/* ============================================================
   shared.css — CQU FIC 统一样式库
   维护说明：修改此文件即可全站生效
   ============================================================ */

/* --- 1. 设计令牌 (Design Tokens) --- */
:root {
    /* 品牌色 */
    --cqu-blue:        #1e4fa1;
    --cqu-dark-blue:   #153a7a;
    --cqu-light-blue:  #2a65c7;
    --cqu-orange:      #f57c00;
    --cqu-red:         #c62828;
    --accent-color:    #1e88e5;

    /* 文字色 */
    --text-primary:    #1d1d1f;
    --text-secondary:  #515154;
    --text-tertiary:   #86868b;

    /* 界面色 */
    --surface-color:   #ffffff;
    --background-color:#f5f5f7;
    --border-color:    #d2d2d7;

    /* 字体 */
    --font-family:     'Times New Roman', Times, serif;
    --font-weight-light:    300;
    --font-weight-normal:   400;
    --font-weight-medium:   500;
    --font-weight-semibold: 600;
    --font-weight-bold:     700;

    /* 间距 */
    --spacing-xs:  8px;
    --spacing-sm:  16px;
    --spacing-md:  24px;
    --spacing-lg:  32px;
    --spacing-xl:  48px;
    --spacing-xxl: 64px;

    /* 圆角 */
    --border-radius-sm: 8px;
    --border-radius-md: 12px;
    --border-radius-lg: 18px;
    --border-radius-xl: 24px;

    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0,0,0,.08);
    --shadow-md: 0 4px 16px rgba(0,0,0,.12);
    --shadow-lg: 0 8px 30px rgba(0,0,0,.16);

    /* 过渡 */
    --transition-fast:   .2s;
    --transition-normal: .4s;
    --transition-slow:   .6s;
    --transition-slower: .8s;

    /* 布局 */
    --header-height:        64px;
    --container-max-width: 1200px;
    --section-min-height:   80vh;
}

/* --- 2. 全局重置 --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-family);
    font-weight: var(--font-weight-normal);
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    min-height: 100vh;
}

/* --- 3. 布局基础 --- */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

section {
    position: relative;
    z-index: 1;
    transition: transform .8s cubic-bezier(.175,.885,.32,1.275);
    padding: var(--spacing-xxl) 0;
    min-height: var(--section-min-height);
    display: flex;
    align-items: center;
}

/* --- 4. 悬浮导航栏 --- */
header {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 90%;
    height: var(--header-height);
    background: rgba(255,255,255,.25);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    transition: all var(--transition-normal) ease;
    border: 1px solid rgba(255,255,255,.3);
}

header.scrolled {
    background: rgba(255,255,255,.35);
    box-shadow: var(--shadow-lg);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
    padding: 0 var(--spacing-md);
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    flex-shrink: 0;
}

.logo-icon {
    font-family: var(--font-family);
    font-size: 1.8rem;
    font-weight: var(--font-weight-bold);
    letter-spacing: 4px;
    background: linear-gradient(135deg, #c62828 0%, #ff7043 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 1px 0 rgba(255,255,255,.5), 0 2px 4px rgba(0,0,0,.2), 0 4px 8px rgba(0,0,0,.1);
}

.logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.logo-main {
    font-size: 1.1rem;
    font-weight: var(--font-weight-semibold);
    color: var(--text-primary);
}

.logo-sub {
    font-size: .7rem;
    color: var(--text-secondary);
}

/* 校徽 */
.nav-center {
    display: flex;
    align-items: center;
    flex-direction: column;
    position: relative;
}

.school-badge {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    transition: all var(--transition-normal) ease;
    cursor: pointer;
}

.school-logo {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

/* 导航链接 */
.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-sm);
    position: relative;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: var(--font-weight-medium);
    font-size: .9rem;
    transition: all .4s cubic-bezier(.175,.885,.32,1.275);
    position: relative;
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255,255,255,.6);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid rgba(255,255,255,.4);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 4px 12px rgba(0,0,0,.1), inset 0 1px 0 rgba(255,255,255,.15);
    cursor: pointer;
    overflow: hidden;
    transform: translateZ(0);
    display: block;
}

