/* =====================================================
   一眼千年 · 中国历史全景  —  样式表
   国风配色：宣纸米白 + 墨色 + 朱砂 + 鎏金 + 黛青
   ===================================================== */

:root{
  --paper:#faf6ee;
  --paper-2:#f3ecdd;
  --ink:#2b2620;
  --ink-soft:#6b6156;
  --red:#b93a32;
  --red-deep:#8e2a24;
  --gold:#c9a227;
  --gold-soft:#e8d9a8;
  --teal:#2c5f6e;
  --card:#fffdf7;
  --line:#e5dcc8;
  --shadow:0 10px 30px rgba(60,45,20,.10);
  --radius:18px;
  --serif:"Noto Serif SC","Source Han Serif SC","STSong","SimSun",serif;
  --sans:"PingFang SC","Microsoft YaHei","Hiragino Sans GB",sans-serif;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:var(--sans);
  background:var(--paper);
  color:var(--ink);
  line-height:1.75;
  overflow-x:hidden;
  background-image:
    radial-gradient(rgba(185,58,50,.03) 1px, transparent 1px),
    radial-gradient(rgba(44,95,110,.03) 1px, transparent 1px);
  background-size:34px 34px, 34px 34px;
  background-position:0 0, 17px 17px;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer}

/* ---------- 顶部进度条 ---------- */
.progress-bar{
  position:fixed;top:0;left:0;height:4px;width:0%;
  background:linear-gradient(90deg,var(--red),var(--gold));
  z-index:1002;border-radius:0 4px 4px 0;
  transition:width .1s linear;
}

/* ---------- 顶部导航 ---------- */
.topbar{
  position:fixed;top:0;left:0;right:0;z-index:1001;
  background:rgba(250,246,238,.92);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
  box-shadow:0 2px 14px rgba(60,45,20,.06);
}
.topbar-inner{
  max-width:1200px;margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;
  padding:10px 20px;gap:16px;flex-wrap:wrap;
}
.brand{display:flex;align-items:center;gap:10px}
.brand-seal{
  width:40px;height:40px;display:grid;place-items:center;
  background:var(--red);color:#fff;font-family:var(--serif);
  font-size:22px;font-weight:700;border-radius:10px;
  box-shadow:0 4px 10px rgba(185,58,50,.35);
}
.brand-text{font-family:var(--serif);font-size:20px;font-weight:700;line-height:1.2}
.brand-sub{display:block;font-size:11px;color:var(--ink-soft);font-weight:400;letter-spacing:2px}

.mode-switch{display:flex;gap:6px;background:var(--paper-2);padding:4px;border-radius:999px}
.mode-btn{
  border:none;background:transparent;border-radius:999px;
  padding:7px 16px;font-size:14px;color:var(--ink-soft);
  transition:all .25s;
}
.mode-btn:hover{color:var(--ink)}
.mode-btn.active{
  background:var(--red);color:#fff;font-weight:600;
  box-shadow:0 3px 10px rgba(185,58,50,.35);
}

/* 朝代快捷导航 */
.era-nav{
  display:flex;gap:6px;overflow-x:auto;padding:4px 16px 10px;
  max-width:1200px;margin:0 auto;
  scrollbar-width:thin;scrollbar-color:var(--gold-soft) transparent;
}
.era-nav::-webkit-scrollbar{height:5px}
.era-nav::-webkit-scrollbar-thumb{background:var(--gold-soft);border-radius:4px}
.era-pill{
  flex:0 0 auto;font-size:13px;padding:4px 13px;border-radius:999px;
  border:1px solid var(--line);background:var(--card);color:var(--ink-soft);
  transition:all .2s;white-space:nowrap;
}
.era-pill:hover{border-color:var(--gold);color:var(--ink);transform:translateY(-1px)}
.era-pill.active{
  background:var(--ink);color:#fff;border-color:var(--ink);
}

