*{margin:0;padding:0;box-sizing:border-box}
:root{
  --blue:#1a56db;--blue-dark:#1e40af;--blue-light:#eff6ff;
  --gold:#f57c00;--gold-light:#fff7ed;
  --white:#fff;--gray-50:#f9fafb;--gray-100:#f3f4f6;--gray-200:#e5e7eb;
  --gray-600:#6b7280;--gray-800:#374151;--gray-900:#111827;
  --red:#dc2626;--green:#059669;
  --shadow:0 2px 16px rgba(0,0,0,0.06);--shadow-lg:0 8px 30px rgba(0,0,0,0.08);
  --radius:12px;
}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;color:var(--gray-900);background:var(--gray-50);line-height:1.7;font-size:15px;padding-bottom:70px}
.container{max-width:750px;margin:0 auto;padding:0 16px}

/* Nav */
.nav{background:var(--white);border-bottom:1px solid var(--gray-200);position:sticky;top:0;z-index:100}
.nav .container{display:flex;align-items:center;justify-content:space-between;height:52px}
.nav .logo{font-size:16px;font-weight:700;color:var(--blue);text-decoration:none;white-space:nowrap}
.nav-links{display:flex;gap:6px;list-style:none}
.nav-links a{display:block;padding:6px 12px;font-size:13px;color:var(--gray-600);text-decoration:none;border-radius:6px;transition:all .15s}
.nav-links a:hover,.nav-links a.active{color:var(--blue);background:var(--blue-light)}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:4px}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--gray-800);margin:4px 0;transition:.2s}

/* Hero */
.hero{background:linear-gradient(135deg,#eff6ff 0%,#dbeafe 50%,#fff7ed 100%);padding:48px 0 36px;text-align:center}
.hero .badge{display:inline-block;background:var(--blue);color:#fff;padding:5px 14px;border-radius:20px;font-size:12px;font-weight:600;margin-bottom:14px}
.hero h1{font-size:24px;color:var(--gray-900);line-height:1.45;margin-bottom:10px}
.hero h1 em{font-style:normal;color:var(--blue)}
.hero .sub{font-size:14px;color:var(--gray-600);margin-bottom:24px;line-height:1.6}
.hero .mission{display:inline-block;background:var(--white);padding:7px 16px;border-radius:6px;font-size:12px;color:var(--blue);font-weight:600;margin-bottom:16px}

.btn{display:inline-flex;align-items:center;justify-content:center;padding:11px 24px;border-radius:24px;font-size:14px;font-weight:600;text-decoration:none;cursor:pointer;border:none;transition:all .15s;min-height:44px}
.btn-blue{background:var(--blue);color:#fff}.btn-blue:hover{background:var(--blue-dark)}
.btn-gold{background:var(--gold);color:#fff}.btn-gold:hover{background:#e65100}
.btn-outline{background:var(--white);color:var(--blue);border:2px solid var(--blue)}.btn-outline:hover{background:var(--blue-light)}
.btn-lg{padding:14px 36px;font-size:16px}

/* Section */
section{padding:40px 0}
.section-title{font-size:20px;color:var(--gray-900);text-align:center;margin-bottom:6px}
.section-sub{font-size:13px;color:var(--gray-600);text-align:center;margin-bottom:28px}

/* Trust bar */
.trust-bar{background:linear-gradient(135deg,#f9fafb,#eff6ff,#fff7ed);padding:28px 0;border-bottom:1px solid var(--gray-200)}
.trust-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;text-align:center}
.trust-item{background:var(--white);border-radius:10px;padding:16px 8px;box-shadow:0 2px 8px rgba(0,0,0,0.04)}
.trust-item .num{font-size:28px;font-weight:800;color:var(--gold);letter-spacing:-1px;line-height:1.1}
.trust-item .lbl{font-size:12px;color:var(--gray-600);margin-top:4px;font-weight:500}

/* Cards */
.card{background:var(--white);border-radius:var(--radius);padding:24px 20px;margin-bottom:16px;box-shadow:var(--shadow)}
.card-blue{border-left:3px solid var(--blue)}

/* Steps */
.steps{display:grid;gap:14px}
.step{display:flex;gap:14px;align-items:flex-start}
.step-num{width:34px;height:34px;background:var(--blue);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:15px;flex-shrink:0}
.step h3{font-size:15px;color:var(--gray-900);margin-bottom:2px}
.step p{font-size:13px;color:var(--gray-600)}

