@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;600;700&display=swap');

:root {
    --text: #252525;
    --subtext: #666;
    --muted: #999;
    --line: #eeeeee;
    --blue: #1677ff;
    --blue-dark: #0f65d8;
    --tip-bg: #f7fbff;
    --tip-border: #dceeff;
    --page-bg: #f6f7f9;
    --content-width: 1000px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    background: var(--page-bg);
    color: var(--text);
    font-family: "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
    font-size: 16px;
    line-height: 1.9;
    -webkit-font-smoothing: antialiased;
}

a {
    color: inherit;
    text-decoration: none;
}

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 999;
    height: 64px;
    background: #fff;
    border-bottom: 1px solid #ededed;
}

.header-inner {
    width: min(var(--content-width), calc(100% - 40px));
    height: 64px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    height: 64px;
    color: #333;
    font-size: 17px;
    font-weight: 600;
    letter-spacing: .1px;
}

.brand img {
    width: 34px;
    height: 34px;
    object-fit: contain;
    display: block;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 36px;
    padding: 0 18px;
    border-radius: 4px;
    background: var(--blue);
    color: #fff;
    font-size: 14px;
    font-weight: 500;
    transition: background .15s ease;
}

.download-btn:hover { background: var(--blue-dark); }

.page {
    width: min(var(--content-width), calc(100% - 40px));
    margin: 92px auto 60px;
}

.article-card {
    background: #fff;
    border: 1px solid #ececec;
    border-radius: 6px;
    overflow: hidden;
}

.article-header {
    padding: 42px 70px 24px;
    text-align: center;
}

.article-title {
    margin: 0;
    color: #222;
    font-size: 30px;
    line-height: 1.45;
    font-weight: 700;
    letter-spacing: .2px;
}

.article-body {
    width: min(900px, calc(100% - 48px));
    margin: 0 auto;
    padding: 0 0 58px;
}

.article-body p {
    margin: 25px 0;
    color: #444;
    font-size: 16px;
    line-height: 2;
    text-align: left;
}

.article-body figure {
    margin: 28px 0 34px;
    text-align: center;
}

.article-body figure img {
    display: block;
    width: auto;
    max-width: 100%;
    max-height: 620px;
    margin: 0 auto;
    border: 1px solid #e9e9e9;
    border-radius: 3px;
    background: #fff;
}

.hero-image img {
    width: 100%;
    max-height: none !important;
}

.image-caption {
    margin-top: 9px;
    color: #aaa;
    font-size: 13px;
    line-height: 1.6;
}

.tip {
    position: relative;
    margin: 30px 0;
    padding: 18px 22px 18px 22px;
    background: var(--tip-bg);
    border: 1px solid var(--tip-border);
    border-left: 3px solid var(--blue);
    border-radius: 4px;
}

.tip-title {
    margin: 0 0 7px;
    color: #1769d1;
    font-size: 15px;
    font-weight: 700;
    line-height: 1.6;
}

.tip p {
    margin: 0;
    color: #555;
    font-size: 14px;
    line-height: 1.85;
}

.summary-tip {
    margin-top: 42px;
    padding: 24px 26px;
    background: #fff;
    border: 1px solid #dfe8f2;
    border-radius: 5px;
}

.summary-tip .tip-title {
    color: #222;
    font-size: 17px;
}

.summary-tip p {
    margin: 0;
    color: #444;
    font-size: 15px;
    line-height: 1.95;
}

.article-footer {
    margin-top: 34px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
    text-align: center;
    color: #aaa;
    font-size: 13px;
}

@media (max-width: 760px) {
    .site-header,
    .header-inner { height: 58px; }

    .header-inner {
        width: calc(100% - 24px);
    }

    .brand {
        height: 58px;
        font-size: 15px;
        gap: 7px;
    }

    .brand img {
        width: 30px;
        height: 30px;
    }

    .download-btn {
        height: 34px;
        padding: 0 13px;
        font-size: 13px;
    }

    .page {
        width: 100%;
        margin: 82px auto 30px;
    }

    .article-card {
        border-left: 0;
        border-right: 0;
        border-radius: 0;
    }

    .article-header {
        padding: 30px 20px 18px;
    }

    .article-title {
        font-size: 24px;
    }

    .article-body {
        width: calc(100% - 32px);
        padding-bottom: 35px;
    }

    .article-body p {
        font-size: 15px;
        line-height: 1.9;
        margin: 21px 0;
    }

    .article-body figure {
        margin: 22px 0 28px;
    }

    .tip {
        padding: 15px 16px;
        margin: 25px 0;
    }
}