/* ---------- Hero 首页 ---------- */
.hero{
  position:relative;min-height:92vh;display:flex;align-items:center;
  overflow:hidden;margin-top:0;padding:120px 20px 90px;
}
.hero-bg{position:absolute;inset:0;z-index:0}
.hero-bg img{
  width:100%;height:100%;object-fit:cover;
  animation:heroZoom 22s ease-in-out infinite alternate;
}
@keyframes heroZoom{from{transform:scale(1)}to{transform:scale(1.08)}}
.hero-veil{
  position:absolute;inset:0;
  background:linear-gradient(180deg,rgba(43,38,32,.42) 0%,rgba(43,38,32,.18) 40%,rgba(250,246,238,.98) 96%);
}
.cloud{position:absolute;font-size:34px;opacity:.8;animation:drift 30s linear infinite}
.cloud.c1{top:14%;left:-60px}
.cloud.c2{top:26%;font-size:24px;animation-duration:44s;animation-delay:-12s}
@keyframes drift{from{transform:translateX(-80px)}to{transform:translateX(110vw)}}

.hero-inner{position:relative;z-index:1;max-width:1000px;margin:0 auto;text-align:center}
.hero-kicker{
  display:inline-block;font-size:15px;letter-spacing:3px;color:#fff;
  background:rgba(185,58,50,.85);padding:6px 20px;border-radius:999px;
  margin-bottom:22px;box-shadow:0 4px 14px rgba(0,0,0,.18);
  animation:fadeUp .9s .1s both;
}
.hero-title{
  font-family:var(--serif);font-size:clamp(56px,10vw,108px);
  color:#fff;text-shadow:0 6px 30px rgba(0,0,0,.35);
  letter-spacing:10px;animation:fadeUp .9s .25s both;
}
.hero-title span{
  background:linear-gradient(120deg,#f5d67b,#c9a227);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero-sub{
  font-size:clamp(18px,3vw,26px);color:#fff;margin-top:8px;
  text-shadow:0 2px 10px rgba(0,0,0,.4);animation:fadeUp .9s .4s both;
}
.hero-note{
  color:rgba(255,255,255,.94);margin-top:16px;font-size:15px;line-height:1.9;
  text-shadow:0 1px 6px rgba(0,0,0,.5);animation:fadeUp .9s .55s both;
}
.hero-stats{
  display:flex;justify-content:center;gap:clamp(14px,4vw,44px);
  margin:34px auto 30px;flex-wrap:wrap;animation:fadeUp .9s .7s both;
}
.stat{
  background:rgba(255,253,247,.9);border:1px solid var(--gold-soft);
  border-radius:16px;padding:14px 22px;min-width:130px;
  box-shadow:0 6px 18px rgba(0,0,0,.14);
}
.stat-num{font-family:var(--serif);font-size:34px;font-weight:800;color:var(--red)}
.stat-plus{font-size:18px;color:var(--gold);font-weight:700}
.stat-label{display:block;font-size:13px;color:var(--ink-soft);margin-top:2px}
.hero-actions{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;animation:fadeUp .9s .85s both}
.btn{
  padding:13px 30px;border-radius:999px;font-size:16px;font-weight:600;
  transition:transform .2s,box-shadow .2s;
}
.btn-primary{
  background:linear-gradient(120deg,var(--red),#d0483f);color:#fff;
  box-shadow:0 8px 22px rgba(185,58,50,.4);
}
.btn-primary:hover{transform:translateY(-3px);box-shadow:0 12px 26px rgba(185,58,50,.5)}
.btn-ghost{
  background:rgba(255,253,247,.9);border:1px solid var(--line);color:var(--ink);
}
.btn-ghost:hover{transform:translateY(-3px);border-color:var(--gold)}
.hero-wave{
  position:absolute;bottom:-2px;left:0;right:0;height:70px;z-index:1;
  background:var(--paper);
  clip-path:polygon(0 55%,8% 40%,16% 58%,25% 36%,34% 55%,43% 38%,52% 58%,61% 40%,70% 56%,79% 36%,88% 54%,100% 40%,100% 100%,0 100%);
}
@keyframes fadeUp{from{opacity:0;transform:translateY(26px)}to{opacity:1;transform:translateY(0)}}

