/* ===================== 基础 ===================== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --primary:#6C5CE7;
  --primary-dark:#5548C8;
  --primary-light:#A29BFE;
  --accent:#00D2D3;
  --yellow:#FFC93C;
  --green:#00C48C;
  --green-dark:#00996E;
  --pink:#FF6B9D;
  --dark:#15132B;
  --text:#2D2A45;
  --gray:#6E6B85;
  --bg:#FFFFFF;
  --bg-soft:#F7F6FF;
  --border:#EAE8F5;
  --radius:20px;
  --shadow-sm:0 2px 8px rgba(108,92,231,.08);
  --shadow:0 12px 32px rgba(108,92,231,.12);
  --shadow-lg:0 24px 60px rgba(108,92,231,.18);
}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  color:var(--text);
  background:var(--bg);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,svg{display:block;max-width:100%}
a{color:inherit}
button{font-family:inherit}
.container{width:100%;max-width:1180px;margin:0 auto;padding:0 24px}

/* ===================== 按钮 ===================== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 24px;border-radius:999px;font-weight:700;font-size:15px;
  text-decoration:none;border:none;cursor:pointer;
  transition:transform .18s ease, box-shadow .18s ease, background .18s ease, color .18s ease;
  white-space:nowrap;line-height:1.2;
}
.btn-primary{
  background:linear-gradient(135deg,#6C5CE7,#8B7CFF);
  color:#fff;
  box-shadow:0 5px 0 #5548C8, 0 12px 24px rgba(108,92,231,.28);
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 7px 0 #5548C8,0 18px 32px rgba(108,92,231,.34)}
.btn-primary:active{transform:translateY(3px);box-shadow:0 2px 0 #5548C8}
.btn-outline{
  background:#fff;color:var(--primary);
  border:2px solid var(--border);
  box-shadow:0 4px 0 var(--border);
}
.btn-outline:hover{border-color:var(--primary-light);color:var(--primary-dark);transform:translateY(-2px);box-shadow:0 6px 0 #DCD8F5}
.btn-outline:active{transform:translateY(2px);box-shadow:0 1px 0 var(--border)}
.btn-ghost{background:transparent;color:var(--text);padding:10px 18px}
.btn-ghost:hover{color:var(--primary);background:var(--bg-soft)}
.btn-lg{padding:17px 34px;font-size:17px;border-radius:999px}

/* ===================== 导航 ===================== */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  padding:14px 0;
  transition:background .3s, box-shadow .3s, padding .3s, backdrop-filter .3s;
}
.nav.scrolled{
  background:rgba(255,255,255,.85);
  backdrop-filter:blur(16px);
  -webkit-backdrop-filter:blur(16px);
  box-shadow:0 2px 20px rgba(21,19,43,.06);
  padding:10px 0;
}
.nav-inner{display:flex;align-items:center;gap:36px}
.logo{display:flex;align-items:center;gap:10px;text-decoration:none;flex-shrink:0}
/* 品牌记号用的就是 App 的图标（generate_assets.py 从 assets/app_icon.png 出的
   icon-192.png），不再是那个印着 Y 的渐变方块。
   裁成圆：源图的圆盘正好内切在方图四条边上、四个角是白的 —— 不裁的话白角会在
   深色页脚上露出一块，裁了圆盘就刚好填满。App 端也是这么蒙的
   （iOS 是超椭圆、Android 的 round 图标是正圆）。
   原来那圈紫色投影留着，记号在导航和页脚里的分量不变。 */
.logo-mark{
  display:block;
  width:38px;height:38px;border-radius:50%;
  box-shadow:0 6px 14px rgba(108,92,231,.35);
}
.logo-text{font-size:21px;font-weight:900;letter-spacing:-.5px;color:var(--dark)}
.logo-text em{font-style:normal;color:var(--primary)}
.nav-links{display:flex;gap:30px;list-style:none;margin-left:auto}
.nav-links a{
  text-decoration:none;font-size:15px;font-weight:600;color:var(--gray);
  position:relative;padding:4px 0;transition:color .2s;
}
.nav-links a::after{
  content:'';position:absolute;left:0;bottom:0;width:100%;height:2px;
  background:var(--primary);border-radius:2px;
  transform:scaleX(0);transform-origin:left;transition:transform .25s ease;
}
.nav-links a:hover{color:var(--dark)}
.nav-links a:hover::after{transform:scaleX(1)}
.nav-actions{display:flex;align-items:center;gap:6px;margin-left:auto}
.nav-toggle{
  display:none;background:none;border:none;cursor:pointer;
  width:40px;height:40px;padding:9px;flex-direction:column;justify-content:space-between;
  flex-shrink:0;   /* 360px 级窄屏下被 flex 压到 18px，汉堡三横线会变形 */
}
.nav-toggle span{display:block;height:2.5px;background:var(--dark);border-radius:3px;transition:.3s}
.nav-toggle.open span:nth-child(1){transform:translateY(9px) rotate(45deg)}
.nav-toggle.open span:nth-child(2){opacity:0}
.nav-toggle.open span:nth-child(3){transform:translateY(-9px) rotate(-45deg)}

