); }
.btn-secondary:hover { background: var(--color-co2); color: white; text-decoration: none; }
.btn-large { padding: 16px 40px; font-size: 1.1rem; }
.btn-small { padding: 8px 16px; font-size: 0.85rem; }
.btn-copy { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px; border-radius: 8px; border: none; cursor: pointer; font-weight: 600; transition: var(--transition-fast); background: var(--bg-light); color: var(--text-primary); border: 1px solid var(--border-color); }
.btn-copy:hover { background: var(--color-co2); color: white; border-color: var(--color-co2); }
.btn:focus-visible { outline: 2px solid var(--color-co2); outline-offset: 2px; }

/* Hero */
.hero { position: relative; overflow: hidden; padding: 80px 0 60px;
    background-image: radial-gradient(circle at 10% 20%, rgba(255,107,107,0.08) 0%, transparent 20%), radial-gradient(circle at 90% 80%, rgba(78,205,196,0.08) 0%, transparent 20%); }
.gradient-bg { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: linear-gradient(135deg, #FF6B6B, #4ECDC4); z-index: -2; animation: gradientShift 20s ease infinite; background-size: 200% 200%; opacity: 0.15; }
@keyframes gradientShift { 0% { background-position: 0% 50%; } 50% { background-position: 100% 50%; } 100% { background-position: 0% 50%; } }
.hero::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: linear-gradient(135deg, rgba(255,255,255,0.92), rgba(255,255,255,0.8)); z-index: -1; }
@media (prefers-color-scheme: dark) { .hero::before { background: linear-gradient(135deg, rgba(18,18,18,0.95), rgba(26,26,26,0.9)); } }
@keyframes pulse { 0% { box-shadow: 0 4px 12px rgba(255,107,107,0.3); } 50% { box-shadow: 0 4px 20px rgba(255,107,107,0.5); } 100% { box-shadow: 0 4px 12px rgba(255,107,107,0.3); } }
.hero-content { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; padding: 40px 20px; max-width: 1100px; margin: 0 auto; }
.hero-title { font-size: 3.2rem; background: linear-gradient(135deg, var(--color-co2), var(--color-temp)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin-bottom: 12px; line-height: 1.15; }
.hero-subtitle { font-size: 1.35rem; color: var(--text-secondary); margin-bottom: 16px; }
.hero-description { font-size: 1.05rem; color: var(--text-secondary); margin-bottom: 28px; line-height: 1.7; }
.hero-buttons { display: flex; gap: 14px; margin-bottom: 20px; flex-wrap: wrap; }
.hero-buttons .btn-primary { animation: pulse 2s infinite; }
.hero-meta { display: flex; align-items: center; gap: 10px; color: var(--text-secondary); font-size: 0.95rem; }
.version-badge { background: var(--color-co2); color: white; padding: 4px 12px; border-radius: 20px; font-size: 0.85rem; font-weight: 600; display: inline-block; }

/* Phone Mockup */
.phone-mockup { display: flex; justify-content: center; }
.phone-screen { width: 260px; height: 490px; border-radius: 28px; border: 3px solid var(--border-color); overflow: hidden; box-shadow: var(--shadow-lg); transition: border-color 0.3s ease, box-shadow 0.3s ease; background: var(--bg-card); }
.app-preview { height: 100%; display: flex; flex-direction: column; }
.preview-header { padding: 16px; display: flex; justify-content: space-between; align-items: center; color: white; }
.preview-title { font-weight: 700; font-size: 1rem; }
.preview-toggle { font-size: 1.1rem; }
.preview-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; padding: 12px; flex: 1; }
.preview-card { background: var(--bg-light); border-radius: 8px; padding: 10px; text-align: center; transition: var(--transition-fast); }
.preview-card:hover { transform: scale(1.03); }
.preview-label { font-size: 0.65rem; color: var(--text-tertiary); margin-bottom: 3px; }
.preview-value { font-size: 1rem; font-weight: 700; color: var(--text-primary); }

