/* 全站公共样式（由 index.html 等页面内嵌样式抽取）
 * 引入位置：所有页面 <head> 内，置于页面内联 <style> 之前
 * 负责：字体栈变量、:root 变量、基础 reset、导航、主题切换、页脚、移动端菜单、深色主题基础开关
 */

:root {
    /* 品牌色（可被页面覆盖） */
    --primary: #004E8C;
    --primary-rgb: 0, 78, 140;
    --deep: #2A3645;
    --gold: #c5b358;
    --ink: #273039;
    --ink-soft: #5f6a75;
    --paper: #f4f6f8;
    --surface: rgba(255, 255, 255, 0.86);
    --line: rgba(0, 78, 140, 0.22);
    --radius-lg: 20px;
    --radius-md: 14px;
    --shadow: 0 20px 44px rgba(28, 39, 50, 0.13);

    /* 字体栈：Google Fonts 首选 + 系统字体 fallback */
    --font-sans: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --font-serif: "Noto Serif SC", ui-serif, Georgia, "Songti SC", STSong, "SimSun", serif;
    --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, "SF Mono",
                 "Cascadia Code", Menlo, Consolas, "Liberation Mono", monospace;
}

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

html {
    scrollbar-gutter: stable;
}

body {
    font-family: var(--font-sans);
    color: var(--ink);
    min-height: 100vh;
    background:
        radial-gradient(1200px 620px at 88% 6%, rgba(var(--primary-rgb), 0.22), transparent 62%),
        radial-gradient(980px 560px at 8% 92%, rgba(42, 54, 69, 0.12), transparent 60%),
        linear-gradient(180deg, #f8fafc 0%, var(--paper) 56%, #eef2f6 100%);
    scrollbar-gutter: stable;
}

body::before {
    content: '';
    position: fixed;
    inset: -8%;
    pointer-events: none;
    background:
        radial-gradient(620px 300px at 22% 12%, rgba(var(--primary-rgb), 0.14), transparent 70%),
        radial-gradient(760px 380px at 78% 88%, rgba(var(--primary-rgb), 0.1), transparent 72%);
    filter: blur(26px);
    opacity: 0.9;
    z-index: -2;
}

body::after {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    background-image:
        radial-gradient(circle at 18% 24%, rgba(18, 26, 34, 0.06) 0.5px, transparent 0.7px),
        radial-gradient(circle at 74% 68%, rgba(255, 255, 255, 0.26) 0.45px, transparent 0.7px);
    background-size: 3px 3px, 4px 4px;
    opacity: 0.1;
    z-index: -1;
}

/* 顶部导航 */
.top-nav {
    position: sticky;
    top: 0;
    z-index: 120;
    background: rgba(244, 246, 248, 0.84);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: min(1200px, 94vw);
    margin: 0 auto;
}

.theme-toggle {
    background: rgba(var(--primary-rgb), 0.08);
    border: 1px solid var(--line);
    color: var(--primary);
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    flex-shrink: 0;
    margin-left: 10px;
}

.theme-toggle:hover {
    background: var(--primary);
    color: #fff;
    transform: rotate(30deg);
}

[data-theme='dark'] .theme-toggle {
    color: var(--gold);
    border-color: var(--line);
    background: rgba(255, 255, 255, 0.05);
}

.nav-links {
    display: flex;
    justify-content: center;
    list-style: none;
    gap: 10px;
    flex-wrap: wrap;
    padding: 14px 0;
}

.nav-links a {
    display: block;
    text-decoration: none;
    color: var(--ink-soft);
    font-weight: 600;
    font-size: 14px;
    padding: 10px 0;
    width: 80px;
    text-align: center;
    border-radius: 999px;
    border: 1px solid transparent;
    transition: all 0.25s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
    border-color: rgba(var(--primary-rgb), 0.36);
    background: rgba(var(--primary-rgb), 0.08);
}

/* 全站页脚 */
.footer {
    width: min(1200px, 94vw);
    margin: 40px auto 34px;
    text-align: center;
    font-size: 13px;
    color: #85909b;
    border-top: 1px solid var(--line);
    padding-top: 30px;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.footer-links a {
    text-decoration: none;
    color: var(--ink-soft);
    display: flex;
    align-items: center;
    gap: 6px;
    font-weight: 500;
    transition: all 0.25s ease;
}

.footer-links a:hover {
    color: var(--primary);
}

.footer-links .link-label {
    color: var(--primary);
    font-weight: 700;
    margin-right: 4px;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--ink);
    font-size: 20px;
    cursor: pointer;
    padding: 8px;
    margin-left: 10px;
}

@media (max-width: 680px) {
    .mobile-menu-btn {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 40px;
        height: 40px;
        border-radius: 50%;
        background: rgba(var(--primary-rgb), 0.08);
        border: 1px solid var(--line);
        color: var(--primary);
        transition: all 0.3s ease;
    }
    [data-theme='dark'] .mobile-menu-btn {
        color: var(--gold);
        border-color: var(--line);
        background: rgba(255, 255, 255, 0.05);
    }
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: rgba(244, 246, 248, 0.95);
        backdrop-filter: blur(14px);
        flex-direction: column;
        padding: 10px 0;
        border-bottom: 1px solid var(--line);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    }
    [data-theme='dark'] .nav-links {
        background: rgba(0, 8, 20, 0.95);
    }
    .nav-links.active {
        display: flex;
    }
    .nav-links a {
        width: 100%;
        border-radius: 0;
        padding: 15px 0;
    }
    .nav-container {
        position: relative;
    }
}

/* 深色主题：全局基础开关（页面特定深色样式仍保留在各自 <style>） */
[data-theme='dark'] {
    --primary: #004E8C;
    --primary-rgb: 0, 78, 140;
    --deep: #000814;
    --gold: #c5b358;
    --ink: #FFFFFF;
    --ink-soft: #A0B3C6;
    --paper: #000814;
    --surface: rgba(0, 78, 140, 0.08);
    --line: rgba(0, 78, 140, 0.4);
    --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.8);
}

[data-theme='dark'] body {
    background:
        radial-gradient(circle at 50% -20%, rgba(0, 78, 140, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 100% 100%, rgba(0, 78, 140, 0.1) 0%, transparent 50%),
        var(--paper) !important;
    color: var(--ink) !important;
}

[data-theme='dark'] .top-nav {
    background: rgba(0, 8, 20, 0.8) !important;
    backdrop-filter: blur(20px) !important;
    border-bottom: 1px solid var(--line);
}

[data-theme='dark'] .nav-links a {
    color: var(--ink-soft);
}

[data-theme='dark'] .nav-links a:hover,
[data-theme='dark'] .nav-links a.active {
    color: #FFFFFF !important;
    background: var(--primary) !important;
    box-shadow: 0 0 20px rgba(0, 78, 140, 0.5) !important;
    border-color: rgba(255, 255, 255, 0.3) !important;
}

[data-theme='dark'] .footer {
    border-top: 1px solid var(--line) !important;
    color: var(--ink-soft) !important;
}