/* ---- 导航栏账号区（markup 由 js/api.js 渲染）----
   放在 style.css 而不是 account.css：首页也要显示登录状态。 */
.nav-user{position:relative}
.nav-user-btn{
  display:inline-flex;align-items:center;gap:8px;
  background:#fff;border:1.5px solid var(--border);border-radius:999px;
  padding:5px 13px 5px 5px;cursor:pointer;
  font-family:inherit;font-size:14px;font-weight:700;color:var(--text);
  max-width:180px;transition:border-color .2s,color .2s;
}
.nav-user-btn:hover{border-color:var(--primary-light);color:var(--primary-dark)}
.nav-user-avatar{
  width:30px;height:30px;border-radius:50%;flex-shrink:0;
  display:grid;place-items:center;
  background:linear-gradient(135deg,#6C5CE7,#00D2D3);
  color:#fff;font-size:14px;font-weight:900;
}
.nav-user-name{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.nav-user-caret{font-size:10px;color:var(--gray);flex-shrink:0}
.nav-user-menu{
  position:absolute;right:0;top:calc(100% + 10px);z-index:120;
  min-width:216px;text-align:left;
  background:#fff;border:1.5px solid var(--border);border-radius:18px;
  box-shadow:var(--shadow);padding:8px;
}
.nav-user-menu[hidden]{display:none}
.nav-user-head{
  display:flex;flex-direction:column;gap:5px;
  padding:10px 12px 12px;margin-bottom:6px;
  border-bottom:1px solid var(--border);
}
.nav-user-head strong{font-size:14.5px;color:var(--dark);overflow-wrap:anywhere}
.nav-user-badge{font-size:12px;font-weight:700;color:var(--gray)}
.nav-user-badge.on{color:var(--primary-dark)}
.nav-user-menu a,.nav-user-menu button{
  display:block;width:100%;text-align:left;
  background:none;border:none;cursor:pointer;
  font-family:inherit;font-size:14px;font-weight:600;color:var(--text);
  text-decoration:none;padding:10px 12px;border-radius:12px;
  transition:background .2s,color .2s;
}
.nav-user-menu a:hover,.nav-user-menu button:hover{background:var(--bg-soft);color:var(--primary-dark)}
.nav-user-menu button[data-logout]{color:var(--gray)}
/* 汉堡菜单里的账号入口：只在窄屏出现（见下方 900px 断点） */
.nav-auth-item{display:none}

/* .btn 自带 display:inline-flex，会盖掉 UA 样式表里 [hidden] 的 display:none */
[hidden]{display:none!important}

/* ===================== Hero ===================== */
.hero{
  position:relative;
  padding:150px 0 100px;
  overflow:hidden;
  background:
    radial-gradient(900px 520px at 88% -8%, rgba(162,155,254,.30), transparent 62%),
    radial-gradient(700px 480px at 4% 8%, rgba(0,210,211,.16), transparent 62%),
    linear-gradient(180deg,#FBFBFF 0%,#FFFFFF 78%);
}
.hero::after{
  content:'';position:absolute;inset:0;pointer-events:none;
  background-image:radial-gradient(rgba(108,92,231,.10) 1px, transparent 1px);
  background-size:26px 26px;
  mask-image:radial-gradient(circle at 50% 30%, #000 0%, transparent 68%);
  -webkit-mask-image:radial-gradient(circle at 50% 30%, #000 0%, transparent 68%);
}
.hero-inner{
  position:relative;z-index:2;
  display:grid;grid-template-columns:1.05fr .95fr;
  gap:60px;align-items:center;
}
.badge{
  display:inline-flex;align-items:center;gap:8px;
  background:#fff;border:1.5px solid var(--border);
  padding:7px 16px;border-radius:999px;
  font-size:13.5px;font-weight:700;color:var(--primary-dark);
  box-shadow:var(--shadow-sm);margin-bottom:22px;
}
.hero h1{
  font-size:clamp(36px,5vw,60px);
  line-height:1.14;
  font-weight:900;
  letter-spacing:-1.6px;
  color:var(--dark);
  margin-bottom:20px;
}
.grad{
  background:linear-gradient(100deg,#6C5CE7 0%,#00D2D3 55%,#00C48C 100%);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
}
.lead{
  font-size:17.5px;color:var(--gray);max-width:520px;
  margin-bottom:34px;line-height:1.75;
}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:34px}
.hero-meta{display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.avatars{display:flex}
.avatars span{
  width:34px;height:34px;border-radius:50%;
  border:2.5px solid #fff;
  display:grid;place-items:center;
  font-size:15px;margin-left:-10px;
  box-shadow:0 2px 6px rgba(0,0,0,.1);
}
.avatars span:first-child{margin-left:0}
.stars{font-size:13.5px;font-weight:700;color:var(--gray)}
.stars b{color:var(--dark)}

