:root {
    --bg-color: #fbfbfd;
    --surface-color: #ffffff;
    --surface-secondary: #f5f5f7;
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;
    --accent-color: #FF7A00;
    --accent-hover: #E06A00;
    --border-color: rgba(0, 0, 0, 0.08);

    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", STHeiti, sans-serif;
    --max-width: 800px;
    --nav-height: 60px;
    --radius-md: 16px;
    --radius-lg: 24px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
}

[hidden] { display: none !important; }

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    scroll-behavior: smooth;
}

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

ul { list-style: none; }

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

button:focus-visible,
a:focus-visible {
    outline: 3px solid rgba(255, 122, 0, 0.45);
    outline-offset: 3px;
}

.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.nav-wrapper {
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: rgba(251, 251, 253, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border-color);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--nav-height);
    padding: 0 24px;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-logo {
    font-weight: 600;
    font-size: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-logo i { color: var(--accent-color); }

.nav-back {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.2s;
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav-back:hover { color: var(--text-primary); }

.section-title {
    font-size: 24px;
    line-height: 1.5;
    font-weight: 600;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.history-section {
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
}

/* 第一个区域紧接导航栏。 */
#latest-section {
    border-top: none;
    padding-top: 32px;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.history-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.history-info { width: 100%; }

.history-header {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px 10px;
    margin-bottom: 12px;
}

.history-version {
    font-size: 18px;
    font-weight: 600;
}

.latest-tag {
    font-size: 11px;
    background: rgba(255, 122, 0, 0.1);
    color: var(--accent-color);
    padding: 3px 8px;
    border-radius: 6px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    vertical-align: middle;
}

.history-date {
    font-size: 13px;
    color: var(--text-secondary);
}

.history-changelog {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
}

.history-changelog ul {
    list-style: disc;
    padding-left: 20px;
    margin-top: 8px;
}

.history-changelog li { margin-bottom: 4px; }

.toggle-assets-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    background: var(--surface-secondary);
    color: var(--text-primary);
    border-radius: 999px;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s;
    width: fit-content;
}

.toggle-assets-btn:hover,
.toggle-assets-btn.active { background: #e5e5ea; }

.toggle-icon { transition: transform 0.3s ease; }

.history-assets {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.3s ease, margin-top 0.3s ease;
    margin-top: 0;
}

.history-assets.open {
    grid-template-rows: 1fr;
    margin-top: 16px;
}

.history-assets-inner {
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.history-files { margin-bottom: 16px; }

.history-files-title {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 6px;
}

.file-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.file-tag {
    background: var(--surface-secondary);
    color: var(--text-primary);
    padding: 5px 12px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    border: 1px solid var(--border-color);
}

.package-block { margin-bottom: 20px; }
.package-block:last-child { margin-bottom: 0; }

.package-header {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0 0 4px 4px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.package-description {
    margin: 0 4px 4px;
    color: var(--text-secondary);
    font-size: 13px;
    line-height: 1.6;
}

.package-size {
    margin: 0 4px 10px;
    color: var(--text-secondary);
    font-size: 12px;
}

.package-channels {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 12px;
}

.channel-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-width: 0;
    padding: 12px 16px;
    background: var(--surface-secondary);
    border-radius: 12px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    transition: all 0.2s;
    border: 1px solid transparent;
    text-align: center;
}

.channel-btn:hover,
.channel-btn:active {
    background: #fff;
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.toggle-history-btn {
    width: 100%;
    padding: 16px;
    margin-top: 16px;
    background: var(--surface-secondary);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-weight: 500;
    font-size: 14px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 6px;
    transition: background 0.2s;
}

.toggle-history-btn:hover { background: #e5e5ea; }

.guide-section {
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.guide-step {
    background: var(--surface-secondary);
    padding: 24px;
    border-radius: var(--radius-md);
    text-align: center;
}

.step-num {
    width: 32px;
    height: 32px;
    background: var(--text-primary);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    margin: 0 auto 12px;
}

.step-text {
    font-size: 15px;
    font-weight: 500;
}

.faq-section {
    padding: 40px 0 80px;
    border-top: 1px solid var(--border-color);
}

.faq-item { border-bottom: 1px solid var(--border-color); }

.faq-question {
    width: 100%;
    text-align: left;
    padding: 20px 0;
    font-size: 16px;
    font-weight: 500;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    color: var(--text-primary);
}

.faq-icon {
    flex: 0 0 auto;
    transition: transform 0.3s ease;
}

.faq-item.active .faq-icon { transform: rotate(45deg); }

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

.faq-answer p { padding-top: 8px; }

.faq-item.active .faq-answer {
    max-height: 300px;
    padding-bottom: 20px;
}

.footer {
    text-align: center;
    padding: 32px 0;
    color: var(--text-secondary);
    font-size: 13px;
    border-top: 1px solid var(--border-color);
    background: var(--surface-color);
}

@media (max-width: 600px) {
    #latest-section { padding-top: 24px; }

    .history-card { padding: 20px; }

    .toggle-assets-btn {
        width: 100%;
        justify-content: center;
        padding: 12px;
    }

    .package-channels { grid-template-columns: 1fr; }

    .channel-btn {
        padding: 14px 16px;
        font-size: 15px;
    }

    .guide-steps { grid-template-columns: 1fr; }

    .guide-step {
        padding: 20px;
        display: flex;
        align-items: center;
        gap: 16px;
        text-align: left;
    }

    .step-num {
        margin: 0;
        flex-shrink: 0;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }
}