/* ============================================
   WaterBudget - Landing Page Stylesheet
   Pure CSS, no frameworks. Loads in <200ms.
   ============================================ */

:root {
    --color-primary: #2563EB;
    --color-primary-dark: #1D4ED8;
    --color-primary-light: #DBEAFE;
    --color-accent: #7C3AED;
    --color-gray-50: #F8FAFC;
    --color-gray-100: #F1F5F9;
    --color-gray-200: #E2E8F0;
    --color-gray-300: #CBD5E1;
    --color-gray-400: #94A3B8;
    --color-gray-500: #64748B;
    --color-gray-600: #475569;
    --color-gray-700: #334155;
    --color-gray-800: #1E293B;
    --color-gray-900: #0F172A;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body { font-family: var(--font-sans); color: var(--color-gray-800); line-height: 1.6; background: #fff; }
a { text-decoration: none; color: inherit; }
img, svg { display: block; max-width: 100%; }

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

/* --- Navigation --- */
.nav { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: rgba(255,255,255,0.9); backdrop-filter: blur(12px); border-bottom: 1px solid var(--color-gray-200); }
.nav-container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; display: flex; align-items: center; justify-content: space-between; height: 64px; }
.nav-logo { display: flex; align-items: center; gap: 0.5rem; font-weight: 700; font-size: 1.125rem; color: var(--color-gray-900); }
.nav-links { display: flex; align-items: center; gap: 1.5rem; }
.nav-links a { font-size: 0.875rem; font-weight: 500; color: var(--color-gray-600); transition: color 0.15s; }
.nav-links a:hover { color: var(--color-gray-900); }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 4px; padding: 4px; }
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--color-gray-700); border-radius: 1px; }

/* --- Buttons --- */
.btn { display: inline-flex; align-items: center; gap: 0.375rem; padding: 0.5rem 1rem; border-radius: var(--radius-sm); font-size: 0.875rem; font-weight: 500; cursor: pointer; border: 1px solid transparent; transition: all 0.15s; }
.btn-primary { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-outline { background: #fff; color: var(--color-gray-700); border-color: var(--color-gray-300); }
.btn-outline:hover { background: var(--color-gray-50); border-color: var(--color-gray-400); }
.btn-ghost { background: transparent; color: var(--color-gray-600); }
.btn-ghost:hover { background: var(--color-gray-100); }
.btn-lg { padding: 0.75rem 1.5rem; font-size: 1rem; border-radius: var(--radius-md); }

/* --- Hero --- */
.hero { position: relative; min-height: 100vh; display: flex; align-items: center; padding-top: 64px; overflow: hidden; }
.hero-bg { position: absolute; inset: 0; z-index: 0; }
.hero-circle { position: absolute; border-radius: 50%; filter: blur(80px); opacity: 0.15; }
.hero-circle-1 { width: 600px; height: 600px; background: var(--color-primary); top: -200px; right: -100px; }
.hero-circle-2 { width: 400px; height: 400px; background: var(--color-accent); bottom: -100px; left: -50px; }
.hero-circle-3 { width: 300px; height: 300px; background: #06B6D4; top: 50%; left: 50%; transform: translate(-50%, -50%); }
.hero-content { position: relative; z-index: 1; display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: center; padding-top: 3rem; padding-bottom: 3rem; }
.hero-text { max-width: 560px; }
.hero-badge { display: inline-block; padding: 0.25rem 0.75rem; background: var(--color-primary-light); color: var(--color-primary); font-size: 0.75rem; font-weight: 600; border-radius: 99px; margin-bottom: 1.5rem; text-transform: uppercase; letter-spacing: 0.05em; }
.hero h1 { font-size: 3.5rem; font-weight: 800; line-height: 1.1; color: var(--color-gray-900); margin-bottom: 1.5rem; }
.text-gradient { background: linear-gradient(135deg, var(--color-primary), var(--color-accent)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-subtitle { font-size: 1.125rem; color: var(--color-gray-600); line-height: 1.7; margin-bottom: 2rem; }
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 2.5rem; margin-top: 2.5rem; padding-top: 2rem; border-top: 1px solid var(--color-gray-200); }
.hero-stat-number { display: block; font-size: 1.5rem; font-weight: 700; color: var(--color-gray-900); }
.hero-stat-label { display: block; font-size: 0.75rem; color: var(--color-gray-500); font-weight: 500; }