/* ---- 手机模型 ---- */
.hero-visual{position:relative;display:flex;justify-content:center;align-items:center;min-height:560px}
.phone{
  position:relative;width:288px;height:576px;
  background:linear-gradient(160deg,#2B2850,#15132B);
  border-radius:46px;padding:11px;
  box-shadow:0 40px 80px rgba(21,19,43,.32), 0 0 0 1.5px rgba(255,255,255,.10) inset;
  animation:floaty 6s ease-in-out infinite;
  z-index:2;
}
@keyframes floaty{
  0%,100%{transform:rotate(-3deg) translateY(0)}
  50%{transform:rotate(-3deg) translateY(-16px)}
}
.phone-notch{
  position:absolute;top:22px;left:50%;transform:translateX(-50%);
  width:84px;height:22px;background:#15132B;border-radius:20px;z-index:5;
}
.phone-screen{
  width:100%;height:100%;background:#fff;border-radius:36px;
  overflow:hidden;display:flex;flex-direction:column;position:relative;
}
.app-top{
  display:flex;align-items:center;gap:10px;
  padding:52px 18px 12px;
  font-size:13px;font-weight:800;color:var(--dark);
}
.app-top .ico{font-size:14px}
.app-progress{flex:1;height:10px;background:#EDEBFA;border-radius:10px;overflow:hidden}
.app-progress i{
  display:block;height:100%;width:64%;border-radius:10px;
  background:linear-gradient(90deg,#00C48C,#00D2D3);
  box-shadow:0 0 10px rgba(0,196,140,.5);
}
.app-body{padding:22px 18px;flex:1}
.app-q{font-size:12.5px;font-weight:700;color:var(--gray);margin-bottom:8px}
.app-word{
  font-size:25px;font-weight:900;color:var(--dark);
  letter-spacing:-.5px;margin-bottom:22px;
}
.app-options{display:flex;flex-direction:column;gap:10px}
.opt{
  padding:12px 15px;border-radius:14px;
  border:2px solid var(--border);background:#fff;
  font-size:14px;font-weight:700;color:var(--text);
  text-align:left;cursor:default;
  box-shadow:0 3px 0 var(--border);
  transition:.25s;
}
.opt.correct{
  border-color:var(--green);background:#E6FBF4;color:var(--green-dark);
  box-shadow:0 3px 0 var(--green);
  animation:pulse 2.6s ease-in-out infinite;
}
@keyframes pulse{
  0%,100%{box-shadow:0 3px 0 var(--green)}
  50%{box-shadow:0 3px 0 var(--green), 0 0 0 6px rgba(0,196,140,.14)}
}
.app-footer{padding:0 18px 26px}
.app-check{
  width:100%;padding:14px;border-radius:16px;border:none;
  background:var(--green);color:#fff;font-weight:900;font-size:15px;
  letter-spacing:.5px;cursor:default;
  box-shadow:0 4px 0 var(--green-dark);
}
.float-badge{
  position:absolute;background:#fff;border-radius:16px;
  padding:10px 16px;box-shadow:var(--shadow);
  font-weight:800;font-size:14px;color:var(--dark);
  display:flex;align-items:center;gap:8px;
  border:1.5px solid var(--border);z-index:3;
  animation:floaty2 5s ease-in-out infinite;
}
@keyframes floaty2{0%,100%{transform:translateY(0)}50%{transform:translateY(-12px)}}
.fb-1{top:52px;left:-8px;animation-delay:-1s}
.fb-2{bottom:150px;right:-16px;animation-delay:-2.4s}
.fb-3{bottom:44px;left:-22px;animation-delay:-3.6s}
.fb-1 em,.fb-2 em,.fb-3 em{font-style:normal;font-size:16px}

/* ===================== 通用 Section ===================== */
.section{padding:96px 0}
.section-head{text-align:center;max-width:660px;margin:0 auto 60px}
.eyebrow{
  display:inline-block;font-size:13px;font-weight:800;letter-spacing:1.4px;
  text-transform:uppercase;color:var(--primary);
  background:var(--bg-soft);padding:6px 16px;border-radius:999px;margin-bottom:16px;
}
.section-head h2{
  font-size:clamp(28px,3.6vw,42px);
  font-weight:900;letter-spacing:-1.1px;line-height:1.22;
  color:var(--dark);margin-bottom:14px;
}
.section-head p{font-size:16.5px;color:var(--gray);line-height:1.75}

