/* ==========================================================================
   实验经济评论 · Shiyan Economics Review
   视觉方向：学生学术刊物的编辑式（editorial）排版
   墨蓝 + 砖红 + 纸白；衬线标题、细规则线、留白与文献感
   ========================================================================== */

:root{
  --ink:        #101c33;
  --ink-2:      #26344f;
  --ink-soft:   #5b6780;
  --paper:      #fbf9f5;
  --paper-2:    #f3efe7;
  --card:       #ffffff;
  --line:       #e2dcd1;
  --line-2:     #cfc7b8;
  --accent:     #a5322a;
  --accent-2:   #c79a4b;
  --teal:       #1f5f5b;
  --radius:     3px;
  --wrap:       1120px;
  --wrap-narrow:760px;
  --serif: "Iowan Old Style", "Palatino Linotype", "Palatino", "Songti SC", "Noto Serif SC", "Source Han Serif SC", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --mono: "SFMono-Regular", ui-monospace, "JetBrains Mono", Menlo, Consolas, monospace;
}

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

html{ scroll-behavior:smooth; }

body{
  margin:0;
  background:var(--paper);
  background-image:
    radial-gradient(circle at 12% -10%, rgba(199,154,75,.10), transparent 45%),
    radial-gradient(circle at 88% 0%, rgba(31,95,91,.08), transparent 40%);
  color:var(--ink);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}

img{ max-width:100%; display:block; }
a{ color:inherit; text-decoration:none; }
a:hover{ color:var(--accent); }
hr{ border:0; border-top:1px solid var(--line); margin:2.5rem 0; }

.wrap{ width:100%; max-width:var(--wrap); margin:0 auto; padding:0 24px; }
.wrap-narrow{ width:100%; max-width:var(--wrap-narrow); margin:0 auto; padding:0 24px; }

.serif{ font-family:var(--serif); }
.meta{ font-family:var(--sans); font-size:.74rem; letter-spacing:.12em; text-transform:uppercase; color:var(--ink-soft); }
.small{ font-size:.86rem; color:var(--ink-soft); }
.center{ text-align:center; }

/* ---------- skip link ---------- */
.skip{
  position:absolute; left:-9999px; top:0; background:var(--ink); color:#fff;
  padding:10px 16px; z-index:99;
}
.skip:focus{ left:12px; top:12px; }

/* ==========================  HEADER  ==================================== */
.topbar{
  border-bottom:1px solid var(--line);
  background:rgba(251,249,245,.86);
  backdrop-filter:blur(8px);
  position:sticky; top:0; z-index:60;
}
.topbar-inner{
  max-width:var(--wrap); margin:0 auto; padding:14px 24px;
  display:flex; align-items:center; gap:26px;
}
.brand{ display:flex; align-items:baseline; gap:12px; margin-right:auto; }
.brand-mark{
  width:34px; height:34px; flex:0 0 34px; border:1px solid var(--ink);
  display:grid; place-items:center; border-radius:50%;
  font-family:var(--serif); font-size:.92rem; letter-spacing:.02em; color:var(--ink);
  background:linear-gradient(140deg,#fff, #f0ebe1);
}
.brand-text{ display:flex; flex-direction:column; line-height:1.15; }
.brand-cn{ font-family:var(--serif); font-size:1.06rem; letter-spacing:.06em; }
.brand-en{ font-size:.6rem; letter-spacing:.22em; text-transform:uppercase; color:var(--ink-soft); }

.nav{ display:flex; align-items:center; gap:4px; }
.nav a{
  font-size:.82rem; letter-spacing:.06em; padding:8px 11px; border-radius:var(--radius);
  color:var(--ink-2); position:relative;
}
.nav a::after{
  content:""; position:absolute; left:11px; right:11px; bottom:4px; height:1px;
  background:var(--accent); transform:scaleX(0); transform-origin:left; transition:transform .28s ease;
}
.nav a:hover::after,.nav a[aria-current="page"]::after{ transform:scaleX(1); }
.nav a[aria-current="page"]{ color:var(--ink); }

