/* AI 科普站 —— 样式（轻量、无依赖） */
:root{
  --bg:#f6f7f9; --card:#fff; --txt:#1f2329; --sub:#6b7280;
  --line:#e5e7eb; --pri:#2563eb; --pri-d:#1d4ed8; --tag:#eef2ff;
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--txt);
  font:16px/1.75 -apple-system,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;}
a{color:var(--txt);text-decoration:none}
a:hover{color:var(--pri)}
.wrap{max-width:1080px;margin:0 auto;padding:0 16px}
.muted{color:var(--sub);font-size:14px}

/* header */
.site-header{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}
.site-header .wrap{display:flex;align-items:center;gap:20px;height:64px}
.logo{font-size:20px;font-weight:700;color:var(--pri);white-space:nowrap}
.main-nav{display:flex;gap:16px;flex:1;overflow:auto}
.main-nav a{font-size:15px;white-space:nowrap}
.search-box{display:flex}
.search-box input{border:1px solid var(--line);border-radius:6px 0 0 6px;
  padding:7px 10px;font-size:14px;outline:none;width:150px}
.search-box input:focus{border-color:var(--pri)}
.search-box button{border:1px solid var(--pri);background:var(--pri);color:#fff;
  border-radius:0 6px 6px 0;padding:7px 14px;cursor:pointer;font-size:14px}

/* layout */
main.wrap{padding-top:24px;padding-bottom:40px}
.grid{display:grid;grid-template-columns:1fr 300px;gap:24px;align-items:start}
.card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:18px 20px;margin-bottom:16px}
.card h1{font-size:26px;margin:0 0 12px}
.card h2{font-size:19px;margin:22px 0 12px;padding-left:10px;border-left:4px solid var(--pri)}
.card h3{font-size:17px;margin:18px 0 10px}
.card img{max-width:100%;height:auto;border-radius:8px}
.card ul,.card ol{padding-left:22px}
.card blockquote{margin:14px 0;padding:10px 14px;background:#f3f4f6;border-left:3px solid var(--line);color:#374151}
.card code{background:#f3f4f6;padding:1px 5px;border-radius:4px;font-size:14px}
.card table{border-collapse:collapse;width:100%;font-size:15px}
.card th,.card td{border:1px solid var(--line);padding:8px 10px;text-align:left}

/* list */
.post-list{list-style:none;padding:0;margin:0}
.post-list li{padding:16px 0;border-bottom:1px dashed var(--line)}
.post-list li:last-child{border-bottom:0}
.post-list .t{font-size:18px;font-weight:600;display:block;margin-bottom:6px}
.post-list .s{color:var(--sub);font-size:14px;margin:0 0 8px}
.meta{color:#9ca3af;font-size:13px}
.meta span+span{margin-left:12px}
.tag{display:inline-block;background:var(--tag);color:var(--pri);
  border-radius:4px;padding:1px 8px;font-size:12px;margin-right:6px}

/* side */
.side h3{font-size:16px;margin:0 0 12px;padding-bottom:8px;border-bottom:1px solid var(--line)}
.rank{list-style:none;padding:0;margin:0;counter-reset:r}
.rank li{padding:7px 0;font-size:14px;display:flex;gap:8px}
.rank li:before{counter-increment:r;content:counter(r);
  flex:0 0 20px;height:20px;line-height:20px;text-align:center;font-size:12px;
  background:#f3f4f6;border-radius:4px;color:var(--sub)}
.rank li:nth-child(-n+3):before{background:var(--pri);color:#fff}

/* pager */
.pager{margin:24px 0;text-align:center}
.pager a,.pager span{display:inline-block;min-width:34px;padding:6px 10px;margin:0 3px;
  border:1px solid var(--line);border-radius:6px;background:#fff;font-size:14px}
.pager .cur{background:var(--pri);border-color:var(--pri);color:#fff}

/* breadcrumb */
.crumb{font-size:13px;color:var(--sub);margin-bottom:12px}
.crumb a{color:var(--sub)}

/* footer */
.site-footer{border-top:1px solid var(--line);background:#fff;padding:24px 0;text-align:center;font-size:14px}
.site-footer p{margin:4px 0}

/* ---- 缩略图 / 封面 / 正文图片（v2 新增） ---- */
.post-list li.post-item{display:flex;gap:14px;align-items:flex-start}
.thumb{flex:0 0 132px;width:132px;height:88px;border-radius:8px;overflow:hidden;display:block;background:#eef1f5}
.thumb img{width:100%;height:100%;object-fit:cover;display:block}
.thumb .ph{display:flex;align-items:center;justify-content:center;width:100%;height:100%;
  font-size:32px;font-weight:700;color:#fff;background:var(--tc,#64748b)}
.post-main{flex:1;min-width:0}
.article-body img{max-width:100%;height:auto;border-radius:8px;margin:12px 0;display:block}

