/* ============================================================
   爱问学长 · 「星云 Nebula」AI 科技风皮肤  v1.0  2026-09-23
   覆盖层方案：加载于 CSS 链末尾，仅覆盖视觉，不改布局逻辑
   回滚方式：删除 meta.php 中对本文件的引入即可
   ============================================================ */

/* ---------- 设计变量 ---------- */
:root {
    --xz-indigo:  #6366f1;
    --xz-violet:  #8b5cf6;
    --xz-cyan:    #06b6d4;
    --xz-deep:    #0b1026;
    --xz-deep2:   #141a35;
    --xz-grad:    linear-gradient(135deg, #6366f1 0%, #8b5cf6 55%, #06b6d4 130%);
    --xz-grad-btn:linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --xz-text:    #1e2440;
    --xz-sub:     #5b6478;
    --xz-bg:      #f4f6fb;
    --xz-card:    #ffffff;
    --xz-radius:  16px;
    --xz-shadow:  0 6px 24px rgba(30, 36, 84, .08);
    --xz-shadow-hover: 0 14px 40px rgba(99, 102, 241, .18);
    --xz-font: "PingFang SC", "HarmonyOS Sans SC", "MiSans", "Microsoft YaHei UI", "Segoe UI", system-ui, sans-serif;
}

/* ---------- 全局基础 ---------- */
html { scroll-behavior: smooth; }
body {
    background: var(--xz-bg) !important;
    font-family: var(--xz-font) !important;
    color: var(--xz-text);
    position: relative;
}
/* 顶部科技光斑装饰 */
body::before {
    content: "";
    position: fixed;
    inset: 0 0 auto 0;
    height: 520px;
    pointer-events: none;
    z-index: 0;
    background:
        radial-gradient(600px 220px at 12% -40px, rgba(99, 102, 241, .14), transparent 70%),
        radial-gradient(520px 200px at 88% -60px, rgba(6, 182, 212, .12), transparent 70%),
        radial-gradient(400px 160px at 55% -80px, rgba(139, 92, 246, .10), transparent 70%);
}
#body, #main { position: relative; z-index: 1; }

::selection { background: rgba(99, 102, 241, .28); }
a { transition: color .2s ease; }

/* 自定义滚动条 */
::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-track { background: #eceff7; }
::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, #6366f1, #8b5cf6);
    border-radius: 8px;
    border: 2px solid #eceff7;
}
::-webkit-scrollbar-thumb:hover { background: #8b5cf6; }

/* ============================================================
   顶栏 #header —— 深空色
   ============================================================ */
#header {
    background: var(--xz-deep) !important;
    border-bottom: none !important;
    height: 36px !important;
    line-height: 36px !important;
}
#header .content { color: #9aa3c0 !important; }
#header a, #header .header-item { color: #9aa3c0 !important; }
#header a:hover, #header .header-item:hover {
    color: #c7d2fe !important;
    text-shadow: 0 0 12px rgba(139, 92, 246, .55);
}

/* ============================================================
   导航 #nav —— 深色玻璃拟态 + 吸顶
   ============================================================ */
#nav {
    position: sticky !important;
    top: 0 !important;
    z-index: 999 !important;
    background: rgba(13, 17, 38, .88) !important;
    -webkit-backdrop-filter: saturate(160%) blur(18px);
    backdrop-filter: saturate(160%) blur(18px);
    box-shadow: 0 8px 32px rgba(11, 16, 38, .35);
    border-bottom: none;
}
/* 导航底部霓虹渐变光线 */
#nav::after {
    content: "";
    position: absolute;
    left: 0; right: 0; bottom: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent 4%, #6366f1 25%, #8b5cf6 50%, #06b6d4 75%, transparent 96%);
    opacity: .85;
    pointer-events: none;
}
#nav .logo { display: flex; align-items: center; filter: drop-shadow(0 0 14px rgba(99, 102, 241, .45)); }
#nav .logo img { max-height: 52px; }

/* 导航项 */
#nav .menu .nav-item {
    color: #c3cbe6 !important;
    font-weight: 500;
    letter-spacing: .5px;
    border-bottom: 2px solid transparent !important;
    position: relative;
    transition: color .22s ease, text-shadow .22s ease;
}
#nav .menu .nav-item::after {
    content: "";
    position: absolute;
    left: 50%; right: 50%; bottom: 4px;
    height: 2px; border-radius: 2px;
    background: linear-gradient(90deg, #6366f1, #06b6d4);
    transition: left .25s ease, right .25s ease;
}
#nav .menu .nav-item:hover,
#nav .menu .nav-item.active {
    color: #ffffff !important;
    text-shadow: 0 0 16px rgba(139, 92, 246, .75);
    border-bottom: 2px solid transparent !important;
}
#nav .menu .nav-item:hover::after,
#nav .menu .nav-item.active::after { left: 8%; right: 8%; }