/* Image grid */
.img-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
.img-grid img{width:100%;border-radius:8px;cursor:pointer;transition:transform .15s;box-shadow:var(--shadow)}
.img-grid.uniform img{aspect-ratio:4/3;object-fit:cover}
.img-grid img:hover{transform:scale(1.02)}
.img-grid .full{grid-column:1/-1}
@media(max-width:480px){.img-grid{grid-template-columns:1fr}}

/* Video */
.video-wrap{position:relative;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);background:#000}
.video-wrap video{width:100%;display:block}

/* Teacher */
.teacher-card{display:flex;gap:16px;align-items:flex-start}
.teacher-photo{width:80px;height:80px;border-radius:50%;object-fit:cover;flex-shrink:0}
.teacher-badges{display:flex;flex-wrap:wrap;gap:6px;margin:6px 0 8px}
.teacher-badges span{background:var(--blue-light);color:var(--blue);padding:3px 10px;border-radius:12px;font-size:12px;font-weight:600}

/* Pricing */
.pricing-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.pricing-card{background:var(--white);border:2px solid var(--gray-200);border-radius:var(--radius);padding:24px;text-align:center}
.pricing-card.featured{border-color:var(--gold);background:var(--gold-light)}
.pricing-card h3{font-size:17px;color:var(--gray-900);margin-bottom:6px}
.pricing-card .price{font-size:26px;font-weight:700;color:var(--blue);margin-bottom:12px}
.pricing-card .features{list-style:none;text-align:left;font-size:13px;color:var(--gray-600);margin-bottom:14px}
.pricing-card .features li{padding:3px 0}
.pricing-card .features li::before{content:"✓ ";color:var(--green);font-weight:700}
@media(max-width:480px){.pricing-grid{grid-template-columns:1fr}}

/* Testimonials */
.testimonial{background:var(--blue-light);border-left:3px solid var(--blue);padding:14px 16px;border-radius:0 var(--radius) var(--radius) 0;margin-bottom:10px}
.testimonial .quote{font-size:13px;color:var(--gray-800);font-style:italic;margin-bottom:6px}
.testimonial .author{font-size:12px;color:var(--gray-600)}

/* CTA */
.cta-section{background:linear-gradient(135deg,var(--blue-dark),var(--blue));color:#fff;text-align:center;padding:40px 16px}
.cta-section h2{font-size:20px;margin-bottom:8px}
.cta-section p{font-size:13px;opacity:.9;margin-bottom:20px}
.cta-section .phone{font-size:18px;font-weight:700}

/* Sticky bar */
.sticky-bar{position:fixed;bottom:0;left:0;right:0;background:var(--white);padding:10px 16px;box-shadow:0 -2px 12px rgba(0,0,0,0.08);display:flex;gap:8px;z-index:999}
.sticky-bar .btn{flex:1;text-align:center;font-size:13px}
.sticky-bar .btn-phone{background:var(--white);color:var(--blue);border:2px solid var(--blue)}
.sticky-bar .btn-wechat{background:var(--blue);color:#fff}

/* QR */
.qr-box{display:flex;align-items:center;gap:16px;padding:16px;background:var(--gray-50);border-radius:var(--radius)}
.qr-box img{width:90px;height:90px;object-fit:cover;border-radius:8px;flex-shrink:0}
.qr-info h4{font-size:14px;margin-bottom:2px}
.qr-info p{font-size:12px;color:var(--gray-600)}

/* Footer */
.footer{background:var(--gray-900);color:var(--gray-600);text-align:center;padding:28px 16px 80px;font-size:12px}
.footer a{color:var(--blue-light)}

/* Lightbox */
.lightbox{display:none;position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,0.9);z-index:9999;align-items:center;justify-content:center}
.lightbox.show{display:flex}
.lightbox img{max-width:90vw;max-height:80vh;border-radius:8px;object-fit:contain}
.lightbox-close{position:absolute;top:16px;right:16px;color:#fff;font-size:28px;cursor:pointer;width:40px;height:40px;display:flex;align-items:center;justify-content:center;background:rgba(255,255,255,0.15);border-radius:50%;border:none}