/* ---------- 使用指南 ---------- */
.guide{padding:30px 20px 10px}
.guide-inner,.scale-inner,.song-inner{max-width:1150px;margin:0 auto}
.sec-title{
  font-family:var(--serif);font-size:clamp(26px,4vw,36px);text-align:center;
  margin-bottom:12px;letter-spacing:3px;
}
.sec-title::after{
  content:"";display:block;width:64px;height:4px;margin:12px auto 0;
  background:linear-gradient(90deg,var(--red),var(--gold));border-radius:4px;
}
.guide-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:18px;margin-top:26px}
.guide-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px 22px;text-align:center;box-shadow:var(--shadow);
  transition:transform .25s;
}
.guide-card:hover{transform:translateY(-6px)}
.guide-emoji{font-size:44px;margin-bottom:10px}
.guide-card h3{font-family:var(--serif);font-size:20px;margin-bottom:8px;color:var(--red-deep)}
.guide-card p{font-size:14px;color:var(--ink-soft)}
.guide-tip{
  text-align:center;margin-top:22px;font-size:14px;color:var(--ink-soft);
  background:var(--paper-2);border:1px dashed var(--gold);border-radius:12px;
  padding:10px 16px;max-width:760px;margin-left:auto;margin-right:auto;
}

/* ---------- 时间轴 ---------- */
.timeline{position:relative;max-width:1200px;margin:50px auto 0;padding:0 20px 30px}
.timeline::before{
  content:"";position:absolute;top:0;bottom:0;left:50%;
  width:5px;transform:translateX(-50%);
  background:linear-gradient(180deg,var(--red),var(--gold),var(--teal),var(--red));
  border-radius:4px;opacity:.35;
}

.era-card{position:relative;margin-bottom:64px}
.era-node{
  position:absolute;left:50%;top:34px;transform:translateX(-50%);
  width:26px;height:26px;border-radius:50%;
  background:var(--era-color,#b93a32);
  border:5px solid var(--paper);box-shadow:0 0 0 3px var(--era-color,#b93a32),0 4px 12px rgba(0,0,0,.2);
  z-index:2;
}
.era-node::after{
  content:attr(data-emoji);
  position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);
  font-size:11px;
}
.era-body{
  width:calc(50% - 46px);background:var(--card);
  border:1px solid var(--line);border-top:6px solid var(--era-color,#b93a32);
  border-radius:var(--radius);box-shadow:var(--shadow);
  overflow:hidden;
}
.era-card:nth-child(even) .era-body{margin-left:calc(50% + 46px)}
.era-card:nth-child(odd) .era-body{margin-left:0}

.era-img{position:relative;overflow:hidden}
.era-img img{
  width:100%;height:240px;object-fit:cover;
  transition:transform .8s ease;
}
.era-body:hover .era-img img{transform:scale(1.06)}
.era-img figcaption{
  position:absolute;left:14px;bottom:10px;font-size:12px;color:#fff;
  background:rgba(0,0,0,.45);padding:3px 12px;border-radius:999px;backdrop-filter:blur(4px);
}

.era-head{padding:20px 24px 14px;border-bottom:1px dashed var(--line)}
.era-order{
  display:inline-block;font-size:12px;letter-spacing:2px;color:#fff;
  background:var(--era-color,#b93a32);border-radius:999px;padding:3px 14px;margin-bottom:10px;
}
.era-title{
  font-family:var(--serif);font-size:clamp(30px,4vw,42px);letter-spacing:6px;
  color:var(--era-color,#b93a32);display:inline-block;
}
.era-title-en{font-size:14px;color:var(--ink-soft);margin-left:10px;letter-spacing:1px}
.era-period{font-size:14px;color:var(--ink-soft);margin-top:6px}

.era-content{padding:18px 24px 24px}

/* 内容块 */
.block{margin-bottom:16px}
.block:last-child{margin-bottom:0}
.block-title{
  font-size:14px;font-weight:700;color:var(--era-color,#b93a32);
  letter-spacing:1px;margin-bottom:8px;display:flex;align-items:center;gap:6px;
}
.block-title::before{content:"";width:5px;height:16px;border-radius:3px;background:currentColor;opacity:.7}

.kid-block{
  background:linear-gradient(120deg,#fff7e0,#fdf0d5);
  border:1px solid var(--gold-soft);border-radius:14px;padding:14px 18px;
  font-size:17px;line-height:1.9;
}
.kid-block .block-title{color:#a07a18}

.capital-list{display:flex;flex-direction:column;gap:8px}
.capital-item{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  background:var(--paper-2);border-radius:10px;padding:8px 14px;font-size:14px;
}
.capital-ancient{font-family:var(--serif);font-weight:700;color:var(--ink)}
.capital-arrow{color:var(--era-color,#b93a32);font-weight:700}
.capital-modern{color:var(--ink-soft)}
.capital-note{width:100%;font-size:12.5px;color:var(--ink-soft);opacity:.85}

.grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.grid2 .block{margin-bottom:0}

.person-list,.event-list,.bld-list,.relic-list{display:flex;flex-direction:column;gap:9px}
.person,.event,.bld,.relic{
  background:var(--paper);border:1px solid var(--line);border-radius:12px;
  padding:9px 13px;font-size:13.5px;transition:border-color .2s,transform .2s;
}
.person:hover,.event:hover,.bld:hover,.relic:hover{border-color:var(--era-color,#b93a32);transform:translateX(3px)}
.p-name{font-weight:700;font-family:var(--serif);font-size:15px;color:var(--ink)}
.p-role{
  display:inline-block;font-size:11px;color:#fff;background:var(--era-color,#b93a32);
  border-radius:999px;padding:1px 9px;margin-left:7px;vertical-align:2px;
}
.p-desc,.e-desc,.b-where,.r-where{display:block;color:var(--ink-soft);margin-top:3px;line-height:1.65}
.e-title{font-weight:700;font-size:14px}
.e-title::before{content:"⚔️ "}

.badge-wh{
  display:inline-block;font-size:10.5px;color:#7a5a00;background:linear-gradient(120deg,#ffe9a8,#ffd76e);
  border-radius:999px;padding:1px 8px;margin-left:7px;font-weight:700;vertical-align:2px;
}
.b-name,.r-name{font-weight:700;font-size:14px}
.b-name::before{content:"🏯 "}
.r-name::before{content:"🏺 "}
.b-where,.r-where{font-size:12.5px}
.b-where::before{content:"📍 "}

/* 更替步骤条 */
.change-steps{display:flex;flex-direction:column;gap:0}
.step{display:flex;gap:14px;position:relative;padding-bottom:16px}
.step:last-child{padding-bottom:0}
.step-num{
  flex:0 0 28px;height:28px;border-radius:50%;
  background:var(--era-color,#b93a32);color:#fff;font-weight:700;font-size:14px;
  display:grid;place-items:center;z-index:1;
}
.step::before{
  content:"";position:absolute;left:13.5px;top:28px;bottom:0;width:2px;
  background:linear-gradient(var(--era-color,#b93a32),transparent);opacity:.4;
}
.step:last-child::before{display:none}
.step-text{font-size:13.5px;padding-top:3px}

/* 文化/考点/趣闻 */
.culture-list{list-style:none;display:flex;flex-direction:column;gap:6px;font-size:13.5px}
.culture-list li::before{content:"💡 "}
.points-list{list-style:none;display:flex;flex-direction:column;gap:6px;font-size:13.5px}
.points-list li{
  background:rgba(44,95,110,.06);border-left:3px solid var(--teal);
  padding:6px 10px;border-radius:0 8px 8px 0;
}
.points-list li::before{content:"📝 "}
.fun-block{
  background:linear-gradient(120deg,#fdeeee,#fff6f0);
  border:1px solid #f2cfc7;border-radius:14px;padding:14px 18px;font-size:14px;
}
.fun-block .block-title{color:var(--red)}

/* ---------- 滚动浮现动画 ---------- */
.reveal{opacity:0;transform:translateY(40px);transition:opacity .8s ease,transform .8s ease}
.reveal.visible{opacity:1;transform:translateY(0)}

/* ---------- 朝代歌 ---------- */
.song{
  margin-top:40px;padding:70px 20px;color:#f7f1e3;
  background:linear-gradient(135deg,#2b2620,#41352a 60%,#2b2620);
}
.song-lines{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));
  gap:16px;margin-top:30px;max-width:1000px;margin-left:auto;margin-right:auto;
}
.song-line{
  background:rgba(255,255,255,.06);border:1px solid rgba(232,217,168,.35);
  border-radius:14px;padding:18px 16px;text-align:center;
  font-family:var(--serif);font-size:19px;letter-spacing:2px;line-height:1.9;
  opacity:0;transform:scale(.94);transition:all .7s ease;
}
.song-line.visible{opacity:1;transform:scale(1)}
.song-line em{font-style:normal;color:#f5d67b;font-weight:700;display:block}
.song-sub{text-align:center;color:rgba(247,241,227,.75);margin-top:4px;font-size:14px}
.song .sec-title{color:#f7f1e3}

