@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@300;400;600;700&display=swap');

/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --bg: #060609;
    --surface: #0d0d14;
    --border: rgba(255, 77, 77, 0.15);
    --accent: #ff4d4d;
    --green: #4ade80;
    --red: #ef4444;
    --text: #e4e4e7;
    --text-dim: #71717a;
    --font: 'JetBrains Mono', monospace;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--font);
    line-height: 1.6;
    padding: 1rem;
    max-width: 1400px;
    margin: 0 auto;
}

/* === Header === */
.header {
    text-align: center;
    padding: 2rem 0 1rem;
}
.header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
}
.subtitle {
    color: var(--text-dim);
    font-size: 0.85rem;
    font-weight: 300;
    margin-top: 0.25rem;
}

/* === Metriky === */
.metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}
.metric-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    transition: border-color 0.2s;
}
.metric-card:hover { border-color: var(--accent); }
.metric-label { font-size: 0.7rem; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.05em; }
.metric-value { font-size: 1.4rem; font-weight: 700; }
.metric-sub { font-size: 0.75rem; color: var(--text-dim); }

/* === Controls === */
.controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem;
    margin: 1rem 0;
}
#search {
    flex: 1;
    min-width: 200px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.6rem 1rem;
    color: var(--text);
    font-family: var(--font);
    font-size: 0.85rem;
    outline: none;
    transition: border-color 0.2s;
}
#search:focus { border-color: var(--accent); }
#search::placeholder { color: var(--text-dim); }

.btn {
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 0.6rem 1.25rem;
    font-family: var(--font);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
    white-space: nowrap;
}
.btn:hover { opacity: 0.85; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.last-update {
    font-size: 0.7rem;
    color: var(--text-dim);
    white-space: nowrap;
}

/* === Loading === */
.loading {
    text-align: center;
    padding: 3rem;
    color: var(--text-dim);
    font-size: 0.9rem;
    display: none;
}
.loading.active { display: block; }

/* === Coins Grid === */
.coins-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
    margin: 1rem 0;
}

.coin-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    transition: border-color 0.2s, transform 0.2s;
}
.coin-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}
.coin-card.hidden { display: none; }

.coin-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}
.coin-icon {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg);
    flex-shrink: 0;
}
.coin-icon-fallback {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    flex-shrink: 0;
}
.coin-name { font-weight: 600; font-size: 0.95rem; }
.coin-ticker { color: var(--text-dim); font-size: 0.75rem; text-transform: uppercase; }

.coin-price { font-size: 1.3rem; font-weight: 700; }
.coin-change { font-size: 0.85rem; font-weight: 600; }
.coin-change.up { color: var(--green); }
.coin-change.down { color: var(--red); }

.coin-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.7rem;
    color: var(--text-dim);
    margin-top: 0.25rem;
}

/* === Popisy === */
.descriptions {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}
.descriptions h2 {
    font-size: 1.3rem;
    color: var(--accent);
    margin-bottom: 1.5rem;
}
.desc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1rem;
}
.desc-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem;
}
.desc-card h3 {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--accent);
}
.desc-card p {
    font-size: 0.8rem;
    color: var(--text-dim);
    line-height: 1.7;
}

/* === Responsive === */
@media (max-width: 640px) {
    .header h1 { font-size: 1.5rem; }
    .coins-grid { grid-template-columns: 1fr; }
    .desc-grid { grid-template-columns: 1fr; }
    .metrics { grid-template-columns: repeat(2, 1fr); }
}