/* Page header */
.page-header{background:linear-gradient(135deg,#eff6ff,#dbeafe);text-align:center;padding:40px 0 32px}
.page-header h1{font-size:24px;color:var(--gray-900);margin-bottom:6px}

/* FAQ */
.faq-list{display:grid;gap:10px;margin-bottom:28px}
.faq-item{background:var(--white);border-radius:var(--radius);padding:16px 18px;box-shadow:var(--shadow);border-left:3px solid var(--blue)}
.faq-item summary{font-size:15px;font-weight:600;color:var(--gray-900);cursor:pointer;list-style:none;outline:none}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:"+";float:right;font-size:20px;color:var(--blue);transition:transform .2s}
.faq-item[open] summary::after{content:"−"}
.faq-item p{font-size:13px;color:var(--gray-600);margin-top:8px;line-height:1.7}

/* Testimonials / Reviews */
.review-list{display:grid;gap:12px}
.review-card{background:var(--white);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow);border-left:3px solid var(--gold)}
.review-card .review-stars{color:var(--gold);font-size:14px;margin-bottom:6px}
.review-card .review-body{font-size:14px;color:var(--gray-800);font-style:italic;line-height:1.7;margin-bottom:8px}
.review-card .review-author{font-size:12px;color:var(--gray-600);font-weight:600}
.review-card .review-result{display:inline-block;background:var(--blue-light);color:var(--blue);padding:3px 10px;border-radius:12px;font-size:12px;font-weight:600;margin-left:6px}

/* Data Cards */
.data-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
.data-card{background:var(--white);border-radius:var(--radius);padding:16px;box-shadow:var(--shadow);text-align:center}
.data-card .data-icon{font-size:24px;margin-bottom:6px}
.data-card .data-num{font-size:22px;font-weight:800;color:var(--blue);margin-bottom:2px}
.data-card .data-lbl{font-size:12px;color:var(--gray-600)}
@media(min-width:641px){.data-grid{grid-template-columns:repeat(4,1fr)}}

/* Credential Badge */
.cred-list{display:grid;gap:12px}
.cred-item{display:flex;gap:12px;align-items:flex-start;background:var(--white);padding:14px 16px;border-radius:var(--radius);box-shadow:var(--shadow)}
.cred-item .cred-icon{font-size:20px;width:36px;height:36px;background:var(--blue-light);border-radius:50%;display:flex;align-items:center;justify-content:center;flex-shrink:0}
.cred-item h4{font-size:14px;color:var(--gray-900);margin-bottom:2px}
.cred-item p{font-size:12px;color:var(--gray-600)}

/* Article schema markup (hidden) */
.schema-markup{display:none}

/* Figure caption for blog images */
figure{margin:16px 0;text-align:center}
figure img{border-radius:8px;max-width:100%}
figure figcaption{font-size:12px;color:var(--gray-600);margin-top:6px;line-height:1.5}

/* Enhanced meta section */
.meta-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.meta-tags span{background:var(--gray-100);color:var(--gray-600);padding:2px 8px;border-radius:4px;font-size:11px}

@media(max-width:640px){
  .nav-links{display:none;position:absolute;top:52px;left:0;right:0;background:var(--white);flex-direction:column;padding:8px 16px;border-bottom:1px solid var(--gray-200)}
  .nav-links.open{display:flex}
  .nav-links a{padding:10px 12px}
  .nav-toggle{display:block}
  .trust-grid{grid-template-columns:repeat(2,1fr);gap:10px}
  .hero h1{font-size:20px}
  .teacher-card{flex-direction:column;align-items:center;text-align:center}
}

/* ===== 五大秘诀：3+2 居中（手机2列，最后1个占满整行） ===== */
.five-grid{grid-template-columns:repeat(2,1fr)}
.five-grid .data-card:nth-child(5){grid-column:1/-1}
@media(min-width:641px){
  .five-grid{grid-template-columns:repeat(6,1fr)}
  .five-grid .data-card:nth-child(1),
  .five-grid .data-card:nth-child(2),
  .five-grid .data-card:nth-child(3){grid-column:span 2}
  .five-grid .data-card:nth-child(4){grid-column:2/4}
  .five-grid .data-card:nth-child(5){grid-column:4/6}
}