/* ============================================================
   LiveBBS 公共基础样式（所有页面共享，最先加载）
   包含：字体、页面背景、顶栏、全局链接胶囊按钮、页脚、正文容器
   页面专属样式写在各自 css 文件中，并在本文件之后加载
   ============================================================ */

@font-face {
    font-family: 'Smileysans';
    src: url('../font/SmileySans.woff2') format('woff2');
    font-weight: normal;
    font-style: normal;
}

body {
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #b0d0e6 0%, #79efff8f 25%, #d0e8f7 45%, #79a4d3 65%, #0e52a0 100%);
    background-attachment: fixed;
    min-height: 100vh;
}

/* ---- 顶栏 ---- */
.topbar {
    width: 100%;
    height: 60px;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    padding: 0 24px;
    background: linear-gradient(90deg, rgba(199, 232, 255, 0.95), rgba(119, 178, 206, 0.9), rgba(44, 93, 146, 0.85));
    backdrop-filter: blur(20px) saturate(120%);
    -webkit-backdrop-filter: blur(20px) saturate(120%);
    border: none;
    border-bottom: 2px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 2px 16px rgba(0, 0, 0, 0.15);
    font-size: 20px;
    color: #1a3a5c;
}

#topbar-logo {
    transition: width 150ms ease, height 150ms ease, opacity 150ms ease;
    opacity: 1;
    /* 按图片原始比例渲染，避免被拉伸/压扁 */
    width: auto;
    height: 100%;
    max-height: 100%;
    object-fit: contain;
    display: inline-block;
    vertical-align: middle;
}

.topbar-links {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 10px;
    padding-right: 35px;
}

.topbar a {
    background: transparent;
    color: inherit;
    box-shadow: none;
    padding: 0;
    margin: 0 3px 0 0;
    border-radius: 0;
}

.topbar a:last-child {
    margin-right: 0;
}

.topbar a:hover,
.topbar a:focus {
    background: transparent;
    color: inherit;
    box-shadow: none;
    text-decoration: none;
}

/* ---- 全局链接胶囊按钮 ---- */
a {
    display: inline-block;
    margin: 4px 6px 4px 0;
    padding: 4px 10px;
    color: #fff;
    background: linear-gradient(135deg, #4a9eff, #004f99);
    border-radius: 12px;
    text-decoration: none;
    font-weight: bold;
    font-size: 15px;
    border: none;
    outline: none;
    cursor: pointer;
}

button {
    background: transparent;
    border: 0;
    cursor: pointer;
}

/* 页脚年份占位：不继承页面全局 span 字号（如 about 页的 30px） */
span.js-year {
    font-size: inherit;
    font-family: inherit;
    color: inherit;
}

/* ---- 页脚 ---- */
.footer {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    margin: 32px 0 16px 0;
    gap: 8px;
}

.footer a {
    background: transparent;
    color: #1a6fbf;
    box-shadow: none;
    border-radius: 0;
    padding: 0 8px;
    margin: 0 2px;
    font-weight: bold;
    text-decoration: none;
    font-size: 15px;
    transition: color 0.2s;
}

.footer a:hover,
.footer a:focus {
    color: #0d5fa0;
    text-decoration: underline;
    background: transparent;
    box-shadow: none;
}

/* ---- 正文容器（关于 / 协议 / 隐私 / 404 页共用） ---- */
main {
    color: #1a3a5c;
    align-items: center;
    text-align: center;
    justify-content: center;
    margin-top: 90px;
}