.nav-toggle{
  display:none; width:40px; height:36px; border:1px solid var(--line-2); background:#fff;
  border-radius:var(--radius); cursor:pointer; padding:0; place-items:center;
}
.nav-toggle span{ display:block; width:16px; height:1.5px; background:var(--ink); position:relative; }
.nav-toggle span::before,.nav-toggle span::after{
  content:""; position:absolute; left:0; width:16px; height:1.5px; background:var(--ink);
}
.nav-toggle span::before{ top:-5px; } .nav-toggle span::after{ top:5px; }

.btn{
  display:inline-flex; align-items:center; gap:8px; font-size:.8rem; letter-spacing:.08em;
  text-transform:uppercase; padding:10px 18px; border:1px solid var(--ink);
  background:var(--ink); color:#fff; border-radius:var(--radius); cursor:pointer;
  transition:transform .2s ease, background .2s ease, color .2s ease;
}
.btn:hover{ background:var(--accent); border-color:var(--accent); color:#fff; transform:translateY(-1px); }
.btn.ghost{ background:transparent; color:var(--ink); }
.btn.ghost:hover{ background:var(--ink); color:#fff; border-color:var(--ink); }
.btn.small-btn{ padding:7px 13px; font-size:.72rem; }

/* ==========================  HERO  ====================================== */
.hero{ padding:74px 0 46px; border-bottom:1px solid var(--line); position:relative; overflow:hidden; }
.hero::after{
  content:""; position:absolute; inset:0; pointer-events:none;
  background-image:linear-gradient(var(--line) 1px, transparent 1px);
  background-size:100% 56px; opacity:.32;
  mask-image:linear-gradient(to bottom, transparent, #000 30%, transparent);
}
.hero .wrap{ position:relative; z-index:1; }
.eyebrow{
  display:inline-flex; align-items:center; gap:10px; font-size:.72rem; letter-spacing:.2em;
  text-transform:uppercase; color:var(--accent);
}
.eyebrow::before{ content:""; width:36px; height:1px; background:var(--accent); }
.hero h1{
  font-family:var(--serif); font-weight:500; font-size:clamp(2.1rem, 5vw, 3.5rem);
  line-height:1.14; letter-spacing:-.01em; margin:18px 0 20px; max-width:22ch;
}
.hero h1 em{ font-style:italic; color:var(--accent); }
.hero p.lede{ font-family:var(--serif); font-size:clamp(1.02rem,1.5vw,1.18rem); color:var(--ink-2); max-width:60ch; }
.hero-actions{ display:flex; flex-wrap:wrap; gap:12px; margin-top:28px; }

.stat-row{
  display:grid; grid-template-columns:repeat(4,1fr); gap:1px; margin-top:52px;
  background:var(--line); border:1px solid var(--line);
}
.stat{ background:var(--paper); padding:18px 20px; }
.stat b{ display:block; font-family:var(--serif); font-size:1.5rem; font-weight:500; }
.stat span{ font-size:.74rem; letter-spacing:.1em; text-transform:uppercase; color:var(--ink-soft); }

/* ==========================  SECTIONS  ================================== */
section{ padding:64px 0; }
section.tight{ padding:44px 0; }
.section-head{ display:flex; align-items:flex-end; justify-content:space-between; gap:24px; margin-bottom:32px; flex-wrap:wrap; }
.section-head h2{
  font-family:var(--serif); font-weight:500; font-size:clamp(1.4rem,2.6vw,2rem); margin:8px 0 0;
  letter-spacing:-.01em;
}
.section-head p{ margin:6px 0 0; max-width:56ch; color:var(--ink-soft); font-size:.92rem; }
.rule-label{
  display:inline-block; font-size:.7rem; letter-spacing:.2em; text-transform:uppercase;
  color:var(--ink-soft); padding-right:12px; border-right:2px solid var(--accent);
}