@media (max-width:820px){
  .grid{grid-template-columns:1fr}
  .site-header .wrap{flex-wrap:wrap;height:auto;padding:10px 16px;gap:8px 10px}
  .logo{order:1;flex:0 0 auto}
  .search-box{order:2;flex:1 1 120px;min-width:0;max-width:340px}
  .search-box input{width:auto;flex:1;min-width:0}
  .user-nav{order:3;flex:0 0 auto;margin-left:auto}
  .main-nav{order:4;flex:1 1 100%;min-width:0;overflow-x:auto;
    -webkit-overflow-scrolling:touch;scrollbar-width:none;padding-right:34px;
    -webkit-mask-image:linear-gradient(90deg,#000 0,#000 calc(100% - 30px),transparent 100%);
    mask-image:linear-gradient(90deg,#000 0,#000 calc(100% - 30px),transparent 100%)}
  .main-nav::-webkit-scrollbar{display:none}
  .user-nav{gap:4px}
  .user-nav .ulink{padding:7px 8px;border-radius:7px;display:inline-block}
  .user-nav .ulink:hover{background:#f1f5f9}
  .user-nav .ulink.reg{padding:7px 13px}
  .logo{font-size:18px}
  .search-box input{padding:7px 9px}
  .thumb{flex-basis:96px;width:96px;height:66px}
  .card{padding:16px}
  .card h1{font-size:22px}
}

/* ================= v2 · 会员 / 评论 ================= */
.avatar{border-radius:50%;display:inline-block;vertical-align:middle;flex:0 0 auto}
.badge{display:inline-block;font-size:11px;line-height:18px;padding:0 7px;border-radius:9px;font-weight:600;vertical-align:middle}
.badge-vip{background:linear-gradient(135deg,#f59e0b,#ef4444);color:#fff}
.badge-user{background:#eef2ff;color:var(--pri)}
.badge-staff{background:#ecfdf5;color:#059669}

/* 头部用户区 */
.user-nav{display:flex;align-items:center;gap:10px;white-space:nowrap;font-size:14px}
.user-nav .ulink{color:var(--sub)}
.user-nav .uname{display:flex;align-items:center;gap:6px;font-weight:600;max-width:130px;overflow:hidden}
.user-nav .ulink.reg{background:var(--pri);color:#fff;border-radius:6px;padding:5px 12px}
.user-nav .ulink.reg:hover{background:var(--pri-d);color:#fff}

/* 表单通用（作用于新页面；搜索框尺寸在文件末尾重新声明） */
input[type=text],input[type=password],input[type=email],input[type=number],textarea,select{
  width:100%;border:1px solid var(--line);border-radius:8px;padding:9px 12px;font-size:15px;
  font-family:inherit;outline:none;background:#fff}
input:focus,textarea:focus,select:focus{border-color:var(--pri)}
label{display:block;margin:12px 0 6px;font-size:13px;color:var(--sub)}
.btn{display:inline-block;border:0;border-radius:8px;padding:9px 18px;font-size:15px;cursor:pointer;
  background:var(--pri);color:#fff;text-decoration:none}
.btn:hover{background:var(--pri-d);color:#fff}
.btn.gray{background:#eef1f5;color:#374151}
.btn.gray:hover{background:#e2e6ea;color:#374151}
.btn[disabled]{opacity:.55;cursor:not-allowed}
.note{border-radius:8px;padding:10px 14px;margin:0 0 14px;font-size:14px}
.note-ok{background:#ecfdf5;color:#065f46;border:1px solid #a7f3d0}
.note-err{background:#fef2f2;color:#991b1b;border:1px solid #fecaca}
.hp{position:absolute;left:-9999px;top:-9999px;width:1px;height:1px;overflow:hidden}

/* 登录 / 注册 */
.auth-wrap{max-width:420px;margin:10px auto 40px}
.auth-card h1{font-size:22px;margin:0 0 6px}
.auth-btns{display:flex;gap:10px;margin-top:18px}