/* Features */
.features { padding: 80px 0; background: var(--bg-white); transition: background-color 0.3s ease; }
.section-title { text-align: center; margin-bottom: 50px; position: relative; opacity: 0; transform: translateY(20px); transition: opacity 0.6s var(--easing-standard), transform 0.6s var(--easing-standard); }
.section-title.visible { opacity: 1; transform: translateY(0); }
.section-title::after { content: ''; display: block; width: 80px; height: 4px; background: linear-gradient(135deg, var(--color-co2), var(--color-temp)); margin: 15px auto 0; border-radius: 2px; }
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 30px; }

/* Fixed: Combined all transition properties into one declaration to prevent override */
.feature-card { background: var(--bg-light); padding: 30px; border-radius: var(--radius); text-align: center; border: 2px solid transparent; opacity: 0; transform: translateY(30px); transition: opacity 0.6s var(--easing-standard), transform 0.6s var(--easing-standard), box-shadow 0.3s var(--easing-standard), border-color 0.3s var(--easing-standard), background-color 0.3s ease; }
.feature-card.visible { opacity: 1; transform: translateY(0); }
.feature-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); border-color: var(--color-co2); }
.feature-card:nth-child(1) { transition-delay: 0ms; } .feature-card:nth-child(2) { transition-delay: 100ms; } .feature-card:nth-child(3) { transition-delay: 200ms; } .feature-card:nth-child(4) { transition-delay: 300ms; }
.feature-icon { font-size: 3rem; margin-bottom: 15px; transition: transform 0.3s var(--easing-standard); display: block; }
.feature-card:hover .feature-icon { transform: scale(1.1); color: var(--color-co2); }
.feature-card h3 { margin-bottom: 10px; color: var(--color-co2); transition: color 0.3s ease; }
.feature-card p { color: var(--text-secondary); font-size: 0.95rem; }

/* Metrics */
.metrics { padding: 80px 0; background: var(--bg-light); transition: background-color 0.3s ease; }
.metrics-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 25px; }
.metric-card { background: var(--bg-card); padding: 30px 20px; border-radius: var(--radius); text-align: center; box-shadow: var(--shadow-sm); transition: opacity 0.6s var(--easing-standard), transform 0.6s var(--easing-standard), box-shadow 0.3s var(--easing-standard), background-color 0.3s ease; opacity: 0; transform: translateY(20px); }
.metric-card.visible { opacity: 1; transform: translateY(0); }
.metric-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); }
.metric-card:nth-child(1) { transition-delay: 0ms; } .metric-card:nth-child(2) { transition-delay: 100ms; } .metric-card:nth-child(3) { transition-delay: 200ms; } .metric-card:nth-child(4) { transition-delay: 300ms; }
.metric-icon { font-size: 2.5rem; margin-bottom: 15px; transition: transform 0.3s var(--easing-standard); display: block; }
.metric-card:hover .metric-icon { transform: scale(1.15); }
.metric-range { color: var(--text-secondary); font-size: 0.9rem; margin: 8px 0; }
.metric-color { width: 60px; height: 4px; border-radius: 2px; margin: 12px auto 0; }

/* CTA Section */
.cta { padding: 80px 0; background: var(--bg-white); transition: background-color 0.3s ease; }
.cta-content { text-align: center; }
.cta h2 { margin-bottom: 15px; }
.cta p { color: var(--text-secondary); margin-bottom: 25px; font-size: 1.1rem; }
.cta-buttons { display: flex; gap: 15px; justify-content: center; flex-wrap: wrap; }
.cta-note { color: var(--text-tertiary); font-size: 0.9rem; margin-top: 20px; }

