/* ===========================================================
   cogito哲学社 · 站点样式表
   纸感浅色主题 + 深绿（💚）/ 紫罗兰（💜）双主色
   =========================================================== */

:root{
  --paper:#f7f5ef;
  --paper-2:#efeade;
  --card:#fffdf8;
  --ink:#131b18;
  --ink-2:#2a352f;
  --muted:#5f6e66;
  --green:#1c6b53;
  --green-2:#0e4436;
  --green-soft:#e3f1ea;
  --green-glow:#8fd9bd;
  --violet:#6a4bb4;
  --violet-2:#3d2a75;
  --violet-soft:#ece5fb;
  --line:rgba(19,27,24,.14);
  --line-strong:rgba(19,27,24,.28);
  --shadow:0 1px 2px rgba(19,27,24,.05),0 12px 30px -18px rgba(19,27,24,.35);
  --radius:16px;
  --radius-sm:10px;
  --serif:"Songti SC","Noto Serif SC","Source Han Serif SC",Georgia,"Times New Roman",serif;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --mono:"SFMono-Regular",Menlo,Consolas,monospace;
  --maxw:1180px;
}

*,*::before,*::after{box-sizing:border-box}

html{scroll-behavior:smooth}

body{
  margin:0;
  font-family:var(--sans);
  font-size:16px;
  line-height:1.75;
  color:var(--ink);
  background-color:var(--paper);
  background-image:
    radial-gradient(1100px 520px at 12% -8%,rgba(28,107,83,.10),transparent 60%),
    radial-gradient(900px 480px at 92% 4%,rgba(106,75,180,.10),transparent 62%),
    repeating-linear-gradient(0deg,rgba(19,27,24,.035) 0 1px,transparent 1px 34px),
    repeating-linear-gradient(90deg,rgba(19,27,24,.035) 0 1px,transparent 1px 34px);
  background-attachment:fixed;
  -webkit-font-smoothing:antialiased;
}

img{max-width:100%;height:auto;display:block}
a{color:var(--green);text-decoration:none}
a:hover{text-decoration:underline}
ul,ol{padding-left:1.2em}
h1,h2,h3,h4{font-family:var(--serif);line-height:1.3;margin:0 0 .5em;font-weight:600;letter-spacing:.01em}
p{margin:0 0 1em}
button,input,select,textarea{font:inherit;color:inherit}
hr{border:0;border-top:1px solid var(--line);margin:2.4rem 0}

.wrap{width:min(var(--maxw),100% - 2.5rem);margin-inline:auto}
.skip{position:absolute;left:-9999px;top:0;background:var(--ink);color:#fff;padding:.6rem 1rem;z-index:99}
.skip:focus{left:1rem;top:1rem}
:focus-visible{outline:2px solid var(--violet);outline-offset:2px;border-radius:4px}

/* ---------- 顶栏 ---------- */
.topbar{
  position:sticky;top:0;z-index:40;
  background:rgba(247,245,239,.82);
  backdrop-filter:blur(10px) saturate(140%);
  border-bottom:1px solid var(--line);
}
.topbar__inner{display:flex;align-items:center;gap:1.25rem;min-height:66px}
.brand{display:flex;align-items:center;gap:.65rem;text-decoration:none;flex:none}
.brand:hover{text-decoration:none}
.brand__mark{width:36px;height:36px;flex:none}
.brand__text{display:flex;flex-direction:column;line-height:1.15}
.brand__name{font-family:var(--serif);font-size:1.12rem;font-weight:700;color:var(--ink);letter-spacing:.02em}
.brand__sub{font-size:.68rem;letter-spacing:.22em;text-transform:uppercase;color:var(--muted)}
.nav{margin-left:auto;display:flex;align-items:center;gap:.15rem;flex-wrap:wrap}
.nav a{
  padding:.45rem .7rem;border-radius:999px;font-size:.94rem;color:var(--ink-2);text-decoration:none;
  white-space:nowrap;
}
.nav a:hover{background:rgba(19,27,24,.06);text-decoration:none}
.nav a[aria-current="page"]{background:var(--green-soft);color:var(--green-2);font-weight:600}
.nav .nav__cta{
  margin-left:.5rem;background:var(--green);color:#fff;font-weight:600;
  box-shadow:0 8px 18px -12px rgba(28,107,83,.9);
}
.nav .nav__cta:hover{background:var(--green-2);color:#fff}
.navtoggle{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:999px;padding:.35rem .8rem;cursor:pointer}