/* 评论 */
.cmt-form{margin:14px 0 20px}
.cmt-row{display:flex;gap:10px;align-items:flex-start}
.cmt-fav{flex:0 0 auto;padding-top:2px}
.cmt-row textarea{flex:1;min-height:76px;resize:vertical}
.cmt-fields{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:10px}
.cmt-fields input[type=text],.cmt-fields input[type=email]{width:auto;flex:0 1 170px}
.cmt-cap{background:#eef2ff;color:var(--pri);border-radius:6px;padding:6px 10px;font-weight:600;letter-spacing:1px}
.cmt-reply-tip{margin:8px 0 0;font-size:13px;color:var(--sub);background:#f8fafc;border-radius:6px;padding:6px 10px}
.cmt-submit{display:flex;align-items:center;gap:14px;margin-top:12px}
.cmt-list{list-style:none;padding:0;margin:0}
.cmt{display:flex;gap:12px;padding:16px 0;border-top:1px solid var(--line)}
.cmt-reply{margin-left:34px;padding:12px 0 4px;border-top:1px dashed var(--line)}
.cmt-av{flex:0 0 auto}
.cmt-main{flex:1;min-width:0}
.cmt-meta{font-size:13px;color:var(--sub);display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.cmt-meta b{color:var(--txt);font-size:14px}
.cmt-time{margin-left:auto}
.cmt-text{margin:6px 0 8px;font-size:15px;line-height:1.75;word-break:break-word}
.cmt-at{color:var(--pri)}
.cmt-act{font-size:13px;color:var(--sub);display:flex;gap:16px}
.cmt-act a.on{color:#ef4444;font-weight:600}

/* 侧栏用户卡 */
.side-me{display:flex;align-items:center;gap:10px;margin-bottom:12px}
.side-user .btn{margin-right:8px;margin-top:6px}

/* 会员专享 */
.lockbox{background:linear-gradient(180deg,#f8fafc,#eef2ff);border:1px dashed #c7d2fe;border-radius:10px;
  padding:22px;text-align:center;margin:18px 0}
.lockbox-t{font-size:17px;font-weight:700;margin-bottom:8px}
.lockbox p{font-size:14px;color:#475569;margin:8px 0}
.lockbox-b{margin-top:14px;display:flex;gap:10px;justify-content:center;flex-wrap:wrap}

/* 会员中心 */
.uc-head{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.uc-info{flex:1;min-width:200px}
.uc-act{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.uc-stats{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-bottom:16px}
.ustat{background:#fff;border:1px solid var(--line);border-radius:10px;padding:14px;text-align:center}
.ustat b{display:block;font-size:22px;color:var(--pri)}
.ustat span{font-size:13px;color:var(--sub)}
.uc-inline{display:flex;gap:10px;align-items:flex-end;flex-wrap:wrap}
.uc-inline input{flex:1;min-width:160px}
.mycmt{list-style:none;padding:0;margin:0}
.mycmt li{padding:12px 0;border-bottom:1px dashed var(--line)}
.mycmt li:last-child{border-bottom:0}
.mycmt-t{font-size:14px;display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.mycmt-c{color:#475569;font-size:14px;margin-top:6px}
.cmt-st{font-size:12px;border-radius:4px;padding:1px 6px;background:#f1f5f9;color:var(--sub)}
.cmt-st1{background:#ecfdf5;color:#059669}
.cmt-st0{background:#fffbeb;color:#b45309}
.cmt-st-1{background:#fef2f2;color:#b91c1c}

/* VIP 页 */
.vip-status{display:flex;align-items:center;gap:14px;background:#f8fafc;border-radius:10px;padding:14px;margin-top:14px}
.vip-table tr td,.vip-table tr th{text-align:center}
.vip-table tr td:first-child,.vip-table tr th:first-child{text-align:left}
.vip-table .y{color:#059669;font-weight:600}
.vip-table .n{color:#cbd5e1}
.vip-two{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.vip-box{border:1px solid var(--line);border-radius:10px;padding:16px}
.vip-box h4{margin:0 0 8px;font-size:15px}

/* 恢复搜索框尺寸（覆盖上方通用表单样式） */
.search-box input{width:150px;border-radius:6px 0 0 6px;padding:7px 10px;font-size:14px}
.search-box button{border-radius:0 6px 6px 0;padding:7px 14px;font-size:14px}

@media (max-width:820px){
  .search-box input{width:120px}
  .uc-stats{grid-template-columns:repeat(2,1fr)}
  .vip-two{grid-template-columns:1fr}
  .user-nav{font-size:13px;gap:8px}
  .user-nav .uname span{display:none}
  .cmt-reply{margin-left:14px}
}

/* 评论：未登录提示 */
.cmt-needlogin{margin:14px 0 6px;padding:20px 18px;border:1px dashed var(--line);border-radius:10px;background:#f8fafc;text-align:center}
.cmt-needlogin p{margin:0 0 14px;color:var(--sub);font-size:14px}
.cmt-needlogin-btns{display:flex;gap:10px;justify-content:center}
.cmt-needlogin-btns .btn{min-width:96px}

