/* ============================================================
   求学通 Design System v1.0
   基于 DESIGN.md — Teal #0d9488 主色系
   参考: Stripe × Airbnb × Linear
   ============================================================ */

/* ========================================
   1. Design Tokens
   ======================================== */
:root {
  /* Brand — Teal */
  --brand-50:#f0fdfa;--brand-100:#ccfbf1;--brand-200:#99f6e4;--brand-300:#5eead4;
  --brand-400:#2dd4bf;--brand-500:#14b8a6;--brand-600:#0d9488;--brand-700:#0f766e;
  --brand-800:#115e59;--brand-900:#134e4a;

  /* Accent — Amber */
  --accent-50:#fffbeb;--accent-100:#fef3c7;--accent-300:#fcd34d;--accent-400:#fbbf24;
  --accent-500:#f59e0b;--accent-600:#d97706;--accent-700:#b45309;

  /* Semantic */
  --success:#10b981;--success-bg:#d1fae5;
  --warning:#f59e0b;--warning-bg:#fef3c7;
  --error:#ef4444;--error-bg:#fee2e2;
  --info:#3b82f6;--info-bg:#dbeafe;

  /* Gray Scale */
  --gray-50:#fafaf9;--gray-100:#f5f5f4;--gray-200:#e7e5e4;--gray-300:#d6d3d1;
  --gray-400:#a8a29e;--gray-500:#78716c;--gray-600:#57534e;--gray-700:#44403c;
  --gray-800:#292524;--gray-900:#1c1917;

  /* School Type Colors */
  --type-zhigao:#8b5cf6;--type-zhongzhuan:#3b82f6;--type-jigong:#f97316;
  --type-dazhuan:#06b6d4;--type-benke:#0d9488;--type-fudu:#ec4899;

  /* Typography */
  --font-sans:-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  --font-serif:'Noto Serif SC','Source Han Serif SC','Songti SC',serif;
  --font-mono:'SF Mono','Fira Code','Consolas',monospace;

  /* Shadows */
  --shadow-xs:0 1px 2px 0 rgba(0,0,0,0.05);
  --shadow-sm:0 1px 3px 0 rgba(0,0,0,0.1),0 1px 2px -1px rgba(0,0,0,0.1);
  --shadow-md:0 4px 6px -1px rgba(0,0,0,0.1),0 2px 4px -2px rgba(0,0,0,0.1);
  --shadow-lg:0 10px 15px -3px rgba(0,0,0,0.1),0 4px 6px -4px rgba(0,0,0,0.1);
  --shadow-xl:0 20px 25px -5px rgba(0,0,0,0.1),0 8px 10px -6px rgba(0,0,0,0.1);
  --shadow-2xl:0 25px 50px -12px rgba(0,0,0,0.25);

  /* Radius */
  --radius-sm:6px;--radius-md:8px;--radius-lg:12px;--radius-xl:16px;--radius-2xl:24px;--radius-full:9999px;

  /* Transitions */
  --ease-fast:150ms cubic-bezier(0.4,0,0.2,1);
  --ease-normal:300ms cubic-bezier(0.4,0,0.2,1);
  --ease-bounce:400ms cubic-bezier(0.34,1.56,0.64,1);

  /* Legacy aliases (for backward compatibility) */
  --primary:#0d9488;--primary-dark:#0f766e;--primary-light:#f0fdfa;
  --brand:#0d9488;--brand-dark:#0f766e;--brand-light:#f0fdfa;
  --accent:#f59e0b;--accent-light:#fef3c7;
  --ink:#111827;--ink-2:#374151;--ink-3:#6b7280;--ink-4:#9ca3af;
  --line:#e5e7eb;--bg:#f9fafb;--white:#ffffff;
  --title:#111827;--text:#374151;--text-secondary:#6b7280;--muted:#9ca3af;
  --card:#ffffff;--border:#e5e7eb;
  --radius-legacy:16px;--radius-sm-legacy:10px;
  --theme-color:#0d9488;--theme-color-dark:#0f766e;
  --header-height:64px;
}

/* ========================================
   2. Base Styles
   ======================================== */
*{margin:0;padding:0;box-sizing:border-box;}
body{font-family:var(--font-sans);color:var(--gray-800);background:var(--gray-50);line-height:1.6;-webkit-font-smoothing:antialiased;}
a{color:var(--brand-600);text-decoration:none;transition:color var(--ease-fast);}
a:hover{color:var(--brand-700);}
img{max-width:100%;height:auto;}
.container{max-width:1200px;margin:0 auto;padding:0 24px;}