/* Download Section */
.download-hero { padding: 60px 0; background: var(--bg-white); border-bottom: 1px solid var(--border-color); transition: background-color 0.3s ease; }
.download-hero h1 { font-size: 2.5rem; margin-bottom: 10px; }
.download-subtitle { color: var(--text-secondary); font-size: 1.15rem; }
.download-section { padding: 60px 0; background: var(--bg-light); transition: background-color 0.3s ease; }
.download-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 25px; align-items: start; }
.download-card { background: var(--bg-card); padding: 30px; border-radius: var(--radius); box-shadow: var(--shadow-sm); transition: var(--transition); border: 1px solid var(--border-color); }
.download-card:hover { box-shadow: var(--shadow-md); }
.download-card.main { grid-column: 1; }
.download-card h2 { margin-bottom: 10px; color: var(--text-primary); }
.download-card h3 { margin-bottom: 15px; color: var(--text-primary); }
.download-description { color: var(--text-secondary); margin-bottom: 20px; }
.download-meta { margin-bottom: 20px; }
.meta-item { display: flex; justify-content: space-between; padding: 8px 0; border-bottom: 1px solid var(--border-color); color: var(--text-secondary); }
.meta-item:last-child { border-bottom: none; }
.meta-label { font-weight: 500; color: var(--text-primary); }
.download-buttons { display: flex; gap: 12px; margin-bottom: 20px; flex-wrap: wrap; }
.qr-card { grid-column: 2; text-align: center; }
.guide-card { grid-column: 3; text-align: center; }

/* Checksum Box */
.checksum-box { margin-top: 20px; padding: 16px; background: var(--bg-light); border-radius: 8px; border: 1px solid var(--border-color); }
.checksum-box h4 { margin-bottom: 10px; font-size: 0.95rem; color: var(--text-secondary); }
.checksum-code { display: block; font-size: 0.75rem; word-break: break-all; background: var(--bg-white); padding: 7px 10px; border-radius: 5px; margin: 10px 0; color: var(--text-primary); border: 1px solid var(--border-color); font-family: 'Courier New', monospace; }
.checksum-help { margin-top: 8px; font-size: 0.85rem; }

/* QR Code */
.qr-container { padding: 20px; }
.qr-placeholder { width: 180px; height: 180px; border: 2px dashed var(--border-color); border-radius: 12px; display: flex; flex-direction: column; align-items: center; justify-content: center; color: var(--text-tertiary); margin: 0 auto; }
.qr-placeholder p { margin: 4px 0; }
.qr-note { font-size: 0.8rem; color: var(--text-tertiary); }
.qr-instruction { margin-top: 12px; color: var(--text-secondary); font-size: 0.9rem; }
#qrImage { max-width: 180px; border-radius: 8px; }

/* Installation Guide */
.install-steps { list-style: none; text-align: left; }
.install-steps li { padding: 10px 0; border-bottom: 1px solid var(--border-color); }
.install-steps li:last-child { border-bottom: none; }
.install-steps li strong { color: var(--color-co2); }
.install-steps li p { margin: 4px 0 0; font-size: 0.9rem; color: var(--text-secondary); }
.guide-link { color: var(--color-temp); font-size: 0.85rem; }

/* Version History / Timeline */
.version-history { padding: 80px 0; background: var(--bg-white); transition: background-color 0.3s ease; }
.timeline { position: relative; padding-left: 30px; }
.timeline::before { content: ''; position: absolute; left: 8px; top: 0; bottom: 0; width: 2px; background: var(--border-color); }
.timeline-item { position: relative; margin-bottom: 30px; opacity: 0; transform: translateX(-20px); transition: opacity 0.6s var(--easing-standard), transform 0.6s var(--easing-standard); }
.timeline-item.visible { opacity: 1; transform: translateX(0); }
.timeline-marker { position: absolute; left: -26px; top: 4px; width: 14px; height: 14px; border-radius: 50%; background: var(--color-co2); border: 3px solid var(--bg-card); box-shadow: 0 0 0 3px var(--color-co2); }
.timeline-marker.current { background: var(--color-temp); border-color: var(--bg-card); box-shadow: 0 0 0 3px var(--color-temp); }
.timeline-marker.empty { background: var(--border-color); border-color: var(--bg-card); box-shadow: 0 0 0 3px var(--border-color); }
.timeline-content { padding: 15px 0; }
.version-header { display: flex; align-items: center; gap: 15px; margin-bottom: 8px; flex-wrap: wrap; }
.version-header h2 { margin: 0; }
.version-header h3 { margin: 0; font-size: 1.3rem; }
.version-date { color: var(--text-tertiary); font-size: 0.9rem; }
.version-badge { background: var(--color-co2); color: white; padding: 3px 10px; border-radius: 12px; font-size: 0.75rem; font-weight: 600; animation: pulse 2s infinite; }
.future .version-badge { animation: none; opacity: 0.6; }
.changelog-section { margin: 12px 0; }
.changelog-section h3 { margin-bottom: 8px; color: var(--text-primary); }
.changelog-container { max-width: 800px; }
.changelog-container ul { padding-left: 20px; }
.changelog-container li { margin-bottom: 6px; color: var(--text-secondary); }
.future-note { color: var(--text-tertiary); font-style: italic; }
.download-btn-container { display: flex; gap: 10px; margin-top: 15px; flex-wrap: wrap; }
.changelog-list { padding-left: 20px; margin: 10px 0; }
.changelog-list li { margin-bottom: 6px; color: var(--text-secondary); }

