:root {
    --primary: #0f1b2d;
    --accent: #f59e0b;
    --success: #16a34a;
    --danger: #dc2626;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --font-heading: 'DM Serif Display', serif;
    --font-body: 'Inter', sans-serif;
}

body.dark-mode {
    --bg: #0f1b2d;
    --card-bg: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #cbd5e1;
    --border: #334155;
    --primary: #f8fafc;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font-body); background: var(--bg); color: var(--text-main); line-height: 1.6; font-size: 16px; transition: background 0.3s, color 0.3s; }
.container { max-width: 1000px; margin: 0 auto; padding: 0 20px; }
h1, h2, h3 { font-family: var(--font-heading); color: var(--primary); }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header { background: var(--card-bg); padding: 15px 0; border-bottom: 1px solid var(--border); }
.header-container { display: flex; justify-content: space-between; align-items: center; }
.logo a { font-family: var(--font-heading); font-size: 1.5rem; color: var(--primary); font-weight: normal; text-decoration: none; }
.main-nav ul { list-style: none; display: flex; gap: 20px; align-items: center; }
.theme-toggle { background: none; border: none; font-size: 1.2rem; cursor: pointer; }

main { padding: 40px 0; min-height: 70vh; }
.hero-section { text-align: center; margin-bottom: 40px; padding: 40px 20px; background: linear-gradient(135deg, var(--card-bg), var(--bg)); border-radius: 12px; border: 1px solid var(--border); }
.hero-section h1 { font-size: 2.5rem; margin-bottom: 15px; }

.calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
@media (max-width: 768px) {
    .calc-grid { grid-template-columns: 1fr; }
}

.calc-panel, .results-panel { background: var(--card-bg); padding: 25px; border-radius: 12px; border: 1px solid var(--border); box-shadow: 0 4px 6px rgba(0,0,0,0.05); }
.form-group { margin-bottom: 15px; }
.form-group label { display: block; font-weight: 500; margin-bottom: 5px; }
.form-control { width: 100%; padding: 10px; border: 1px solid var(--border); border-radius: 6px; font-family: var(--font-body); background: var(--bg); color: var(--text-main); }
.toggle-group { display: flex; align-items: center; justify-content: space-between; padding: 10px 0; border-bottom: 1px solid var(--border); }

.hero-number-box { text-align: center; background: var(--danger); color: white; padding: 20px; border-radius: 8px; margin-bottom: 20px; }
.hero-number-box h2 { color: white; font-size: 2.5rem; font-family: var(--font-body); margin: 5px 0; }
.hero-number-box p { margin: 0; opacity: 0.9; }
.btn { display: inline-block; padding: 12px 24px; border-radius: 6px; font-weight: 600; cursor: pointer; text-align: center; transition: opacity 0.2s; border: none; font-family: var(--font-body); text-decoration: none; }
.btn-primary { background: var(--accent); color: white; }
.btn-block { display: block; width: 100%; }
.btn-primary:hover { opacity: 0.9; text-decoration: none; }

.breakdown-table { width: 100%; border-collapse: collapse; margin-top: 20px; }
.breakdown-table th, .breakdown-table td { padding: 12px; border-bottom: 1px solid var(--border); text-align: left; }
.chart-container { position: relative; height: 300px; margin-top: 20px; }

.ad-zone { background: var(--border); min-height: 90px; margin: 20px 0; display: none; /* change to display: flex; to show ads */ align-items: center; justify-content: center; color: var(--text-muted); font-size: 0.8rem; border-radius: 6px; }
.mobile-sticky-cta { position: fixed; bottom: 0; left: 0; width: 100%; padding: 10px; background: var(--card-bg); box-shadow: 0 -2px 10px rgba(0,0,0,0.1); display: none; z-index: 100; }
@media (max-width: 768px) { .mobile-sticky-cta { display: block; } }

.site-footer { background: var(--card-bg); padding: 40px 0; margin-top: 60px; border-top: 1px solid var(--border); }
.footer-container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 20px; }
.footer-col p { margin-bottom: 10px; font-size: 0.9rem; }
.disclaimer-text { font-size: 0.8rem; color: var(--text-muted); max-width: 500px; }
.content-box { background: var(--card-bg); padding: 40px; border-radius: 12px; border: 1px solid var(--border); margin-bottom: 30px; box-shadow: 0 4px 6px rgba(0,0,0,0.05); }
.content-box h1 { margin-bottom: 20px; }
.content-box h2 { margin-top: 30px; margin-bottom: 15px; }
.content-box p { margin-bottom: 15px; line-height: 1.8; }
.content-box ul { margin-left: 20px; margin-bottom: 15px; }
.content-box li { margin-bottom: 8px; }