@media (max-width:880px){
  .navtoggle{display:block}
  .nav{
    position:absolute;left:0;right:0;top:100%;flex-direction:column;align-items:stretch;
    background:var(--card);border-bottom:1px solid var(--line);padding:.5rem .8rem 1rem;gap:.15rem;
    box-shadow:var(--shadow);display:none;
  }
  .nav.is-open{display:flex}
  .nav a{padding:.6rem .7rem}
  .nav .nav__cta{margin:.4rem 0 0;text-align:center}
}

/* ---------- 通用排版 ---------- */
.eyebrow{
  display:inline-flex;align-items:center;gap:.5rem;font-size:.76rem;letter-spacing:.2em;
  text-transform:uppercase;color:var(--green);font-weight:700;margin-bottom:.75rem
}
.eyebrow::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--green);box-shadow:0 0 0 4px rgba(28,107,83,.14)}
.lede{font-size:1.06rem;color:var(--ink-2);max-width:62ch}
.muted{color:var(--muted)}
.small{font-size:.87rem}
.center{text-align:center}
.section{padding:3.4rem 0}
.section--tight{padding:2.2rem 0}
.section__head{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:1rem;margin-bottom:1.6rem}
.section__head h2{font-size:clamp(1.5rem,3vw,2rem);margin:0}
.section__head p{margin:0;color:var(--muted);max-width:52ch}

.btn{
  display:inline-flex;align-items:center;gap:.5rem;justify-content:center;
  padding:.7rem 1.15rem;border-radius:999px;border:1px solid transparent;background:var(--green);color:#fff;
  font-weight:600;font-size:.95rem;cursor:pointer;text-decoration:none;transition:transform .15s ease,box-shadow .15s ease,background .15s ease;
}
.btn:hover{text-decoration:none;background:var(--green-2);transform:translateY(-1px);box-shadow:0 10px 22px -14px rgba(14,68,54,.9)}
.btn--ghost{background:transparent;color:var(--ink);border-color:var(--line-strong)}
.btn--ghost:hover{background:rgba(19,27,24,.05);color:var(--ink);box-shadow:none}
.btn--violet{background:var(--violet)}
.btn--violet:hover{background:var(--violet-2);box-shadow:0 10px 22px -14px rgba(61,42,117,.9)}
.btn--sm{padding:.42rem .85rem;font-size:.86rem}
.btn--block{width:100%}
.btn-group{display:flex;flex-wrap:wrap;gap:.6rem}

.chips{display:flex;flex-wrap:wrap;gap:.4rem}
.chip{
  display:inline-block;padding:.2rem .6rem;border-radius:999px;font-size:.76rem;font-weight:600;
  background:rgba(19,27,24,.06);color:var(--ink-2);border:1px solid transparent
}
.chip--green{background:var(--green-soft);color:var(--green-2)}
.chip--violet{background:var(--violet-soft);color:var(--violet-2)}
.chip--pin{background:var(--violet);color:#fff}

.card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:1.4rem;box-shadow:var(--shadow);position:relative
}
.card__title{font-size:1.16rem;margin:0 0 .35rem}
.grid{display:grid;gap:1.15rem}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(320px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.grid--auto{grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}
.stack>*+*{margin-top:1rem}
.notice{
  border-left:3px solid var(--green);background:var(--green-soft);padding:.85rem 1rem;border-radius:0 var(--radius-sm) var(--radius-sm) 0;
  font-size:.92rem;color:var(--green-2)
}
.notice--violet{border-color:var(--violet);background:var(--violet-soft);color:var(--violet-2)}
.placeholder{
  border:1px dashed var(--line-strong);border-radius:var(--radius-sm);padding:1.1rem;color:var(--muted);font-size:.9rem;text-align:center
}

/* ---------- 首页 Hero ---------- */
.hero{position:relative;padding:3.6rem 0 2.6rem;overflow:hidden}
.hero__inner{display:grid;grid-template-columns:minmax(0,1.08fr) minmax(0,.92fr);gap:2.4rem;align-items:center}
@media (max-width:900px){.hero__inner{grid-template-columns:1fr;gap:1.6rem}}
.hero h1{
  font-size:clamp(2.1rem,5.4vw,3.5rem);line-height:1.18;margin:0 0 .8rem;letter-spacing:.01em
}
.hero h1 .accent{
  background:linear-gradient(100deg,var(--green) 0%,var(--violet) 78%);
  -webkit-background-clip:text;background-clip:text;color:transparent
}
.hero__slogan{font-size:1.12rem;color:var(--ink-2);max-width:46ch;margin-bottom:1.4rem}
.hero__kicker{
  font-family:var(--serif);font-size:.95rem;color:var(--violet-2);letter-spacing:.28em;text-transform:uppercase;margin-bottom:1rem
}
.hero__art{position:relative}
.hero__art svg{width:100%;height:auto;display:block}