/* Content Section (About, Changelog) */
.content-section { padding: 80px 0; background: var(--bg-white); transition: background-color 0.3s ease; }
.content-section.faq-section { background: var(--bg-light); }
.content-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 40px; }
.content-main h2 { margin-bottom: 15px; color: var(--text-primary); }
.content-main p { color: var(--text-secondary); margin-bottom: 15px; line-height: 1.7; }
.content-main h4 { color: var(--text-primary); margin: 20px 0 10px; }

/* Features List (About page) */
.features-list { margin: 15px 0 25px; }
.feature-item { display: flex; gap: 15px; align-items: flex-start; padding: 15px 0; border-bottom: 1px solid var(--border-color); transition: background-color 0.3s ease; }
.feature-item:last-child { border-bottom: none; }
.feature-icon-small { font-size: 1.5rem; flex-shrink: 0; margin-top: 2px; transition: transform 0.3s ease; }
.feature-item:hover .feature-icon-small { transform: scale(1.15); color: var(--color-co2); }
.feature-item h4 { color: var(--text-primary); margin-bottom: 4px; }
.feature-item p { color: var(--text-secondary); font-size: 0.9rem; margin: 0; }

/* Specs Table (About page) */
.specs-table { margin: 15px 0; }
.spec-row { display: flex; justify-content: space-between; padding: 10px 0; border-bottom: 1px solid var(--border-color); }
.spec-row:last-child { border-bottom: none; }
.spec-label { font-weight: 600; color: var(--text-primary); }
.spec-value { color: var(--text-secondary); }

/* Screenshots */
.screenshots-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 15px; margin: 15px 0; }
.screenshot-item { border-radius: var(--radius); overflow: hidden; }
.screenshot-placeholder { width: 100%; height: 180px; display: flex; align-items: center; justify-content: center; background: var(--bg-light); border: 2px solid var(--border-color); border-radius: var(--radius); color: var(--text-tertiary); font-size: 0.9rem; transition: border-color 0.3s ease, background-color 0.3s ease; }
.screenshot-placeholder.dark { background: #1a1a2e; border-color: #333; color: #b2bec3; }
.screenshot-note { color: var(--text-tertiary); font-size: 0.85rem; font-style: italic; margin-top: 10px; }

/* Color Palette */
.color-palette { margin-top: 5px; }
.color-swatches { display: flex; gap: 10px; margin: 10px 0; flex-wrap: wrap; }
.color-swatch { width: 45px; height: 45px; border-radius: 10px; transition: transform 0.3s ease; cursor: default; box-shadow: var(--shadow-sm); }
.color-swatch:hover { transform: scale(1.15); }
.color-palette p { color: var(--text-tertiary); font-size: 0.85rem; margin-top: 5px; }

/* Sidebar Card */
.sidebar-card { background: var(--bg-card); padding: 20px; border-radius: var(--radius); margin-bottom: 20px; border: 1px solid var(--border-color); transition: background-color 0.3s ease, border-color 0.3s ease; }
.sidebar-card h3 { margin-bottom: 12px; color: var(--text-primary); }
.sidebar-card ul { list-style: none; }
.sidebar-card ul li { margin-bottom: 8px; }
.sidebar-card ul li a { color: var(--text-secondary); text-decoration: none; transition: var(--transition); display: flex; align-items: center; gap: 6px; }
.sidebar-card ul li a:hover { color: var(--color-co2); text-decoration: none; }