.nav-link:hover {
    color: var(--cqu-blue);
    transform: translateY(-2px) scale(1.05);
    background: rgba(255,255,255,.7);
    box-shadow: 0 8px 20px rgba(0,0,0,.2), inset 0 1px 0 rgba(255,255,255,.2);
}

.nav-link:active {
    transform: translateY(0) scale(.98);
    transition: all .1s ease;
}

.nav-link.active-page {
    color: var(--cqu-blue);
    background: rgba(255,255,255,.8);
    font-weight: var(--font-weight-semibold);
}

/* 光晕效果 */
.nav-link::before, .hero-cta::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    border-radius: var(--border-radius-lg);
    background: linear-gradient(135deg, rgba(255,255,255,.1) 0%, rgba(255,255,255,.05) 30%, rgba(255,255,255,.1) 70%, rgba(255,255,255,.05) 100%);
    opacity: 0;
    transition: opacity .3s ease;
    pointer-events: none;
}

.nav-link:hover::before, .hero-cta:hover::before { opacity: 1; }

.nav-link::after, .hero-cta::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,.2), transparent);
    transition: left .6s ease;
}

.nav-link:hover::after, .hero-cta:hover::after { left: 100%; }

/* 下拉菜单 */
.dropdown { position: relative; }

.dropdown:hover .nav-link {
    color: var(--cqu-blue);
    transform: translateY(-2px) scale(1.05);
    background: rgba(255,255,255,.7);
    box-shadow: 0 8px 20px rgba(0,0,0,.2), inset 0 1px 0 rgba(255,255,255,.2);
}

.dropdown-content {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 135px;
    background: rgba(255,255,255,.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-sm) 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all .5s cubic-bezier(.175,.885,.32,1.275);
    z-index: 1001;
    border: 1px solid rgba(255,255,255,.4);
    margin-top: 8px;
}

.dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    color: var(--text-secondary);
    transition: all var(--transition-fast) ease;
    white-space: nowrap;
}

.dropdown-item:hover {
    background: rgba(255,255,255,.5);
    color: var(--cqu-blue);
    transform: translateX(5px);
}

/* 移动端汉堡菜单 */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 28px;
    height: 20px;
    cursor: pointer;
    z-index: 1001;
    padding: 2px 0;
}

.mobile-menu-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-normal) ease;
}

.mobile-menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(6px, 6px); }
.mobile-menu-toggle.active span:nth-child(2) { opacity: 0; }
.mobile-menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(6px, -6px); }

/* --- 5. 页脚 --- */
footer {
    background: rgba(29,29,31,.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    color: rgba(255,255,255,.7);
    padding: var(--spacing-xxl) 0 var(--spacing-lg);
    position: relative;
    z-index: 10;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-column h3 {
    font-size: 1rem;
    font-weight: var(--font-weight-semibold);
    color: #fff;
    margin-bottom: var(--spacing-md);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255,255,255,.6);
    text-decoration: none;
    font-size: .9rem;
    transition: color var(--transition-fast) ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-links a:hover { color: rgba(255,255,255,.9); }

.copyright {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255,255,255,.1);
    font-size: .85rem;
    color: rgba(255,255,255,.4);
}

/* --- 6. 通用内容组件 --- */
.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
    text-align: center;
    line-height: 1.6;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.feature-card {
    background: rgba(255,255,255,.7);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal) ease;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,.3);
    text-decoration: none;
    color: inherit;
    opacity: 0;
    transform: translateY(20px);
}

.feature-card.visible {
    opacity: 1;
    transform: translateY(0);
    transition: opacity var(--transition-slow) ease, transform var(--transition-slow) ease, box-shadow var(--transition-normal) ease, background var(--transition-normal) ease;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    background: rgba(255,255,255,.9);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--cqu-blue) 0%, var(--cqu-orange) 100%);
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    color: #fff;
    font-size: 2rem;
    flex-shrink: 0;
}