/* ---------- featured ---------- */
.featured{
  display:grid; grid-template-columns:1.15fr .85fr; gap:0;
  border:1px solid var(--line); background:var(--card); overflow:hidden;
}
.featured-body{ padding:34px 36px; }
.featured-body h3{ font-family:var(--serif); font-weight:500; font-size:clamp(1.3rem,2.2vw,1.8rem); margin:14px 0 12px; line-height:1.24; }
.featured-body p{ color:var(--ink-2); margin:0 0 20px; }
.chips{ display:flex; flex-wrap:wrap; gap:8px; margin-bottom:6px; }
.chip{
  font-size:.7rem; letter-spacing:.1em; text-transform:uppercase; padding:4px 9px;
  border:1px solid var(--line-2); border-radius:99px; color:var(--ink-2); background:var(--paper-2);
}
.chip.accent{ border-color:var(--accent); color:var(--accent); background:transparent; }

/* 用 CSS 生成的封面（本站无图片素材，故以版式图形代替照片） */
.cover{ position:relative; min-height:260px; overflow:hidden; background:var(--ink); }
.cover::before{
  content:""; position:absolute; inset:0;
  background-image:
    repeating-linear-gradient(45deg, rgba(255,255,255,.055) 0 12px, transparent 12px 24px);
}
.cover::after{
  content:attr(data-label); position:absolute; left:24px; bottom:20px; right:24px;
  font-family:var(--serif); color:#fff; font-size:1.05rem; letter-spacing:.02em;
}
.cover .cover-glyph{
  position:absolute; top:-14px; right:-6px; font-family:var(--serif); font-size:8rem;
  color:rgba(255,255,255,.12); line-height:1;
}
.cover.tone-a{ background:linear-gradient(150deg,#12213c,#33507e 65%,#1f5f5b); }
.cover.tone-b{ background:linear-gradient(150deg,#3a1b1a,#a5322a 70%,#c79a4b); }
.cover.tone-c{ background:linear-gradient(150deg,#122032,#1f5f5b 75%,#3f7f74); }
.cover.tone-d{ background:linear-gradient(150deg,#2b2418,#8a6a2a 70%,#c79a4b); }
.cover.slim{ min-height:150px; }
.cover.slim::after{ font-size:.9rem; }

/* ---------- card grid ---------- */
.grid{ display:grid; gap:26px; grid-template-columns:repeat(3,1fr); }
.grid.two{ grid-template-columns:repeat(2,1fr); }
.card{
  background:var(--card); border:1px solid var(--line); border-radius:var(--radius);
  display:flex; flex-direction:column; overflow:hidden;
  transition:transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.card:hover{ transform:translateY(-4px); box-shadow:0 16px 34px -22px rgba(16,28,51,.45); border-color:var(--line-2); }
.card-body{ padding:22px 24px 24px; display:flex; flex-direction:column; gap:10px; flex:1; }
.card-body h3{ font-family:var(--serif); font-weight:500; font-size:1.16rem; line-height:1.3; margin:2px 0 0; }
.card-body p{ margin:0; color:var(--ink-2); font-size:.93rem; }
.card-foot{ margin-top:auto; display:flex; align-items:center; justify-content:space-between; gap:12px; padding-top:12px; border-top:1px solid var(--line); }
.link-arrow{ font-size:.78rem; letter-spacing:.1em; text-transform:uppercase; color:var(--accent); }
.link-arrow::after{ content:" →"; }

/* ---------- 栏目 ---------- */
.columns-grid{ display:grid; grid-template-columns:repeat(2,1fr); gap:1px; background:var(--line); border:1px solid var(--line); }
.col-card{ background:var(--paper); padding:28px 30px; }
.col-card h3{ font-family:var(--serif); font-weight:500; font-size:1.22rem; margin:12px 0 8px; }
.col-card p{ margin:0; font-size:.93rem; color:var(--ink-2); }
.col-card .num{ font-family:var(--mono); font-size:.78rem; color:var(--accent-2); letter-spacing:.14em; }