/* ===================== 功能卡片 ===================== */
.features{background:var(--bg-soft);position:relative;overflow:hidden}
.features::before{
  content:'';position:absolute;top:-160px;left:-160px;
  width:460px;height:460px;border-radius:50%;
  background:radial-gradient(circle,rgba(162,155,254,.35),transparent 70%);
  filter:blur(30px);
}
.features .container{position:relative;z-index:1}
.feat-grid{
  display:grid;grid-template-columns:repeat(3,1fr);gap:22px;
}
.feat-card{
  background:#fff;border-radius:24px;padding:32px 28px;
  border:1.5px solid var(--border);
  transition:transform .3s cubic-bezier(.2,.7,.3,1), box-shadow .3s, border-color .3s;
  position:relative;overflow:hidden;
}
.feat-card::before{
  content:'';position:absolute;top:0;left:0;right:0;height:4px;
  background:linear-gradient(90deg,var(--c1),var(--c2));
  transform:scaleX(0);transform-origin:left;transition:transform .4s ease;
}
.feat-card:hover{
  transform:translateY(-6px);
  box-shadow:var(--shadow-lg);
  border-color:transparent;
}
.feat-card:hover::before{transform:scaleX(1)}
.feat-icon{
  width:56px;height:56px;border-radius:18px;
  display:grid;place-items:center;font-size:26px;
  background:linear-gradient(135deg,var(--c1),var(--c2));
  margin-bottom:20px;
  box-shadow:0 10px 22px rgba(108,92,231,.20);
}
.feat-card h3{font-size:19px;font-weight:800;color:var(--dark);margin-bottom:10px;letter-spacing:-.3px}
.feat-card p{font-size:15px;color:var(--gray);line-height:1.72}

/* ===================== 学习方式 ===================== */
.how-wrap{position:relative}
.how-note{
  display:flex;align-items:center;justify-content:center;gap:10px;
  background:#fff;border:1.5px dashed var(--primary-light);
  border-radius:18px;padding:16px 24px;margin-bottom:44px;
  font-size:15px;font-weight:700;color:var(--primary-dark);
  text-align:center;flex-wrap:wrap;
}
.how-note span{font-size:20px}
.how-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.step{
  position:relative;padding:34px 24px 30px;
  background:#fff;border-radius:24px;
  border:1.5px solid var(--border);
  transition:transform .3s cubic-bezier(.2,.7,.3,1), box-shadow .3s;
}
.step:hover{transform:translateY(-6px);box-shadow:var(--shadow)}
.step-num{
  position:absolute;top:-18px;left:24px;
  width:44px;height:44px;border-radius:14px;
  display:grid;place-items:center;
  font-size:18px;font-weight:900;color:#fff;
  background:linear-gradient(135deg,#6C5CE7,#8B7CFF);
  box-shadow:0 8px 18px rgba(108,92,231,.35);
}
.step:nth-child(2) .step-num{background:linear-gradient(135deg,#00D2D3,#00C48C);box-shadow:0 8px 18px rgba(0,196,140,.3)}
.step:nth-child(3) .step-num{background:linear-gradient(135deg,#FFC93C,#FF9F43);box-shadow:0 8px 18px rgba(255,159,67,.3)}
.step:nth-child(4) .step-num{background:linear-gradient(135deg,#FF6B9D,#FF8FB1);box-shadow:0 8px 18px rgba(255,107,157,.3)}
.step h3{font-size:18px;font-weight:800;color:var(--dark);margin:14px 0 10px;letter-spacing:-.3px}
.step p{font-size:14.5px;color:var(--gray);line-height:1.72}
.step .step-emoji{font-size:32px;margin-top:8px}
.how-cta{text-align:center;margin-top:48px}

/* ===================== 数据 ===================== */
.stats{
  background:linear-gradient(135deg,#15132B 0%,#2B2461 50%,#3B2E7E 100%);
  position:relative;overflow:hidden;
}
.stats::before{
  content:'';position:absolute;top:-120px;right:-120px;
  width:520px;height:520px;border-radius:50%;
  background:radial-gradient(circle,rgba(0,210,211,.25),transparent 68%);
  filter:blur(20px);
}
.stats::after{
  content:'';position:absolute;bottom:-160px;left:-100px;
  width:460px;height:460px;border-radius:50%;
  background:radial-gradient(circle,rgba(108,92,231,.5),transparent 68%);
  filter:blur(20px);
}
.stats .container{position:relative;z-index:1}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;text-align:center}
.stat h3{
  font-size:clamp(32px,4.4vw,50px);
  font-weight:900;letter-spacing:-1.6px;
  background:linear-gradient(120deg,#fff,#A29BFE 60%,#00D2D3);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
  line-height:1.1;margin-bottom:10px;
}
.stat p{font-size:14.5px;color:rgba(255,255,255,.62);font-weight:600}