/* ---------- 社团简介 ---------- */
.intro{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);gap:2.2rem;align-items:start}
@media (max-width:900px){.intro{grid-template-columns:1fr}}
.intro__text p{font-family:var(--serif);font-size:1.06rem;line-height:2;color:var(--ink-2)}
.intro__text p:first-of-type::first-letter{
  font-size:2.6rem;float:left;line-height:.95;padding:.15rem .5rem 0 0;color:var(--green);font-weight:700
}
.intro__text p.highlight{
  margin-top:1.4rem;padding:1rem 1.2rem;background:var(--violet-soft);border-radius:var(--radius-sm);
  font-size:1.05rem;color:var(--violet-2)
}

/* ---------- 招新 / 二维码 ---------- */
.join{
  display:grid;grid-template-columns:minmax(0,1fr) minmax(280px,.72fr);gap:2rem;align-items:center;
  background:linear-gradient(120deg,#0e4436,#153d31 45%,#3d2a75);
  color:#f2f7f4;border-radius:22px;padding:2.4rem;box-shadow:0 24px 50px -30px rgba(14,68,54,.9);
  position:relative;overflow:hidden
}
@media (max-width:820px){.join{grid-template-columns:1fr;padding:1.6rem}}
.join h2{color:#fff;font-size:clamp(1.5rem,3.2vw,2.1rem)}
.join p{color:rgba(242,247,244,.88)}
.join a{color:#c8f0dd}
.join .btn{background:#fff;color:var(--green-2)}
.join .btn:hover{background:var(--green-soft)}
.qr{
  background:#fff;border-radius:18px;padding:.9rem;text-align:center;color:var(--ink);
  box-shadow:0 18px 40px -24px rgba(0,0,0,.6)
}
.qr img{border-radius:12px;width:100%;max-width:320px;margin:0 auto}
.qr figcaption{font-size:.86rem;color:var(--muted);margin-top:.6rem}
.qr__badge{
  display:inline-block;font-size:.72rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;
  color:var(--violet-2);background:var(--violet-soft);border-radius:999px;padding:.2rem .65rem;margin-bottom:.6rem
}

/* ---------- 活动列表 ---------- */
.filters{display:flex;flex-wrap:wrap;gap:.45rem;margin-bottom:1.4rem}
.filter{
  border:1px solid var(--line-strong);background:transparent;border-radius:999px;padding:.35rem .85rem;
  font-size:.88rem;cursor:pointer
}
.filter:hover{background:rgba(19,27,24,.05)}
.filter[aria-pressed="true"]{background:var(--ink);color:#fff;border-color:var(--ink)}

.act{
  display:grid;grid-template-columns:96px minmax(0,1fr);gap:1.2rem;padding:1.25rem 1.35rem;
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);
  position:relative;overflow:hidden
}
.act::before{content:"";position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--green);opacity:.35}
.act.is-pinned::before{background:var(--violet);opacity:1}
.act__date{
  font-family:var(--serif);text-align:center;border-right:1px dashed var(--line);padding-right:.6rem
}
.act__day{display:block;font-size:1.9rem;font-weight:700;line-height:1;color:var(--green-2)}
.act__mon{display:block;font-size:.8rem;letter-spacing:.1em;color:var(--muted);margin-top:.25rem}
.act__year{display:block;font-size:.74rem;color:var(--muted)}
.act__title{font-size:1.18rem;margin:0 0 .4rem;display:flex;flex-wrap:wrap;align-items:center;gap:.5rem}
.act__meta{display:flex;flex-wrap:wrap;gap:.9rem;font-size:.87rem;color:var(--muted);margin-bottom:.55rem}
.act__meta span{display:inline-flex;align-items:center;gap:.35rem}
.act__sum{margin:0;color:var(--ink-2);font-size:.96rem}
.act.is-past{opacity:.72}
@media (max-width:640px){
  .act{grid-template-columns:1fr;gap:.7rem}
  .act__date{display:flex;align-items:baseline;gap:.5rem;border-right:0;border-bottom:1px dashed var(--line);padding:0 0 .5rem;text-align:left}
  .act__day{font-size:1.35rem}
}

