/* ============================================================
   ai-public.css —— 全站公共样式
   包含：全局基础样式、整体布局、左侧导航模块、
        右侧顶部导航栏模块、Hero 搜索区公共样式、底部 Footer 模块
   适用页面：index.html / list-ai.html / list-ai-article.html /
            show-ai.html / show-ai-article.html
   ============================================================ */

/* ================= 基础重置 ================= */
* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: #333; height: 100vh; overflow: hidden;
}

/* ================= 整体布局 ================= */
.app-layout { display: flex; height: 100vh; width: 100vw; }

/* ================= 左侧导航模块 ================= */
.sidebar {
    width: 250px; background-color: #ffffff; border-right: 1px solid #f0f0f0;
    height: 100%; flex-shrink: 0; display: flex; flex-direction: column;
    overflow: hidden; z-index: 200; transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.sidebar.collapsed { width: 72px; }

.logo-area {
    display: flex; align-items: center; padding: 24px 20px; gap: 12px;
    background-color: #ffffff; flex-shrink: 0; border-bottom: 1px solid #f9fafb;
    transition: padding 0.3s ease;
}
.sidebar.collapsed .logo-area { padding: 24px 0; justify-content: center; }
.logo-icon { font-size: 24px; color: #2563eb; flex-shrink: 0; }
.logo-area h1 { font-size: 20px; font-weight: 800; color: #1e3a8a; letter-spacing: 0.5px; white-space: nowrap; }
.sidebar.collapsed .logo-area h1 { display: none; }

.nav-menu {
    flex: 1; overflow-y: auto; overflow-x: hidden; padding: 12px 8px 24px 8px;
    scrollbar-width: thin; scrollbar-color: transparent transparent;
}
.nav-menu::-webkit-scrollbar { width: 0.75px; } /* 滚动条宽度为原宽度(1.5px)的一半 */
.nav-menu::-webkit-scrollbar-thumb { background-color: transparent; border-radius: 4px; transition: background-color 0.3s ease; }
.nav-menu::-webkit-scrollbar-track { background-color: transparent; }
.sidebar:hover .nav-menu::-webkit-scrollbar-thumb { background-color: #cbd5e1; }
.sidebar:hover .nav-menu { scrollbar-color: #cbd5e1 transparent; }

.nav-menu ul { list-style: none; }
.nav-menu > ul > li { margin-bottom: 4px; }
.nav-menu > ul > li > a {
    display: flex; align-items: center; padding: 12px 16px; text-decoration: none;
    color: #4b5563; font-size: 15px; border-radius: 8px; transition: all 0.2s ease;
    gap: 12px; cursor: pointer; white-space: nowrap;
}
.sidebar.collapsed .nav-menu > ul > li > a { padding: 12px 0; justify-content: center; }
.nav-menu > ul > li > a:hover, .nav-menu > ul > li > a.active { background-color: #eff6ff; color: #2563eb; }
.nav-menu > ul > li > a.active { font-weight: 500; }

.nav-icon { font-size: 16px; width: 20px; text-align: center; color: #6b7280; transition: color 0.2s ease; flex-shrink: 0; }
.nav-menu > ul > li > a:hover .nav-icon, .nav-menu > ul > li > a.active .nav-icon { color: #2563eb; }

.arrow { margin-left: auto; color: #9ca3af; font-size: 12px; transition: transform 0.3s ease; }
.has-submenu.open > a .arrow { transform: rotate(90deg); }
.has-submenu.open > a { color: #2563eb; }
.has-submenu.open > a .nav-icon { color: #2563eb; }

.sidebar.collapsed .nav-menu > ul > li > a span,
.sidebar.collapsed .arrow, .sidebar.collapsed .sub-menu { display: none !important; }

.sub-menu { max-height: 0; overflow: hidden; transition: max-height 0.3s ease-in-out; background-color: transparent; margin: 0; }
.sub-menu.open { max-height: 300px; }
.sub-menu li a { display: block; padding: 10px 16px 10px 48px; text-decoration: none; color: #6b7280; font-size: 14px; border-radius: 8px; transition: all 0.2s ease; }
.sub-menu li a:hover, .sub-menu li a.active { background-color: #eff6ff; color: #2563eb; }
.sub-menu li a.active { font-weight: 500; }