/* ===================== 评价 ===================== */
.review-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.review{
  background:#fff;border-radius:24px;padding:30px 28px;
  border:1.5px solid var(--border);
  display:flex;flex-direction:column;gap:16px;
  transition:transform .3s cubic-bezier(.2,.7,.3,1), box-shadow .3s;
}
.review:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg)}
.review-stars{color:#FFC93C;font-size:15px;letter-spacing:2px}
.review-text{font-size:15.5px;color:var(--text);line-height:1.78;flex:1}
.review-user{display:flex;align-items:center;gap:12px;padding-top:6px;border-top:1px solid var(--border)}
.review-avatar{
  width:44px;height:44px;border-radius:50%;
  display:grid;place-items:center;font-size:20px;
  background:linear-gradient(135deg,#EDEBFA,#DCD8F5);flex-shrink:0;
}
.review-user strong{display:block;font-size:14.5px;color:var(--dark);font-weight:800}
.review-user span{font-size:13px;color:var(--gray)}

/* ===================== 价格（免费 + 超级会员） ===================== */
.pricing{background:var(--bg-soft);position:relative;overflow:hidden}
.pricing::before{
  content:'';position:absolute;bottom:-200px;right:-160px;
  width:520px;height:520px;border-radius:50%;
  background:radial-gradient(circle,rgba(0,210,211,.22),transparent 70%);
  filter:blur(30px);
}
.pricing .container{position:relative;z-index:1}
.price-grid{
  display:grid;
  grid-template-columns:1fr 1.35fr;
  gap:28px;
  max-width:980px;
  margin:0 auto;
  align-items:start;
}
.plan{
  background:#fff;border-radius:26px;padding:40px 34px;
  border:2px solid var(--border);
  position:relative;
  transition:transform .3s cubic-bezier(.2,.7,.3,1), box-shadow .3s, border-color .3s;
}
.plan:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg)}
.plan.featured{
  border-color:var(--primary);
  box-shadow:0 20px 50px rgba(108,92,231,.22);
}
.plan.featured:hover{transform:translateY(-6px)}
.plan-tag{
  position:absolute;top:-14px;left:50%;transform:translateX(-50%);
  background:linear-gradient(135deg,#6C5CE7,#8B7CFF);color:#fff;
  font-size:12.5px;font-weight:800;padding:6px 18px;border-radius:999px;
  letter-spacing:.6px;box-shadow:0 8px 18px rgba(108,92,231,.35);white-space:nowrap;
}
.plan h3{font-size:21px;font-weight:800;color:var(--dark);margin-bottom:6px}
.plan .plan-desc{font-size:14.5px;color:var(--gray);margin-bottom:24px}
.plan-price{display:flex;align-items:baseline;gap:6px;margin-bottom:6px}
.plan-price b{font-size:48px;font-weight:900;letter-spacing:-2px;color:var(--dark);line-height:1}
.plan-price i{font-style:normal;font-size:16px;font-weight:700;color:var(--gray)}
.plan-note{font-size:13.5px;color:var(--gray);margin-bottom:28px}
.plan ul{list-style:none;display:flex;flex-direction:column;gap:14px;margin-bottom:32px}
.plan li{font-size:15px;color:var(--text);display:flex;gap:10px;align-items:flex-start;line-height:1.6}
.plan li .ck{
  flex-shrink:0;width:20px;height:20px;border-radius:50%;
  background:#E6FBF4;color:var(--green-dark);
  display:grid;place-items:center;font-size:12px;font-weight:900;margin-top:2px;
}
.plan li.off{color:#B4B1C6}
.plan li.off .ck{background:#F1F0F8;color:#B4B1C6}
.plan .btn{width:100%}

/* ---- 超级会员：三种购买周期 ---- */
.plan-options{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:10px;
  margin-bottom:26px;
}
.plan-option{
  position:relative;
  border:1.5px solid var(--border);
  border-radius:16px;
  padding:16px 10px 14px;
  text-align:center;
  background:#fff;
  transition:border-color .25s, box-shadow .25s, transform .25s;
}
.plan-option.best{
  border-color:var(--primary);
  background:linear-gradient(180deg,#F7F6FF 0%,#fff 70%);
  box-shadow:0 8px 20px rgba(108,92,231,.14);
}
.plan-option:hover{transform:translateY(-3px);box-shadow:var(--shadow-sm)}
/* 三个周期卡片是 <a>，点进去带着 plan 参数到购买页 */
a.plan-option{text-decoration:none;color:inherit;cursor:pointer}
.po-label{
  font-size:12.5px;font-weight:800;color:var(--gray);
  margin-bottom:8px;letter-spacing:.3px;
}
.plan-option.best .po-label{color:var(--primary)}
.po-badge{
  display:inline-block;
  background:linear-gradient(135deg,#6C5CE7,#8B7CFF);
  color:#fff;font-size:10px;padding:2px 7px;border-radius:999px;
  margin-left:3px;vertical-align:middle;font-weight:800;line-height:1.5;
}
.po-price{
  display:flex;align-items:baseline;justify-content:center;gap:2px;
  margin-bottom:4px;
}
.po-price b{
  font-size:27px;font-weight:900;letter-spacing:-1px;
  color:var(--dark);line-height:1;
}
.plan-option.best .po-price b{color:var(--primary-dark)}
.po-price i{font-style:normal;font-size:13px;font-weight:700;color:var(--gray)}
.po-original{
  font-size:12px;color:#B4B1C6;text-decoration:line-through;font-weight:600;
}
.po-save{
  display:inline-block;margin-top:6px;
  font-size:11px;font-weight:800;color:var(--green-dark);
  background:#E6FBF4;padding:2px 8px;border-radius:999px;
}

