/* ═══════════════════════════════════════════════════
   Music-Lab 数智音乐教学空间 · 全站共享样式
   页面：index3（门户）/ 各课程文件夹（和声学·复调音乐·配器法·作曲）
         / 视唱练耳 / 声乐 / 钢琴 / 考研专区
   ═══════════════════════════════════════════════════ */

/* ═══════════ 设计变量 ═══════════ */
:root{
  --ink:#0A1018; --ink-2:#111A28; --ink-3:#18243A; --ink-4:#22304A;
  --paper:#FBFAF6; --paper-2:#F4F2EA; --paper-3:#EDEAE0;
  --line:#E4E1D5; --line-2:#D8D4C4;
  --text:#141D2B; --text-2:#3A465C; --muted:#6B7590; --muted-2:#8B94A8;
  --gold:#C8952E; --gold-2:#E8B755; --gold-3:#F5D899;
  --jade:#4FA691; --jade-2:#7CC5B2;
  --indigo:#6C7CE0; --indigo-2:#9AA6F0;
  --rose:#C97C8E;
  --slate:#5A6B85;
  --mono:ui-monospace,"SF Mono","JetBrains Mono",Menlo,Consolas,monospace;
  --sans:"PingFang SC","Microsoft YaHei","Hiragino Sans GB","Helvetica Neue",Helvetica,Arial,sans-serif;
  --r:14px; --r-lg:20px; --r-xl:26px;
  --sh:0 10px 30px rgba(20,29,43,.07);
  --sh-lg:0 22px 56px rgba(20,29,43,.13);
  --maxw:1220px;
  --nav-h:70px;
}
*{box-sizing:border-box;}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;}
body{
  margin:0;font-family:var(--sans);color:var(--text);background:var(--paper);
  font-size:16px;line-height:1.72;overflow-x:hidden;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
button,input{font-family:inherit;}
h1,h2,h3,h4,h5{margin:0;line-height:1.3;font-weight:750;letter-spacing:-.015em;}
p{margin:0;}
ul{margin:0;padding:0;list-style:none;}
::selection{background:var(--gold-3);color:var(--ink);}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 26px;}
.mono{font-family:var(--mono);}
a.btn{display:inline-flex;align-items:center;justify-content:center;text-decoration:none;}

/* 阅读进度 */
.prog{position:fixed;top:0;left:0;height:2px;z-index:200;width:0;pointer-events:none;
  background:linear-gradient(90deg,var(--jade),var(--gold) 60%,var(--gold-2));}

/* ═══════════ 五线谱母题元素 ═══════════ */
.stave-mark{display:flex;flex-direction:column;gap:4px;width:46px;margin:22px auto 0;position:relative;}
.stave-mark i{height:1px;background:linear-gradient(90deg,transparent,var(--gold),transparent);opacity:.7;}
.stave-mark::before{
  content:"";position:absolute;right:-7px;top:-3px;bottom:-3px;width:1px;
  background:var(--gold);opacity:.45;
}
.stave-mark.light i{background:linear-gradient(90deg,transparent,rgba(255,255,255,.7),transparent);}
.stave-mark.light::before{background:rgba(255,255,255,.6);}

/* ═══════════ 顶部条 ═══════════ */
.topbar{background:var(--ink);color:#8E9AB4;font-size:12.5px;height:34px;display:flex;align-items:center;position:relative;z-index:60;}
.topbar .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;width:100%;}
.topbar .lft{display:flex;align-items:center;gap:9px;letter-spacing:.02em;}
.beat{width:6px;height:6px;border-radius:50%;background:var(--jade-2);animation:beat 1.6s ease-in-out infinite;}
@keyframes beat{0%,100%{transform:scale(1);opacity:1}50%{transform:scale(1.5);opacity:.45}}
.topbar .rgt a{margin-left:20px;opacity:.8;transition:.2s;}
.topbar .rgt a:hover{opacity:1;color:var(--gold-3);}
@media(max-width:820px){.topbar .rgt{display:none;}}

/* ═══════════ 导航 ═══════════ */
.nav{position:sticky;top:0;z-index:70;height:var(--nav-h);
  background:rgba(10,16,24,.82);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid rgba(255,255,255,.07);transition:.3s;}
.nav.scrolled{background:rgba(10,16,24,.96);box-shadow:0 8px 32px rgba(0,0,0,.34);}
.nav .wrap{height:var(--nav-h);display:flex;align-items:center;gap:30px;}

.logo{display:flex;align-items:center;gap:12px;flex-shrink:0;}
.logo-mark{width:38px;height:38px;border-radius:11px;flex-shrink:0;display:grid;place-items:center;position:relative;
  background:linear-gradient(140deg,var(--gold),var(--gold-2) 55%,var(--jade-2));
  box-shadow:0 5px 16px rgba(200,149,46,.32);}
.logo-mark svg{width:21px;height:21px;display:block;}
.logo-txt b{display:block;font-size:18.5px;color:#fff;line-height:1.18;letter-spacing:.01em;}
.logo-txt b span{color:var(--gold-2);}
.logo-txt small{display:block;font-size:11px;color:#7C88A3;letter-spacing:.14em;}

.menu{display:flex;align-items:center;gap:2px;margin-left:4px;}
.menu a{color:#A5B0C8;font-size:14.8px;padding:9px 13px;border-radius:9px;transition:.22s;font-weight:500;position:relative;}
.menu a:hover{color:#fff;background:rgba(255,255,255,.07);}
.menu a.active{color:var(--gold-3);background:rgba(200,149,46,.13);}
.nav-right{margin-left:auto;display:flex;align-items:center;gap:12px;}

.btn{border:0;cursor:pointer;border-radius:10px;padding:9px 19px;font-size:14.8px;font-weight:600;
  transition:.24s cubic-bezier(.2,.7,.3,1);white-space:nowrap;}
.btn-login{background:transparent;color:#D3DAEA;border:1px solid rgba(255,255,255,.26);}
.btn-login:hover{color:#fff;border-color:var(--gold);background:rgba(200,149,46,.12);}
.btn-gold{background:linear-gradient(120deg,var(--gold),var(--gold-2));color:#2A1C05;box-shadow:0 6px 18px rgba(200,149,46,.3);}
.btn-gold:hover{transform:translateY(-2px);box-shadow:0 11px 26px rgba(200,149,46,.42);}
.btn-outline{background:rgba(255,255,255,.06);color:#fff;border:1px solid rgba(255,255,255,.28);}
.btn-outline:hover{background:rgba(255,255,255,.13);transform:translateY(-2px);}
.btn-light{background:#fff;color:var(--ink);box-shadow:0 8px 22px rgba(0,0,0,.16);}
.btn-light:hover{transform:translateY(-2px);}
.btn-lg{padding:14px 30px;font-size:16px;border-radius:12px;}
.burger{display:none;width:38px;height:36px;border-radius:9px;border:1px solid rgba(255,255,255,.2);
  background:transparent;color:#fff;cursor:pointer;align-items:center;justify-content:center;}
.burger i{display:block;width:17px;height:1.6px;background:currentColor;position:relative;}
.burger i::before,.burger i::after{content:"";position:absolute;left:0;width:17px;height:1.6px;background:currentColor;}
.burger i::before{top:-5.5px}.burger i::after{top:5.5px}

/* ═══════════ 课程下拉菜单 ═══════════ */
.menu .has-sub{position:relative;}
.menu .has-sub > a{display:flex;align-items:center;}
.caret{display:inline-block;width:0;height:0;border-left:4px solid transparent;
  border-right:4px solid transparent;border-top:5px solid currentColor;margin-left:7px;margin-top:2px;
  transition:transform .22s;opacity:.7;}
.menu .has-sub:hover .caret,.menu .has-sub.open .caret{transform:rotate(180deg);opacity:1;}
.menu .has-sub:hover > a{color:#fff;}
.sub{
  position:absolute;top:calc(100% + 9px);left:50%;
  transform:translateX(-50%) translateY(8px);
  min-width:236px;background:rgba(13,20,32,.98);
  border:1px solid rgba(255,255,255,.11);border-radius:14px;padding:9px;
  opacity:0;visibility:hidden;pointer-events:none;
  transition:.22s cubic-bezier(.2,.7,.3,1);
  box-shadow:0 24px 58px rgba(0,0,0,.5);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
}
.sub::before{content:"";position:absolute;top:-10px;left:0;right:0;height:10px;}
.menu .has-sub:hover .sub,.menu .has-sub.open .sub{
  opacity:1;visibility:visible;pointer-events:auto;transform:translateX(-50%) translateY(0);
}
.sub a{display:flex;align-items:center;gap:11px;padding:10px 13px;border-radius:9px;
  font-size:14.4px;color:#C3CCDE;white-space:nowrap;}
.sub a:hover{background:rgba(255,255,255,.08);color:#fff;}
.sub a.active{background:rgba(200,149,46,.15);color:var(--gold-3);}
.sub .dot{width:7px;height:7px;border-radius:50%;flex-shrink:0;box-shadow:0 0 8px currentColor;}
.sub .sub-en{margin-left:auto;font-size:10.5px;color:#6E7A94;font-family:var(--mono);letter-spacing:.05em;}
.sub .plan-tag{margin-left:auto;font-size:10px;color:#8B94A8;border:1px solid rgba(255,255,255,.16);
  padding:1px 7px;border-radius:5px;letter-spacing:.04em;}
.sub a.planned{opacity:.5;}
.sub a.planned:hover{background:transparent;color:#C3CCDE;cursor:default;}
.sub hr{border:0;border-top:1px solid rgba(255,255,255,.09);margin:6px 12px;}

