/* === CSS Variables & Theme === */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --gradient-start: #2563eb;
    --gradient-end: #7c3aed;
    --card-bg: #ffffff;
    --card-shadow: 0 10px 25px -5px rgba(0,0,0,0.05), 0 8px 10px -6px rgba(0,0,0,0.02);
    --border-color: #e2e8f0;
    --header-bg: rgba(255,255,255,0.85);
    --footer-bg: #0f172a;
    --footer-text: #cbd5e1;
    --input-bg: #fff;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --bg-primary: #0b1120;
    --bg-secondary: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --card-bg: #1e293b;
    --card-shadow: 0 10px 25px -5px rgba(0,0,0,0.3);
    --border-color: #334155;
    --header-bg: rgba(11,17,32,0.9);
    --footer-bg: #020617;
    --input-bg: #1e293b;
}

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

html { scroll-behavior: smooth; }
body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background var(--transition), color var(--transition);
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.container.narrow { max-width: 800px; }

.skip-link {
    position: absolute; top: -100%; left: 0; background: var(--accent); color: #fff; padding: 0.5rem 1rem; z-index: 1000;
}
.skip-link:focus { top: 0; }

/* Typography */
h1, h2, h3 { line-height: 1.2; }
.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.75rem 1.75rem; border-radius: 50px;
    font-weight: 600; text-decoration: none; transition: all var(--transition); border: 2px solid transparent; cursor: pointer;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-2px); box-shadow: 0 10px 20px -10px var(--accent); }
.btn-outline { border-color: var(--text-primary); color: var(--text-primary); background: transparent; }
.btn-outline:hover { background: var(--text-primary); color: var(--bg-primary); }
.btn-white { background: #fff; color: #0f172a; }
.btn-white:hover { background: #f1f5f9; }
.btn-outline-white { border-color: rgba(255,255,255,0.5); color: #fff; }
.btn-outline-white:hover { background: #fff; color: #0f172a; }
.btn-lg { padding: 0.9rem 2.2rem; font-size: 1.05rem; }

/* Header & Navigation */
.site-header {
    position: sticky; top: 0; z-index: 100; background: var(--header-bg); backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color); transition: background var(--transition);
}
.navbar { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.logo-link { text-decoration: none; }
.logo { display: flex; align-items: center; gap: 0.5rem; }
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-name { font-weight: 700; font-size: 1.25rem; color: var(--text-primary); }
.logo-sub { font-size: 0.7rem; color: var(--text-secondary); letter-spacing: 0.05em; text-transform: uppercase; }
.nav-links { display: flex; gap: 1.5rem; list-style: none; }
.nav-link { text-decoration: none; color: var(--text-secondary); font-weight: 500; transition: color 0.2s; position: relative; }
.nav-link:hover, .nav-link.active { color: var(--accent); }
.nav-link.active::after { content: ''; position: absolute; bottom: -6px; left: 0; right: 0; height: 2px; background: var(--accent); border-radius: 2px; }
.mobile-menu-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 0.5rem; }
.hamburger-line { width: 24px; height: 2px; background: var(--text-primary); transition: all 0.3s; }
.theme-toggle { background: none; border: 1px solid var(--border-color); border-radius: 50%; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; cursor: pointer; color: var(--text-primary); }
[data-theme="light"] .moon-icon { display: none; }
[data-theme="dark"] .sun-icon { display: none; }

/* Hero */
.hero { position: relative; overflow: hidden; padding: 5rem 0; background: var(--bg-secondary); }
.hero-bg-shapes .shape { position: absolute; border-radius: 50%; opacity: 0.15; filter: blur(60px); }
.shape-1 { width: 400px; height: 400px; background: var(--accent); top: -100px; right: -100px; }
.shape-2 { width: 300px; height: 300px; background: var(--gradient-end); bottom: -50px; left: -50px; }
.shape-3 { width: 200px; height: 200px; background: var(--accent); top: 40%; left: 10%; }
.hero-content { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: center; }
.hero-badge { display: inline-block; background: rgba(37,99,235,0.1); color: var(--accent); padding: 0.3rem 1rem; border-radius: 50px; font-size: 0.9rem; font-weight: 500; margin-bottom: 1.5rem; }
.hero-title { font-size: clamp(2.2rem, 5vw, 3.5rem); margin-bottom: 1.5rem; }
.hero-description { font-size: 1.1rem; color: var(--text-secondary); margin-bottom: 2rem; max-width: 500px; }
.hero-cta { display: flex; gap: 1rem; flex-wrap: wrap; margin-bottom: 2.5rem; }
.hero-stats { display: flex; gap: 2rem; }
.stat-item { display: flex; flex-direction: column; }
.stat-number { font-size: 1.5rem; font-weight: 700; color: var(--accent); }
.stat-label { font-size: 0.85rem; color: var(--text-secondary); }
.hero-visual { display: flex; justify-content: center; }
.hero-phone-mockup { width: 260px; height: 520px; background: #111; border-radius: 40px; padding: 12px; box-shadow: 0 20px 50px rgba(0,0,0,0.3); }
.mockup-screen { background: #fff; height: 100%; border-radius: 30px; padding: 20px; display: flex; flex-direction: column; }
.mockup-status-bar { height: 20px; background: #e2e8f0; border-radius: 10px; margin-bottom: 20px; }
.mockup-app-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 12px; }
.mockup-app-icon { width: 100%; aspect-ratio: 1; border-radius: 16px; }