/* ===================== FAQ ===================== */
.faq-list{max-width:780px;margin:0 auto;display:flex;flex-direction:column;gap:14px}
.faq-item{
  background:#fff;border:1.5px solid var(--border);border-radius:20px;
  overflow:hidden;transition:border-color .25s, box-shadow .25s;
}
.faq-item.open{border-color:var(--primary-light);box-shadow:var(--shadow-sm)}
.faq-q{
  width:100%;background:none;border:none;cursor:pointer;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:22px 26px;text-align:left;
  font-size:16px;font-weight:800;color:var(--dark);letter-spacing:-.2px;
}
.faq-icon{
  flex-shrink:0;width:28px;height:28px;border-radius:50%;
  background:var(--bg-soft);color:var(--primary);
  display:grid;place-items:center;font-size:17px;font-weight:700;
  transition:transform .3s, background .3s, color .3s;
}
.faq-item.open .faq-icon{transform:rotate(45deg);background:var(--primary);color:#fff}
.faq-a{
  max-height:0;overflow:hidden;
  transition:max-height .35s cubic-bezier(.2,.7,.3,1);
}
.faq-a p{padding:0 26px 24px;font-size:15px;color:var(--gray);line-height:1.8}

/* ===================== CTA + 下载 ===================== */
.cta-section{padding:0 0 96px}
.cta-box{
  position:relative;overflow:hidden;
  background:linear-gradient(135deg,#6C5CE7 0%,#7C5CF0 45%,#00B8C4 100%);
  border-radius:36px;
  padding:74px 48px;
  text-align:center;
  box-shadow:0 30px 70px rgba(108,92,231,.35);
}
.cta-box::before{
  content:'';position:absolute;inset:0;
  background-image:radial-gradient(rgba(255,255,255,.18) 1.5px, transparent 1.5px);
  background-size:30px 30px;
  mask-image:radial-gradient(circle at 50% 50%, #000, transparent 72%);
  -webkit-mask-image:radial-gradient(circle at 50% 50%, #000, transparent 72%);
}
.cta-box::after{
  content:'';position:absolute;top:-140px;right:-100px;
  width:400px;height:400px;border-radius:50%;
  background:radial-gradient(circle,rgba(255,255,255,.22),transparent 68%);
}
.cta-inner{position:relative;z-index:1}
.cta-box h2{
  font-size:clamp(28px,4vw,44px);font-weight:900;color:#fff;
  letter-spacing:-1.2px;line-height:1.2;margin-bottom:16px;
}
.cta-box > .cta-inner > p.cta-sub{
  font-size:17px;color:rgba(255,255,255,.85);
  max-width:520px;margin:0 auto 34px;
}

/* 下载平台选择 */
.dl-hint{
  font-size:13.5px;font-weight:800;letter-spacing:1px;
  color:rgba(255,255,255,.75);text-transform:uppercase;
  margin-bottom:16px;
}
.download-grid{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:14px;
  max-width:680px;
  margin:0 auto 22px;
}
.dl-card{
  display:flex;align-items:center;gap:13px;
  background:#fff;
  border-radius:18px;
  padding:14px 18px;
  text-decoration:none;
  box-shadow:0 6px 0 rgba(0,0,0,.13);
  transition:transform .2s ease, box-shadow .2s ease;
  text-align:left;
}
.dl-card:hover{transform:translateY(-3px);box-shadow:0 9px 0 rgba(0,0,0,.13)}
.dl-card:active{transform:translateY(2px);box-shadow:0 3px 0 rgba(0,0,0,.13)}
.dl-icon{
  width:30px;height:30px;flex-shrink:0;
  display:grid;place-items:center;
}
.dl-icon svg{width:100%;height:100%;display:block}
.dl-text{display:flex;flex-direction:column;line-height:1.25;min-width:0}
.dl-text small{
  font-size:10.5px;color:var(--gray);font-weight:700;
  letter-spacing:.2px;white-space:nowrap;
}
.dl-text strong{
  font-size:15.5px;color:var(--dark);font-weight:900;
  letter-spacing:-.2px;white-space:nowrap;
}
/* 各平台图标配色 */
.dl-apple .dl-icon{color:#15132B}
.dl-android .dl-icon{color:#00C48C}
.dl-harmony .dl-icon{color:#0A59F7}