/* NEW 徽标 */
#nav .menu .nav-item .mask {
    background: var(--xz-grad-btn) !important;
    box-shadow: 0 0 10px rgba(139, 92, 246, .8);
    border-radius: 6px 6px 6px 0;
    font-weight: 700;
}

/* 搜索框 —— 深色胶囊 + 聚焦发光 */
#nav .search {
    background: rgba(255, 255, 255, .10) !important;
    border: 1px solid rgba(139, 92, 246, .45) !important;
    border-radius: 999px !important;
    width: 220px !important;
    position: relative;
    transition: box-shadow .25s ease, border-color .25s ease, width .3s ease;
}
#nav .search:focus-within {
    border-color: #8b5cf6 !important;
    box-shadow: 0 0 0 3px rgba(139, 92, 246, .22), 0 0 22px rgba(139, 92, 246, .35);
    width: 260px !important;
}
#nav #search {
    background: transparent !important;
    color: #e6e9f7 !important;
    border: none !important;
    outline: none !important;
}
#nav #search::placeholder { color: #7e88ab !important; }
#nav .search-icon {
    float: none;
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
    filter: invert(64%) sepia(88%) saturate(2812%) hue-rotate(224deg) brightness(96%) contrast(92%);
    cursor: pointer;
    border-radius: 50%;
    transition: transform .2s ease;
}
#nav .search-icon:hover { transform: translateY(-50%) scale(1.15); }

/* 发布按钮 —— 渐变发光胶囊 */
#nav .send, .send-menu > .send {
    background: var(--xz-grad-btn) !important;
    border-radius: 999px !important;
    box-shadow: 0 4px 18px rgba(99, 102, 241, .55);
    font-weight: 600;
    letter-spacing: 1px;
    transition: transform .22s ease, box-shadow .22s ease, filter .22s ease;
}
#nav .send:hover, .send-menu > .send:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 28px rgba(139, 92, 246, .7);
    filter: brightness(1.1);
}
.send-menu ul {
    background: rgba(20, 26, 53, .96) !important;
    -webkit-backdrop-filter: blur(14px);
    backdrop-filter: blur(14px);
    border: 1px solid rgba(139, 92, 246, .35);
    border-radius: 12px;
    box-shadow: 0 16px 48px rgba(11, 16, 38, .5);
    overflow: hidden;
}
.send-menu ul li a { color: #c3cbe6 !important; }
.send-menu ul li a:hover {
    color: #fff !important;
    background: rgba(139, 92, 246, .18) !important;
}

/* ============================================================
   首页 Banner 区
   ============================================================ */
#main #banner { margin-bottom: 34px !important; }
#banner .banner-img,
#banner .banner-con img,
.banner-left img {
    border-radius: var(--xz-radius) !important;
    box-shadow: var(--xz-shadow);
    transition: box-shadow .3s ease, transform .3s ease;
}
#banner .banner-img:hover { box-shadow: var(--xz-shadow-hover); }

/* 顶部公告条 */
#banner .banner-head {
    background: #ffffff url("../index/img/notice.png") no-repeat 18px center !important;
    border-radius: 12px;
    border: 1px solid rgba(99, 102, 241, .16);
    box-shadow: var(--xz-shadow);
}

/* ============================================================
   区块标题 .same-list-menu —— 渐变竖条 + 科技标题
   ============================================================ */
.same-list-menu .menu-title {
    border-left: 5px solid transparent !important;
    border-image: linear-gradient(180deg, #6366f1, #06b6d4) 1 !important;
    padding-left: 16px !important;
    color: var(--xz-text) !important;
    font-weight: 800 !important;
    letter-spacing: 1px;
    position: relative;
}
/* 标题后的小光点 */
.same-list-menu .menu-title::after {
    content: "";
    display: inline-block;
    width: 7px; height: 7px;
    margin-left: 10px;
    border-radius: 50%;
    background: var(--xz-grad-btn);
    box-shadow: 0 0 10px rgba(139, 92, 246, .9);
    vertical-align: middle;
    animation: xzPulse 2.2s ease-in-out infinite;
}
@keyframes xzPulse {
    0%, 100% { opacity: 1; box-shadow: 0 0 8px rgba(139, 92, 246, .8); }
    50%      { opacity: .45; box-shadow: 0 0 18px rgba(6, 182, 212, .9); }
}

