:root {
    --bg: #f5f7fb;
    --panel: #ffffff;
    --text-main: #1d2433;
    --text-muted: #5f687a;
    --line: #e5eaf3;
    --accent: #315efb;
    --accent-soft: #ebf0ff;
    --shadow: 0 12px 30px rgba(16, 33, 72, 0.08);
    --radius: 14px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text-main);
    font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.65;
}

.site {
    max-width: 1240px;
    margin: 0 auto;
    padding: 28px;
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 24px;
    min-height: 100vh;
}

.sidebar {
    position: sticky;
    top: 28px;
    align-self: start;
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.sidebar-inner {
    padding: 24px 22px;
}

.content {
    display: grid;
    gap: 18px;
    align-content: start;
}

.section {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px 22px;
}

.section h2 {
    margin: 0 0 14px;
    font-size: 22px;
    border-bottom: 1px solid var(--line);
    padding-bottom: 10px;
    color: #111827;
}

@media (max-width: 960px) {
    .site {
        grid-template-columns: 1fr;
        padding: 14px;
    }

    .sidebar {
        position: static;
    }
}