.cta-note{font-size:13.5px;color:rgba(255,255,255,.7);font-weight:600}

/* ===================== Footer ===================== */
footer{background:#100E22;color:rgba(255,255,255,.65);padding:70px 0 34px}
.foot-grid{
  display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;
  gap:44px;margin-bottom:52px;
}
.foot-brand .logo-text{color:#fff}
.foot-brand p{font-size:14.5px;line-height:1.8;margin-top:18px;max-width:290px;color:rgba(255,255,255,.55)}
.foot-social{display:flex;gap:10px;margin-top:22px}
.foot-social a{
  width:38px;height:38px;border-radius:12px;
  background:rgba(255,255,255,.07);
  display:grid;place-items:center;font-size:16px;
  text-decoration:none;transition:background .25s, transform .25s;
}
.foot-social a:hover{background:rgba(108,92,231,.55);transform:translateY(-3px)}
.foot-col h4{font-size:14px;font-weight:800;color:#fff;margin-bottom:18px;letter-spacing:.3px}
.foot-col ul{list-style:none;display:flex;flex-direction:column;gap:12px}
.foot-col a{font-size:14px;color:rgba(255,255,255,.55);text-decoration:none;transition:color .2s}
.foot-col a:hover{color:#fff}
.foot-bottom{
  border-top:1px solid rgba(255,255,255,.09);
  padding-top:28px;display:flex;justify-content:space-between;
  gap:18px;flex-wrap:wrap;font-size:13.5px;color:rgba(255,255,255,.42);
}

/* ===================== 滚动动画 ===================== */
.reveal{opacity:0;transform:translateY(30px);
  transition:opacity .75s cubic-bezier(.2,.7,.3,1), transform .75s cubic-bezier(.2,.7,.3,1)}
.reveal.in{opacity:1;transform:none}
.d1{transition-delay:.07s}.d2{transition-delay:.14s}.d3{transition-delay:.21s}
.d4{transition-delay:.28s}.d5{transition-delay:.35s}.d6{transition-delay:.42s}

/* ===================== 响应式 ===================== */
@media (max-width:1024px){
  .feat-grid{grid-template-columns:repeat(2,1fr)}
  .how-grid{grid-template-columns:repeat(2,1fr)}
  .stats-grid{grid-template-columns:repeat(2,1fr);gap:44px 24px}
  .review-grid{grid-template-columns:1fr}
  .price-grid{grid-template-columns:1fr;max-width:620px}
  .foot-grid{grid-template-columns:1fr 1fr;gap:36px}
}
@media (max-width:900px){
  .nav-links{
    position:absolute;top:100%;left:16px;right:16px;
    flex-direction:column;gap:0;
    background:#fff;border-radius:22px;padding:12px;
    box-shadow:0 20px 50px rgba(21,19,43,.16);
    border:1.5px solid var(--border);
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:.28s cubic-bezier(.2,.7,.3,1);
  }
  .nav-links.open{opacity:1;visibility:visible;transform:translateY(0)}
  .nav-links li{width:100%}
  .nav-links a{display:block;padding:13px 16px;border-radius:14px;font-size:15.5px}
  .nav-links a::after{display:none}
  .nav-links a:hover{background:var(--bg-soft)}
  .nav-toggle{display:flex;margin-left:8px}
  .nav-actions .btn-ghost{display:none}
  /* 窄屏导航栏塞不下账号区，改用汉堡菜单里的入口 */
  .nav-user{display:none}
  .nav-auth-item{display:block}
  .hero{padding:120px 0 70px}
  .hero-inner{grid-template-columns:1fr;gap:56px;text-align:center}
  .hero .badge{margin-inline:auto}
  .lead{margin-inline:auto}
  .hero-cta{justify-content:center}
  .hero-meta{justify-content:center}
  .hero-visual{min-height:auto;padding:20px 0}
  .section{padding:72px 0}
  .section-head{margin-bottom:44px}
}
@media (max-width:640px){
  .container{padding:0 18px}
  .feat-grid,.how-grid{grid-template-columns:1fr}
  .stats-grid{grid-template-columns:repeat(2,1fr);gap:36px 18px}
  .price-grid{max-width:440px}
  .plan-options{grid-template-columns:1fr;gap:10px}
  .plan-option{
    display:flex;align-items:center;justify-content:space-between;
    text-align:left;padding:14px 16px;gap:12px;
  }
  .po-label{margin-bottom:0}
  .po-price{margin-bottom:0}
  .po-save{margin-top:0}
  .plan-option .po-right{display:flex;flex-direction:column;align-items:flex-end;gap:2px}
  .cta-box{padding:52px 22px;border-radius:28px}
  .download-grid{grid-template-columns:1fr;gap:12px;max-width:340px}
  .dl-card{padding:13px 18px}
  .foot-grid{grid-template-columns:1fr;gap:32px}
  .foot-bottom{flex-direction:column;text-align:center;align-items:center}
  .phone{width:250px;height:500px}
  .fb-1{left:-6px;top:34px;padding:8px 13px;font-size:12.5px}
  .fb-2{right:-8px;padding:8px 13px;font-size:12.5px}
  .fb-3{left:-10px;padding:8px 13px;font-size:12.5px}
  .btn-lg{padding:15px 26px;font-size:16px}
  .hero-cta{flex-direction:column;align-items:stretch;width:100%;max-width:340px;margin-inline:auto}
  .hero-cta .btn{width:100%}
  .plan{padding:32px 22px}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
  html{scroll-behavior:auto}
}