.feature-title {
    font-size: 1.4rem;
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* CTA 按钮 */
.hero-cta {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: rgba(30,79,161,.6);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid rgba(255,255,255,.4);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 4px 12px rgba(0,0,0,.1), inset 0 1px 0 rgba(255,255,255,.15);
    color: #fff;
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    font-size: 1.1rem;
    transition: all .4s cubic-bezier(.175,.885,.32,1.275);
    position: relative;
    overflow: hidden;
    transform: translateZ(0);
}

.hero-cta:hover {
    background: rgba(30,79,161,.7);
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 8px 24px rgba(0,0,0,.2), inset 0 1px 0 rgba(255,255,255,.2);
}

/* --- 7. 动画 --- */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes bounceIn {
    0%   { opacity: 0; transform: scale(0.3); }
    50%  { opacity: 1; transform: scale(1.05); }
    70%  { transform: scale(0.9); }
    100% { transform: scale(1); }
}

@keyframes bounceOut {
    0%   { opacity: 1; transform: scale(1); }
    50%  { transform: scale(1.05); }
    100% { opacity: 0; transform: scale(0.3); }
}

.bounce-in  { animation: bounceIn  .8s cubic-bezier(.34, 1.56, .64, 1) both; }
.bounce-out { animation: bounceOut .6s cubic-bezier(.34, 1.56, .64, 1) both; }

/* --- 8. 响应式 --- */
@media (max-width: 768px) {
    header { width: 95%; top: 10px; }

    .mobile-menu-toggle { display: flex; }

    .nav-center { display: none; }

    .nav-links {
        display: none;
        position: fixed;
        top: calc(var(--header-height) + 30px);
        left: 50%;
        transform: translateX(-50%);
        width: 90%;
        background: rgba(255,255,255,.9);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        border-radius: var(--border-radius-xl);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-md);
        flex-direction: column;
        gap: var(--spacing-sm);
        border: 1px solid rgba(255,255,255,.4);
        z-index: 999;
    }

    .nav-links.active { display: flex; }

    .dropdown-content {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background: rgba(255,255,255,.4);
        margin-top: var(--spacing-xs);
        margin-left: var(--spacing-md);
    }

    section {
        padding: var(--spacing-xl) 0;
        min-height: auto;
    }

    .container { padding: 0 var(--spacing-sm); }

    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        margin-top: var(--spacing-lg);
    }

    .feature-card { padding: var(--spacing-md); }
    .feature-icon { width: 70px; height: 70px; font-size: 1.7rem; margin-bottom: var(--spacing-sm); }
    .feature-title { font-size: 1.3rem; margin-bottom: var(--spacing-xs); }
    .feature-description { font-size: .95rem; line-height: 1.4; }

    footer { padding: var(--spacing-xl) 0 var(--spacing-md); }
    .footer-content { grid-template-columns: 1fr; gap: var(--spacing-lg); }
    .footer-column { margin-bottom: var(--spacing-md); }
}

@media (max-width: 480px) {
    .section-title { font-size: 1.6rem; }
    .section-subtitle { font-size: 1rem; }
    .feature-card { padding: var(--spacing-sm); }
    .feature-icon { width: 60px; height: 60px; font-size: 1.5rem; }
    .feature-title { font-size: 1.2rem; }
    .logo-main { font-size: .95rem; }
    .logo-icon { font-size: 1.5rem; }
}

@media (hover: none) and (pointer: coarse) {
    .nav-link:hover,
    .dropdown:hover .nav-link,
    .feature-card:hover,
    .hero-cta:hover { transform: none; }

    .nav-link:active,
    .feature-card:active,
    .hero-cta:active { transform: scale(.98); }

    .feature-card:active { background: rgba(255,255,255,.9); }
}