@media(max-width:1080px){
  .menu{display:none;position:absolute;top:var(--nav-h);left:0;right:0;flex-direction:column;align-items:stretch;
    background:rgba(10,16,24,.99);padding:12px 22px 20px;gap:1px;margin:0;border-bottom:1px solid rgba(255,255,255,.09);
    max-height:calc(100vh - var(--nav-h));overflow-y:auto;}
  .menu.open{display:flex;}
  .menu a{padding:12px;font-size:15.5px;}
  .menu .has-sub > a{justify-content:space-between;}
  .menu .has-sub > a .caret{margin-left:auto;}
  .sub{position:static;transform:none;opacity:1;visibility:visible;pointer-events:auto;display:none;
    min-width:0;margin:4px 0 8px;background:rgba(255,255,255,.04);
    border:1px solid rgba(255,255,255,.08);box-shadow:none;backdrop-filter:none;-webkit-backdrop-filter:none;}
  .menu .has-sub.open .sub{display:block;}
  /* ⚠ 必须在媒体查询里再写一次：桌面版 `.menu .has-sub.open .sub{transform:translateX(-50%)}` 权重更高，
     媒体查询不加权重，否则手机上展开的课程列表整行被左移半屏（只剩右侧序号可见、课程名跑到屏幕外） */
  .menu .has-sub:hover .sub,
  .menu .has-sub.open .sub{transform:none;}
  .burger{display:flex;}
}

/* ═══════════ HERO（首页） ═══════════ */
.hero{position:relative;overflow:hidden;color:#fff;
  background:
    radial-gradient(900px 560px at 6% -14%,rgba(200,149,46,.19),transparent 60%),
    radial-gradient(820px 520px at 96% 4%,rgba(79,199,190,.20),transparent 62%),
    radial-gradient(760px 520px at 52% 118%,rgba(108,124,224,.20),transparent 64%),
    linear-gradient(168deg,#0C1524 0%,#122238 46%,#0F2B3A 78%,#0B1626 100%);
  padding:112px 0 100px;}

/* 透视五线谱隧道 */
.st-tunnel{
  position:absolute;left:0;right:0;top:0;bottom:0;
  perspective:720px;perspective-origin:50% 46%;
  overflow:hidden;pointer-events:none;z-index:0;
  mask-image:radial-gradient(ellipse 78% 62% at 50% 46%,#000 12%,transparent 82%);
  -webkit-mask-image:radial-gradient(ellipse 78% 62% at 50% 46%,#000 12%,transparent 82%);
}
.st-plane{
  position:absolute;left:-45%;right:-45%;top:46%;
  transform-style:preserve-3d;transform-origin:50% 0;
  animation:flyThru 11s linear infinite;opacity:0;
}
.st-plane i{
  display:block;height:1px;margin-bottom:15px;
  background:linear-gradient(90deg,transparent,rgba(232,183,85,.55) 18%,rgba(124,197,178,.5) 50%,rgba(232,183,85,.55) 82%,transparent);
}
.st-p1{animation-delay:0s}
.st-p2{animation-delay:2.2s}
.st-p3{animation-delay:4.4s}
.st-p4{animation-delay:6.6s}
.st-p5{animation-delay:8.8s}
@keyframes flyThru{
  0%   {transform:rotateX(78deg) translateZ(-1500px);opacity:0}
  10%  {opacity:.9}
  55%  {opacity:.62}
  85%  {opacity:.16}
  100% {transform:rotateX(78deg) translateZ(360px);opacity:0}
}

/* 近景平面谱线 */
.hero-lines{position:absolute;inset:0;display:flex;flex-direction:column;justify-content:center;gap:28px;
  padding:0 7%;opacity:.42;pointer-events:none;z-index:0;
  mask-image:radial-gradient(ellipse at 50% 50%,transparent 6%,#000 42%,transparent 78%);
  -webkit-mask-image:radial-gradient(ellipse at 50% 50%,transparent 6%,#000 42%,transparent 78%);}
.hero-lines i{height:1px;
  background:linear-gradient(90deg,transparent,rgba(232,183,85,.3) 22%,rgba(124,197,178,.28) 50%,rgba(232,183,85,.3) 78%,transparent);}

/* 科技光带 */
.hero-glow{position:absolute;inset:0;pointer-events:none;z-index:0;
  background:
    linear-gradient(112deg,transparent 42%,rgba(124,197,178,.09) 50%,transparent 58%),
    radial-gradient(520px 3px at 26% 26%,rgba(232,183,85,.5),transparent),
    radial-gradient(420px 3px at 74% 72%,rgba(124,197,178,.42),transparent);
  animation:glowDrift 13s ease-in-out infinite alternate;}
@keyframes glowDrift{from{transform:translate3d(-16px,10px,0) scale(1)}to{transform:translate3d(16px,-10px,0) scale(1.04)}}

/* 星尘粒子 */
.hero-dust{position:absolute;inset:0;pointer-events:none;z-index:0;overflow:hidden;}
.hero-dust b{position:absolute;display:block;border-radius:50%;background:rgba(232,183,85,.75);
  animation:dustRise 9s linear infinite;}
@keyframes dustRise{
  0%{transform:translateY(0) scale(.6);opacity:0}
  15%{opacity:.85}
  75%{opacity:.5}
  100%{transform:translateY(-190px) scale(1.15);opacity:0}
}

.hero .wrap{position:relative;z-index:2;display:grid;grid-template-columns:1fr 1.02fr;gap:60px;align-items:center;}

.hero h1{font-size:clamp(37px,5vw,66px);margin:6px 0 0;letter-spacing:-.03em;font-weight:800;}
.hero h1 .en{display:block;color:var(--gold-2);letter-spacing:.005em;}
.hero h1 .cn{display:block;color:#fff;margin-top:2px;}
.hero .cn-sub{
  display:block;margin-top:20px;font-size:clamp(14px,1.28vw,18px);font-weight:500;letter-spacing:.16em;
  color:#8FBFB4;
}
.hero .hero-acts{display:flex;gap:13px;margin-top:34px;flex-wrap:wrap;}
.waveform{display:flex;align-items:flex-end;gap:3px;height:76px;margin-top:40px;}
.waveform i{display:block;width:3px;border-radius:2px;
  background:linear-gradient(180deg,var(--jade-2),var(--gold) 70%,var(--gold-2));
  animation:wv 1.15s ease-in-out infinite alternate;opacity:.88;box-shadow:0 0 9px rgba(200,149,46,.3);}
@keyframes wv{from{transform:scaleY(.2)}to{transform:scaleY(1)}}

/* 乐谱视窗 */
.score{position:relative;border-radius:var(--r-xl);overflow:hidden;
  background:linear-gradient(158deg,rgba(255,255,255,.075),rgba(255,255,255,.02));
  border:1px solid rgba(255,255,255,.13);box-shadow:0 34px 78px rgba(0,0,0,.46);backdrop-filter:blur(14px);}
.score-top{display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding:15px 20px;border-bottom:1px solid rgba(255,255,255,.09);}
.score-top .t{font-size:12.5px;color:#9AA6C0;letter-spacing:.05em;}
.score-top .live{display:flex;align-items:center;gap:6px;font-size:11.5px;font-weight:700;
  color:#7CC5B2;background:rgba(79,166,145,.14);border:1px solid rgba(79,166,145,.32);
  padding:4px 11px;border-radius:999px;white-space:nowrap;}
.score-top .live em{width:5px;height:5px;border-radius:50%;background:var(--jade-2);animation:beat 1.4s infinite;font-style:normal;}