/* ---------- 流程 ---------- */
.flow{ display:flex; flex-wrap:wrap; gap:10px; align-items:center; margin-top:8px; }
.flow span{
  font-size:.8rem; padding:9px 14px; border:1px solid var(--line-2); background:var(--card);
  border-radius:99px; color:var(--ink-2);
}
.flow i{ color:var(--accent); font-style:normal; }

/* ---------- 长表格 / 列表 ---------- */
.deflist{ border-top:1px solid var(--line); margin:0; }
.deflist > div{ display:grid; grid-template-columns:220px 1fr; gap:20px; padding:18px 0; border-bottom:1px solid var(--line); }
.deflist dt{ font-size:.78rem; letter-spacing:.12em; text-transform:uppercase; color:var(--ink-soft); }
.deflist dd{ margin:0; color:var(--ink-2); }

.timeline{ list-style:none; margin:0; padding:0 0 0 26px; border-left:1px solid var(--line-2); }
.timeline li{ position:relative; padding:0 0 30px 22px; }
.timeline li::before{
  content:""; position:absolute; left:-32px; top:8px; width:9px; height:9px; border-radius:50%;
  background:var(--paper); border:1.5px solid var(--accent);
}
.timeline h3{ font-family:var(--serif); font-weight:500; font-size:1.1rem; margin:0 0 6px; }
.timeline p{ margin:0; color:var(--ink-2); font-size:.94rem; }

.callout{
  border-left:3px solid var(--accent-2); background:var(--paper-2);
  padding:20px 24px; margin:26px 0; font-size:.94rem; color:var(--ink-2);
}
.callout strong{ color:var(--ink); }

/* ---------- 下载卡 ---------- */
.dl{
  display:flex; align-items:center; gap:16px; padding:18px 20px; border:1px dashed var(--line-2);
  background:var(--card); border-radius:var(--radius);
}
.dl .dl-ico{
  width:38px; height:38px; flex:0 0 38px; display:grid; place-items:center; border-radius:50%;
  background:var(--ink); color:#fff; font-family:var(--mono); font-size:.68rem;
}
.dl b{ display:block; font-family:var(--serif); font-weight:500; font-size:1rem; }
.dl span{ font-size:.8rem; color:var(--ink-soft); }

/* ==========================  ARTICLE  ================================== */
.progress{ position:fixed; top:0; left:0; height:2px; background:var(--accent); width:0; z-index:70; }
.article-head{ padding:56px 0 30px; border-bottom:1px solid var(--line); }
.article-head h1{
  font-family:var(--serif); font-weight:500; font-size:clamp(1.8rem,4vw,2.9rem); line-height:1.16;
  margin:16px 0 18px; letter-spacing:-.01em;
}
.article-head .dek{ font-family:var(--serif); font-size:1.08rem; color:var(--ink-soft); max-width:64ch; }
.byline{ display:flex; flex-wrap:wrap; gap:18px; margin-top:22px; font-size:.8rem; color:var(--ink-soft); letter-spacing:.04em; }