/* ================= v3.1 · 会员登录 / 注册（分栏精装版） ================= */
.auth-page{
  display:grid;grid-template-columns:1fr 1fr;
  max-width:980px;margin:8px auto 48px;background:#fff;
  border:1px solid var(--line);border-radius:20px;overflow:hidden;
  box-shadow:0 24px 60px -30px rgba(23,37,84,.36),0 2px 8px rgba(15,23,42,.04);
}
/* 左：品牌栏（三段式：顶部标识 / 中部内容 / 底部标语，撑满不留死白） */
.auth-brand{
  position:relative;isolation:isolate;overflow:hidden;
  padding:44px;color:#fff;
  background:linear-gradient(155deg,#0f1b45 0%,#2547c8 54%,#5b21b6 100%);
  display:flex;flex-direction:column;justify-content:space-between;gap:26px;
}
.auth-brand:before{
  content:"";position:absolute;z-index:-1;width:380px;height:380px;border-radius:50%;
  top:-150px;right:-140px;
  background:radial-gradient(circle,rgba(255,255,255,.24),rgba(255,255,255,0) 68%);
}
.auth-brand:after{
  content:"";position:absolute;z-index:-1;width:310px;height:310px;border-radius:50%;
  bottom:-140px;left:-110px;
  background:radial-gradient(circle,rgba(56,189,248,.30),rgba(56,189,248,0) 70%);
}
.ab-logo{
  flex:0 0 auto;width:54px;height:54px;border-radius:15px;
  background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.30);
  display:flex;align-items:center;justify-content:center;
}
.auth-brand h2{
  font-size:25px;line-height:1.4;margin:0 0 10px;color:#fff;
  font-weight:700;letter-spacing:.5px;
}
.auth-brand .ab-sub{margin:0 0 22px;font-size:14px;line-height:1.85;color:rgba(255,255,255,.88)}
.auth-feats{list-style:none;margin:0;padding:0;display:grid;gap:14px}
.auth-feats li{
  display:flex;gap:11px;align-items:flex-start;
  font-size:14px;line-height:1.65;color:rgba(255,255,255,.97);
}
.auth-feats .af-ico{
  flex:0 0 21px;width:21px;height:21px;border-radius:50%;margin-top:2px;
  background:rgba(255,255,255,.22);display:flex;align-items:center;justify-content:center;
}
.auth-feats b{font-weight:700}
/* 站长寄语（补足高栏留白，也增加一点人味） */
.ab-note{
  margin-top:20px;padding:11px 0 11px 14px;
  border-left:2px solid rgba(255,255,255,.34);
  font-size:13px;line-height:1.85;color:rgba(255,255,255,.86);
}
.ab-note span{display:block;margin-top:4px;font-size:12px;color:rgba(255,255,255,.58)}
.ab-foot{
  font-size:12.5px;color:rgba(255,255,255,.72);
  padding-top:16px;border-top:1px solid rgba(255,255,255,.18);
}
.ab-foot a{color:#fff;font-weight:600;text-decoration:underline;text-underline-offset:3px}
.ab-foot a:hover{color:#fff;opacity:.82}
/* 右：表单栏 */
.auth-panel{
  position:relative;isolation:isolate;
  padding:44px 46px;display:flex;flex-direction:column;justify-content:center;
}
.auth-panel:before{
  content:"";position:absolute;z-index:-1;top:-110px;right:-90px;width:250px;height:250px;border-radius:50%;
  background:radial-gradient(circle,rgba(37,99,235,.075),rgba(37,99,235,0) 70%);
}
.auth-panel h1{font-size:24px;margin:0 0 8px;font-weight:700}
.auth-panel .auth-lead{margin:0 0 22px;font-size:14px;color:var(--sub)}
.auth-panel .auth-lead a{color:var(--pri);font-weight:600}
.auth-panel .auth-lead a:hover{text-decoration:underline}
.auth-panel .note{margin:0 0 16px}
/* 输入框（带图标） */
.auth-field{position:relative;margin-bottom:13px}
.auth-field .af-label{display:block;margin:0 0 6px;font-size:13px;font-weight:600;color:#4b5563}
.auth-field .af-label em{font-style:normal;font-weight:400;color:#9ca3af}
.auth-field .af-in{position:relative}
.auth-field .af-in>svg{
  position:absolute;left:13px;top:50%;transform:translateY(-50%);
  width:18px;height:18px;stroke:#6b7280;fill:none;stroke-width:1.9;
  pointer-events:none;
}
.auth-field input{
  width:100%;height:46px;padding:0 14px 0 44px;font-size:15px;