.score-body{position:relative;height:186px;background:linear-gradient(180deg,#FDFCF8,#F2EFE4);
  margin:16px 18px;border-radius:11px;overflow:hidden;}
.score-body .lines{position:absolute;left:0;right:0;top:50%;transform:translateY(-50%);
  height:52px;display:flex;flex-direction:column;justify-content:space-between;}
.score-body .lines i{height:1px;background:rgba(20,29,43,.22);}
.clef{position:absolute;left:15px;top:50%;transform:translateY(-52%);line-height:1;
  font-size:58px;color:rgba(20,29,43,.28);
  font-family:"Bravura","Noto Music","Segoe UI Symbol","Apple Symbols",Georgia,serif;}
.timesig{position:absolute;left:72px;top:50%;transform:translateY(-50%);
  font-family:var(--mono);font-size:18px;font-weight:700;color:rgba(20,29,43,.42);
  line-height:1.06;text-align:center;}

.nt{position:absolute;width:14px;height:11px;border-radius:50%;
  background:currentColor;color:#2A3648;
  transform:translate(-50%,-50%) rotate(-16deg);
  opacity:.62;
  transition:opacity .18s ease;
  animation:ntLit 3.4s linear infinite;
  animation-delay:var(--d,0s);}
.nt::after{content:"";position:absolute;right:0;top:-23px;width:1.7px;height:25px;
  background:currentColor;border-radius:2px;}
.nt::before{
  content:"";position:absolute;left:50%;top:50%;width:30px;height:30px;
  margin:-15px 0 0 -15px;border-radius:50%;border:1.5px solid rgba(200,149,46,.85);
  opacity:0;pointer-events:none;
  animation:ntPing 3.4s ease-out infinite;animation-delay:var(--d,0s);
}
@keyframes ntLit{
  0%   {opacity:.62;color:#2A3648;transform:translate(-50%,-50%) rotate(-16deg) scale(1)}
  7%   {opacity:1;color:var(--gold);transform:translate(-50%,-50%) rotate(-16deg) scale(1.22)}
  9%   {opacity:1;color:var(--gold);transform:translate(-50%,-50%) rotate(-16deg) scale(1.16)}
  26%  {opacity:1;color:var(--gold);transform:translate(-50%,-50%) rotate(-16deg) scale(1.16)}
  36%  {opacity:.62;color:#2A3648;transform:translate(-50%,-50%) rotate(-16deg) scale(1)}
  100% {opacity:.62;color:#2A3648;transform:translate(-50%,-50%) rotate(-16deg) scale(1)}
}
@keyframes ntPing{
  0%   {opacity:0;transform:scale(.4)}
  8%   {opacity:.95;transform:scale(1)}
  22%  {opacity:0;transform:scale(1.75)}
  100% {opacity:0;transform:scale(1.75)}
}
.playhead{position:absolute;top:0;bottom:0;width:2px;left:0;
  background:linear-gradient(180deg,transparent,var(--gold) 20%,var(--gold-2) 50%,var(--gold) 80%,transparent);
  box-shadow:0 0 18px rgba(200,149,46,.95);animation:scan 3.4s linear infinite;}
@keyframes scan{from{left:18%}to{left:92%}}
.corr-tip{position:absolute;top:12px;left:55%;transform:translateX(-50%);
  background:rgba(201,124,142,.15);border:1px solid rgba(201,124,142,.5);color:#9E4B60;
  font-size:11.5px;padding:3px 10px;border-radius:7px;white-space:nowrap;opacity:0;
  animation:tipShow 3.4s linear infinite;}
.corr-tip::after{content:"";position:absolute;left:50%;bottom:-4px;transform:translateX(-50%) rotate(45deg);
  width:6px;height:6px;border-right:1px solid rgba(201,124,142,.5);border-bottom:1px solid rgba(201,124,142,.5);
  background:rgba(201,124,142,.14);}
@keyframes tipShow{
  0%,48%{opacity:0;transform:translateX(-50%) translateY(5px)}
  52%{opacity:1;transform:translateX(-50%) translateY(0)}
  66%{opacity:1;transform:translateX(-50%) translateY(0)}
  71%,100%{opacity:0;transform:translateX(-50%) translateY(5px)}
}

.score-foot{display:flex;align-items:center;gap:12px;padding:0 20px 17px;flex-wrap:wrap;}
.score-foot span{font-size:12px;color:#A8B3CB;background:rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.1);padding:4px 11px;border-radius:7px;font-family:var(--mono);}
@media(max-width:1080px){
  .hero .wrap{grid-template-columns:1fr;gap:46px;}
  .hero{padding:72px 0 88px;}
  .waveform{height:60px;margin-top:30px;}
}

/* ═══════════ 子页 HERO ═══════════ */
.phero{position:relative;overflow:hidden;color:#fff;padding:82px 0 74px;
  background:
    radial-gradient(820px 480px at 10% -12%,rgba(200,149,46,.17),transparent 60%),
    radial-gradient(720px 460px at 94% 6%,rgba(79,199,190,.16),transparent 62%),
    linear-gradient(168deg,#0C1524 0%,#122238 50%,#0F2B3A 100%);}
.phero::after{content:"";position:absolute;inset:0;pointer-events:none;opacity:.5;
  background-image:repeating-linear-gradient(0deg,transparent 0 15px,rgba(255,255,255,.028) 15px 16px);
  mask-image:radial-gradient(ellipse 80% 80% at 50% 40%,#000,transparent 78%);
  -webkit-mask-image:radial-gradient(ellipse 80% 80% at 50% 40%,#000,transparent 78%);}
.phero .wrap{position:relative;z-index:2;}
.phero .crumb{font-size:12.5px;color:#8E9AB4;letter-spacing:.04em;margin-bottom:24px;}
.phero .crumb a{color:#A5B0C8;transition:.2s;}
.phero .crumb a:hover{color:var(--gold-3);}
.phero .crumb i{font-style:normal;margin:0 9px;opacity:.45;}
.phero .chip{display:inline-flex;align-items:center;gap:9px;font-family:var(--mono);font-size:11.5px;font-weight:700;
  letter-spacing:.16em;color:var(--gold-2);border:1px solid rgba(232,183,85,.3);background:rgba(232,183,85,.1);
  padding:5px 14px;border-radius:999px;margin-bottom:20px;}
.phero .chip .cdot{width:7px;height:7px;border-radius:50%;}
.phero h1{font-size:clamp(30px,4vw,50px);color:#fff;}
.phero .pen{font-family:var(--mono);font-size:13px;color:#7CC5B2;letter-spacing:.2em;margin-top:10px;}
.phero .pdesc{color:#AEBAD3;font-size:15.5px;line-height:1.92;max-width:680px;margin-top:20px;}
.phero .pmeta{display:flex;flex-wrap:wrap;gap:9px;margin-top:26px;}
.phero .pmeta span{font-size:12.5px;color:#C0CADD;background:rgba(255,255,255,.07);
  border:1px solid rgba(255,255,255,.15);padding:5px 14px;border-radius:8px;}
.phero .pacts{display:flex;gap:12px;margin-top:32px;flex-wrap:wrap;}
@media(max-width:640px){.phero{padding:60px 0 56px;}}

/* ═══════════ 区块通用 ═══════════ */
section{padding:98px 0;}
.sec-head{max-width:740px;margin:0 auto 50px;text-align:center;}
.sec-head .eyebrow{display:inline-block;font-family:var(--mono);font-size:11.5px;font-weight:700;
  letter-spacing:.2em;color:var(--gold);text-transform:uppercase;margin-bottom:14px;
  padding-bottom:7px;border-bottom:1px solid rgba(200,149,46,.3);}
.sec-head h2{font-size:clamp(25px,2.9vw,37px);margin-bottom:13px;}
.sec-head p{color:var(--muted);font-size:16.2px;}
.reveal{opacity:0;transform:translateY(24px);transition:opacity .7s ease,transform .7s cubic-bezier(.2,.7,.3,1);}
.reveal.in{opacity:1;transform:none;}
@media(max-width:760px){section{padding:66px 0;}}