/* ================= 右侧内容模块（容器） ================= */
.main-content {
    flex: 1; overflow-y: auto;
    background: linear-gradient(135deg, #fbfdff 0%, #f0f6fc 30%, #eef6fb 70%, #fbfcfe 100%);
    background-image:
        radial-gradient(circle at 10% 20%, rgba(147, 197, 253, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(191, 219, 254, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 50% 50%, rgba(191, 219, 254, 0.1) 0%, transparent 60%);
    position: relative; display: flex; flex-direction: column;
}

/* ================= 头部导航栏模块 ================= */
.top-navbar {
    display: flex; justify-content: space-between; align-items: center;
    padding: 16px 40px; font-size: 14px; color: #374151;
    z-index: 1000; background: transparent;
    transition: background 0.3s ease, box-shadow 0.3s ease, backdrop-filter 0.3s ease;
    position: sticky; top: 0; width: 100%; flex-shrink: 0;
}
.top-navbar.scrolled {
    background: rgba(251, 253, 255, 0.9); backdrop-filter: blur(12px);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
    border-bottom: 1px solid rgba(0, 0, 0, 0.03);
}
.nav-left, .nav-right { display: flex; align-items: center; gap: 24px; }
.top-navbar a { text-decoration: none; color: inherit; display: flex; align-items: center; gap: 6px; transition: color 0.2s; }
.top-navbar a:hover { color: #2563eb; }
.nav-right .register-btn { background-color: #2563eb; color: #fff !important; padding: 8px 18px; border-radius: 999px; font-weight: 500; box-shadow: 0 4px 10px rgba(37, 99, 235, 0.2); transition: all 0.3s; }
.nav-right .register-btn:hover { background-color: #1d4ed8; transform: translateY(-1px); }
.hamburger-btn { display: flex; flex-direction: column; justify-content: space-between; width: 24px; height: 18px; cursor: pointer; margin-right: 16px; }
.hamburger-btn span { display: block; height: 2px; background-color: #374151; border-radius: 2px; transition: all 0.3s; }
.hamburger-btn span:nth-child(1) { width: 16px; } .hamburger-btn span:nth-child(2) { width: 24px; } .hamburger-btn span:nth-child(3) { width: 16px; }
.sidebar.collapsed .hamburger-btn span { width: 24px; }
.has-dropdown { position: relative; height: 100%; display: flex; align-items: center; }
.dropdown-menu { position: absolute; top: 100%; left: 0; background: #fff; box-shadow: 0 10px 30px rgba(0,0,0,0.08); border-radius: 8px; padding: 8px 0; min-width: 160px; max-height: 0; opacity: 0; visibility: hidden; overflow: hidden; transform: translateY(10px); transition: all 0.4s; z-index: 100; list-style: none; }
.has-dropdown:hover .dropdown-menu { max-height: 300px; opacity: 1; visibility: visible; transform: translateY(0); }
.dropdown-menu li a { display: block; padding: 10px 20px; color: #4b5563; font-size: 14px; text-decoration: none; }
.dropdown-menu li a:hover { background-color: #eff6ff; color: #2563eb; }