/* FAQ Accordion */
.faq-list { max-width: 800px; }
.faq-item { margin-bottom: 12px; border: 1px solid var(--border-color); border-radius: var(--radius); overflow: hidden; transition: border-color 0.3s ease; background: var(--bg-card); }
.faq-item:hover { border-color: var(--color-co2); }
.faq-question { display: flex; justify-content: space-between; align-items: center; width: 100%; padding: 16px 20px; background: none; border: none; cursor: pointer; text-align: left; color: var(--text-primary); font-size: 1rem; font-weight: 500; transition: background-color 0.3s ease; font-family: inherit; }
.faq-question:hover { background: var(--bg-light); }
.faq-icon { font-size: 1.3rem; color: var(--color-co2); font-weight: 300; transition: transform 0.3s ease; flex-shrink: 0; margin-left: 10px; }
.faq-item.open .faq-icon { transform: rotate(45deg); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease, padding 0.3s ease; padding: 0 20px; color: var(--text-secondary); line-height: 1.7; }
.faq-answer.open { max-height: 500px; padding: 0 20px 16px; }
.faq-answer ol { padding-left: 20px; margin: 10px 0; }
.faq-answer li { margin-bottom: 6px; }
.faq-answer a { color: var(--color-co2); }

/* Footer */
.footer { background: var(--bg-dark); color: white; padding: 60px 0 30px; transition: background-color 0.3s ease; }
.footer-content { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; margin-bottom: 40px; }
.footer-section h4 { color: white; margin-bottom: 15px; font-size: 1.1rem; }
.footer-section a { color: #b2bec3; text-decoration: none; transition: color 0.3s ease; }
.footer-section a:hover { color: white; }
.footer-section ul { list-style: none; }
.footer-section ul li { margin-bottom: 6px; }
.footer-bottom { text-align: center; padding-top: 30px; border-top: 1px solid #636E72; color: #b2bec3; font-size: 0.9rem; }

/* Scroll to top */
.scroll-top { position: fixed; bottom: 30px; right: 30px; width: 44px; height: 44px; border-radius: 50%; background: var(--color-co2); color: white; border: none; font-size: 1.2rem; cursor: pointer; box-shadow: var(--shadow-md); transition: var(--transition); z-index: 999; opacity: 0; visibility: hidden; }
.scroll-top.visible { opacity: 1; visibility: visible; }
.scroll-top:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); background: var(--color-temp); }

/* Responsive */
@media (max-width: 768px) {
    .mobile-menu-btn { display: block; }
    .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background: var(--bg-white); flex-direction: column; padding: 20px; box-shadow: var(--shadow-md); z-index: 999; border-bottom: 1px solid var(--border-color); transform-origin: top; animation: slideDown 0.3s ease; }
    .nav-links:not(.active) { display: none; }
    .nav-links.active { display: flex; }
    @keyframes slideDown { from { opacity: 0; transform: scaleY(0.95); } to { opacity: 1; transform: scaleY(1); } }
    .hero-content { grid-template-columns: 1fr; text-align: center; padding: 40px 20px; }
    .hero-title { font-size: 3rem; }
    .hero-buttons { justify-content: center; }
    .download-grid { grid-template-columns: 1fr; }
    .download-card.main, .download-card.qr-card, .download-card.guide-card { grid-column: auto; }
    .content-grid { grid-template-columns: 1fr; }
    h1 { font-size: 2.2rem; }
    h2 { font-size: 1.8rem; }
    .timeline { padding-left: 25px; }
    .timeline-marker { left: -21px; }
}
@media (max-width: 480px) {
    .hero-title { font-size: 2.5rem; }
    .hero-subtitle { font-size: 1.2rem; }
    .nav-container { padding: 12px 15px; }
}