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

:root {
    --bg-primary: #0b1120;
    --bg-secondary: #111827;
    --bg-card: #1a2332;
    --bg-card-hover: #1f2b3d;
    --text-primary: #f0f4f8;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-day: #f59e0b;
    --accent-night: #6366f1;
    --accent-glow-day: rgba(245, 158, 11, 0.15);
    --accent-glow-night: rgba(99, 102, 241, 0.15);
    --border-color: #1e293b;
    --border-light: #334155;
    --hero-gradient-1: #0f172a;
    --hero-gradient-2: #1e1b4b;
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei',
                 'Helvetica Neue', Arial, sans-serif;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--border-light);
    border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ===== Hero Section ===== */
.hero {
    background: linear-gradient(135deg, var(--hero-gradient-1) 0%, var(--hero-gradient-2) 50%, #1a0a2e 100%);
    padding: 48px 20px 56px;
    text-align: center;
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid var(--border-color);
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 40%, rgba(99, 102, 241, 0.04) 0%, transparent 50%),
                radial-gradient(circle at 70% 60%, rgba(245, 158, 11, 0.03) 0%, transparent 50%);
    pointer-events: none;
    animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
    0%   { transform: translate(0, 0); }
    100% { transform: translate(-2%, 2%); }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
}

.hero-icon {
    font-size: 40px;
    margin-bottom: 8px;
    display: block;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(-6px); }
}

.hero-title {
    font-size: clamp(1.4rem, 3.5vw, 2.2rem);
    font-weight: 700;
    letter-spacing: 0.02em;
    margin-bottom: 4px;
    background: linear-gradient(135deg, #f0f4f8, #a5b4fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(0.85rem, 1.5vw, 1rem);
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.local-clock {
    font-family: var(--font-mono);
    font-size: clamp(3.2rem, 8vw, 5.5rem);
    font-weight: 300;
    letter-spacing: 0.05em;
    line-height: 1.1;
    margin-bottom: 8px;
    text-shadow: 0 0 40px rgba(99, 102, 241, 0.2);
    background: linear-gradient(135deg, #ffffff, #c7d2fe);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.local-details {
    font-size: clamp(0.85rem, 1.4vw, 1rem);
    color: var(--text-secondary);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.local-details .separator {
    color: var(--text-muted);
    font-size: 0.7em;
}

/* ===== Main Layout ===== */
.main {
    max-width: 1300px;
    margin: 0 auto;
    padding: 24px 16px 40px;
}

/* ===== Controls ===== */
.controls {
    margin-bottom: 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.search-wrapper {
    position: relative;
    width: 100%;
}

.search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 16px;
    pointer-events: none;
    opacity: 0.6;
}

.search-input {
    width: 100%;
    padding: 14px 44px 14px 44px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: var(--font-sans);
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input::placeholder {
    color: var(--text-muted);
}

.search-input:focus {
    border-color: var(--accent-night);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.search-clear {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 16px;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    display: none;
    transition: color 0.2s;
}

.search-clear:hover {
    color: var(--text-primary);
}

.search-input:not(:placeholder-shown) ~ .search-clear {
    display: block;
}

/* ===== Filter Bar ===== */
.filter-bar {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}

.filter-btn:hover {
    border-color: var(--border-light);
    color: var(--text-primary);
    background: var(--bg-card);
}

.filter-btn.active {
    border-color: var(--accent-night);
    color: #c7d2fe;
    background: rgba(99, 102, 241, 0.12);
}

/* ===== Timezone Grid ===== */
.tz-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 12px;
}

.tz-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px 18px;
    cursor: default;
    transition: all 0.2s ease;
    position: relative;
    overflow: hidden;
}

.tz-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    transition: background 0.3s;
}

.tz-card.day::before {
    background: var(--accent-day);
    box-shadow: 0 0 12px var(--accent-glow-day);
}

.tz-card.night::before {
    background: var(--accent-night);
    box-shadow: 0 0 12px var(--accent-glow-night);
}

.tz-card:hover {
    border-color: var(--border-light);
    background: var(--bg-card-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-card);
}

.tz-card.local-highlight {
    border-color: var(--accent-night);
    background: linear-gradient(135deg, var(--bg-card), rgba(99, 102, 241, 0.08));
}

.tz-card.local-highlight::after {
    content: '📍 当前位置';
    position: absolute;
    top: 8px;
    right: 12px;
    font-size: 0.7rem;
    color: var(--accent-night);
    background: rgba(99, 102, 241, 0.15);
    padding: 2px 8px;
    border-radius: 10px;
}

.tz-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 12px;
}

.tz-card-name {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.3;
}

.tz-card-tz {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
    margin-top: 2px;
}