/* ---------- 读书会 ---------- */
.term{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);
  overflow:hidden;margin-bottom:1.1rem
}
.term__summary{
  cursor:pointer;list-style:none;padding:1.25rem 1.4rem;display:flex;flex-wrap:wrap;gap:.8rem;align-items:center
}
.term__summary::-webkit-details-marker{display:none}
.term__no{
  flex:none;font-family:var(--mono);font-size:.8rem;font-weight:700;letter-spacing:.08em;
  color:#fff;background:var(--green);border-radius:8px;padding:.35rem .55rem
}
.term__head{flex:1 1 260px;min-width:0}
.term__title{font-size:1.2rem;margin:0}
.term__sub{font-size:.85rem;color:var(--muted);margin:.25rem 0 0}
.term__caret{margin-left:auto;font-size:.9rem;color:var(--muted);transition:transform .2s ease}
.term[open] .term__caret{transform:rotate(180deg)}
.term__body{padding:0 1.4rem 1.5rem;border-top:1px dashed var(--line)}
.term__grid{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,1fr);gap:1.6rem;padding-top:1.3rem}
@media (max-width:900px){.term__grid{grid-template-columns:1fr}}
.guide h4,.media h4{font-size:.8rem;letter-spacing:.18em;text-transform:uppercase;color:var(--green);margin-bottom:.6rem}
.guide p{font-family:var(--serif);font-size:1.02rem;line-height:2;color:var(--ink-2)}
.figure{margin:0 0 1rem}
.figure img{border:1px solid var(--line);border-radius:var(--radius-sm);background:#fff;cursor:zoom-in}
.figure figcaption{font-size:.82rem;color:var(--muted);margin-top:.45rem}
.deck{
  border:1px solid var(--line);border-radius:var(--radius-sm);overflow:hidden;background:#fff
}
.deck iframe{width:100%;height:430px;border:0;display:block;background:#fff}
.term__footer{
  display:flex;flex-wrap:wrap;gap:.7rem;align-items:center;justify-content:space-between;
  margin-top:1.4rem;padding-top:1.1rem;border-top:1px dashed var(--line)
}
.term__resources{margin-top:1.2rem}
.term__resources h4{font-size:.8rem;letter-spacing:.18em;text-transform:uppercase;color:var(--violet);margin-bottom:.6rem}

/* ---------- 资源 / 大礼包 ---------- */
.reslist{list-style:none;padding:0;margin:0;display:grid;gap:.6rem}
.reslist li{
  display:grid;grid-template-columns:auto minmax(0,1fr);gap:.7rem;align-items:start;
  padding:.7rem .85rem;border:1px solid var(--line);border-radius:var(--radius-sm);background:var(--card)
}
.reslist a{font-weight:600}
.reslist .res__note{display:block;font-size:.85rem;color:var(--muted);font-weight:400}
.kind{
  font-size:.72rem;font-weight:700;padding:.15rem .5rem;border-radius:999px;background:var(--violet-soft);color:var(--violet-2);
  white-space:nowrap;margin-top:.2rem
}
.kind--pdf{background:#fdeaea;color:#9c2f2f}
.kind--video{background:#e6f0fd;color:#1f5aa8}
.kind--term{background:var(--green-soft);color:var(--green-2)}
.kind--tool{background:#fdf1e3;color:#8a5a16}

.gift{
  display:flex;flex-direction:column;background:var(--card);border:1px solid var(--line);
  border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden
}
.gift__cover{aspect-ratio:1/1;background:var(--paper-2);overflow:hidden}
.gift__cover img{width:100%;height:100%;object-fit:cover}
.gift__body{padding:1rem 1.1rem 1.2rem;display:flex;flex-direction:column;gap:.5rem;flex:1}
.gift__title{font-size:1.05rem;margin:0}
.gift__sub{font-size:.82rem;color:var(--muted);margin:0}
.gift__desc{font-size:.92rem;color:var(--ink-2);margin:0;flex:1}
.gift__link{margin-top:.35rem}

.subnav{display:flex;flex-wrap:wrap;gap:.5rem;margin-bottom:1.6rem}
.subnav a{
  padding:.4rem 1rem;border-radius:999px;border:1px solid var(--line-strong);font-size:.9rem;color:var(--ink-2);text-decoration:none
}
.subnav a:hover{background:rgba(19,27,24,.05);text-decoration:none}