/* ============ 学习实验室引导区 ============ */
/* 纸色铺底，和主站的紫色拉开距离——这里长出来的是一块「在线学习区」，
   不跟营销页强行融合视觉。 */
.lab-promo { background: #faf8f3; }
.lab-promo-card {
  display: grid; grid-template-columns: 1.05fr .95fr; gap: 36px; align-items: center;
  border: 2px solid #33302b; border-radius: 255px 22px 225px 22px / 22px 225px 22px 255px;
  padding: 34px 38px; background: #faf8f3;
}
/* 字号/字重/字距手工对齐 .section-head h2 —— 引导区是 .section 里的一块，
   h2 不写就是 UA 默认的 24px/700，夹在满页 42px/900 的标题里像掉了一级。 */
.lab-promo-copy h2 {
  color: #33302b; margin: 8px 0 12px;
  font-size: clamp(28px, 3.6vw, 42px); font-weight: 900; letter-spacing: -1.1px; line-height: 1.22;
}
.lab-promo-copy p  { color: #6b665e; font-size: 15px; line-height: 1.85; margin: 0 0 22px; }
.lab-promo-copy .eyebrow { color: #8a5a34; }
.lab-promo-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.lab-promo-art { padding: 6px 0; }
/* 音标三格，角半径是 lab/lab.css 里 .lab-explorer-group 那两个值的逐字拷贝
   （奇偶镜像同上），那边一改这边要跟着改。 */
.lab-promo-phonemes { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
/* 手写体那一栈只写这一处，音标三格和 SVG 里那四行字共用——写成 CSS 规则而不是
   SVG 上的 font-family 属性，是因为属性得抄四遍。栈照 lab 的 --font-note 抄，
   区别在这里没有 Caveat：那 73KB 的 caveat-latin.woff2 由 lab.css 的 @font-face
   加载，落地页不引它，所以拉丁字母也落到系统楷体（Kaiti SC / STKaiti / KaiTi）。 */
.lab-promo-art svg text,
.lab-promo-phonemes span { font-family: 'Caveat', 'Kaiti SC', 'STKaiti', 'KaiTi', '楷体', cursive; }
.lab-promo-phonemes span {
  border: 2px solid #33302b; padding: 5px 13px;
  border-radius: 255px 14px 225px 14px / 14px 225px 14px 255px;
  font-size: 19px; color: #33302b;
}
.lab-promo-phonemes span:nth-child(even) { border-radius: 14px 255px 14px 225px / 225px 14px 255px 14px; }
.lab-promo-phonemes b { font-weight: 400; color: #9a948a; font-size: 15px; margin-left: 4px; }
@media (max-width: 860px) {
  .lab-promo-card { grid-template-columns: 1fr; gap: 22px; padding: 26px 22px; }
}

@media (max-width: 420px) {
  /* 页头本来只放得下一个 .legal-back，现在有两个（学习实验室 + 返回首页）。
     .legal-top-inner 是 flex 且默认 nowrap：挤不下时两个丸不会掉行，而是被压窄、
     丸里的中文字自己折成两行，把 64px 的粘性页头顶到 87px（条款页）/ 107px
     （账户页——.acct-top-side 里空着的登录槽位也占一格）。
     实测（Playwright + 系统 Chrome，量 .legal-top 的高度）：
       只收内边距和账户页间距  条款页 ≤364px 折行，账户页 ≤354px 折行
       再加上下面那条 inner 间距  条款页 ≤348px 折行，账户页 ≤346px 折行
       （差 16px = 条款页 2 个间距 × 8px，账户页差 8px = 1 个间距 × 8px）
     三条都按 legal.css / account.css 的默认值算：丸内边距 8px 16px → 8px 10px
     （每丸省 12px，共 24px）、.legal-top-inner 间距 18px → 10px、
     .acct-top-side 间距 8px → 4px。
     最紧的一档是条款页 349px：容器内宽 313px（349 - 18×2），恰好等于
     110px logo + 182.5px 两个丸 + 2×10px 间距。再窄就只能折行——那是它唯一
     不重叠的出路，320px 无论如何都不够。
     这里靠多一级的选择器压过 legal.css，不改那张表——三张条款页还在直接引它。 */
  .legal-top .legal-top-inner { gap: 10px; }
  .legal-top .legal-back { padding: 8px 10px; }
  .legal-top .acct-top-side { gap: 4px; }
}