.tz-card-actions {
    display: flex;
    align-items: center;
    gap: 4px;
    flex-shrink: 0;
}

.tz-card-star {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.25rem;
    line-height: 1;
    padding: 2px 4px;
    color: var(--text-muted);
    transition: transform 0.2s, color 0.2s, text-shadow 0.2s;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.tz-card-star:hover {
    transform: scale(1.25);
}

.tz-card-star.favorited {
    color: #f59e0b;
    text-shadow: 0 0 10px rgba(245, 158, 11, 0.5);
}

.tz-card.favorited {
    border-color: rgba(245, 158, 11, 0.25);
    background: linear-gradient(135deg, var(--bg-card), rgba(245, 158, 11, 0.04));
}

.tz-card-status {
    font-size: 1.2rem;
    flex-shrink: 0;
}

.tz-card-time {
    font-family: var(--font-mono);
    font-size: 1.6rem;
    font-weight: 600;
    letter-spacing: 0.03em;
    line-height: 1.2;
    margin-bottom: 4px;
}

.tz-card.day .tz-card-time {
    color: #fbbf24;
}

.tz-card.night .tz-card-time {
    color: #a5b4fc;
}

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

.tz-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 0.78rem;
}

.tz-card-offset {
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.tz-card-diff {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.tz-card-diff strong {
    color: var(--text-secondary);
    font-weight: 500;
}

/* ===== No Results ===== */
.no-results {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.no-results.visible {
    display: flex;
}

.no-results-icon {
    font-size: 48px;
    margin-bottom: 16px;
    opacity: 0.5;
}

.no-results p {
    font-size: 1rem;
}

/* ===== Footer ===== */
.footer {
    border-top: 1px solid var(--border-color);
    background: var(--bg-secondary);
    padding: 20px 16px;
    text-align: center;
}

.footer-content {
    max-width: 1300px;
    margin: 0 auto;
}

.footer p {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.footer .footer-hint {
    font-size: 0.72rem;
    margin-top: 4px;
    opacity: 0.7;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .hero {
        padding: 32px 16px 40px;
    }

    .local-clock {
        letter-spacing: 0.03em;
    }

    .tz-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 10px;
    }

    .filter-bar {
        overflow-x: auto;
        flex-wrap: nowrap;
        padding-bottom: 4px;
        -webkit-overflow-scrolling: touch;
    }

    .filter-btn {
        flex-shrink: 0;
    }

    .tz-card-time {
        font-size: 1.4rem;
    }

    .tz-card.local-highlight::after {
        font-size: 0.65rem;
        padding: 1px 6px;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 24px 12px 32px;
    }

    .tz-grid {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .main {
        padding: 16px 12px 24px;
    }

    .tz-card {
        padding: 14px 14px;
    }
}

/* ===== Top Navigation ===== */
.top-nav {
    border-bottom: 1px solid var(--border-color);
    background: rgba(11, 17, 32, 0.85);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    position: sticky;
    top: 0;
    z-index: 100;
}

.top-nav-inner {
    max-width: 1300px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    height: 54px;
}

.top-nav-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.95rem;
    transition: opacity 0.2s;
    flex-shrink: 0;
}

.top-nav-brand:hover {
    opacity: 0.8;
}

.top-nav-brand .brand-icon {
    font-size: 1.2rem;
}

.top-nav-links {
    display: flex;
    align-items: center;
    gap: 2px;
}

.top-nav-link {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 7px 14px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 450;
    transition: all 0.2s;
    white-space: nowrap;
    border: 1px solid transparent;
}

.top-nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-card);
    border-color: var(--border-color);
}

.top-nav-link.active {
    color: #c7d2fe;
    background: rgba(99, 102, 241, 0.12);
    border-color: rgba(99, 102, 241, 0.2);
}

.top-nav-link.active:hover {
    background: rgba(99, 102, 241, 0.18);
}

@media (max-width: 480px) {
    .top-nav-inner {
        padding: 0 12px;
        height: 48px;
    }
    .top-nav-brand .brand-text {
        display: none;
    }
    .top-nav-link {
        padding: 6px 10px;
        font-size: 0.8rem;
    }
}

/* ===== Print ===== */
@media print {
    .hero {
        padding: 24px;
        background: #fff !important;
        color: #000 !important;
        border-bottom: 2px solid #333;
    }
    .hero-title, .local-clock {
        -webkit-text-fill-color: initial;
        background: none;
        color: #000;
    }
    .controls { display: none; }
    .tz-card { break-inside: avoid; border: 1px solid #ccc; }
    .footer { display: none; }
}