/* ================================================================
   Layout — 全局布局、背景、主内容区
   ================================================================ */

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font-family);
    background: #1A1C1E;
    color: var(--color-text-primary);
    display: flex;
    position: relative;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== 背景装饰球体 ===== */
.bg-orb {
    position: fixed;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.12;
    pointer-events: none;
    z-index: 0;
}
.bg-orb--1 {
    width: 520px; height: 520px;
    background: var(--color-primary);
    top: -180px; right: -120px;
}
.bg-orb--2 {
    width: 400px; height: 400px;
    background: var(--color-accent);
    bottom: -140px; left: -100px;
}
.bg-orb--3 {
    width: 300px; height: 300px;
    background: var(--color-primary-light);
    top: 40%; left: 45%;
    opacity: 0.06;
}

/* ===== 主内容区域 ===== */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    height: 100vh;
    overflow-y: auto;
    overflow-x: hidden;
    position: relative;
    z-index: 1;
    padding: 32px;
    scroll-behavior: smooth;
    /* 侧栏收起/展开时跟着滑动，别硬跳 */
    transition: margin-left var(--transition-normal);
}

/* ===== 页面容器 ===== */
.page {
    display: none;
    max-width: var(--content-max-width);
    margin: 0 auto;
    animation: pageEnter 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}
.page--active {
    display: block;
}

@keyframes pageEnter {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== 页面标题 ===== */
.page-header {
    margin-bottom: 28px;
}
.page-header--with-icon {
    display: flex;
    align-items: center;
    gap: 16px;
}
.page-header__icon {
    flex-shrink: 0;
}
.page-header__icon svg {
    display: block;
    width: 100%;
    height: 100%;
}
.page-header__title {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: #96D8B8;
}
.page-header__subtitle {
    font-size: 13px;
    color: #A0A8A6;
    margin-top: 4px;
}

/* ===== 两列布局 ===== */
.grid-2col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

/* ===== 三列布局 ===== */

/* ===== 四列布局 ===== */
.grid-4col {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

/* ===== Section spacing ===== */
.section {
    margin-bottom: 28px;
}
.section__title {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.section__title svg {
    width: 18px;
    height: 18px;
    opacity: 0.7;
}

/* ===== Responsive ===== */
@media (max-width: 1200px) {
    .grid-3col { grid-template-columns: repeat(2, 1fr); }
    .grid-4col { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 900px) {
    .grid-2col { grid-template-columns: 1fr; }
    .grid-3col { grid-template-columns: 1fr; }
    .grid-4col { grid-template-columns: repeat(2, 1fr); }
    .main-content { padding: 20px; }
}
@media (max-width: 700px) {
    /* ⚠️ 这里必须用 !important：
       sidebar.css 里有一条 `:root.is-collapsed { --sidebar-width: ... }`，
       它的特异性（0,2,0）和下面这条 `:root.is-collapsed` 完全相同，
       而 sidebar.css 在 layout.css **之后**加载 → 不加 !important 的话它会赢，
       收起态会把移动端的 0px 顶成 76px。
       实测过：不加 !important 时窄屏下 side bar 宽度是 76px 而不是 0。 */
    :root,
    :root.is-collapsed { --sidebar-width: 0px !important; }
    .sidebar { transform: translateX(-100%); }
    .sidebar--open { transform: translateX(0); }
    .main-content { margin-left: 0; }
    /* 抽屉模式下开合由滑动决定，收起按钮没有意义 */
    .sidebar__toggle { display: none; }
}