  border:1.5px solid var(--line);border-radius:10px;background:#fbfcfe;
  transition:border-color .16s,background .16s,box-shadow .16s;
}
.auth-field input::placeholder{color:#b6bcc6}
.auth-field input:focus{
  border-color:var(--pri);background:#fff;
  box-shadow:0 0 0 4px rgba(37,99,235,.11);
}
.auth-field.pw input{padding-right:46px}
.auth-eye{
  position:absolute;right:6px;top:50%;transform:translateY(-50%);
  width:34px;height:34px;border:0;background:none;cursor:pointer;border-radius:8px;
  display:flex;align-items:center;justify-content:center;color:#6b7280;
}
.auth-eye:hover{background:#f1f5f9;color:#374151}
.auth-eye:focus-visible{outline:2px solid var(--pri);outline-offset:1px}
.auth-eye svg{position:static;transform:none;width:19px;height:19px;stroke:currentColor;fill:none}
/* 提交按钮（与站内 .btn 同色系，仅做极浅竖向明暗，避免花哨渐变） */
.auth-submit{
  width:100%;height:48px;margin-top:6px;border:0;border-radius:10px;cursor:pointer;
  font-size:16px;font-weight:600;color:#fff;font-family:inherit;
  letter-spacing:2px;text-indent:2px;
  background:linear-gradient(180deg,#2f6bea,#2563eb);
  box-shadow:0 10px 20px -12px rgba(37,99,235,.80);
  transition:filter .2s,box-shadow .2s,transform .12s;
}
.auth-submit:hover{filter:brightness(1.06);box-shadow:0 12px 24px -12px rgba(37,99,235,.90)}
.auth-submit:active{transform:translateY(1px)}
.auth-submit:focus-visible{outline:2px solid #1d4ed8;outline-offset:2px}
/* 底部辅助链接 */
.auth-foot{
  margin-top:20px;padding-top:16px;border-top:1px solid var(--line);
  display:flex;justify-content:space-between;align-items:center;gap:12px;
  flex-wrap:wrap;font-size:13px;color:var(--sub);
}
.auth-foot a{color:var(--pri);font-weight:600}
.auth-foot a:hover{text-decoration:underline}
/* 注册页积分小贴士 */
.auth-tip{
  margin-top:16px;padding:11px 14px;border-radius:10px;
  font-size:13px;line-height:1.85;color:#5b6472;
  background:#f7f8fc;border:1px solid #e9ecf5;
}
.auth-tip b{color:#4f46e5;font-weight:700}
@media (max-width:860px){
  .auth-page{grid-template-columns:1fr;border-radius:16px;margin-top:4px}
  .auth-brand{padding:26px;gap:18px}
  .ab-logo{width:46px;height:46px;border-radius:12px}
  .auth-brand h2{font-size:20px;margin-bottom:8px}
  .auth-brand .ab-sub{margin-bottom:14px;font-size:13px;line-height:1.7}
  .auth-feats{gap:10px}
  .auth-feats li{font-size:13px}
  .auth-feats .af-ico{flex-basis:19px;width:19px;height:19px;margin-top:1px}
  .ab-note{margin-top:14px;font-size:12.5px;padding:9px 0 9px 12px}
  .ab-foot{padding-top:13px;font-size:11.5px}
  .ab-note,.ab-foot{display:none}
  .auth-panel{padding:26px 22px 32px}
  .auth-panel h1{font-size:21px}
  .auth-panel .auth-lead{margin-bottom:18px}
}

/* ===== 返回顶部 ===== */
@media (prefers-reduced-motion:no-preference){html{scroll-behavior:smooth}}
.to-top{
  position:fixed;right:22px;bottom:26px;z-index:60;
  width:46px;height:46px;border-radius:12px;
  display:flex;align-items:center;justify-content:center;
  background:#fff;border:1px solid var(--line);color:var(--pri);
  box-shadow:0 6px 18px -6px rgba(15,23,42,.28);
  opacity:0;visibility:hidden;transform:translateY(8px);
  transition:opacity .22s ease,transform .22s ease,visibility .22s;
  -webkit-tap-highlight-color:transparent;
}
.to-top.show{opacity:1;visibility:visible;transform:translateY(0)}
.to-top:hover{background:var(--pri);color:#fff;border-color:var(--pri)}
.to-top svg{width:20px;height:20px;display:block}
.to-top:focus-visible{outline:2px solid var(--pri);outline-offset:2px}
@media (prefers-reduced-motion:reduce){.to-top{transition:none}}
@media (max-width:600px){.to-top{right:14px;bottom:18px;width:42px;height:42px;border-radius:11px}}