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

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

:root {
    --bg: #0f0f13;
    --card: #1a1a2e;
    --border: rgba(255,255,255,0.06);
    --text: #e4e4e7;
    --text-muted: #a1a1aa;
    --accent-1: #60a5fa;
    --accent-2: #3b82f6;
    --accent-3: #2563eb;
    --gradient: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
    --radius: 1rem;
    --radius-sm: 0.75rem;
}

html { scroll-behavior: smooth; }

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

.hidden { display: none !important; }

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.25rem;
}

/* Header */
.site-header {
    background: rgba(15,15,19,0.85);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--text);
}

.logo-icon {
    width: 2.2rem;
    height: 2.2rem;
    background: var(--gradient);
    border-radius: 0.6rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    font-weight: 800;
}

nav { display: flex; gap: 1.5rem; }

nav a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.88rem;
    font-weight: 500;
    transition: color 0.2s;
}

nav a:hover { color: var(--accent-1); }

/* Hero */
.hero {
    text-align: center;
    padding: 3rem 0 2rem;
}

.hero h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.75rem;
}

.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 rgba(96,165,250,0.15);
    border-radius: var(--radius);
    padding: 1rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.8rem;
    margin: 1.5rem 0;
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Card */
.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.75rem;
    margin-bottom: 1.5rem;
}

/* Current Time */
.current-time-bar {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1.75rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.current-time-bar .label {
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.current-time-bar .time-display {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.current-time-bar .tz-label {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* Converter Section */
.converter-section {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 1rem;
    align-items: end;
    margin-bottom: 1.5rem;
}

.tz-group label {
    display: block;
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.4rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.tz-group select,
.tz-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: 0.92rem;
    transition: border-color 0.2s;
    appearance: none;
}

.tz-group select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%23a1a1aa' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2.5rem;
}

.tz-group select:focus,
.tz-group input:focus {
    outline: none;
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(59,130,246,0.15);
}

.swap-btn {
    width: 3rem;
    height: 3rem;
    background: var(--gradient);
    border: none;
    border-radius: 50%;
    color: #fff;
    font-size: 1.3rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s, box-shadow 0.3s;
    margin-bottom: 0.25rem;
}

.swap-btn:hover {
    transform: rotate(180deg);
    box-shadow: 0 4px 20px rgba(59,130,246,0.3);
}

/* Convert Button */
.btn-convert {
    width: 100%;
    padding: 0.85rem;
    background: var(--gradient);
    border: none;
    border-radius: var(--radius-sm);
    color: #fff;
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: box-shadow 0.3s, transform 0.1s;
}

.btn-convert:hover {
    box-shadow: 0 6px 24px rgba(59,130,246,0.3);
}

.btn-convert:active { transform: scale(0.98); }

/* Result Card */
.result-card {
    background: linear-gradient(135deg, rgba(96,165,250,0.08), rgba(37,99,235,0.08));
    border: 1px solid rgba(96,165,250,0.15);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    margin-top: 1.25rem;
}

.result-card .result-time {
    font-family: 'JetBrains Mono', monospace;
    font-size: 2rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.3rem;
}

.result-card .result-details {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Multi-zone display */
.multi-zone-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.multi-zone-header h2 {
    font-size: 1.2rem;
    font-weight: 700;
}

.btn-add-zone {
    padding: 0.5rem 1rem;
    background: rgba(96,165,250,0.1);
    border: 1px solid rgba(96,165,250,0.2);
    border-radius: var(--radius-sm);
    color: var(--accent-1);
    font-family: 'Inter', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.btn-add-zone:hover { background: rgba(96,165,250,0.2); }

.zone-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1rem;
}

.zone-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1.1rem;
    position: relative;
}

.zone-card .zone-name {
    font-weight: 700;
    font-size: 0.95rem;
    margin-bottom: 0.15rem;
}

.zone-card .zone-offset {
    color: var(--text-muted);
    font-size: 0.78rem;
    margin-bottom: 0.6rem;
}

.zone-card .zone-time {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--accent-1);
}

.zone-card .zone-date {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.zone-card .btn-remove-zone {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 1.1rem;
    padding: 0.2rem;
    line-height: 1;
    transition: color 0.2s;
}

.zone-card .btn-remove-zone:hover { color: #ef4444; }

/* 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, .content-section li {
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 0.75rem;
}

.content-section ul { padding-left: 1.25rem; list-style: disc; }

.faq-item {
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
}

.faq-item:last-child { border-bottom: none; }

.faq-item h3 { margin-top: 0; }

/* Footer */
.site-footer {
    background: var(--card);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    margin-top: 3rem;
}

.site-footer .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.site-footer p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.site-footer nav { display: flex; gap: 1.5rem; }

.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); }

/* Responsive */
@media (max-width: 768px) {
    .converter-section {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    .swap-btn {
        justify-self: center;
        transform: rotate(90deg);
    }
    .swap-btn:hover { transform: rotate(270deg); }
    .current-time-bar {
        flex-direction: column;
        text-align: center;
    }
    .zone-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
    .card { padding: 1.25rem; }
    .hero h1 { font-size: 1.75rem; }
}