/* ========================================
   3. Buttons
   ======================================== */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;font-family:var(--font-sans);font-weight:600;text-decoration:none;border:none;cursor:pointer;transition:all var(--ease-fast);user-select:none;white-space:nowrap;}
.btn-primary{background:var(--brand-600);color:#fff;padding:12px 24px;border-radius:var(--radius-md);font-size:16px;box-shadow:0 1px 2px rgba(13,148,136,0.3);}
.btn-primary:hover{background:var(--brand-700);transform:translateY(-1px);box-shadow:0 4px 12px rgba(13,148,136,0.35);}
.btn-accent{background:var(--accent-500);color:#fff;padding:12px 24px;border-radius:var(--radius-md);font-size:16px;box-shadow:0 1px 2px rgba(245,158,11,0.3);}
.btn-accent:hover{background:var(--accent-600);transform:translateY(-1px);box-shadow:0 4px 12px rgba(245,158,11,0.35);}
.btn-secondary{background:#fff;color:var(--brand-700);padding:12px 24px;border-radius:var(--radius-md);font-size:16px;border:1.5px solid var(--brand-300);}
.btn-secondary:hover{border-color:var(--brand-500);background:var(--brand-50);}
.btn-outline{background:#fff;color:var(--gray-700);padding:8px 18px;border-radius:var(--radius-md);font-size:14px;font-weight:600;border:1.5px solid var(--gray-300);transition:all var(--ease-fast);display:inline-flex;align-items:center;}
.btn-outline:hover{border-color:var(--brand-400);color:var(--brand-700);background:var(--brand-50);}
.btn-ghost{background:transparent;color:var(--gray-600);padding:12px 24px;border-radius:var(--radius-md);font-size:16px;}
.btn-ghost:hover{background:var(--gray-100);color:var(--gray-900);}
.btn-danger{background:var(--error);color:#fff;padding:12px 24px;border-radius:var(--radius-md);font-size:16px;}
.btn-danger:hover{background:#dc2626;transform:translateY(-1px);}
.btn-sm{padding:8px 16px;font-size:14px;border-radius:var(--radius-sm);}
.btn-lg{padding:16px 32px;font-size:18px;border-radius:var(--radius-lg);}

/* ========================================
   4. Cards
   ======================================== */
.card{background:#fff;border-radius:var(--radius-xl);border:1px solid var(--gray-200);box-shadow:var(--shadow-xs);transition:all var(--ease-normal);overflow:hidden;}
.card:hover{box-shadow:var(--shadow-lg);transform:translateY(-2px);border-color:var(--brand-200);}
.card-body{padding:20px;}

/* ========================================
   5. Badges / Tags
   ======================================== */
.badge{display:inline-flex;align-items:center;gap:4px;padding:4px 12px;border-radius:var(--radius-full);font-size:12px;font-weight:600;}
.badge-zhigao{background:rgba(139,92,246,0.1);color:var(--type-zhigao);}
.badge-zhongzhuan{background:rgba(59,130,246,0.1);color:var(--type-zhongzhuan);}
.badge-jigong{background:rgba(249,115,22,0.1);color:var(--type-jigong);}
.badge-dazhuan{background:rgba(6,182,212,0.1);color:var(--type-dazhuan);}
.badge-benke{background:rgba(13,148,136,0.1);color:var(--type-benke);}
.badge-fudu{background:rgba(236,72,153,0.1);color:var(--type-fudu);}
.badge-public{background:var(--success-bg);color:var(--success);}
.badge-private{background:var(--info-bg);color:var(--info);}
.badge-hot{background:var(--error-bg);color:var(--error);}
.badge-brand{background:var(--brand-50);color:var(--brand-700);}
.badge-accent{background:var(--accent-100);color:var(--accent-700);}

/* ========================================
   6. Forms
   ======================================== */
.form-group{margin-bottom:18px;}
.form-label{display:block;margin-bottom:6px;font-weight:600;color:var(--gray-700);font-size:13px;}
.form-label .required{color:var(--error);margin-left:2px;font-weight:700;}
.form-input,.form-select,.form-textarea{
  width:100%;padding:12px 14px;border:1.5px solid var(--gray-300);border-radius:var(--radius-md);
  font-size:14px;font-family:var(--font-sans);background:#fff;color:var(--gray-800);
  transition:all var(--ease-fast);outline:none;
}
.form-input:focus,.form-select:focus,.form-textarea:focus{
  border-color:var(--brand-500);box-shadow:0 0 0 3px rgba(13,148,136,0.12);background:#fff;
}
.form-input::placeholder{color:var(--gray-400);}
.form-row{display:flex;gap:14px;}
.form-row>*{flex:1;}