/* ================= Hero 搜索区（公共部分） =================
   注：.page-header 的 min-height、.hero-title 字号等
   各页面略有差异，在各自的页面 css 中覆盖 */
.page-header { position: relative; display: flex; flex-direction: column; flex-shrink: 0; }
.hero-section { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; padding-bottom: 20px; }
.hero-badge { font-family: monospace; font-size: 12px; font-weight: 700; color: #1e40af; background: rgba(255,255,255,0.7); border: 1px solid rgba(37, 99, 235, 0.2); padding: 5px 16px; border-radius: 999px; box-shadow: 0 4px 15px rgba(37, 99, 235, 0.1); backdrop-filter: blur(10px); margin-bottom: 20px; }
.hero-title { font-size: 36px; font-weight: 900; color: #1e3a8a; display: flex; align-items: center; gap: 14px; margin-bottom: 30px; }
.hero-title i { font-size: 34px; color: #2563eb; }
.hero-tabs { display: flex; gap: 16px; margin-bottom: 20px; font-size: 15px; color: #6b7280; }
.hero-tabs span { cursor: pointer; position: relative; padding: 0 10px; transition: all 0.3s; }
.hero-tabs span.active { color: #1e3a8a; font-weight: 600; }
.hero-tabs span.active::after { content: ''; position: absolute; bottom: -6px; left: 50%; transform: translateX(-50%); width: 20px; height: 3px; background: #1e3a8a; border-radius: 3px; }
.search-area { position: relative; width: 100%; max-width: 680px; display: flex; flex-direction: column; align-items: center; }
.search-wrapper { position: relative; width: 100%; }
.search-wrapper input { width: 100%; padding: 18px 28px; padding-right: 60px; border-radius: 999px; border: 1px solid transparent; background: rgba(0,0,0,0.2); font-size: 16px; color: #333; outline: none; transition: all 0.3s; }
.search-wrapper input::placeholder { color: #f3f4f6; }
.search-wrapper input:focus { background: #fff; border-color: rgba(37, 99, 235, 0.3); box-shadow: 0 10px 40px rgba(37, 99, 235, 0.15); }
.search-wrapper input:focus::placeholder { color: #9ca3af; }
.search-icon { position: absolute; right: 24px; top: 50%; transform: translateY(-50%); font-size: 20px; color: #6b7280; cursor: pointer; }
.search-icon:hover { color: #2563eb; }
.triangle-pointer { position: absolute; bottom: -6px; width: 0; height: 0; border-left: 5px solid transparent; border-right: 5px solid transparent; border-top: 6px solid rgba(0,0,0,0.2); transition: left 0.3s; pointer-events: none; }
.search-sources { display: flex; justify-content: center; gap: 0; white-space: nowrap; margin-top: 5px; font-size: 14px; color: #6b7280; }
.search-sources span { cursor: pointer; padding: 4px 10px; transition: color 0.3s; }
.search-sources span.active { color: #1e3a8a; }

/* ================= 底部 Footer 模块 ================= */
.site-footer {
    margin-top: auto;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-top: 1px solid rgba(0, 0, 0, 0.04);
    padding: 50px 40px 30px 40px;
    flex-shrink: 0;
    z-index: 10;
}

.footer-top {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand { display: flex; flex-direction: column; gap: 16px; }
.footer-brand .brand-logo {
    display: flex; align-items: center; gap: 10px;
    font-size: 20px; font-weight: 800; color: #1e3a8a;
}
.footer-brand .brand-logo i { color: #2563eb; font-size: 24px; }
.footer-brand p { font-size: 13px; color: #6b7280; line-height: 1.6; max-width: 300px; }
.footer-socials { display: flex; gap: 12px; margin-top: 6px; }
.footer-socials a {
    width: 36px; height: 36px; border-radius: 50%;
    background: #ffffff; color: #6b7280;
    display: flex; align-items: center; justify-content: center;
    text-decoration: none; font-size: 16px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.03);
    transition: all 0.3s ease;
}
.footer-socials a:hover {
    background: #2563eb; color: #ffffff; transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(37, 99, 235, 0.3);
}

.footer-links { display: flex; flex-direction: column; gap: 14px; }
.footer-links h4 { font-size: 14px; font-weight: 700; color: #1e3a8a; margin-bottom: 4px; }
.footer-links a { text-decoration: none; color: #6b7280; font-size: 13px; transition: color 0.2s; }
.footer-links a:hover { color: #2563eb; }

.footer-bottom {
    display: flex; justify-content: space-between; align-items: center;
    padding-top: 24px;
    border-top: 1px solid rgba(0, 0, 0, 0.04);
    font-size: 12px; color: #9ca3af;
}
.footer-bottom-links { display: flex; gap: 20px; }
.footer-bottom-links a { text-decoration: none; color: #9ca3af; transition: color 0.2s; }
.footer-bottom-links a:hover { color: #2563eb; }

/* Footer 响应式适配 */
@media (max-width: 1024px) {
    .footer-top { grid-template-columns: 1fr 1fr; gap: 30px; }
}
@media (max-width: 768px) {
    .footer-top { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; gap: 12px; align-items: flex-start; }
}