@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;700&display=swap');

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

:root {
    --bg: #0f0f13;
    --card: #1a1a2e;
    --card-hover: #22223a;
    --border: rgba(255,255,255,0.06);
    --text: #e4e4e7;
    --text-muted: #a1a1aa;
    --accent-1: #22d3ee;
    --accent-2: #06b6d4;
    --accent-3: #0891b2;
    --gradient: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    --radius: 1rem;
    --radius-sm: 0.75rem;
}

body {
    font-family: 'Inter', system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.container { max-width: 900px; margin: 0 auto; padding: 0 1.25rem; }

/* Header */
.site-header {
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    background: rgba(15,15,19,0.9);
    backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 100;
}
.site-header .container { display: flex; justify-content: space-between; align-items: center; }
.logo { display: flex; align-items: center; gap: 0.6rem; text-decoration: none; color: var(--text); font-weight: 800; font-size: 1.2rem; }
.logo-icon {
    font-size: 1.4rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.site-header nav { display: flex; gap: 1.25rem; }
.site-header nav a { color: var(--text-muted); text-decoration: none; font-size: 0.9rem; font-weight: 500; transition: color 0.2s; }
.site-header nav a:hover { color: var(--accent-1); }

/* Hero */
.hero { text-align: center; padding: 3.5rem 0 2rem; }
.hero h1 { font-size: 2.5rem; font-weight: 800; margin-bottom: 0.75rem; background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero p { color: var(--text-muted); font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

/* Ad slots */
.ad-slot { background: var(--card); border: 1px dashed var(--border); border-radius: var(--radius-sm); min-height: 90px; display: flex; align-items: center; justify-content: center; color: var(--text-muted); font-size: 0.8rem; margin: 1.5rem 0; }

/* Cards */
.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 1.5rem;
    transition: border-color 0.3s;
}
.card:hover { border-color: rgba(34,211,238,0.15); }

/* Input group */
.input-group { margin-bottom: 1.25rem; }
.input-group label {
    display: block;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
    color: var(--text-muted);
}
.input-group input {
    width: 100%;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    color: var(--text);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    transition: border-color 0.3s;
}
.input-group input:focus {
    outline: none;
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(6,182,212,0.15);
}

.input-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }

/* Calculate button */
.btn-calculate {
    width: 100%;
    padding: 0.85rem;
    background: var(--gradient);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.1s;
    margin-top: 0.5rem;
}
.btn-calculate:hover { opacity: 0.9; }
.btn-calculate:active { transform: scale(0.98); }

/* Results */
.results-section { display: none; }
.results-section.show { display: block; }

/* Primary age display */
.age-display {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.age-box {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1.25rem;
    text-align: center;
}
.age-box .value {
    font-size: 2.5rem;
    font-weight: 800;
    font-family: 'JetBrains Mono', monospace;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}
.age-box .label { font-size: 0.85rem; color: var(--text-muted); margin-top: 0.25rem; }

/* Stats grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}
.stat-item {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.stat-item .stat-label { font-size: 0.85rem; color: var(--text-muted); }
.stat-item .stat-value {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--accent-1);
}

/* Info cards */
.info-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.info-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1.25rem;
    text-align: center;
}
.info-card .info-icon { font-size: 2rem; margin-bottom: 0.5rem; }
.info-card .info-title { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 0.25rem; }
.info-card .info-value { font-weight: 700; font-size: 1rem; }

/* Birthday countdown */
.birthday-card {
    background: linear-gradient(135deg, rgba(34,211,238,0.08), rgba(6,182,212,0.05));
    border: 1px solid rgba(34,211,238,0.15);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    margin-bottom: 1.5rem;
}
.birthday-card .countdown-value {
    font-size: 3rem;
    font-weight: 800;
    font-family: 'JetBrains Mono', monospace;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.birthday-card .countdown-label { color: var(--text-muted); font-size: 0.95rem; }

/* Life stats */
.life-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}
.life-stat {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1rem;
    text-align: center;
}
.life-stat .life-value {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--accent-1);
}
.life-stat .life-label { font-size: 0.8rem; color: var(--text-muted); margin-top: 0.25rem; }

/* Section headings */
.section-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Content section */
.content-section { margin-top: 1.5rem; }
.content-section h2 {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.content-section h3 { font-size: 1.1rem; font-weight: 700; margin: 1.25rem 0 0.5rem; color: var(--text); }
.content-section p { color: var(--text-muted); margin-bottom: 0.75rem; line-height: 1.7; }

/* Footer */
.site-footer {
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    margin-top: 3rem;
    text-align: center;
}
.site-footer p { color: var(--text-muted); font-size: 0.85rem; }
.site-footer nav { display: flex; justify-content: center; gap: 1.5rem; margin-top: 0.75rem; }
.site-footer nav a { color: var(--text-muted); text-decoration: none; font-size: 0.85rem; transition: color 0.2s; }
.site-footer nav a:hover { color: var(--accent-1); }

.hidden { display: none !important; }

@media (max-width: 640px) {
    .hero h1 { font-size: 1.8rem; }
    .age-display { grid-template-columns: repeat(3, 1fr); gap: 0.5rem; }
    .age-box .value { font-size: 1.8rem; }
    .stats-grid, .info-grid, .life-stats { grid-template-columns: 1fr; }
    .input-row { grid-template-columns: 1fr; }
    .card { padding: 1.25rem; }
}