/* ========================================
   7. Navigation
   ======================================== */
.nav{display:flex;align-items:center;justify-content:space-between;padding:16px 32px;background:#fff;border-bottom:1px solid var(--gray-200);position:sticky;top:0;z-index:50;}
.nav-logo{display:flex;align-items:center;gap:8px;font-size:20px;font-weight:800;color:var(--brand-700);text-decoration:none;}
.nav-links{display:flex;gap:28px;}
.nav-link{font-size:14px;font-weight:500;color:var(--gray-600);text-decoration:none;transition:color var(--ease-fast);position:relative;padding:8px 0;}
.nav-link:hover,.nav-link.active{color:var(--brand-700);}
.nav-link.active::after{content:'';position:absolute;bottom:-16px;left:0;right:0;height:2px;background:var(--brand-500);border-radius:var(--radius-full);}
.nav-actions{display:flex;gap:10px;align-items:center;}

/* ========================================
   8. Pagination
   ======================================== */
.pagination{display:flex;justify-content:center;gap:8px;margin-top:48px;}
.page-btn{width:40px;height:40px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-md);border:1px solid var(--gray-200);background:#fff;color:var(--gray-600);font-size:14px;font-weight:600;cursor:pointer;transition:all var(--ease-fast);text-decoration:none;}
.page-btn:hover{border-color:var(--brand-300);color:var(--brand-700);}
.page-btn.active{background:var(--brand-600);color:#fff;border-color:var(--brand-600);}

/* ========================================
   9. Section Headers
   ======================================== */
.section{padding:56px 0;max-width:1200px;margin:0 auto;padding-left:24px;padding-right:24px;}
.section-header{text-align:center;margin-bottom:36px;}
.section-eyebrow{font-size:12px;font-weight:700;color:var(--brand-600);letter-spacing:0.1em;text-transform:uppercase;margin-bottom:8px;background:var(--brand-50);padding:4px 14px;border-radius:20px;display:inline-block;}
.section-title{font-size:clamp(24px,3.5vw,32px);font-weight:800;color:var(--gray-900);letter-spacing:-0.02em;}
.section-desc{font-size:15px;color:var(--gray-500);margin-top:8px;}
.section-header-row{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:32px;flex-wrap:wrap;gap:12px;}
.section-header-row h2{font-size:26px;font-weight:800;color:var(--gray-900);letter-spacing:-0.02em;}
.section-link{color:var(--brand-600);font-size:14px;font-weight:600;display:inline-flex;align-items:center;gap:4px;transition:gap var(--ease-fast);text-decoration:none;}
.section-link:hover{gap:8px;}

/* ========================================
   10. Breadcrumb
   ======================================== */
.breadcrumb{max-width:1200px;margin:0 auto;padding:12px 24px;font-size:0.82rem;color:var(--gray-400);}
.breadcrumb a{color:var(--gray-600);text-decoration:none;}
.breadcrumb a:hover{color:var(--brand-600);}
.breadcrumb span{margin:0 5px;color:var(--gray-300);}

/* ========================================
   11. Hero Sections
   ======================================== */
.hero-dark{background:linear-gradient(165deg,#0f172a 0%,#172554 25%,#134e4a 55%,#0f766e 100%);padding:0;position:relative;overflow:hidden;min-height:480px;display:flex;align-items:center;}
.hero-dark::before{content:'';position:absolute;width:600px;height:600px;background:radial-gradient(circle,rgba(20,184,166,0.15) 0%,transparent 70%);top:-200px;right:-100px;border-radius:50%;}
.hero-dark::after{content:'';position:absolute;width:400px;height:400px;background:radial-gradient(circle,rgba(245,158,11,0.08) 0%,transparent 70%);bottom:-100px;left:-100px;border-radius:50%;}
.hero-teal{background:linear-gradient(135deg,var(--brand-900) 0%,var(--brand-600) 60%,var(--brand-500) 100%);padding:40px 0;text-align:center;position:relative;overflow:hidden;color:#fff;}
.hero-teal::after{content:'';position:absolute;top:0;right:-5%;width:300px;height:300px;background:radial-gradient(circle,rgba(255,255,255,0.08) 0%,transparent 70%);border-radius:50%;}