.article{ font-family:var(--serif); font-size:1.075rem; line-height:1.85; }
.article > p{ margin:0 0 1.35em; }
.article h2{
  font-family:var(--serif); font-weight:500; font-size:1.35rem; margin:2.2em 0 .7em;
  padding-bottom:.4em; border-bottom:1px solid var(--line);
}
.article ul,.article ol{ margin:0 0 1.4em; padding-left:1.3em; }
.article li{ margin-bottom:.5em; }
.article blockquote{
  margin:1.6em 0; padding:6px 0 6px 22px; border-left:2px solid var(--accent);
  font-style:italic; color:var(--ink-2);
}
.article .abstract{
  background:var(--card); border:1px solid var(--line); padding:24px 26px; margin-bottom:34px;
  font-family:var(--sans); font-size:.95rem; line-height:1.8; color:var(--ink-2);
}
.article .abstract h2{ font-family:var(--sans); font-size:.74rem; letter-spacing:.18em; text-transform:uppercase; border:0; margin:0 0 10px; color:var(--accent); }
.lead-cap::first-letter{
  float:left; font-size:3.6rem; line-height:.82; padding:6px 10px 0 0; color:var(--accent);
  font-family:var(--serif);
}
.data-table{ width:100%; border-collapse:collapse; font-family:var(--sans); font-size:.88rem; margin:0 0 1.6em; }
.data-table caption{ text-align:left; font-size:.76rem; letter-spacing:.1em; text-transform:uppercase; color:var(--ink-soft); padding-bottom:10px; }
.data-table th,.data-table td{ text-align:left; padding:11px 12px; border-bottom:1px solid var(--line); vertical-align:top; }
.data-table thead th{ background:var(--paper-2); font-weight:600; }
.article-foot{ margin-top:44px; padding-top:24px; border-top:1px solid var(--line); font-family:var(--sans); font-size:.86rem; color:var(--ink-soft); }

.toc{ border:1px solid var(--line); background:var(--card); padding:18px 22px; font-family:var(--sans); font-size:.88rem; }
.toc b{ display:block; font-size:.72rem; letter-spacing:.16em; text-transform:uppercase; color:var(--ink-soft); margin-bottom:10px; }
.toc a{ display:block; padding:4px 0; color:var(--ink-2); }

/* ==========================  FOOTER  =================================== */
footer{ border-top:1px solid var(--line); background:var(--paper-2); margin-top:20px; padding:52px 0 30px; }
.foot-grid{ display:grid; grid-template-columns:1.4fr 1fr 1fr 1fr; gap:30px; }
.foot-grid h4{ font-size:.72rem; letter-spacing:.18em; text-transform:uppercase; color:var(--ink-soft); margin:0 0 14px; }
.foot-grid a{ display:block; padding:3px 0; font-size:.9rem; color:var(--ink-2); }
.foot-bottom{
  margin-top:40px; padding-top:20px; border-top:1px solid var(--line);
  display:flex; justify-content:space-between; gap:16px; flex-wrap:wrap;
  font-size:.78rem; color:var(--ink-soft);
}
.foot-brand p{ font-family:var(--serif); color:var(--ink-2); max-width:36ch; }

/* ==========================  MOTION  =================================== */
/* 仅当 JS 可用时才隐藏待显示内容（渐进增强，禁用 JS 时内容照常可见） */
html.js .reveal{ opacity:0; transform:translateY(14px); transition:opacity .6s ease, transform .6s ease; }
html.js .reveal.in{ opacity:1; transform:none; }
@media (prefers-reduced-motion:reduce){
  html.js .reveal{ opacity:1; transform:none; transition:none; }
  html{ scroll-behavior:auto; }
}

/* ==========================  RESPONSIVE  =============================== */
@media (max-width:960px){
  .grid{ grid-template-columns:repeat(2,1fr); }
  .featured{ grid-template-columns:1fr; }
  .stat-row{ grid-template-columns:repeat(2,1fr); }
  .foot-grid{ grid-template-columns:1fr 1fr; }
  .columns-grid{ grid-template-columns:1fr; }
}
@media (max-width:720px){
  .nav-toggle{ display:grid; }
  .nav{
    display:none; position:absolute; left:0; right:0; top:100%;
    flex-direction:column; align-items:stretch; gap:0; background:var(--paper);
    border-bottom:1px solid var(--line); padding:8px 16px 16px;
  }
  .nav.open{ display:flex; }
  .nav a{ padding:12px 8px; border-bottom:1px solid var(--line); }
  .nav a::after{ display:none; }
  .topbar{ position:sticky; }
  .hero{ padding:52px 0 36px; }
  .grid,.grid.two{ grid-template-columns:1fr; }
  .deflist > div{ grid-template-columns:1fr; gap:6px; }
  .foot-grid{ grid-template-columns:1fr; }
  section{ padding:48px 0; }
}