/* ============================================================
   ARK 英语乐园 · 主样式（首页）
   ============================================================ */
:root{
  --clr-orange:#ff8a3d;
  --clr-orange-deep:#f0522b;
  --clr-sun:#ffc94d;
  --clr-green:#2e9e4e;
  --clr-blue:#2f6fd0;
  --clr-purple:#6b45c4;
  --clr-ink:#3a2a1f;
  --clr-ink-soft:#7a6b5f;
  --clr-line:#f0e4d6;
  --clr-bg:#fff7ef;
  --clr-white:#ffffff;
  --grad-sun:linear-gradient(150deg,#ff8a3d,#f0522b);
  --grad-green:linear-gradient(150deg,#4fbf6e,#2e9e4e);
  --grad-blue:linear-gradient(150deg,#43a6f0,#2f6fd0);
  --grad-purple:linear-gradient(150deg,#9c6ade,#6b45c4);
  --font-display:'Baloo 2','Comic Sans MS',cursive;
  --font-body:'Nunito','Segoe UI',system-ui,sans-serif;
  --radius:16px;
  --radius-lg:24px;
  --shadow-sm:0 6px 18px rgba(240,82,43,.10);
  --shadow-md:0 12px 30px rgba(58,42,31,.14);
  --shadow-lg:0 20px 50px rgba(58,42,31,.18);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font-body);color:var(--clr-ink);background:var(--clr-bg);line-height:1.6;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit}
ul{list-style:none}
.container{width:min(1120px,92%);margin:0 auto}
section{scroll-margin-top:80px}

h1,h2,h3,.display{font-family:var(--font-display)}

/* 按钮 */
.btn{display:inline-flex;align-items:center;gap:8px;padding:.9rem 1.9rem;border-radius:999px;font-weight:800;font-family:var(--font-body);font-size:1rem;border:none;cursor:pointer;transition:.25s;box-shadow:var(--shadow-sm)}
.btn-primary{background:var(--grad-sun);color:#fff}
.btn-primary:hover{transform:translateY(-3px);box-shadow:var(--shadow-md)}
.btn-ghost{background:var(--clr-white);color:var(--clr-orange-deep);border:2px solid var(--clr-orange)}
.btn-ghost:hover{background:var(--clr-sun);border-color:var(--clr-sun);color:var(--clr-ink)}
.btn-white{background:#fff;color:var(--clr-orange-deep)}
.btn-white:hover{transform:translateY(-3px)}
.btn-green{background:var(--grad-green);color:#fff}
.btn-blue{background:var(--grad-blue);color:#fff}
.btn-purple{background:var(--grad-purple);color:#fff}

/* 上标/badge */
.eyebrow{display:inline-block;background:var(--clr-sun);color:var(--clr-orange-deep);font-weight:800;font-size:.8rem;letter-spacing:1px;padding:.35rem 1rem;border-radius:999px}

/* ============================================================
   顶部导航
   ============================================================ */
.main-header{position:fixed;top:0;left:0;right:0;z-index:100;transition:.3s}
.main-header.scrolled{background:rgba(255,247,239,.95);backdrop-filter:blur(10px);box-shadow:0 4px 20px rgba(58,42,31,.08)}
.nav{display:flex;align-items:center;justify-content:space-between;padding-block:14px}
.logo{display:flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:800;font-size:1.3rem;color:var(--clr-ink)}
.logo .logo-badge{width:42px;height:42px;border-radius:50%;background:var(--grad-sun);display:grid;place-items:center;color:#fff;font-size:1.2rem;flex-shrink:0;box-shadow:var(--shadow-sm)}
.logo .logo-badge svg{width:26px;height:26px}
.nav-links{display:flex;align-items:center;gap:26px}
.nav-links a{font-weight:700;color:var(--clr-ink);position:relative;padding:4px 0}
.nav-links a::after{content:"";position:absolute;left:0;bottom:-2px;width:0;height:3px;border-radius:3px;background:var(--grad-sun);transition:.25s}
.nav-links a:hover::after,.nav-links a.active::after{width:100%}
.nav-cta{margin-left:6px}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;color:var(--clr-ink)}
.nav-toggle svg{width:30px;height:30px}