/* ═══════════ 课程体系（首页） ═══════════ */
.band-paper{background:var(--paper);}
.course-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;}
.cc{background:#fff;border:1px solid var(--line);border-radius:var(--r);overflow:hidden;
  display:flex;flex-direction:column;transition:.3s cubic-bezier(.2,.7,.3,1);cursor:pointer;position:relative;}
.cc:hover{transform:translateY(-5px);box-shadow:var(--sh);border-color:var(--line-2);}
.cc .bar{height:3px;flex-shrink:0;}
.cc .top{padding:20px 20px 0;position:relative;}
.cc .no{font-family:var(--mono);font-size:12px;font-weight:700;color:var(--muted-2);letter-spacing:.08em;}
.cc .watermark{position:absolute;right:14px;top:8px;font-size:52px;line-height:1;opacity:.09;pointer-events:none;}
.cc h4{font-size:17.5px;margin-top:9px;letter-spacing:-.01em;}
.cc .en{font-size:11.5px;color:var(--muted-2);letter-spacing:.05em;margin-top:3px;min-height:17px;}
.cc .desc{font-size:13.6px;color:var(--muted);padding:13px 20px 0;line-height:1.78;flex:1;}
.cc .lv{display:flex;align-items:center;gap:8px;padding:15px 20px 0;font-size:12.5px;color:var(--muted);}
.cc .lv b{font-size:11px;font-weight:700;padding:3px 9px;border-radius:6px;letter-spacing:.03em;}
.cc .lv .focus{margin-left:auto;font-family:var(--mono);font-size:11.5px;color:var(--muted-2);}
.cc .lv .flow{font-size:10.5px;font-weight:700;color:#3F7A6A;background:rgba(79,166,145,.14);
  padding:2px 8px;border-radius:5px;letter-spacing:.04em;}
.cc .tags{display:flex;flex-wrap:wrap;gap:6px;padding:13px 20px 0;}
.cc .tags span{font-size:11.5px;padding:3px 9px;border-radius:6px;background:var(--paper-2);color:var(--muted);}
.cc .tags span.hi{background:rgba(200,149,46,.12);color:#96691A;font-weight:600;}
.cc .go{font-size:13.5px;font-weight:700;color:var(--text);display:flex;align-items:center;gap:6px;
  border-top:1px solid var(--line);margin:15px 20px 0;padding:12px 0 14px;}
.cc .go i{transition:.25s;font-style:normal;color:var(--muted-2);}
.cc:hover .go i{transform:translateX(5px);color:var(--gold);}

.cc.plan{border-style:dashed;border-color:#DAD5C6;background:#FCFBF7;}
.cc.plan:hover{border-color:#C9C2AE;box-shadow:none;transform:translateY(-3px);}
.cc.plan .watermark{opacity:.055;}
.cc.plan h4{color:var(--muted);}
.cc.plan .badge-plan{position:absolute;right:16px;top:18px;font-size:11px;font-weight:700;
  background:#F0E9D6;color:#8A6D1F;padding:3px 9px;border-radius:6px;letter-spacing:.04em;}

/* AI 特色卡 */
.cc-ai{grid-column:span 2;color:#fff;border:0;border-radius:var(--r);overflow:hidden;position:relative;
  background:
    radial-gradient(560px 300px at 88% 8%,rgba(200,149,46,.2),transparent 64%),
    radial-gradient(480px 280px at 6% 96%,rgba(79,199,190,.18),transparent 64%),
    linear-gradient(128deg,#17223A 0%,#253252 50%,#15313A 100%);
  box-shadow:0 16px 44px rgba(20,29,43,.2);}
.cc-ai:hover{transform:translateY(-5px);box-shadow:0 24px 56px rgba(20,29,43,.28);}
.cc-ai .pr{position:absolute;inset:0;opacity:.5;display:grid;
  grid-template-columns:repeat(11,1fr);grid-template-rows:repeat(5,1fr);gap:5px;padding:16px;}
.cc-ai .pr span{border-radius:2px;background:rgba(255,255,255,.05);}
.cc-ai .pr span.on{background:rgba(232,183,85,.85);box-shadow:0 0 10px rgba(232,183,85,.6);
  animation:prOn 2.8s ease-in-out infinite;}
@keyframes prOn{0%,100%{opacity:.14;transform:scale(.82)}45%{opacity:1;transform:scale(1)}}
.cc-ai .in{position:relative;z-index:2;padding:28px 30px;display:flex;flex-direction:column;height:100%;}
.cc-ai .no{color:rgba(232,183,85,.75);}
.cc-ai .tag-ai{position:absolute;right:26px;top:26px;font-size:11px;font-weight:800;letter-spacing:.06em;
  background:linear-gradient(100deg,var(--jade-2),var(--gold-2));color:#08131A;padding:4px 11px;border-radius:6px;}
.cc-ai h4{font-size:23px;margin-top:9px;color:#fff;}
.cc-ai .en{color:rgba(255,255,255,.45);}
.cc-ai .desc{color:#AEBAD3;padding:13px 0 0;font-size:14.2px;line-height:1.82;flex:1;}
.cc-ai .lv{padding:16px 0 0;color:#8E9AB4;}
.cc-ai .lv b{background:rgba(232,183,85,.16);color:var(--gold-3);}
.cc-ai .lv .focus{color:rgba(255,255,255,.5);}
.cc-ai .tags{padding:13px 0 0;}
.cc-ai .tags span{background:rgba(255,255,255,.08);color:#B7C2D8;}
.cc-ai .tags span.hi{background:rgba(232,183,85,.18);color:var(--gold-3);}
.cc-ai .go{border-top-color:rgba(255,255,255,.12);margin:16px 0 0;color:var(--gold-2);}
.cc-ai .go i{color:var(--gold-2);}
@media(max-width:1080px){
  .course-grid{grid-template-columns:repeat(2,1fr);}
  .cc-ai{grid-column:span 2;}
}
@media(max-width:560px){
  .course-grid{grid-template-columns:1fr;}
  .cc-ai{grid-column:span 1;}
  .cc-ai .in{padding:24px 22px;}
}
.course-note{margin-top:28px;text-align:center;font-size:13.8px;color:var(--muted-2);
  border-top:1px dashed var(--line-2);padding-top:20px;}

/* ═══════════ 数智能力 ═══════════ */
.band-grey{background:var(--paper-2);border-top:1px solid var(--line);border-bottom:1px solid var(--line);}
.cap-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;}
.cap{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:28px 26px;
  transition:.32s cubic-bezier(.2,.7,.3,1);position:relative;overflow:hidden;}
.cap:hover{transform:translateY(-5px);box-shadow:var(--sh);border-color:var(--line-2);}
.cap::after{content:"";position:absolute;top:0;left:-110%;width:52%;height:100%;pointer-events:none;
  background:linear-gradient(90deg,transparent,rgba(200,149,46,.09),transparent);transition:left .7s ease;}
.cap:hover::after{left:130%;}
.cap .ico{width:46px;height:46px;border-radius:12px;display:grid;place-items:center;margin-bottom:17px;
  font-size:22px;background:var(--paper-2);border:1px solid var(--line);}
.cap h3{font-size:18px;margin-bottom:8px;}
.cap p{color:var(--muted);font-size:14.4px;line-height:1.8;}
.cap ul{margin-top:15px;display:flex;flex-wrap:wrap;gap:6px;}
.cap ul li{font-size:12px;color:#96691A;background:rgba(200,149,46,.1);padding:3px 10px;border-radius:6px;}

.cap-ai{grid-column:1/-1;display:grid;grid-template-columns:1.04fr .96fr;gap:0;padding:0;overflow:hidden;
  border:0;border-radius:var(--r-lg);color:#fff;
  background:
    radial-gradient(700px 380px at 6% 10%,rgba(200,149,46,.18),transparent 62%),
    radial-gradient(620px 340px at 96% 92%,rgba(79,199,190,.18),transparent 62%),
    linear-gradient(118deg,#16203A 0%,#273356 50%,#132F38 100%);
  box-shadow:0 18px 48px rgba(20,29,43,.22);}
.cap-ai:hover{transform:translateY(-4px);box-shadow:0 26px 60px rgba(20,29,43,.3);}
.cap-ai::after{display:none;}
.cap-ai-l{padding:40px 42px;}
.cap-ai-l .mini{display:inline-block;font-family:var(--mono);font-size:11px;font-weight:800;letter-spacing:.2em;
  color:var(--gold-2);background:rgba(232,183,85,.12);border:1px solid rgba(232,183,85,.28);
  padding:5px 12px;border-radius:999px;}
.cap-ai-l h3{font-size:clamp(20px,2.2vw,26px);margin:16px 0 12px;color:#fff;}
.cap-ai-l p{color:#AEBAD3;font-size:14.8px;line-height:1.85;}
.cap-ai-l ul{margin-top:19px;}
.cap-ai-l ul li{font-size:12px;color:#C4B48A;background:rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.12);padding:4px 11px;border-radius:6px;}
.cap-ai-r{padding:34px 38px;background:rgba(0,0,0,.2);display:flex;flex-direction:column;gap:15px;justify-content:center;}
.gstep{display:flex;gap:13px;align-items:flex-start;}
.gstep .gn{width:25px;height:25px;flex-shrink:0;border-radius:7px;display:grid;place-items:center;
  font-family:var(--mono);font-size:12.5px;font-weight:800;color:#12222A;
  background:linear-gradient(135deg,var(--jade-2),var(--gold-2));}
.gstep b{display:block;font-size:14.5px;color:#fff;font-weight:700;}
.gstep i{font-style:normal;font-size:12.5px;color:#94A0B8;}
.gbar{margin-top:4px;height:5px;border-radius:99px;background:rgba(255,255,255,.1);position:relative;overflow:hidden;}
.gbar i{position:absolute;top:0;bottom:0;width:36%;border-radius:99px;
  background:linear-gradient(90deg,var(--jade-2),var(--gold-2));animation:grun 2.9s ease-in-out infinite;}
@keyframes grun{0%{left:-38%}100%{left:100%}}
.gnote{font-size:11.8px;color:#7E8AA2;line-height:1.75;}
@media(max-width:980px){
  .cap-ai{grid-template-columns:1fr;}
  .cap-ai-l{padding:30px 26px;} .cap-ai-r{padding:26px;}
  .cap-grid{grid-template-columns:repeat(2,1fr);}
}
@media(max-width:620px){.cap-grid{grid-template-columns:1fr;}}

