/* ================================================================
   layout.css · 顶部栏、侧边栏、主内容区等页面骨架
   ================================================================ */

/* ========== 顶部栏 ========== */
.top-bar {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--bg-tertiary);
    padding: 12px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 17px;
    color: var(--text-primary);
}

.logo-mark {
    color: var(--accent-cyan);
    font-size: 20px;
}

.logo-sub {
    color: var(--text-secondary);
    font-weight: 400;
    font-size: 13px;
    padding-left: 10px;
    border-left: 1px solid var(--bg-tertiary);
    margin-left: 4px;
}

.top-nav {
    display: flex;
    gap: 4px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-base);
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.nav-link.active {
    color: var(--accent-cyan);
    background: rgba(6, 182, 212, 0.1);
}

/* ========== 页面主布局 ========== */
.page-layout {
    display: grid;
    grid-template-columns: 240px 1fr;
    min-height: calc(100vh - 57px);
}

/* ========== 侧边栏 ========== */
.sidebar {
    background: var(--bg-secondary);
    border-right: 1px solid var(--bg-tertiary);
    padding: 20px 12px;
    overflow-y: auto;
    position: sticky;
    top: 57px;
    height: calc(100vh - 57px);
}

.sidebar-section-title {
    font-size: 11px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1.2px;
    font-weight: 700;
    padding: 0 12px;
    margin-bottom: 12px;
    margin-top: 8px;
}

.sidebar-section-title:not(:first-child) {
    margin-top: 24px;
}

.sidebar-nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    border: 1px solid transparent;
    margin-bottom: 4px;
    font-size: 14px;
    color: var(--text-secondary);
    background: transparent;
    width: 100%;
    text-align: left;
}

.sidebar-nav-item:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.sidebar-nav-item.active {
    background: rgba(59, 130, 246, 0.15);
    border-color: var(--accent-blue);
    color: var(--accent-blue);
    font-weight: 600;
}

.sidebar-nav-item .nav-icon {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    font-size: 13px;
    flex-shrink: 0;
    background: var(--bg-tertiary);
}

.sidebar-nav-item.active .nav-icon {
    background: var(--accent-blue);
    color: white;
}

.sidebar-nav-item .nav-label {
    flex: 1;
}

.sidebar-nav-item .nav-status {
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 4px;
    background: var(--bg-tertiary);
    color: var(--text-muted);
}

.sidebar-nav-item.coming-soon {
    opacity: 0.45;
    cursor: not-allowed;
}

.sidebar-nav-item.coming-soon:hover {
    background: transparent;
    color: var(--text-secondary);
}

/* ========== 主内容区 ========== */
.main-content {
    padding: 24px;
    max-width: 1280px;
    width: 100%;
}

/* ========== 模式切换栏 ========== */
.mode-switcher {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    background: var(--bg-secondary);
    padding: 6px;
    border-radius: var(--radius-md);
    width: fit-content;
}

.mode-btn {
    padding: 10px 24px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
}

.mode-btn:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.mode-btn.active {
    background: var(--accent-blue);
    color: white;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

/* ========== 面板 ========== */
.panel {
    display: none;
    animation: fadeIn 0.35s ease;
}

.panel.active {
    display: block;
}

/* ========== 演示区两栏布局 ========== */
.demo-layout {
    display: grid;
    grid-template-columns: 1fr 360px;
    gap: 24px;
    align-items: start;
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
    .page-layout { grid-template-columns: 1fr; }
    .sidebar {
        position: static;
        height: auto;
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
        padding: 12px;
    }
    .sidebar-section-title { display: none; }
    .sidebar-nav-item { width: auto; }
    .demo-layout { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
    .main-content { padding: 12px; }
    .mode-btn { padding: 8px 14px; font-size: 12px; }
    .logo-sub { display: none; }
    .top-nav { display: none; }
}