/* ============================================================
   Hero
   ============================================================ */
.hero{position:relative;padding:140px 0 90px;overflow:hidden;
  background:
    radial-gradient(1200px 500px at 85% -10%,rgba(255,201,77,.55),transparent 60%),
    radial-gradient(900px 400px at -10% 110%,rgba(255,138,61,.35),transparent 60%),
    linear-gradient(180deg,#fff4e6,#fff7ef)}
.hero-bg{position:absolute;inset:0;pointer-events:none}
.hero-bg span{position:absolute;font-size:2.6rem;opacity:.18;font-family:var(--font-display);color:var(--clr-orange-deep)}
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:50px;align-items:center;position:relative;z-index:2}
.hero h1{font-size:clamp(2.2rem,5vw,3.6rem);line-height:1.15;font-weight:800;margin:16px 0}
.hero h1 .hl{background:var(--grad-sun);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p{font-size:1.15rem;color:var(--clr-ink-soft);max-width:480px;margin-bottom:26px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:34px}
.hero-stats{display:flex;gap:38px;flex-wrap:wrap}
.hstat strong{font-family:var(--font-display);font-size:1.6rem;color:var(--clr-orange-deep);display:block}
.hstat span{color:var(--clr-ink-soft);font-size:.9rem}
.hero-visual{position:relative;display:flex;justify-content:center}
.hero-img-wrap{width:min(400px,100%);position:relative}
.hero-img-wrap img{width:100%;border-radius:var(--radius-lg);box-shadow:var(--shadow-lg)}
.float-chip{position:absolute;background:#fff;border-radius:14px;padding:10px 14px;box-shadow:var(--shadow-md);display:flex;align-items:center;gap:8px;font-weight:800;font-size:.85rem;animation:float 3.5s ease-in-out infinite}
.float-chip svg{width:20px;height:20px;color:var(--clr-green)}
.float-chip.c1{top:6%;left:-8%;color:var(--clr-green)}
.float-chip.c2{bottom:12%;right:-6%;color:var(--clr-blue);animation-delay:1s}
.float-chip.c3{bottom:-4%;left:2%;color:var(--clr-purple);animation-delay:2s}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-10px)}}

/* 波浪分隔 */
.wave{display:block;width:100%;height:60px;fill:var(--clr-white)}

/* ============================================================
   Section 通用
   ============================================================ */
.section{padding:80px 0}
.section-head{text-align:center;max-width:640px;margin:0 auto 46px}
.section-head .eyebrow{margin-bottom:14px}
.section-head h2{font-size:clamp(1.8rem,3.6vw,2.6rem);font-weight:800;margin-bottom:10px}
.section-head p{color:var(--clr-ink-soft)}

/* ============================================================
   四大能力卡片
   ============================================================ */
.abilities-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:22px} /* 田字格：始终两行两列 */
.ab-card{background:var(--clr-white);border-radius:var(--radius-lg);padding:28px 22px;box-shadow:var(--shadow-sm);transition:.3s;position:relative;overflow:hidden;display:flex;flex-direction:column;gap:12px}
.ab-card:hover{transform:translateY(-8px);box-shadow:var(--shadow-md)}
.ab-card .ab-ico{width:60px;height:60px;border-radius:16px;display:grid;place-items:center;color:#fff}
.ab-card .ab-ico svg{width:30px;height:30px}
.ab-card.o .ab-ico{background:var(--grad-sun)}
.ab-card.g .ab-ico{background:var(--grad-green)}
.ab-card.b .ab-ico{background:var(--grad-blue)}
.ab-card.p .ab-ico{background:var(--grad-purple)}
.ab-card h3{font-size:1.3rem;font-weight:800}
.ab-card p{color:var(--clr-ink-soft);font-size:.95rem;flex:1}
.ab-link{font-weight:800;color:var(--clr-orange-deep);display:inline-flex;align-items:center;gap:6px}
.ab-card.o .ab-link{color:var(--clr-orange-deep)}
.ab-card.g .ab-link{color:var(--clr-green)}
.ab-card.b .ab-link{color:var(--clr-blue)}
.ab-card.p .ab-link{color:var(--clr-purple)}
.ab-link svg{width:18px;height:18px;transition:.2s}
.ab-card:hover .ab-link svg{transform:translateX(4px)}