/* ═══════════ 深色横幅（通用） ═══════════ */
.band-ink{
  background:
    radial-gradient(900px 460px at 12% 8%,rgba(79,199,190,.16),transparent 60%),
    radial-gradient(820px 440px at 88% 92%,rgba(200,149,46,.14),transparent 62%),
    linear-gradient(168deg,#101B2C,#17253C 52%,#122A33 100%);
  color:#fff;position:relative;overflow:hidden;}
.band-ink .ink-tunnel{position:absolute;inset:0;perspective:900px;perspective-origin:50% 48%;
  overflow:hidden;pointer-events:none;z-index:0;opacity:.55;
  mask-image:radial-gradient(ellipse 76% 60% at 50% 48%,#000 10%,transparent 80%);
  -webkit-mask-image:radial-gradient(ellipse 76% 60% at 50% 48%,#000 10%,transparent 80%);}
.band-ink .ink-plane{position:absolute;left:-45%;right:-45%;top:48%;transform-origin:50% 0;
  transform-style:preserve-3d;animation:flyThru 17s linear infinite;opacity:0;}
.band-ink .ink-plane i{display:block;height:1px;margin-bottom:17px;
  background:linear-gradient(90deg,transparent,rgba(124,197,178,.42) 30%,rgba(232,183,85,.34) 70%,transparent);}
.band-ink .ink-plane:nth-child(1){animation-delay:0s}
.band-ink .ink-plane:nth-child(2){animation-delay:4.25s}
.band-ink .ink-plane:nth-child(3){animation-delay:8.5s}
.band-ink .ink-plane:nth-child(4){animation-delay:12.75s}
.band-ink::before{content:"";position:absolute;inset:0;z-index:0;
  background-image:linear-gradient(rgba(255,255,255,.026) 1px,transparent 1px);
  background-size:100% 42px;
  mask-image:radial-gradient(ellipse at 50% 42%,#000,transparent 74%);
  -webkit-mask-image:radial-gradient(ellipse at 50% 42%,#000,transparent 74%);}
.band-ink .wrap{position:relative;z-index:2;}
.band-ink .sec-head h2{color:#fff;}
.band-ink .sec-head p{color:#93A0BA;}
.band-ink .sec-head .eyebrow{color:var(--gold-2);border-bottom-color:rgba(232,183,85,.3);}
.path-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;position:relative;z-index:2;}
.pstep{border:1px solid rgba(255,255,255,.11);border-radius:var(--r-lg);padding:30px 26px;
  background:linear-gradient(165deg,rgba(255,255,255,.055),rgba(255,255,255,.015));transition:.3s;position:relative;}
.pstep:hover{transform:translateY(-5px);border-color:rgba(232,183,85,.36);
  background:linear-gradient(165deg,rgba(255,255,255,.085),rgba(255,255,255,.025));}
.pstep .lv{width:42px;height:42px;border-radius:11px;display:grid;place-items:center;font-weight:800;
  font-family:var(--mono);font-size:14px;background:linear-gradient(135deg,var(--jade-2),var(--gold-2));
  color:#0C1A22;margin-bottom:17px;}
.pstep h3{font-size:19.5px;margin-bottom:5px;color:#fff;}
.pstep .grade{font-family:var(--mono);font-size:11.5px;color:var(--jade-2);letter-spacing:.06em;margin-bottom:15px;}
.pstep ul li{font-size:14.2px;color:#B4BFD6;padding:7px 0 7px 19px;position:relative;
  border-bottom:1px dashed rgba(255,255,255,.08);}
.pstep ul li:last-child{border-bottom:0;}
.pstep ul li::before{content:"♪";position:absolute;left:0;color:var(--gold-2);font-size:11.5px;}
.pstep .out{margin-top:17px;font-size:13.2px;color:#93A0BA;background:rgba(0,0,0,.24);
  padding:12px 14px;border-radius:10px;line-height:1.75;}
.pstep .out b{color:var(--gold-3);}
@media(max-width:900px){.path-grid{grid-template-columns:1fr;}}

/* ═══════════ 演示中心 ═══════════ */
.vid-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;}
.vc{background:#fff;border:1px solid var(--line);border-radius:var(--r);overflow:hidden;transition:.3s;}
.vc:hover{transform:translateY(-4px);box-shadow:var(--sh);border-color:var(--line-2);}
.vc .vbox{position:relative;background:#0B111C;aspect-ratio:16/9;}
.vc video{width:100%;height:100%;object-fit:cover;display:block;cursor:pointer;background:#0B111C;}
.vc .vmeta{padding:15px 18px 17px;}
.vc h4{font-size:15.5px;margin-bottom:4px;}
.vc p{font-size:12.8px;color:var(--muted);}
.vc .badge{position:absolute;top:11px;left:11px;z-index:2;font-family:var(--mono);font-size:11px;font-weight:700;
  background:rgba(10,16,24,.74);color:var(--gold-3);padding:4px 10px;border-radius:6px;letter-spacing:.04em;}
.vc.wide{grid-column:span 2;}
@media(max-width:980px){.vid-grid{grid-template-columns:repeat(2,1fr);}.vc.wide{grid-column:span 2;}}
@media(max-width:620px){.vid-grid{grid-template-columns:1fr;}.vc.wide{grid-column:span 1;}}

/* ═══════════ AI 学伴 ═══════════ */
.ai-box{border-radius:var(--r-xl);overflow:hidden;display:grid;grid-template-columns:1.06fr .94fr;
  position:relative;color:#fff;box-shadow:var(--sh-lg);
  background:
    radial-gradient(620px 340px at 8% 12%,rgba(200,149,46,.17),transparent 62%),
    radial-gradient(560px 320px at 94% 88%,rgba(79,199,190,.17),transparent 62%),
    linear-gradient(122deg,#152034,#233050 54%,#123039);}
.ai-box::before{content:"";position:absolute;inset:0;pointer-events:none;z-index:0;
  background-image:repeating-linear-gradient(0deg,transparent 0 15px,rgba(255,255,255,.035) 15px 16px);
  mask-image:radial-gradient(ellipse 82% 76% at 30% 40%,#000,transparent 76%);
  -webkit-mask-image:radial-gradient(ellipse 82% 76% at 30% 40%,#000,transparent 76%);}
.ai-l,.ai-r{position:relative;z-index:1;}
.ai-l{padding:50px 46px;}
.ai-l h2{font-size:clamp(23px,2.5vw,32px);margin-bottom:13px;color:#fff;}
.ai-l > p{color:#AEBAD3;font-size:15.5px;line-height:1.85;}
.ai-l ul{margin:24px 0 28px;}
.ai-l ul li{display:flex;gap:13px;padding:8px 0;color:#C6D0E4;font-size:14.8px;}
.ai-l ul li b{font-family:var(--mono);color:var(--gold-2);font-size:13px;padding-top:2px;}
.ai-r{padding:32px;display:flex;flex-direction:column;gap:13px;background:rgba(0,0,0,.2);}
.chat{border-radius:14px;padding:13px 16px;font-size:14.2px;max-width:87%;line-height:1.72;
  animation:pop .5s cubic-bezier(.2,.7,.3,1) both;}
@keyframes pop{from{opacity:0;transform:translateY(9px) scale(.98)}to{opacity:1;transform:none}}
.chat.bot{background:rgba(255,255,255,.09);border:1px solid rgba(255,255,255,.12);align-self:flex-start;}
.chat.me{background:linear-gradient(120deg,var(--gold),var(--gold-2));color:#2A1C05;align-self:flex-end;}
.chat small{display:block;font-size:11px;opacity:.6;margin-bottom:3px;}
.ai-input{margin-top:auto;display:flex;align-items:center;gap:10px;background:rgba(255,255,255,.07);
  border:1px solid rgba(255,255,255,.13);border-radius:11px;padding:9px 13px;}
.ai-input span{font-size:13.8px;color:#8E9AB4;flex:1;}
.ai-input button{border:0;border-radius:8px;padding:7px 14px;font-size:13px;font-weight:700;cursor:pointer;
  background:linear-gradient(120deg,var(--jade-2),var(--gold-2));color:#0C1A22;}
@media(max-width:980px){.ai-box{grid-template-columns:1fr;}.ai-l{padding:34px 26px;}.ai-r{padding:24px;}}