/* Sections */
.section { padding: 5rem 0; }
.section-header { text-align: center; margin-bottom: 3rem; }
.section-badge { display: inline-block; background: rgba(37,99,235,0.1); color: var(--accent); padding: 0.25rem 1rem; border-radius: 50px; font-size: 0.85rem; font-weight: 600; margin-bottom: 0.8rem; }
.section-title { font-size: 2.2rem; margin-bottom: 0.75rem; }
.section-description { color: var(--text-secondary); max-width: 600px; margin: 0 auto; }

/* App Cards */
.apps-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.5rem; }
.app-card {
    background: var(--card-bg); border: 1px solid var(--border-color); border-radius: 20px; padding: 1.8rem;
    transition: transform 0.3s, box-shadow 0.3s; display: flex; flex-direction: column; gap: 0.8rem;
}
.app-card:hover { transform: translateY(-6px); box-shadow: 0 20px 30px -15px rgba(0,0,0,0.1); }
.app-icon { width: 60px; height: 60px; border-radius: 16px; background: var(--accent); display: flex; align-items: center; justify-content: center; color: #fff; font-size: 1.5rem; }
.app-name { font-size: 1.25rem; font-weight: 700; }
.app-category { font-size: 0.8rem; color: var(--accent); background: rgba(37,99,235,0.1); padding: 0.2rem 0.8rem; border-radius: 50px; align-self: flex-start; }
.app-desc { color: var(--text-secondary); font-size: 0.9rem; flex: 1; }
.app-rating { display: flex; align-items: center; gap: 0.25rem; color: #f59e0b; font-weight: 600; }
.app-card .btn { align-self: flex-start; margin-top: 0.5rem; }

/* Achievements */
.achievements-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px,1fr)); gap: 1.5rem; }
.achievement-card { background: var(--card-bg); border-radius: 20px; padding: 2rem; text-align: center; border: 1px solid var(--border-color); transition: transform 0.3s; }
.achievement-card:hover { transform: translateY(-5px); }
.achievement-icon-wrapper { width: 70px; height: 70px; border-radius: 20px; background: rgba(37,99,235,0.1); display: flex; align-items: center; justify-content: center; margin: 0 auto 1rem; color: var(--accent); }
.achievement-title { font-size: 1.8rem; font-weight: 700; margin-bottom: 0.25rem; }
.achievement-desc { color: var(--text-secondary); }

/* CTA Section */
.cta-section { background: var(--bg-secondary); }
.cta-card { background: linear-gradient(135deg, #2563eb, #4f46e5); border-radius: 30px; padding: 3.5rem 2rem; text-align: center; color: #fff; }
.cta-title { font-size: 2.2rem; margin-bottom: 1rem; }
.cta-description { opacity: 0.9; margin-bottom: 2rem; max-width: 600px; margin-left: auto; margin-right: auto; }
.cta-buttons { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* Page Hero (inner pages) */
.page-hero { padding: 4rem 0 2rem; text-align: center; background: var(--bg-secondary); }
.page-title { font-size: 2.8rem; }
.page-subtitle { color: var(--text-secondary); font-size: 1.1rem; margin-top: 0.5rem; }

/* Filter Bar */
.filter-bar { display: flex; justify-content: center; gap: 0.5rem; margin: 2rem 0; flex-wrap: wrap; }
.filter-btn { padding: 0.5rem 1.5rem; border-radius: 50px; border: 1px solid var(--border-color); background: var(--card-bg); color: var(--text-secondary); cursor: pointer; transition: all 0.2s; font-weight: 500; }
.filter-btn.active, .filter-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }

/* App Detail */
.app-detail { display: grid; grid-template-columns: 300px 1fr; gap: 3rem; align-items: start; }
.app-detail-header { display: flex; align-items: center; gap: 1rem; margin-bottom: 1.5rem; }
.detail-icon { width: 80px; height: 80px; border-radius: 22px; }
.detail-info h1 { font-size: 2rem; }
.screenshots-slider { display: flex; gap: 1rem; overflow-x: auto; padding: 1rem 0; }
.screenshot-thumb { min-width: 200px; height: 350px; background: var(--bg-secondary); border-radius: 16px; display: flex; align-items: center; justify-content: center; color: var(--text-secondary); border: 1px solid var(--border-color); }
.feature-list { list-style: none; display: grid; gap: 0.5rem; }
.feature-list li::before { content: "✓"; color: var(--accent); margin-right: 0.5rem; font-weight: bold; }

/* About / Privacy content */
.about-block, .privacy-text { margin-bottom: 2.5rem; }
.about-block h2, .privacy-text h2 { margin-bottom: 0.8rem; font-size: 1.8rem; }
.approach-list { list-style: none; padding-left: 0; }
.approach-list li { margin-bottom: 0.6rem; }

/* Contact Cards */
.contact-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px,1fr)); gap: 1.5rem; margin-bottom: 2.5rem; }
.contact-card { background: var(--card-bg); border-radius: 20px; padding: 2rem; text-align: center; border: 1px solid var(--border-color); }
.contact-card svg { color: var(--accent); margin-bottom: 1rem; }
.contact-card a { color: var(--accent); text-decoration: none; font-weight: 600; }
.social-connect { text-align: center; }
.social-links-large { display: flex; justify-content: center; gap: 1rem; margin-top: 1rem; flex-wrap: wrap; }
.social-btn { background: var(--bg-secondary); padding: 0.6rem 1.8rem; border-radius: 50px; text-decoration: none; color: var(--text-primary); font-weight: 500; transition: background 0.2s; border: 1px solid var(--border-color); }
.social-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }

/* Footer */
.site-footer { background: var(--footer-bg); color: var(--footer-text); padding: 4rem 0 2rem; margin-top: 3rem; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 2rem; }
.footer-desc { margin-top: 0.8rem; font-size: 0.9rem; }
.footer-heading { font-size: 1rem; font-weight: 600; margin-bottom: 1rem; color: #fff; }
.footer-links { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.footer-links a { color: var(--footer-text); text-decoration: none; font-size: 0.9rem; transition: color 0.2s; }
.footer-links a:hover { color: #fff; }
.social-links { display: flex; gap: 1rem; }
.social-link { color: var(--footer-text); transition: color 0.2s; }
.social-link:hover { color: #fff; }
.footer-email { display: flex; align-items: center; gap: 0.5rem; font-size: 0.85rem; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); margin-top: 2.5rem; padding-top: 1.5rem; text-align: center; font-size: 0.85rem; }

/* Back to Top */
.back-to-top { position: fixed; bottom: 2rem; right: 2rem; background: var(--accent); color: #fff; width: 45px; height: 45px; border-radius: 50%; border: none; cursor: pointer; opacity: 0; visibility: hidden; transition: all 0.3s; display: flex; align-items: center; justify-content: center; z-index: 99; box-shadow: 0 5px 15px rgba(0,0,0,0.2); }
.back-to-top.visible { opacity: 1; visibility: visible; }

/* Animations */
.animate-fade-up { opacity: 0; transform: translateY(30px); animation: fadeUp 0.8s forwards; }
.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }
.delay-400 { animation-delay: 0.4s; }
@keyframes fadeUp { to { opacity: 1; transform: translateY(0); } }

/* Responsive */
@media (max-width: 768px) {
    .hero-content { grid-template-columns: 1fr; }
    .hero-phone-mockup { display: none; }
    .mobile-menu-toggle { display: flex; }
    .nav-links { position: fixed; top: 70px; left: 0; right: 0; background: var(--header-bg); flex-direction: column; padding: 2rem; gap: 1.5rem; transform: translateX(100%); transition: transform 0.3s; backdrop-filter: blur(12px); }
    .nav-links.active { transform: translateX(0); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .app-detail { grid-template-columns: 1fr; }
}