/* ============================================================
   每日学习流程
   ============================================================ */
.flow{background:var(--clr-white)}
.flow-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:26px}
.flow-step{text-align:center;padding:30px 20px;border-radius:var(--radius-lg);background:var(--clr-bg);position:relative}
.flow-step .f-num{width:52px;height:52px;border-radius:50%;margin:0 auto 14px;display:grid;place-items:center;font-family:var(--font-display);font-size:1.4rem;font-weight:800;color:#fff}
.flow-step:nth-child(1) .f-num{background:var(--grad-sun)}
.flow-step:nth-child(2) .f-num{background:var(--grad-green)}
.flow-step:nth-child(3) .f-num{background:var(--grad-blue)}
.flow-step h3{font-size:1.25rem;margin-bottom:8px}
.flow-step p{color:var(--clr-ink-soft);font-size:.95rem}
.flow-step .f-tag{display:inline-block;margin-top:12px;font-weight:800;font-size:.8rem;color:var(--clr-orange-deep);background:rgba(255,138,61,.15);padding:.3rem .9rem;border-radius:999px}

/* ============================================================
   双语双页卡片（纯文本示例区）
   ============================================================ */
.showcase .demo{background:var(--clr-white);border-radius:var(--radius-lg);padding:30px;box-shadow:var(--shadow-sm)}
.demo-row{display:flex;align-items:center;gap:16px;padding:14px 0;border-bottom:1px solid var(--clr-line)}
.demo-row:last-child{border-bottom:none}
.demo-en{font-family:var(--font-display);font-size:1.2rem;font-weight:800;color:var(--clr-ink);flex:1}
.demo-cn{color:var(--clr-ink-soft)}
.demo-say{width:40px;height:40px;border-radius:50%;border:none;background:var(--grad-sun);color:#fff;cursor:pointer;display:grid;place-items:center}
.demo-say svg{width:18px;height:18px}

/* ============================================================
   CTA
   ============================================================ */
.cta{background:var(--grad-sun);color:#fff;text-align:center;padding:80px 0;position:relative;overflow:hidden}
.cta::before,.cta::after{content:"";position:absolute;border-radius:50%;background:rgba(255,255,255,.12)}
.cta::before{width:220px;height:220px;top:-70px;left:-60px}
.cta::after{width:300px;height:300px;bottom:-120px;right:-80px}
.cta h2{font-size:clamp(1.8rem,3.6vw,2.6rem);font-weight:800;margin-bottom:12px;position:relative;z-index:2}
.cta p{font-size:1.1rem;opacity:.95;margin-bottom:28px;position:relative;z-index:2}
.cta .btn{position:relative;z-index:2}

/* ============================================================
   底部
   ============================================================ */
.main-footer{background:#2f2118;color:#d8c9b8;padding:60px 0 0}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:30px;padding-bottom:40px}
.footer-brand p{margin-top:12px;color:#b8a894;font-size:.9rem;max-width:280px}
.footer-brand .logo{color:#fff;margin-bottom:14px}
.footer-col h4{color:#fff;font-family:var(--font-display);font-weight:800;margin-bottom:14px;font-size:1.1rem}
.footer-col li{margin-bottom:10px}
.footer-col a{color:#b8a894;font-size:.92rem}
.footer-col a:hover{color:var(--clr-sun)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:18px 0;text-align:center;font-size:.85rem;color:#9c8870}

/* ============================================================
   响应式
   ============================================================ */
@media(max-width:900px){
  .abilities-grid{grid-template-columns:repeat(2,1fr)} /* 田字格保持2列 */
  .flow-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .hero-grid{grid-template-columns:1fr;gap:40px}
  .hero{padding:120px 0 60px}
  .hero-visual{order:-1}
  .float-chip.c1{left:0}
  .float-chip.c2{right:0}
}
@media(max-width:640px){
  .nav-links{position:fixed;top:72px;left:0;right:0;background:#fff;flex-direction:column;gap:0;padding:12px 0;box-shadow:var(--shadow-md);transform:translateY(-150%);transition:.3s;align-items:stretch}
  .nav-links.open{transform:translateY(0)}
  .nav-links a{padding:14px 22px;border-bottom:1px solid var(--clr-line)}
  .nav-links .nav-cta{width:100%;margin:0;padding:12px 22px}
  .nav-cta .btn{width:100%;justify-content:center}
  .nav-toggle{display:block}
  .abilities-grid{grid-template-columns:repeat(2,1fr);gap:14px} /* 手机田字格：保持两行两列 */
  .hero-stats{gap:20px}
}