/* ═══════════ 考研专区 ═══════════ */
.band-exam{
  background:
    radial-gradient(900px 460px at 10% 6%,rgba(200,149,46,.16),transparent 60%),
    radial-gradient(820px 440px at 90% 94%,rgba(79,199,190,.15),transparent 62%),
    linear-gradient(168deg,#101A2B,#182740 54%,#12262F 100%);
  color:#fff;position:relative;overflow:hidden;
}
.band-exam .ex-tunnel{position:absolute;inset:0;perspective:900px;perspective-origin:50% 48%;
  overflow:hidden;pointer-events:none;z-index:0;opacity:.5;
  mask-image:radial-gradient(ellipse 76% 60% at 50% 48%,#000 10%,transparent 80%);
  -webkit-mask-image:radial-gradient(ellipse 76% 60% at 50% 48%,#000 10%,transparent 80%);}
.band-exam .ex-plane{position:absolute;left:-45%;right:-45%;top:48%;transform-origin:50% 0;
  transform-style:preserve-3d;animation:flyThru 20s linear infinite;opacity:0;}
.band-exam .ex-plane i{display:block;height:1px;margin-bottom:17px;
  background:linear-gradient(90deg,transparent,rgba(232,183,85,.42) 30%,rgba(124,197,178,.34) 70%,transparent);}
.band-exam .ex-plane:nth-child(1){animation-delay:0s}
.band-exam .ex-plane:nth-child(2){animation-delay:5s}
.band-exam .ex-plane:nth-child(3){animation-delay:10s}
.band-exam .ex-plane:nth-child(4){animation-delay:15s}
.band-exam .wrap{position:relative;z-index:2;}
.band-exam .sec-head h2{color:#fff;}
.band-exam .sec-head p{color:#93A0BA;}
.band-exam .sec-head .eyebrow{color:var(--gold-2);border-bottom-color:rgba(232,183,85,.3);}

.ex-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;}
.ex{background:linear-gradient(165deg,rgba(255,255,255,.07),rgba(255,255,255,.02));
  border:1px solid rgba(255,255,255,.12);border-radius:var(--r-lg);padding:28px 26px;
  transition:.3s cubic-bezier(.2,.7,.3,1);}
.ex:hover{transform:translateY(-5px);border-color:rgba(232,183,85,.4);
  background:linear-gradient(165deg,rgba(255,255,255,.1),rgba(255,255,255,.03));}
.ex .tag{display:inline-block;font-family:var(--mono);font-size:11px;font-weight:700;letter-spacing:.1em;
  color:var(--gold-2);background:rgba(232,183,85,.13);border:1px solid rgba(232,183,85,.28);
  padding:4px 10px;border-radius:6px;margin-bottom:15px;}
.ex h3{font-size:19px;color:#fff;margin-bottom:6px;}
.ex .sub{font-family:var(--mono);font-size:11.5px;color:var(--jade-2);letter-spacing:.05em;margin-bottom:15px;}
.ex ul li{font-size:14px;color:#B4BFD6;padding:6px 0 6px 18px;position:relative;
  border-bottom:1px dashed rgba(255,255,255,.08);line-height:1.7;}
.ex ul li:last-child{border-bottom:0;}
.ex ul li::before{content:"♪";position:absolute;left:0;color:var(--gold-2);font-size:11px;}
.ex .tool{margin-top:16px;font-size:12.8px;color:#8E9AB4;background:rgba(0,0,0,.22);
  padding:11px 13px;border-radius:9px;line-height:1.7;}
.ex .tool b{color:var(--gold-3);}

.ex-note{margin-top:30px;border:1px dashed rgba(255,255,255,.18);border-radius:var(--r-lg);
  padding:20px 26px;font-size:13.5px;color:#93A0BA;line-height:1.85;text-align:center;
  background:rgba(0,0,0,.16);}
.ex-note b{color:var(--gold-3);}
.ex-cta{margin-top:34px;text-align:center;}
@media(max-width:900px){.ex-grid{grid-template-columns:1fr;}}

/* ═══════════ 曲目库 ═══════════ */
.lib-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;}
.lib{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:27px 25px;transition:.3s;}
.lib:hover{transform:translateY(-4px);box-shadow:var(--sh);border-color:var(--line-2);}
.lib .ico{font-size:24px;margin-bottom:13px;}
.lib h4{font-size:16.5px;margin-bottom:7px;}
.lib p{font-size:13.8px;color:var(--muted);line-height:1.8;}
.lib ul{margin-top:14px;display:flex;flex-wrap:wrap;gap:6px;}
.lib ul li{font-size:11.8px;padding:3px 10px;border-radius:6px;background:var(--paper-2);color:var(--muted);}
.honor{margin-top:30px;border:1px dashed var(--line-2);border-radius:var(--r-lg);padding:25px 28px;
  display:flex;align-items:center;justify-content:space-between;gap:26px;flex-wrap:wrap;background:var(--paper);}
.honor img{height:52px;object-fit:contain;}
.honor .ht{font-size:14px;color:var(--muted);max-width:640px;line-height:1.85;}
.honor .ht b{color:var(--text);}
@media(max-width:900px){.lib-grid{grid-template-columns:1fr;}}

/* ═══════════ 子页：课程信息区 ═══════════ */
.info-grid{display:grid;grid-template-columns:1.5fr 1fr;gap:34px;align-items:start;}
.info-main h3{font-size:21px;margin-bottom:14px;}
.info-main p{font-size:15px;color:var(--text-2);line-height:1.95;margin-bottom:13px;}
.info-main p b{color:var(--text);}
.info-points{margin-top:22px;display:grid;grid-template-columns:1fr 1fr;gap:12px;}
.info-points li{display:flex;gap:10px;font-size:13.8px;color:var(--text-2);line-height:1.7;
  background:var(--paper-2);border:1px solid var(--line);border-radius:10px;padding:12px 14px;}
.info-points li::before{content:"♪";color:var(--gold);flex-shrink:0;}
.info-card{background:var(--ink);color:#AEBAD3;border-radius:var(--r-lg);padding:26px 28px;position:relative;overflow:hidden;}
.info-card::after{content:"";position:absolute;top:0;right:0;width:130px;height:130px;pointer-events:none;
  background:radial-gradient(circle at top right,rgba(200,149,46,.18),transparent 70%);}
.info-card h4{color:#fff;font-size:15.5px;margin-bottom:14px;padding-bottom:12px;border-bottom:1px solid rgba(255,255,255,.1);}
.info-card .irow{display:flex;justify-content:space-between;gap:14px;padding:9px 0;font-size:13.4px;
  border-bottom:1px dashed rgba(255,255,255,.08);}
.info-card .irow:last-child{border-bottom:0;}
.info-card .irow b{color:#E8EDF6;font-weight:600;text-align:right;}
.info-card .irow a{color:var(--gold-3);}
.info-card .irow a:hover{text-decoration:underline;}
@media(max-width:980px){.info-grid{grid-template-columns:1fr;}}
@media(max-width:620px){.info-points{grid-template-columns:1fr;}}

/* ═══════════ 子页：教学单元 ═══════════ */
.unit-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;}
.unit{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:22px 20px;
  transition:.3s;position:relative;overflow:hidden;}
.unit::before{content:"";position:absolute;top:0;left:0;right:0;height:2px;
  background:linear-gradient(90deg,var(--gold),var(--jade-2));opacity:0;transition:.3s;}
.unit:hover{transform:translateY(-4px);box-shadow:var(--sh);border-color:var(--gold);}
.unit:hover::before{opacity:1;}
.unit .un{font-family:var(--mono);font-size:12px;font-weight:800;color:var(--gold);letter-spacing:.12em;}
.unit h4{font-size:15.8px;margin:9px 0 7px;}
.unit p{font-size:13px;color:var(--muted);line-height:1.78;}
@media(max-width:1080px){.unit-grid{grid-template-columns:repeat(2,1fr);}}
@media(max-width:620px){.unit-grid{grid-template-columns:1fr;}}