/* ========================================
   12. School Cards (shared)
   ======================================== */
.school-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;}
.school-card{background:#fff;border-radius:var(--radius-xl);overflow:hidden;border:1px solid #EEF2F7;transition:all .3s cubic-bezier(.4,0,.2,1);display:flex;flex-direction:column;position:relative;box-shadow:0 1px 4px rgba(0,0,0,0.04);cursor:pointer;text-decoration:none;color:inherit;}
.school-card:hover{transform:translateY(-5px);box-shadow:0 16px 48px rgba(0,0,0,0.1);border-color:#ccfbf1;}
.school-card.featured{border-top:3px solid var(--brand-600);}
.school-card.featured::before{content:'推荐';position:absolute;top:12px;left:12px;z-index:2;background:linear-gradient(135deg,#F59E0B,#D97706);color:#fff;font-size:11px;font-weight:700;padding:3px 12px;border-radius:20px;letter-spacing:0.03em;box-shadow:0 2px 8px rgba(245,158,11,0.3);}
.school-card-img{height:170px;position:relative;overflow:hidden;display:flex;align-items:center;justify-content:center;font-size:52px;}
.school-card-img img{width:100%;height:100%;object-fit:cover;transition:transform .4s ease;}
.school-card:hover .school-card-img img{transform:scale(1.06);}
.school-card-img-tag{position:absolute;bottom:10px;right:10px;z-index:2;background:rgba(255,255,255,0.92);backdrop-filter:blur(4px);color:#115e59;font-size:11px;font-weight:700;padding:4px 12px;border-radius:8px;box-shadow:0 1px 4px rgba(0,0,0,0.1);}
.school-card-body{padding:18px 18px 16px;flex:1;display:flex;flex-direction:column;}
.school-card-title{font-size:15px;font-weight:700;color:var(--gray-900);margin-bottom:6px;line-height:1.35;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.school-card-meta{font-size:12px;color:var(--gray-400);margin-bottom:6px;display:flex;align-items:center;gap:4px;}
.school-card-desc{font-size:13px;color:var(--gray-600);line-height:1.55;flex:1;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin-bottom:12px;}
.school-card-btn{display:inline-flex;align-items:center;justify-content:center;padding:8px 20px;background:#F0F5FF;color:var(--brand-600);font-size:13px;font-weight:600;border-radius:8px;transition:all .25s;align-self:flex-start;}
.school-card:hover .school-card-btn{background:var(--brand-600);color:#fff;box-shadow:0 2px 12px rgba(15,118,110,0.25);}

/* ========================================
   13. Filter Pills
   ======================================== */
.filter-opts{display:flex;flex-wrap:wrap;gap:7px;}
.filter-pill{display:inline-flex;align-items:center;gap:4px;padding:7px 13px;border-radius:20px;font-size:0.78rem;font-weight:500;text-decoration:none;color:var(--gray-600);background:var(--gray-50);border:1.5px solid var(--gray-200);transition:all var(--ease-fast);white-space:nowrap;cursor:pointer;line-height:1.3;}
.filter-pill:hover{color:var(--brand-600);background:var(--brand-50);border-color:var(--brand-200);}
.filter-pill.active{background:var(--brand-600);color:#fff;font-weight:700;border-color:var(--brand-600);box-shadow:0 2px 10px rgba(13,148,136,0.25);}

/* ========================================
   14. Tabs
   ======================================== */
.tabs{display:flex;border-bottom:2px solid var(--gray-200);margin-bottom:28px;}
.tab{flex:1;padding:14px 20px;background:none;border:none;font-size:15px;font-weight:600;color:var(--gray-500);cursor:pointer;transition:all var(--ease-normal);border-bottom:2px solid transparent;margin-bottom:-2px;font-family:var(--font-sans);}
.tab:hover{color:var(--brand-600);}
.tab.active{color:var(--brand-600);border-bottom-color:var(--brand-600);}

/* ========================================
   15. Empty State
   ======================================== */
.empty-state{text-align:center;padding:80px 20px;background:#fff;border-radius:var(--radius-xl);border:1px solid var(--gray-200);}
.empty-state .icon{font-size:56px;margin-bottom:16px;opacity:0.4;}
.empty-state h3{color:var(--gray-600);margin:0 0 8px;font-weight:600;}
.empty-state p{color:var(--gray-400);font-size:0.9rem;}

