:root, [data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --bg-hover: #f1f3f5;
    --text-primary: #1a1a2e;
    --text-secondary: #495057;
    --text-muted: #868e96;
    --border-color: #dee2e6;
    --accent: #16a34a;
    --accent-hover: #15803d;
    --accent-light: #dcfce7;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: 0.2s ease;
}
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-hover: #253348;
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #334155;
    --accent: #22c55e;
    --accent-hover: #16a34a;
    --accent-light: #14532d;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary); color: var(--text-primary);
    line-height: 1.6; min-height: 100vh;
    transition: background var(--transition), color var(--transition);
}
.landing-nav {
    position: sticky; top: 0; z-index: 100;
    background: rgba(255,255,255,0.85); backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}
[data-theme="dark"] .landing-nav { background: rgba(15,23,42,0.85); }
.nav-inner {
    max-width: 1200px; margin: 0 auto; padding: 1rem 1.5rem;
    display: flex; align-items: center; justify-content: space-between;
}
.nav-inner .logo {
    display: flex; align-items: center; gap: 0.5rem;
    font-size: 1.25rem; font-weight: 700; color: var(--text-primary);
    text-decoration: none;
}
.nav-inner .logo-text { color: var(--accent); }
.nav-links { display: flex; align-items: center; gap: 1.5rem; }
.nav-links a {
    color: var(--text-secondary); text-decoration: none; font-size: 0.9rem;
    transition: color var(--transition);
}
.nav-links a:hover { color: var(--accent); }
.btn-cta {
    padding: 0.5rem 1.25rem; background: var(--accent); color: white;
    border-radius: var(--radius-sm); text-decoration: none; font-weight: 600;
    font-size: 0.875rem; transition: all var(--transition);
}
.btn-cta:hover { background: var(--accent-hover); transform: translateY(-1px); }
.btn-cta-primary { background: var(--accent); color: white; padding: 0.75rem 1.75rem; font-size: 1rem; }
.btn-cta-secondary { background: transparent; color: var(--text-primary); border: 1px solid var(--border-color); }

.hero {
    text-align: center; padding: 5rem 1.5rem 3rem;
    max-width: 900px; margin: 0 auto;
}
.hero h1 {
    font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 800;
    line-height: 1.1; margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--text-primary), var(--accent));
    -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub { font-size: 1.125rem; color: var(--text-secondary); margin-bottom: 2rem; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero-cta { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

.features-section, .how-section, .cleaning-section, .privacy-section, .cta-section {
    padding: 4rem 1.5rem; max-width: 1200px; margin: 0 auto;
}
.features-section h2, .how-section h2, .cleaning-section h2,
.privacy-section h2, .cta-section h2 {
    font-size: 2rem; font-weight: 700; text-align: center;
    margin-bottom: 2.5rem;
}
.features-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}
.feature-card {
    padding: 2rem; background: var(--bg-secondary);
    border: 1px solid var(--border-color); border-radius: var(--radius-lg);
    transition: all var(--transition);
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--accent); }
.feature-icon { font-size: 2.5rem; margin-bottom: 1rem; }
.feature-card h3 { font-size: 1.125rem; margin-bottom: 0.5rem; }
.feature-card p { color: var(--text-secondary); font-size: 0.9rem; }

.steps-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2rem;
}
.step-card { text-align: center; }
.step-number {
    width: 56px; height: 56px; margin: 0 auto 1rem;
    display: flex; align-items: center; justify-content: center;
    background: var(--accent); color: white; border-radius: 50%;
    font-size: 1.5rem; font-weight: 700;
}
.step-card h3 { font-size: 1.125rem; margin-bottom: 0.5rem; }
.step-card p { color: var(--text-secondary); font-size: 0.9rem; }

.cleaning-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
}
.cleaning-item {
    display: flex; align-items: center; gap: 0.75rem;
    padding: 0.75rem 1rem; background: var(--bg-secondary);
    border-radius: var(--radius-md); border: 1px solid var(--border-color);
    font-size: 0.9rem;
}
.clean-icon { font-size: 1.25rem; }

.privacy-section { background: var(--bg-secondary); max-width: 100%; text-align: center; padding: 4rem 1.5rem; }
.privacy-section h2 { margin-bottom: 1rem; }
.privacy-section p { max-width: 700px; margin: 0 auto 1rem; color: var(--text-secondary); }
.privacy-section a { color: var(--accent); text-decoration: none; font-weight: 600; }
.privacy-note { font-size: 0.875rem; }

.cta-section { text-align: center; padding: 5rem 1.5rem; }

.landing-footer {
    background: var(--bg-secondary); padding: 2rem 1.5rem;
    border-top: 1px solid var(--border-color);
}
.landing-footer-inner {
    max-width: 1200px; margin: 0 auto;
    display: flex; align-items: center; justify-content: space-between; gap: 1rem;
    flex-wrap: wrap;
}
.footer-brand { font-weight: 600; }
.footer-links { display: flex; gap: 1.5rem; }
.footer-links a { color: var(--text-secondary); text-decoration: none; font-size: 0.875rem; }
.footer-links a:hover { color: var(--accent); }
.footer-copy { color: var(--text-muted); font-size: 0.8125rem; }

@media (max-width: 768px) {
    .nav-links { gap: 1rem; }
    .nav-links a:not(.btn-cta) { display: none; }
    .features-section h2, .how-section h2, .cleaning-section h2 { font-size: 1.5rem; }
}
.hero-brand { color: var(--text-muted); font-size: 0.875rem; margin-top: 1rem; }
.hero-brand strong { color: var(--accent); font-weight: 600; }