/* ═══════════ 子页：数智工具卡 ═══════════ */
.tool-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:22px;align-items:stretch;position:relative;z-index:2;}
.tool-main{background:#fff;border-radius:var(--r-lg);padding:0;position:relative;overflow:hidden;
  box-shadow:0 22px 58px rgba(0,0,0,.34);display:flex;flex-direction:column;}
.tool-main:hover{transform:translateY(-4px);box-shadow:0 28px 66px rgba(0,0,0,.4);}
.tc-visual{position:relative;height:128px;flex-shrink:0;
  background:
    radial-gradient(420px 200px at 88% 0%,rgba(200,149,46,.22),transparent 66%),
    radial-gradient(360px 190px at 8% 100%,rgba(79,199,190,.2),transparent 66%),
    linear-gradient(160deg,#101B2C,#1C2B46);overflow:hidden;}
.tc-visual .vl{position:absolute;left:28px;right:28px;top:50%;transform:translateY(-50%);
  height:40px;display:flex;flex-direction:column;justify-content:space-between;}
.tc-visual .vl i{height:1px;background:rgba(255,255,255,.2);}
.tc-visual .nt2{position:absolute;width:10px;height:8px;border-radius:50%;background:var(--gold-2);
  transform:rotate(-16deg);box-shadow:0 0 10px rgba(232,183,85,.55);}
.tc-visual .nt2::after{content:"";position:absolute;right:0;top:-16px;width:1.5px;height:17px;background:var(--gold-2);}
.tc-visual .ph{position:absolute;top:0;bottom:0;width:2px;
  background:linear-gradient(180deg,transparent,rgba(232,183,85,.95),transparent);
  box-shadow:0 0 14px rgba(232,183,85,.8);animation:scan2 3.2s linear infinite;}
@keyframes scan2{from{left:18%}to{left:84%}}
.tc-visual .tc-badge{position:absolute;top:14px;right:14px;font-size:11px;font-weight:800;letter-spacing:.08em;
  background:linear-gradient(100deg,var(--jade-2),var(--gold-2));color:#08131A;padding:4px 12px;border-radius:6px;}
.tc-visual .tc-live{position:absolute;left:16px;bottom:12px;display:flex;align-items:center;gap:6px;
  font-size:11px;font-weight:700;color:#7CC5B2;letter-spacing:.08em;font-family:var(--mono);}
.tc-visual .tc-live em{width:5px;height:5px;border-radius:50%;background:var(--jade-2);animation:beat 1.4s infinite;font-style:normal;}
.tool-main .tc-body{padding:26px 30px 28px;display:flex;flex-direction:column;flex:1;}
.tool-main h3{font-size:22px;}
.tool-main .tc-en{font-family:var(--mono);font-size:11.5px;color:var(--jade);letter-spacing:.1em;margin:6px 0 13px;}
.tool-main p{font-size:14.4px;color:var(--text-2);line-height:1.88;}
.tc-feats{display:flex;flex-wrap:wrap;gap:7px;margin:18px 0 22px;}
.tc-feats li{font-size:12px;padding:4px 12px;border-radius:6px;background:rgba(200,149,46,.1);
  color:#96691A;font-weight:600;}
.tc-actions{display:flex;align-items:center;gap:16px;flex-wrap:wrap;margin-top:auto;}
.tc-note{font-size:12px;color:var(--muted-2);line-height:1.6;}

.tool-side{display:flex;flex-direction:column;gap:20px;}
.mini-tool{background:linear-gradient(165deg,rgba(255,255,255,.07),rgba(255,255,255,.02));
  border:1px solid rgba(255,255,255,.12);border-radius:var(--r-lg);padding:24px 26px;color:#fff;
  transition:.3s;flex:1;display:flex;flex-direction:column;}
.mini-tool:hover{border-color:rgba(232,183,85,.4);transform:translateY(-4px);}
.mini-tool .mt-ico{font-size:22px;margin-bottom:12px;}
.mini-tool h4{font-size:17px;color:#fff;margin-bottom:8px;}
.mini-tool p{font-size:13.4px;color:#AEBAD3;line-height:1.8;}
.mini-tool .go2{margin-top:auto;padding-top:16px;display:inline-flex;align-items:center;gap:6px;
  font-size:13.5px;font-weight:700;color:var(--gold-2);}
.mini-tool .go2 i{font-style:normal;transition:.25s;}
.mini-tool:hover .go2 i{transform:translateX(4px);}
@media(max-width:980px){.tool-grid{grid-template-columns:1fr;}}

/* 子页底部关联横带 */
.link-band{margin-top:44px;border:1px dashed rgba(255,255,255,.2);border-radius:var(--r-lg);
  padding:24px 30px;display:flex;align-items:center;justify-content:space-between;gap:22px;flex-wrap:wrap;
  background:rgba(0,0,0,.18);position:relative;z-index:2;}
.link-band p{color:#93A0BA;font-size:14px;line-height:1.85;}
.link-band b{color:var(--gold-3);}

/* ═══════════ 页脚 ═══════════ */
footer{background:var(--ink);color:#7F8CA6;padding:62px 0 0;font-size:13.8px;position:relative;}
footer::before{content:"";position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(200,149,46,.6),rgba(79,166,145,.6),transparent);}
.f-grid{display:grid;grid-template-columns:1.55fr 1fr 1fr 1.15fr;gap:34px;padding-bottom:42px;}
.f-grid h5{color:#fff;font-size:14.5px;margin-bottom:15px;font-weight:700;}
.f-grid li{padding:4px 0;}
.f-grid li a{opacity:.78;transition:.2s;}
.f-grid li a:hover{opacity:1;color:var(--gold-3);padding-left:3px;}
.f-about p{opacity:.72;line-height:1.88;margin-top:13px;max-width:350px;}
.f-contact div{padding:4px 0;opacity:.78;}
.f-contact .f-tel{color:var(--gold-3);font-weight:700;opacity:1;letter-spacing:.4px;text-decoration:none;}
.f-contact .f-tel:hover{text-decoration:underline;}
.f-bottom{border-top:1px solid rgba(255,255,255,.08);padding:22px 0;display:flex;
  justify-content:space-between;align-items:center;gap:18px;flex-wrap:wrap;opacity:.8;font-size:12.8px;}
.f-bottom .cr{color:var(--gold-2);font-weight:700;letter-spacing:.04em;opacity:1;}
@media(max-width:900px){.f-grid{grid-template-columns:repeat(2,1fr);}}
@media(max-width:560px){.f-grid{grid-template-columns:1fr;}}

/* ═══════════ 模态框 ═══════════ */
.modal{display:none;position:fixed;inset:0;z-index:120;background:rgba(8,12,20,.66);backdrop-filter:blur(4px);}
.modal .box{background:#fff;border-radius:var(--r-lg);width:414px;max-width:92vw;margin:9vh auto;
  padding:32px 30px;position:relative;box-shadow:0 30px 78px rgba(0,0,0,.34);
  animation:pop .32s cubic-bezier(.2,.7,.3,1) both;}
.modal .box h3{font-size:22px;margin-bottom:5px;}
.modal .box .tip{font-size:13.2px;color:var(--muted);margin-bottom:20px;}
.modal .x{position:absolute;right:16px;top:12px;font-size:25px;color:#B0B6C6;cursor:pointer;line-height:1;transition:.2s;}
.modal .x:hover{color:var(--text);}
.field{margin-bottom:13px;}
.field label{display:block;font-size:12.5px;color:var(--muted);margin-bottom:6px;font-weight:600;}
.field input{width:100%;padding:12px 13px;border:1px solid var(--line);border-radius:10px;font-size:14.8px;
  transition:.22s;background:var(--paper);}
.field input:focus{outline:0;border-color:var(--gold);background:#fff;box-shadow:0 0 0 3px rgba(200,149,46,.14);}
.roles{display:flex;gap:8px;margin:15px 0 19px;}
.roles label{flex:1;text-align:center;cursor:pointer;padding:9px 0;border:1px solid var(--line);
  border-radius:10px;font-size:13.8px;transition:.22s;color:var(--muted);position:relative;}
.roles input{position:absolute;opacity:0;pointer-events:none;}
.roles label:has(input:checked){border-color:var(--gold);background:rgba(200,149,46,.09);color:#96691A;font-weight:700;}
.modal .row{display:flex;gap:9px;align-items:center;margin-top:17px;}
.modal .row .btn{flex:1;}
.link-row{display:flex;justify-content:space-between;font-size:12.8px;margin-top:15px;}
.link-row a{color:#96691A;cursor:pointer;}
.link-row a:hover{text-decoration:underline;}
.err{display:none;background:#FBEDEE;color:#B03A4E;padding:9px 12px;border-radius:9px;font-size:13px;margin-bottom:13px;}
.err.show{display:block;}
.guest-note{background:var(--paper-2);border-radius:10px;padding:11px 13px;font-size:12.3px;
  color:var(--muted);margin-top:15px;line-height:1.72;}