/* Tab —— 胶囊化 */
.same-list-left .menu-fun-list li {
    border-radius: 999px !important;
    color: var(--xz-sub) !important;
    font-weight: 500;
    transition: all .22s ease;
    margin: 0 4px !important;
}
.same-list-left .menu-fun-list li:hover {
    color: var(--xz-indigo) !important;
    background: rgba(99, 102, 241, .10) !important;
}
.same-list-left .menu-fun-list li.active {
    background: var(--xz-grad-btn) !important;
    color: #fff !important;
    box-shadow: 0 4px 16px rgba(99, 102, 241, .45);
}

/* ============================================================
   问题列表 —— 卡片容器 + 行悬浮光效
   ============================================================ */
.same-list-left .same-list-main {
    background: var(--xz-card);
    border-radius: var(--xz-radius);
    box-shadow: var(--xz-shadow);
    padding: 6px 10px;
    border: 1px solid rgba(99, 102, 241, .08);
}
.same-list-left .same-list-main li {
    border-bottom: 1px solid #eef0f8 !important;
    padding: 12px 10px 14px !important;
    border-radius: 10px;
    transition: background .2s ease, transform .2s ease;
    position: relative;
}
.same-list-left .same-list-main li:hover {
    background: linear-gradient(90deg, rgba(99, 102, 241, .06), rgba(6, 182, 212, .04));
}
.same-list-left .same-list-main li .title {
    color: var(--xz-text) !important;
    font-weight: 600;
    transition: color .2s ease;
}
.same-list-left .same-list-main li .title:hover {
    color: var(--xz-indigo) !important;
    text-shadow: 0 0 1px rgba(99, 102, 241, .3);
}
/* 分类标签 chip */
.same-list-left .same-list-main li .list-bottom .tag {
    background: rgba(99, 102, 241, .10) !important;
    color: var(--xz-indigo) !important;
    border-radius: 999px !important;
    border: 1px solid rgba(99, 102, 241, .18);
    transition: all .2s ease;
}
.same-list-left .same-list-main li .list-bottom .tag:hover {
    background: var(--xz-grad-btn) !important;
    color: #fff !important;
    box-shadow: 0 3px 12px rgba(99, 102, 241, .4);
}
.same-list-left .same-list-main li .list-bottom .price { color: #f97316 !important; }

/* 右侧栏卡片 */
.same-list-right .same-right-main,
.same-list-right .same-right-imgbox,
#banner .banner-right img {
    border-radius: var(--xz-radius) !important;
    box-shadow: var(--xz-shadow);
    overflow: hidden;
}
.same-right-main .title {
    border-bottom: 1px solid #eef0f8 !important;
    font-weight: 700;
    color: var(--xz-text);
}

/* ============================================================
   学长学姐专家卡 —— 玻璃卡 + 头像光环
   ============================================================ */
#industryExperts li {
    background: var(--xz-card);
    border: 1px solid rgba(99, 102, 241, .10) !important;
    border-radius: var(--xz-radius) !important;
    box-shadow: var(--xz-shadow);
    transition: transform .28s ease, box-shadow .28s ease, border-color .28s ease;
    position: relative;
    overflow: hidden;
}
/* 卡片顶部渐变细线 */
#industryExperts li::before {
    content: "";
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, #6366f1, #8b5cf6, #06b6d4);
    opacity: 0;
    transition: opacity .28s ease;
}
#industryExperts li:hover {
    transform: translateY(-6px);
    box-shadow: var(--xz-shadow-hover);
    border-color: rgba(139, 92, 246, .35) !important;
}
#industryExperts li:hover::before { opacity: 1; }
#industryExperts .character { border-bottom: 1px solid #eef0f8 !important; }
#industryExperts .character .character-img {
    border-radius: 50% !important;
    padding: 2px;
    background: var(--xz-grad-btn);
    box-shadow: 0 0 16px rgba(139, 92, 246, .45);
    transition: transform .28s ease;
}
#industryExperts li:hover .character-img { transform: scale(1.06) rotate(3deg); }
#industryExperts .ask-btn {
    border: none !important;
    background: var(--xz-grad-btn) !important;
    color: #fff !important;
    border-radius: 999px !important;
    box-shadow: 0 4px 14px rgba(99, 102, 241, .4);
    transition: transform .22s ease, box-shadow .22s ease;
}
#industryExperts .ask-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 22px rgba(139, 92, 246, .6);
    background: var(--xz-grad-btn) !important;
    color: #fff !important;
}
#industryExperts .help-counts { color: var(--xz-cyan) !important; font-weight: 700; }

/* ============================================================
   通用按钮 / 链接色统一
   ============================================================ */
.btn-primary, .main-theme {
    background: var(--xz-grad-btn) !important;
    border: none !important;
    color: #fff !important;
    border-radius: 10px !important;
    box-shadow: 0 4px 14px rgba(99, 102, 241, .35);
}
.main-theme:hover {
    background: var(--xz-grad-btn) !important;
    color: #fff !important;
    filter: brightness(1.12);
}
.second-theme:hover {
    background: var(--xz-grad-btn) !important;
    color: #fff !important;
}