/* ========================================
   16. Alert
   ======================================== */
.alert{padding:12px 16px;border-radius:var(--radius-md);margin-bottom:18px;font-size:13px;}
.alert-error{background:var(--error-bg);color:var(--error);border:1px solid #f5c6cb;}
.alert-success{background:var(--success-bg);color:var(--success);border:1px solid #c3e6cb;}
.alert-warning{background:var(--warning-bg);color:var(--warning);border:1px solid #fcd34d;}
.alert-info{background:var(--info-bg);color:var(--info);border:1px solid #93c5fd;}

/* ========================================
   17. Stats Banner
   ======================================== */
.stats-banner{background:linear-gradient(135deg,#0f172a,#134e4a);padding:48px 0;margin:56px 0 0;}
.stats-row{display:flex;justify-content:center;gap:0;max-width:900px;margin:0 auto;}
.stat-item{flex:1;text-align:center;padding:0 32px;border-right:1px solid rgba(255,255,255,0.1);}
.stat-item:last-child{border-right:none;}
.stat-num{font-size:44px;font-weight:900;color:#fff;letter-spacing:-0.04em;line-height:1;}
.stat-item:nth-child(1) .stat-num{color:#2dd4bf;}
.stat-item:nth-child(2) .stat-num{color:#34d399;}
.stat-item:nth-child(3) .stat-num{color:#fbbf24;}
.stat-item:nth-child(4) .stat-num{color:#f472b6;}
.stat-label{font-size:14px;color:rgba(255,255,255,0.55);margin-top:6px;font-weight:500;}

/* ========================================
   18. CTA Section
   ======================================== */
.cta-section{padding:64px 24px;background:linear-gradient(135deg,var(--brand-600),var(--brand-700));text-align:center;position:relative;overflow:hidden;}
.cta-section::before{content:"";position:absolute;width:500px;height:500px;background:radial-gradient(circle,rgba(255,255,255,0.06) 0%,transparent 70%);top:-200px;right:-100px;border-radius:50%;}
.cta-section>*{position:relative;z-index:1;}
.cta-section h2{font-size:32px;font-weight:800;color:#fff;letter-spacing:-0.02em;margin-bottom:8px;}
.cta-section p{font-size:16px;color:rgba(255,255,255,0.75);margin-bottom:28px;}
.cta-btn-big{display:inline-block;background:#fff;color:var(--brand-600);padding:16px 48px;border-radius:var(--radius-full);font-size:17px;font-weight:700;transition:all var(--ease-normal);text-decoration:none;}
.cta-btn-big:hover{transform:translateY(-3px);box-shadow:0 8px 30px rgba(0,0,0,0.2);}

/* ========================================
   19. Responsive
   ======================================== */
@media (max-width:1024px){
  .school-grid{grid-template-columns:repeat(2,1fr);gap:16px;}
}
@media (max-width:768px){
  .nav-links{display:none;}
  .nav-actions .btn-outline{display:none;}
  .stats-row{flex-wrap:wrap;gap:16px;}
  .stat-item{flex:1 1 45%;border-right:none;padding:16px;}
  .stat-num{font-size:32px;}
}
@media (max-width:640px){
  .school-grid{grid-template-columns:1fr;gap:14px;}
  .section{padding:40px 16px;}
  .cta-section h2{font-size:24px;}
}

/* ========================================
   20. Utility Classes
   ======================================== */
.text-center{text-align:center;}
.text-left{text-align:left;}
.text-right{text-align:right;}
.mt-0{margin-top:0!important;}.mt-2{margin-top:8px;}.mt-4{margin-top:16px;}.mt-6{margin-top:24px;}.mt-8{margin-top:32px;}
.mb-0{margin-bottom:0!important;}.mb-2{margin-bottom:8px;}.mb-4{margin-bottom:16px;}.mb-6{margin-bottom:24px;}.mb-8{margin-bottom:32px;}
.flex{display:flex;}.flex-col{flex-direction:column;}.items-center{align-items:center;}.justify-center{justify-content:center;}.justify-between{justify-content:space-between;}
.gap-2{gap:8px;}.gap-4{gap:16px;}.gap-6{gap:24px;}
.hidden{display:none;}.block{display:block;}.inline-block{display:inline-block;}
.w-full{width:100%;}.max-w-md{max-width:480px;}.max-w-lg{max-width:600px;}.max-w-xl{max-width:720px;}
.rounded{border-radius:var(--radius-md);}.rounded-lg{border-radius:var(--radius-lg);}.rounded-xl{border-radius:var(--radius-xl);}.rounded-full{border-radius:var(--radius-full);}
.shadow-sm{box-shadow:var(--shadow-sm);}.shadow-md{box-shadow:var(--shadow-md);}.shadow-lg{box-shadow:var(--shadow-lg);}