/* ---------- 千年比例尺 ---------- */
.scale-sec{padding:70px 20px}
.scale-wrap{margin-top:30px}
.scale-bar{
  position:relative;height:120px;border-radius:14px;
  background:var(--paper-2);border:1px solid var(--line);overflow:hidden;
}
.scale-seg{
  position:absolute;top:0;height:100%;min-width:2px;
  border-top:6px solid var(--seg-color);
  background:var(--seg-color);opacity:.82;cursor:pointer;
  transition:opacity .2s,filter .2s;overflow:hidden;
}
.scale-seg:hover{opacity:1;filter:brightness(1.1)}
.scale-seg span{
  position:absolute;inset:0;display:grid;place-items:center;
  font-size:12px;color:#fff;font-weight:700;text-shadow:0 1px 3px rgba(0,0,0,.5);
  white-space:nowrap;overflow:hidden;
}
.scale-ruler{position:relative;height:26px;margin-top:8px;font-size:12px;color:var(--ink-soft)}
.scale-ruler span{position:absolute;transform:translateX(-50%);white-space:nowrap}
.scale-tip{
  margin-top:26px;font-size:14px;color:var(--ink-soft);
  background:var(--paper-2);border:1px dashed var(--gold);border-radius:12px;
  padding:12px 18px;max-width:860px;margin-left:auto;margin-right:auto;
}
.scale-pop{
  position:absolute;bottom:130%;left:50%;transform:translateX(-50%);
  background:var(--ink);color:#fff;padding:10px 16px;border-radius:12px;
  font-size:12.5px;white-space:nowrap;box-shadow:0 8px 20px rgba(0,0,0,.3);
  opacity:0;pointer-events:none;transition:opacity .25s;z-index:5;
}
.scale-seg:hover .scale-pop{opacity:1}

/* ---------- 页脚 ---------- */
.footer{
  margin-top:30px;background:var(--ink);color:rgba(247,241,227,.8);
  padding:56px 20px 40px;text-align:center;font-size:13.5px;line-height:2;
}
.footer-seal{
  width:52px;height:52px;margin:0 auto 14px;display:grid;place-items:center;
  background:var(--red);color:#fff;font-family:var(--serif);font-size:28px;
  border-radius:12px;font-weight:700;
}
.footer strong{color:#f7f1e3;font-size:16px}
.footer-heart{margin-top:10px;color:var(--gold-soft)}

/* ---------- 返回顶部 ---------- */
.back-top{
  position:fixed;right:22px;bottom:26px;width:48px;height:48px;border:none;
  border-radius:50%;background:var(--red);color:#fff;font-size:20px;
  box-shadow:0 8px 20px rgba(185,58,50,.45);z-index:1000;
  opacity:0;pointer-events:none;transform:translateY(14px);
  transition:all .3s;
}
.back-top.show{opacity:1;pointer-events:auto;transform:translateY(0)}
.back-top:hover{transform:translateY(-4px)}

/* ---------- 学段模式显隐规则 ----------
   only-kid：仅幼儿园模式显示
   only-primary：仅小学模式显示
   only-senior：仅中学模式显示 ---------- */
body.mode-senior .only-kid,body.mode-senior .only-primary{display:none!important}
body.mode-primary .only-kid,body.mode-primary .only-senior{display:none!important}
body.mode-kid .only-primary,body.mode-kid .only-senior{display:none!important}

/* 幼儿园模式放大字号 */
body.mode-kid .era-content{font-size:17px}
body.mode-kid .kid-block{font-size:19px}
body.mode-kid .b-where,body.mode-kid .r-where{font-size:14px}
body.mode-kid .era-img img{height:220px}

/* ---------- 响应式 ---------- */
@media (max-width:860px){
  .timeline::before{left:22px}
  .era-node{left:22px}
  .era-body,.era-card:nth-child(even) .era-body{
    width:calc(100% - 58px);margin-left:58px;
  }
  .grid2{grid-template-columns:1fr}
  .topbar-inner{padding:8px 12px}
  .hero{padding-top:140px}
  .scale-bar{height:150px}
  .scale-seg span{font-size:11px}
}
@media (max-width:520px){
  .brand-text{font-size:16px}
  .mode-btn{padding:6px 10px;font-size:12.5px}
  .era-body,.era-card:nth-child(even) .era-body{width:calc(100% - 48px);margin-left:48px}
}