/* --- Hero Visual / Demo Card --- */
.hero-visual { position: relative; }
.hero-card {
    background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-xl);
    padding: 1.5rem; border: 1px solid var(--color-gray-200);
}
.demo-chart-canvas-wrap { position: relative; width: 100%; height: 220px; }
.demo-chart-canvas-wrap canvas { position: absolute; top: 0; left: 0; width: 100% !important; height: 100% !important; }
.demo-chart-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.demo-chart-title { font-weight: 600; font-size: 0.9375rem; color: var(--color-gray-800); }
.demo-chart-badge { padding: 0.125rem 0.5rem; background: var(--color-primary-light); color: var(--color-primary); font-size: 0.6875rem; font-weight: 600; border-radius: 99px; }
.demo-chart-footer { display: flex; gap: 1.5rem; margin-top: 1rem; padding-top: 1rem; border-top: 1px solid var(--color-gray-100); }
.demo-metric-label { display: block; font-size: 0.6875rem; color: var(--color-gray-500); font-weight: 500; text-transform: uppercase; letter-spacing: 0.05em; }
.demo-metric-value { display: block; font-size: 0.9375rem; font-weight: 600; color: var(--color-gray-800); }

/* --- Features --- */
.features { padding: 6rem 0; background: var(--color-gray-50); }
.section-header { text-align: center; max-width: 640px; margin: 0 auto 3rem; }
.section-badge { display: inline-block; padding: 0.25rem 0.75rem; background: var(--color-primary-light); color: var(--color-primary); font-size: 0.75rem; font-weight: 600; border-radius: 99px; margin-bottom: 1rem; text-transform: uppercase; letter-spacing: 0.05em; }
.section-header h2 { font-size: 2rem; font-weight: 700; margin-bottom: 0.75rem; }
.section-header p { color: var(--color-gray-500); font-size: 1.0625rem; }
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.feature-card { background: #fff; border: 1px solid var(--color-gray-200); border-radius: var(--radius-md); padding: 1.75rem; transition: box-shadow 0.2s, transform 0.2s; }
.feature-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); }
.feature-icon { width: 44px; height: 44px; border-radius: var(--radius-sm); background: var(--color-primary-light); color: var(--color-primary); display: flex; align-items: center; justify-content: center; margin-bottom: 1rem; }
.feature-card h3 { font-size: 1.0625rem; margin-bottom: 0.5rem; }
.feature-card p { font-size: 0.875rem; color: var(--color-gray-500); line-height: 1.6; }

/* --- How It Works --- */
.how-it-works { padding: 6rem 0; }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; }
.step { text-align: center; }
.step-number { width: 48px; height: 48px; border-radius: 50%; background: var(--color-primary); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 1.25rem; font-weight: 700; margin: 0 auto 1rem; }
.step-content h3 { font-size: 1.0625rem; margin-bottom: 0.5rem; }
.step-content p { font-size: 0.875rem; color: var(--color-gray-500); line-height: 1.6; }

/* --- CTA --- */
.cta { padding: 6rem 0; background: linear-gradient(135deg, #1E3A5F 0%, #2563EB 100%); color: #fff; }
.cta-content { text-align: center; max-width: 600px; margin: 0 auto; }
.cta-content h2 { font-size: 2rem; color: #fff; margin-bottom: 0.75rem; }
.cta-content p { opacity: 0.85; font-size: 1.0625rem; margin-bottom: 2rem; }
.cta .btn-primary { background: #fff; color: var(--color-primary); border-color: #fff; font-size: 1rem; padding: 0.75rem 2rem; }
.cta .btn-primary:hover { background: var(--color-gray-100); }

/* --- Footer --- */
.footer { padding: 3rem 0 1.5rem; border-top: 1px solid var(--color-gray-200); }
.footer-content { display: flex; justify-content: space-between; margin-bottom: 2rem; }
.footer-brand p { color: var(--color-gray-500); font-size: 0.875rem; margin-top: 0.5rem; }
.footer-links { display: flex; gap: 4rem; }
.footer-col h4 { font-size: 0.8125rem; font-weight: 600; color: var(--color-gray-900); margin-bottom: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; }
.footer-col a { display: block; font-size: 0.875rem; color: var(--color-gray-500); margin-bottom: 0.5rem; }
.footer-col a:hover { color: var(--color-gray-800); }
.footer-bottom { padding-top: 1.5rem; border-top: 1px solid var(--color-gray-200); text-align: center; font-size: 0.8125rem; color: var(--color-gray-400); }

/* --- Responsive --- */
@media (max-width: 1024px) {
    .hero-content { grid-template-columns: 1fr; gap: 2rem; }
    .hero-visual { max-width: 500px; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .hero h1 { font-size: 2.5rem; }
    .hero-stats { gap: 1.5rem; }
    .nav-links { display: none; }
    .nav-toggle { display: flex; }
    .features-grid { grid-template-columns: 1fr; }
    .steps { grid-template-columns: 1fr; }
    .footer-content { flex-direction: column; gap: 2rem; }
    .footer-links { gap: 2rem; }
}

@media (max-width: 480px) {
    .hero h1 { font-size: 2rem; }
    .hero-actions { flex-direction: column; }
    .hero-stats { flex-direction: column; gap: 1rem; }
}