/* ========== 基础层：变量 / reset / 页面骨架 / 三端适配 ========== */
:root {
    --brand: #00adb5;
    --brand-dark: #008c93;
    --text: #222;
    --text-strong: #000;
    --muted: #666;
    --muted-light: #888;
    --line: #e5e5e5;
    --line-light: #f0f0f0;
    --bg-soft: #f5f5f5;
    --radius: 10px;
    --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-card-hover: 0 6px 20px rgba(0, 0, 0, 0.12);
    --wrap: 60%;
    --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Microsoft YaHei", sans-serif;
    --btn-size-desktop: 48px;
    --btn-size-mobile: 42px;
}

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

body {
    font-family: var(--font-stack);
    background: #fff;
    color: var(--text);
    line-height: 1.6;
}

img {
    max-width: 100%;
}

a {
    color: inherit;
}

/* ========== 顶部导航 ========== */
header {
    border-bottom: 1px solid #eee;
    position: sticky;
    top: 0;
    background: #fff;
    z-index: 99;
}

header .nav-container {
    width: var(--wrap);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

header .logo {
    font-size: 36px;
    font-weight: bold;
    color: var(--brand);
}

header .nav-menu {
    display: flex;
    gap: 42px;
    list-style: none;
}

header .nav-menu li a {
    text-decoration: none;
    color: var(--text);
    font-size: 18px;
    display: flex;
    align-items: center;
    gap: 4px;
}

header .nav-menu li a:hover,
header .nav-menu li a[aria-current="page"] {
    color: var(--brand);
}

header .mobile-menu-btn {
    display: none;
    font-size: 28px;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text);
    padding: 0 4px;
}

/* ========== 媒体中心标题横幅 ========== */
.media-center-page {
    padding-top: 88px;
}

.media-center-banner {
    width: 100%;
    background-color: var(--bg-soft);
    border-bottom: 1px solid var(--line);
    text-align: center;
    padding: 28px 0;
}

.media-center-banner h1 {
    font-size: 32px;
    font-weight: 700;
    color: #000;
    letter-spacing: 2px;
}

/* ========== 主内容容器 ========== */
.main-wrap {
    width: var(--wrap);
    margin: 40px auto;
}

#cardList {
    min-height: 120px;
}



.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 40px;
    flex-wrap: wrap;
}

/* ========== 返回顶部按钮 ========== */
.back-to-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    width: var(--btn-size-desktop);
    height: var(--btn-size-desktop);
    border-radius: 50%;
    background: #2db7a8;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    border: 0;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--brand-dark);
}

.back-to-top:focus-visible {
    outline: 2px solid #fff;
    outline-offset: 2px;
}

.back-to-top svg {
    display: block;
}

/* ========== 平板：768 ~ 1200px ========== */
@media screen and (max-width: 1200px) {
    :root {
        --wrap: 80%;
    }
}

@media screen and (max-width: 992px) {
    .media-center-banner h1 {
        font-size: 28px;
    }
    .main-wrap {
        margin: 32px auto;
    }
    /* 汉堡菜单：下拉展开 */
    header .mobile-menu-btn {
        display: block;
    }
    header .nav-menu {
        display: none;
        position: absolute;
        left: 0;
        right: 0;
        top: 100%;
        flex-direction: column;
        gap: 0;
        background: #fff;
        border-top: 1px solid #eee;
        border-bottom: 1px solid #eee;
        box-shadow: 0 6px 16px rgba(0, 0, 0, 0.08);
        padding: 8px 0;
    }
    header .nav-menu.open {
        display: flex;
    }
    header .nav-menu li a {
        padding: 14px 6%;
        font-size: 16px;
    }
}

/* ========== 手机：< 768px ========== */
@media screen and (max-width: 768px) {
    :root {
        --wrap: 92%;
    }
    header .logo {
        font-size: 28px;
    }
    .media-center-page {
        padding-top: 72px;
    }
    .media-center-banner {
        padding: 22px 0;
    }
    .media-center-banner h1 {
        font-size: 24px;
    }
    .main-wrap {
        margin: 24px auto;
    }
    .pagination {
        gap: 8px;
    }
    .back-to-top {
        right: 16px;
        bottom: 16px;
        width: var(--btn-size-mobile);
        height: var(--btn-size-mobile);
    }
}

@media screen and (max-width: 420px) {
    header .nav-container {
        padding: 14px 0;
    }
    header .logo {
        font-size: 24px;
    }
    .media-center-banner h1 {
        font-size: 21px;
        letter-spacing: 1px;
    }
}

/* ========== 无障碍：减少动效 ========== */
@media (prefers-reduced-motion: reduce) {
    .back-to-top {
        transition: none;
    }
}