/*=============================================
 * base.css - Reset, Variables, Typography
 * 基础变量与全局样式，可被所有子页面复用
 *=============================================*/

/* MiSans Web Font */
@font-face {
    font-family: 'MiSans';
    src: url('../../../fonts/MiSans-Regular.woff2') format('woff2');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}
@font-face {
    font-family: 'MiSans';
    src: url('../../../fonts/MiSans-Medium.woff2') format('woff2');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}
@font-face {
    font-family: 'MiSans';
    src: url('../../../fonts/MiSans-Semibold.woff2') format('woff2');
    font-weight: 600;
    font-style: normal;
    font-display: swap;
}
@font-face {
    font-family: 'MiSans';
    src: url('../../../fonts/MiSans-Heavy.woff2') format('woff2');
    font-weight: 900;
    font-style: normal;
    font-display: swap;
}

:root {
    /* 主色调 */
    --color-primary: #0a1e3d;
    --color-primary-light: #132d56;
    --color-accent: #0066cc;
    --color-accent-light: #0088ff;
    --color-accent-dark: #004d99;

    /* 辅助色 */
    --color-orange: #e87722;
    --color-gold: #c9a84c;
    --color-red: #d32f2f;
    --color-green: #2e7d32;
    --color-teal: #00695c;

    /* 中性色 */
    --color-white: #ffffff;
    --color-off-white: #f7f8fa;
    --color-light-gray: #e8eaed;
    --color-mid-gray: #9aa0a6;
    --color-dark-gray: #5f6368;
    --color-text: #1a1a2e;
    --color-text-light: #545865;
    --color-border: #e0e0e0;

    /* 间距 */
    --space-xs: 8px;
    --space-sm: 16px;
    --space-md: 24px;
    --space-lg: 40px;
    --space-xl: 60px;
    --space-2xl: 80px;
    --space-3xl: 120px;

    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 20px;

    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
    --shadow-xl: 0 16px 48px rgba(0,0,0,0.16);

    /* 字体 */
    --font-primary: 'MiSans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --font-heading: 'MiSans', 'PingFang SC', 'Microsoft YaHei', sans-serif;

    /* 过渡 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;

    /* 容器 */
    --container-max: clamp(1200px, 85%, 1600px);
    --container-narrow: 960px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    line-height: 1.6;
    background: var(--color-white);
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

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

ul, ol {
    list-style: none;
}

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-md);
    padding-bottom: 5px;
}

.container-narrow {
    max-width: var(--container-narrow);
}

/* 通用文字排版 */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.3;
    color: var(--color-primary);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: var(--space-md);
    color: var(--color-text-light);
}

/* 通用区域标题 */
.section-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.section-header .section-subtitle {
    display: inline-block;
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
    position: relative;
}

.section-header .section-subtitle::after {
    content: '';
    display: block;
    width: 50px;
    height: 3px;
    background: var(--color-accent);
    margin: 10px auto 0;
    border-radius: 2px;
}

.section-header .section-title {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
}

.section-header .section-desc {
    font-size: 1.05rem;
    color: var(--color-text-light);
    max-width: 700px;
    margin: 0 auto;
}

/* 通用区域间距 */
.section {
    padding: var(--space-3xl) 0;
}

.section-dark {
    background: var(--color-primary);
    color: var(--color-white);
}

.section-dark .section-title {
    color: var(--color-white);
}

.section-dark .section-desc {
    color: rgba(255,255,255,0.7);
}

.section-gray {
    background: var(--color-off-white);
}

/* 滚动动画基础类 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 页内锚点偏移 */
[id]::before {
    content: '';
    display: block;
    height: 80px;
    margin-top: -80px;
    visibility: hidden;
}