/* ============================================================
   页脚 —— 深空色
   ============================================================ */
#footer .link-wrap {
    background: transparent !important;
    margin-top: 30px;
}
#footer .footer-title .title {
    background: var(--xz-grad-btn) !important;
    border-radius: 999px;
    box-shadow: 0 4px 16px rgba(99, 102, 241, .4);
}
#footer .footer-link { color: var(--xz-sub) !important; transition: all .2s ease; }
#footer .footer-link:hover { color: var(--xz-indigo) !important; text-shadow: 0 0 10px rgba(99,102,241,.4); }
#footer .copyrigth-wrap {
    background: var(--xz-deep) !important;
    color: #9aa3c0 !important;
    padding: 22px 0;
    margin-top: 20px;
    position: relative;
}
#footer .copyrigth-wrap::before {
    content: "";
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, #6366f1 30%, #8b5cf6 50%, #06b6d4 70%, transparent);
}
#footer .copyrigth-wrap a { color: #9aa3c0 !important; }
#footer .copyrigth-wrap a:hover { color: #c7d2fe !important; }

/* ============================================================
   回到顶部 —— 渐变发光圆钮
   ============================================================ */
.side-tool #to_top .function-button {
    background: var(--xz-grad-btn) !important;
    border-radius: 50% !important;
    box-shadow: 0 6px 20px rgba(99, 102, 241, .55);
    color: #fff !important;
    transition: transform .22s ease, box-shadow .22s ease;
}
.side-tool #to_top .function-button:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(139, 92, 246, .75);
}
.side-tool #to_top .function-button .fa { color: #fff !important; }

/* ============================================================
   内容页通用（问题详情/文章/列表页共用元素）
   ============================================================ */
.bg-fff {
    background: var(--xz-card);
    border-radius: var(--xz-radius);
    box-shadow: var(--xz-shadow);
}
.widget-tag-nav a.current span { border-bottom: 2px solid var(--xz-indigo) !important; }

/* 渐入动画 */
@keyframes xzFadeUp {
    from { opacity: 0; transform: translateY(14px); }
    to   { opacity: 1; transform: translateY(0); }
}
#banner, #answers, #industryExperts { animation: xzFadeUp .55s ease both; }
#industryExperts { animation-delay: .12s; }

/* ============================================================
   导航"发布"按钮 —— 登录控制 + 位置修正  v1.2  2026-09-23
   未登录显示「登录 / 免费注册」，登录后显示「发布」下拉
   导航行改 flex 居中，修复右侧元素浮到顶栏的问题
   ============================================================ */
#nav .content {
    display: flex !important;
    align-items: center;
    height: 66px;
    box-sizing: border-box;
}
#nav .menu {
    flex: 0 0 auto;
    display: flex;
    align-items: center;
    white-space: nowrap;
}
#nav .menu .nav-item { flex: 0 0 auto; }
.send-menu {
    margin-left: 26px !important;
    flex-shrink: 0;
}
#nav .send {
    width: 84px !important;
}
/* 下拉菜单：还原原始几何（按钮正下方、左对齐、与按钮同宽） */
.send-menu ul {
    left: 0 !important;
    right: auto !important;
    width: 84px !important;
    min-width: 0 !important;
    top: calc(100% + 6px) !important;
    padding: 10px 0 !important;
}

/* 未登录：登录 / 免费注册 */
.nav-auth {
    height: 36px;
    display: flex;
    align-items: center;
    margin-left: 26px;
    flex-shrink: 0;
}
.nav-auth-login {
    color: #c3cbe6 !important;
    font-size: 14px;
    letter-spacing: 1px;
    padding-right: 16px;
    white-space: nowrap;
    transition: color .22s ease, text-shadow .22s ease;
}
.nav-auth-login:hover {
    color: #fff !important;
    text-shadow: 0 0 14px rgba(139, 92, 246, .8);
}
.nav-auth-reg {
    background: var(--xz-grad-btn) !important;
    color: #fff !important;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 1px;
    padding: 8px 18px;
    white-space: nowrap;
    border-radius: 999px;
    box-shadow: 0 4px 16px rgba(99, 102, 241, .5);
    transition: transform .22s ease, box-shadow .22s ease, filter .22s ease;
}
.nav-auth-reg:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 26px rgba(139, 92, 246, .7);
    filter: brightness(1.1);
    color: #fff !important;
}

/* 尊重减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation: none !important; transition: none !important; }
}