/* 遮罩 */
.veil{display:none;position:fixed;inset:0;z-index:200;background:rgba(8,12,20,.74);backdrop-filter:blur(5px);
  align-items:center;justify-content:center;}
.veil .vbox{background:#fff;border-radius:var(--r-lg);padding:36px 42px;text-align:center;max-width:390px;width:90%;}
.spin{width:42px;height:42px;border:3px solid var(--paper-3);border-top:3px solid var(--gold);
  border-radius:50%;animation:sp 1s linear infinite;margin:0 auto 18px;}
@keyframes sp{to{transform:rotate(360deg)}}
.veil h4{font-size:18px;margin-bottom:7px;}
.veil p{font-size:13.5px;color:var(--muted);}

/* 返回顶部 */
.totop{position:fixed;right:24px;bottom:28px;width:44px;height:44px;border-radius:12px;border:0;cursor:pointer;
  background:linear-gradient(135deg,var(--gold),var(--gold-2));color:#2A1C05;font-size:18px;
  box-shadow:0 11px 26px rgba(200,149,46,.36);opacity:0;pointer-events:none;transition:.3s;z-index:90;}
.totop.show{opacity:1;pointer-events:auto;}
.totop:hover{transform:translateY(-3px);}

@media(prefers-reduced-motion:reduce){
  *{animation-duration:.01ms !important;animation-iteration-count:1 !important;transition-duration:.01ms !important;}
}

/* 导航栏「注册」按钮：与登录同款描边；窄屏收起（原只在 index3.html 内联，课程页统一导航后需要共用，故补到这里） */
.nav .btn-reg{padding:9px 14px;font-size:14px;}
@media(max-width:1080px){ .nav .btn-reg{padding:8px 12px;font-size:13.6px;} }
@media(max-width:860px){ .nav .btn-reg{display:none;} }

/* ── 站内搜索框（原只在 index3.html 内联，课程页统一导航后需要共用） ── */
/* ═══════════ 站内搜索（导航右侧） ═══════════ */
.srch{position:relative;display:flex;align-items:center;}
.srch .si{position:absolute;left:11px;top:50%;transform:translateY(-50%);width:15px;height:15px;
  color:#8B96AE;pointer-events:none;display:flex;}
.srch .si svg{width:15px;height:15px;}
.srch input{width:206px;height:38px;padding:0 30px 0 32px;border-radius:10px;outline:none;
  border:1px solid rgba(255,255,255,.15);background:rgba(255,255,255,.06);color:#EDF1F8;
  font-size:13.6px;font-family:inherit;transition:width .24s,border-color .22s,background .22s,box-shadow .22s;
  -webkit-appearance:none;appearance:none;}
.srch input::-webkit-search-cancel-button{display:none;}
.srch input::placeholder{color:#7E8AA3;}
.srch input:hover{background:rgba(255,255,255,.09);}
.srch input:focus{width:246px;border-color:rgba(232,183,85,.55);background:rgba(255,255,255,.1);
  box-shadow:0 0 0 3px rgba(232,183,85,.13);}
.srch .clr{position:absolute;right:8px;top:50%;transform:translateY(-50%);width:18px;height:18px;
  display:none;align-items:center;justify-content:center;border:0;border-radius:50%;cursor:pointer;
  background:rgba(255,255,255,.14);color:#D3DAEA;font-size:13px;line-height:1;padding:0;}
.srch .clr:hover{background:rgba(255,255,255,.24);color:#fff;}
.srch.filled .clr{display:flex;}
.srch-out{position:absolute;top:calc(100% + 9px);right:0;width:352px;max-height:62vh;overflow:auto;
  display:none;padding:7px;z-index:80;background:#fff;border:1px solid var(--line);
  border-radius:var(--r-lg);box-shadow:0 26px 60px rgba(8,12,20,.3);}
.srch-out.show{display:block;}
.srch-out .so-h{font-family:var(--mono);font-size:11px;letter-spacing:.14em;color:var(--muted-2);
  padding:7px 10px 5px;text-transform:uppercase;}
.srch-out a{display:flex;align-items:center;gap:11px;padding:9px 11px;border-radius:10px;
  color:var(--text);text-decoration:none;transition:.16s;}
.srch-out a.on,.srch-out a:hover{background:#F2F4FA;}
.srch-out .so-d{width:4px;height:30px;border-radius:3px;background:var(--gold);flex:0 0 auto;}
.srch-out .so-t{flex:1;min-width:0;}
.srch-out .so-t b{display:block;font-size:14.2px;font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.srch-out .so-t small{display:block;font-size:11.6px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;margin-top:2px;}
.srch-out .so-k{font-size:11px;font-weight:700;padding:3px 9px;border-radius:7px;flex:0 0 auto;
  background:rgba(108,124,224,.12);color:#4A57B5;}
.srch-out a.on .so-k{background:rgba(108,124,224,.2);}
.srch-out .so-empty{padding:16px 12px 18px;text-align:center;font-size:13.4px;color:var(--muted);line-height:1.9;}
.srch-out .so-empty em{font-style:normal;color:#96691A;font-weight:700;}
.srch-out .so-hot{display:flex;flex-wrap:wrap;gap:7px;justify-content:center;margin-top:9px;}
.srch-out .so-hot span{font-size:12.2px;padding:4px 11px;border-radius:8px;cursor:pointer;
  background:#F2F4FA;color:#4A57B5;font-weight:600;}
.srch-out .so-hot span:hover{background:rgba(108,124,224,.16);}
@media(max-width:1080px){
  /* 窄屏：收成一个放大镜图标；聚焦时输入框与结果面板「贴视口固定」，
     不再从图标处向右撑开（否则会挤出屏幕/压住 logo） */
  .srch input{width:38px;padding-right:6px;}
  .srch input::placeholder{color:transparent;}
  .srch .si{left:12px;}
  .srch input:focus{position:fixed;right:12px;top:calc((var(--nav-h) - 38px)/2);
    width:min(300px,72vw);padding-right:30px;z-index:96;background:#101926;}
  .srch input:focus::placeholder{color:#7E8AA3;}
  .srch input:focus ~ .clr{position:fixed;right:18px;top:calc((var(--nav-h) - 18px)/2);z-index:97;}
  .srch-out{position:fixed;left:12px;right:12px;width:auto;top:calc(var(--nav-h) - 2px);z-index:95;max-height:64vh;}
}
@media(max-width:560px){
  /* 窄屏给导航右侧腾地方：收紧 wrap 间距、搜索图标再小一点（只改「收起态」，别覆盖聚焦展开宽度） */
  .nav .wrap{gap:8px;}
  .srch input:not(:focus){width:30px;padding:0 4px 0 26px;height:34px;}
  .srch .si{left:9px;}
  .nav .btn-login{padding:8px 12px;font-size:13.6px;}
}
/* 极窄屏（≤359px）：导航已放不下「搜索+登录+菜单」，先收起搜索，保证不出现横向滚动条 */
@media(max-width:359px){
  .srch{display:none;}
}

/* ══════════ 课程页紧凑 HERO（压缩约一半高度，让章节尽早露出） ══════════ */
.phero.slim-hero{padding:34px 0 28px}
.phero.slim-hero .crumb{margin-bottom:8px;font-size:12px}
.phero.slim-hero .chip{margin-bottom:4px}
.phero.slim-hero h1{font-size:clamp(26px,3vw,34px);margin:2px 0 0}
.phero.slim-hero .pen{font-size:11px;letter-spacing:.2em;margin-top:2px;margin-bottom:4px}
.phero.slim-hero .pdesc{margin-top:6px;font-size:13.6px;line-height:1.7;max-width:1000px;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.phero.slim-hero .pmeta{margin-top:8px;gap:8px;font-size:12px}
.phero.slim-hero .pmeta span{padding:3px 9px}
.phero.slim-hero .pacts{margin-top:10px}
.phero.slim-hero .pacts .btn{padding:8px 16px !important;font-size:14px !important}