/* ---------- 投稿 ---------- */
.post{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);padding:1.6rem 1.7rem
}
.post__title{font-size:1.35rem;margin:0 0 .35rem}
.post__meta{font-size:.84rem;color:var(--muted);margin-bottom:1rem;display:flex;flex-wrap:wrap;gap:.8rem}
.post__body{font-family:var(--serif);font-size:1.03rem;line-height:2;color:var(--ink-2);white-space:pre-wrap}
.post__body--clamp{max-height:15rem;overflow:hidden;position:relative}
.post__body--clamp::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:4rem;
  background:linear-gradient(transparent,var(--card))
}

/* ---------- 页脚 ---------- */
.footer{margin-top:3rem;border-top:1px solid var(--line);background:rgba(239,234,222,.6);padding:2.4rem 0 2rem}
.footer__grid{display:grid;grid-template-columns:minmax(0,1.4fr) repeat(2,minmax(0,.8fr));gap:1.6rem}
@media (max-width:760px){.footer__grid{grid-template-columns:1fr}}
.footer h4{font-size:.8rem;letter-spacing:.18em;text-transform:uppercase;color:var(--muted);margin-bottom:.6rem}
.footer ul{list-style:none;padding:0;margin:0;display:grid;gap:.35rem;font-size:.92rem}
.footer__note{font-size:.83rem;color:var(--muted);margin-top:1.6rem;display:flex;flex-wrap:wrap;gap:.6rem;align-items:center}
.datasource{font-family:var(--mono);font-size:.74rem;padding:.15rem .5rem;border-radius:999px;background:rgba(19,27,24,.07)}

/* ---------- 弹层 / 灯箱 ---------- */
.lightbox{
  position:fixed;inset:0;background:rgba(12,18,16,.88);display:none;align-items:center;justify-content:center;
  z-index:80;padding:2rem
}
.lightbox.is-open{display:flex}
.lightbox img{max-width:min(1200px,96vw);max-height:88vh;border-radius:12px;background:#fff}
.lightbox__close{
  position:absolute;top:1rem;right:1rem;background:rgba(255,255,255,.14);color:#fff;border:0;border-radius:999px;
  width:42px;height:42px;font-size:1.2rem;cursor:pointer
}

/* ---------- 后台 ---------- */
.adminbar{background:var(--ink);color:#fff;font-size:.85rem;padding:.5rem 0}
.adminbar .wrap{display:flex;gap:1rem;flex-wrap:wrap;align-items:center;justify-content:space-between}
.adminbar a{color:#9fe0c4}
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:1.4rem}
.tabs{display:flex;flex-wrap:wrap;gap:.4rem;margin:1.4rem 0 1.2rem}
.tab{
  border:1px solid var(--line-strong);background:transparent;border-radius:999px;padding:.4rem .95rem;cursor:pointer;font-size:.9rem
}
.tab[aria-selected="true"]{background:var(--green);color:#fff;border-color:var(--green);font-weight:600}
.field{display:grid;gap:.3rem;margin-bottom:.85rem}
.field label{font-size:.82rem;font-weight:600;color:var(--ink-2);letter-spacing:.02em}
.field input,.field textarea,.field select{
  width:100%;padding:.55rem .7rem;border:1px solid var(--line-strong);border-radius:var(--radius-sm);
  background:var(--paper);font-size:.94rem
}
.field textarea{min-height:7rem;resize:vertical;font-family:var(--sans)}
.field--row{grid-template-columns:1fr 1fr;gap:.85rem}
.field--row .field{margin:0}
.hint{font-size:.78rem;color:var(--muted)}
.adminitem{
  border:1px solid var(--line);border-radius:var(--radius-sm);padding:.85rem 1rem;background:var(--paper);
  display:flex;gap:.8rem;align-items:flex-start;flex-wrap:wrap
}
.adminitem__main{flex:1 1 260px;min-width:0}
.adminitem__title{font-weight:600;margin:0 0 .2rem}
.adminitem__meta{font-size:.8rem;color:var(--muted);margin:0;word-break:break-all}
.status{font-size:.88rem;border-radius:var(--radius-sm);padding:.7rem .9rem;margin-bottom:1rem;display:none}
.status.is-on{display:block}
.status--ok{background:var(--green-soft);color:var(--green-2)}
.status--err{background:#fdeaea;color:#8f2626}
.status--info{background:var(--violet-soft);color:var(--violet-2)}

/* ---------- 动效 ---------- */
@media (prefers-reduced-motion:no-preference){
  .rise{animation:rise .6s cubic-bezier(.2,.7,.3,1) both}
  @keyframes rise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
}

/* ---------- 打印 ---------- */
@media print{
  .topbar,.footer,.nav,.btn,.lightbox{display:none!important}
  body{background:#fff}
  .term__body{display:block!important}
}