/* ===== 主题变量 ===== */
:root {
    --bg: #f4f6fb;
    --bg-gradient: radial-gradient(1200px 600px at 20% -10%, #e3ecff 0%, transparent 55%),
                   radial-gradient(1000px 500px at 90% 0%, #d9f7f2 0%, transparent 50%);
    --card-bg: #ffffff;
    --card-border: rgba(30, 41, 59, 0.08);
    --text: #1e293b;
    --text-sub: #64748b;
    --accent: #4f7cff;
    --accent-2: #00b8a9;
    --shadow: 0 6px 24px rgba(30, 41, 59, 0.08);
    --shadow-hover: 0 12px 32px rgba(30, 41, 59, 0.14);
    --input-bg: #ffffff;
    --header-bg: rgba(255, 255, 255, 0.72);
    --kbd-bg: #eef2f7;
    --kbd-border: #d3dae5;
}

[data-theme="dark"] {
    --bg: #0e1420;
    --bg-gradient: radial-gradient(1200px 600px at 20% -10%, rgba(79, 124, 255, 0.16) 0%, transparent 55%),
                   radial-gradient(1000px 500px at 90% 0%, rgba(0, 184, 169, 0.14) 0%, transparent 50%);
    --card-bg: #171f2e;
    --card-border: rgba(255, 255, 255, 0.07);
    --text: #e2e8f0;
    --text-sub: #94a3b8;
    --shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
    --shadow-hover: 0 12px 32px rgba(0, 0, 0, 0.5);
    --input-bg: #1b2436;
    --header-bg: rgba(14, 20, 32, 0.72);
    --kbd-bg: #1b2436;
    --kbd-border: #2c3a52;
}

/* ===== 基础 ===== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    -webkit-text-size-adjust: 100%;
}

body {
    min-height: 100vh;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg);
    background-image: var(--bg-gradient);
    background-attachment: fixed;
    color: var(--text);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a {
    color: var(--accent);
    text-decoration: none;
}

/* ===== 顶栏 ===== */
.topbar {
    position: sticky;
    top: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 28px;
    background: var(--header-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--card-border);
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
}

.brand-logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    color: #fff;
    font-size: 18px;
}

.topbar-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.clock {
    font-size: 13px;
    color: var(--text-sub);
    font-variant-numeric: tabular-nums;
}

.theme-btn {
    padding: 6px 14px;
    font-size: 13px;
    color: var(--text);
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 999px;
    cursor: pointer;
    transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.theme-btn:hover {
    box-shadow: var(--shadow);
    transform: translateY(-1px);
}

/* ===== 主体 ===== */
.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 24px 60px;
}

.hero {
    text-align: center;
    padding: 64px 0 36px;
}

.hero-title {
    font-size: clamp(26px, 4vw, 40px);
    font-weight: 800;
    letter-spacing: 0.5px;
}

.hero-sub {
    margin-top: 10px;
    color: var(--text-sub);
    font-size: 15px;
}

kbd {
    display: inline-block;
    padding: 1px 8px;
    font-family: inherit;
    font-size: 13px;
    border: 1px solid var(--kbd-border);
    border-bottom-width: 2px;
    border-radius: 6px;
    background: var(--kbd-bg);
}

.search-box {
    position: relative;
    max-width: 560px;
    margin: 28px auto 0;
}

.search-icon {
    position: absolute;
    left: 18px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 20px;
    color: var(--text-sub);
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: 14px 20px 14px 48px;
    font-size: 15px;
    color: var(--text);
    background: var(--input-bg);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    box-shadow: var(--shadow);
    outline: none;
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.search-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(79, 124, 255, 0.18), var(--shadow);
}

.result-count {
    margin-top: 12px;
    font-size: 13px;
    color: var(--text-sub);
}

/* ===== 分组与卡片 ===== */
.group {
    margin-top: 34px;
}

.group-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
}

.group-title::before {
    content: "";
    width: 4px;
    height: 16px;
    border-radius: 2px;
    background: linear-gradient(180deg, var(--accent), var(--accent-2));
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 16px;
}

.nav-card {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 16px;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    box-shadow: var(--shadow);
    color: var(--text);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.nav-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.nav-icon {
    flex: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 46px;
    height: 46px;
    border-radius: 12px;
    color: #fff;
    font-size: 20px;
    font-weight: 700;
}

.nav-info {
    flex: 1;
    min-width: 0;
}

.nav-name {
    display: block;
    font-size: 15px;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.nav-desc {
    display: block;
    margin-top: 3px;
    font-size: 12.5px;
    color: var(--text-sub);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.nav-arrow {
    flex: none;
    color: var(--text-sub);
    opacity: 0;
    transform: translateX(-6px);
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.nav-card:hover .nav-arrow {
    opacity: 1;
    transform: translateX(0);
}

.empty {
    margin-top: 34px;
    padding: 48px 0;
    text-align: center;
    color: var(--text-sub);
}

/* ===== 页脚 ===== */
.footer {
    padding: 28px 0 40px;
    text-align: center;
    font-size: 13px;
    color: var(--text-sub);
}

/* ===== 404 ===== */
.notfound {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 70vh;
    text-align: center;
    gap: 10px;
}

.nf-code {
    font-size: 72px;
    font-weight: 800;
    line-height: 1;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.nf-desc {
    color: var(--text-sub);
}

.nf-back {
    margin-top: 12px;
    padding: 10px 22px;
    border-radius: 999px;
    color: #fff;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    font-size: 14px;
    font-weight: 600;
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.nf-back:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

/* ===== 响应式 ===== */
@media (max-width: 640px) {
    .topbar {
        padding: 12px 16px;
    }

    .clock {
        display: none;
    }

    .container {
        padding: 0 16px 40px;
    }

    .hero {
        padding: 44px 0 24px;
    }
}