/* Bitcoin HK - Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #f7931a;
    --dark: #1a1a1a;
    --light: #f5f5f5;
    --gray: #666;
    --white: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background: var(--light);
}

/* Header */
header {
    background: var(--dark);
    color: var(--white);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--white);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: background 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    background: var(--primary);
    color: var(--dark);
}

/* Main */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Hero */
.hero {
    text-align: center;
    padding: 3rem 1rem;
    background: linear-gradient(135deg, var(--dark) 0%, #2d2d2d 100%);
    color: var(--white);
    border-radius: 12px;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.btc-price-banner {
    margin-top: 1.5rem;
    padding: 1rem;
    background: rgba(247, 147, 26, 0.2);
    border-radius: 8px;
    display: inline-block;
}

.price-label {
    font-size: 1rem;
    opacity: 0.8;
}

.price-value {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
}

/* News */
.news h2,
.lessons h2,
.glossary h2,
.price-stats h2,
.chart-section h2,
.chain-stats h2,
.recent-blocks h2 {
    margin-bottom: 1.5rem;
    color: var(--dark);
}

.news-grid,
.stats-grid,
.lesson-list,
.terms-grid,
.chain-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.news-card,
.stat-card,
.lesson-card,
.term,
.chain-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.news-card h3,
.lesson-card h3 {
    margin-bottom: 0.5rem;
}

.date {
    font-size: 0.875rem;
    color: var(--gray);
    margin-bottom: 0.5rem;
}

.read-more {
    display: inline-block;
    margin-top: 1rem;
    color: var(--primary);
    text-decoration: none;
}

/* Price Page */
.price-hero {
    text-align: center;
    padding: 3rem;
    background: var(--dark);
    color: var(--white);
    border-radius: 12px;
    margin-bottom: 2rem;
}

.price-display {
    font-size: 2rem;
    margin: 1rem 0;
}

.price-display .usd {
    color: var(--primary);
    font-weight: bold;
}

.price-display .hkd {
    display: block;
    font-size: 1.25rem;
    opacity: 0.8;
}

.price-change {
    font-size: 1.25rem;
}

.price-change.positive {
    color: #4caf50;
}

.price-change.negative {
    color: #f44336;
}

.chart-controls {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.chart-controls button {
    padding: 0.5rem 1rem;
    border: 1px solid #ddd;
    background: var(--white);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

.chart-controls button:hover,
.chart-controls button.active {
    background: var(--primary);
    border-color: var(--primary);
}

.chart-container {
    background: var(--white);
    padding: 1rem;
    border-radius: 8px;
    height: 400px;
}

/* Learn Page */
.learn-hero {
    text-align: center;
    padding: 3rem;
    background: linear-gradient(135deg, var(--primary) 0%, #e8820f 100%);
    color: var(--dark);
    border-radius: 12px;
    margin-bottom: 2rem;
}

.lesson-card .tag {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.25rem 0.75rem;
    background: var(--primary);
    color: var(--dark);
    font-size: 0.75rem;
    border-radius: 4px;
}

.term h3 {
    color: var(--primary);
    margin-bottom: 0.5rem;
}

/* Stats Page */
.stats-hero {
    text-align: center;
    padding: 3rem;
    background: var(--dark);
    color: var(--white);
    border-radius: 12px;
    margin-bottom: 2rem;
}

.stat-card.highlight {
    background: var(--primary);
    color: var(--dark);
}

.stat-card.highlight .stat-label {
    opacity: 0.8;
}

.stat-value {
    font-size: 2rem;
    font-weight: bold;
    margin: 0.5rem 0;
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.7;
}

/* Blocks Table */
.blocks-table {
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
}

.block-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    padding: 1rem;
    border-bottom: 1px solid #eee;
}

.block-row.header {
    background: var(--dark);
    color: var(--white);
    font-weight: bold;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    background: var(--dark);
    color: var(--gray);
    margin-top: 3rem;
}

/* Responsive */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .news-grid,
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .block-row {
        font-size: 0.875rem;
        padding: 0.75rem;
    }
}