* { margin:0; padding:0; box-sizing:border-box; }
body { font-family:'Segoe UI', Arial, sans-serif; background:#f0f2f5; color:#333; line-height:1.6; }
.site-header { background: linear-gradient(135deg, #1a3a5c 0%, #0f2b3d 100%); padding:15px 24px; }
.header-container { max-width:1400px; margin:0 auto; }
.logo h1 { color:white; font-size:24px; }
.logo p { color:#ccc; font-size:12px; }
.container { max-width:1400px; margin:30px auto; padding:0 20px; }
.chapter-top-nav { background:white; border-radius:16px; padding:10px 15px; margin-bottom:25px; overflow-x:auto; box-shadow:0 2px 8px rgba(0,0,0,.05); }
.nav-links { display:flex; gap:8px; min-width:min-content; }
.nav-link { padding:8px 16px; background:#f8f9fa; border-radius:25px; text-decoration:none; color:#666; font-size:13px; font-weight:500; white-space:nowrap; }
.nav-link.active { background: linear-gradient(135deg, #1e5799 0%, #2b8c5e 100%); color:white; }
.chapter-banner { background: linear-gradient(135deg, #1e5799 0%, #2b8c5e 100%); color:white; padding:30px; border-radius:20px; margin-bottom:30px; text-align:center; }
.chapter-banner h1 { font-size:32px; margin-bottom:10px; }
.chapter-number { background:#ffc107; color:#1e5799; padding:5px 15px; border-radius:25px; font-size:14px; font-weight:bold; display:inline-block; margin-bottom:10px; }
.section-box { background:white; padding:25px; margin-bottom:25px; border-radius:16px; box-shadow:0 5px 15px rgba(0,0,0,.08); }
.section-box h2 { font-size:22px; color:#2b8c5e; padding-bottom:12px; border-bottom:3px solid #e8f0fe; margin-bottom:20px; }
.quick-links-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(150px,1fr)); gap:12px; }
.quick-link-card { background:#f8f9fa; padding:12px; border-radius:12px; text-align:center; text-decoration:none; color:inherit; }
.question-card { background:#f8f9fa; border-radius:12px; margin-bottom:14px; overflow:hidden; border:1px solid #e0e0e0; }
.question { background:#e8f0fe; padding:12px 18px; font-weight:bold; color:#1e5799; cursor:pointer; display:flex; justify-content:space-between; align-items:center; }
.answer { padding:0 18px; max-height:0; overflow:hidden; transition:max-height .4s ease; background:white; }
.answer.show { max-height:600px; padding:16px 18px; }
.final { font-weight:bold; color:#2b8c5e; }
.next-chapter { background: linear-gradient(135deg, #1e5799 0%, #2b8c5e 100%); padding:20px 30px; border-radius:16px; display:flex; justify-content:space-between; align-items:center; margin-top:30px; color:white; }
.next-chapter a { background:#ffc107; color:#1e5799; padding:12px 20px; border-radius:40px; text-decoration:none; font-weight:bold; }
.chapter-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(280px,1fr)); gap:10px; margin-top:15px; }
.chapter-link { display:block; padding:12px 16px; background:#f8f9fa; border-radius:12px; text-decoration:none; color:#1e5799; font-size:14px; border-left:3px solid transparent; }
.chapter-link.active { background: linear-gradient(135deg, #e8f5e9 0%, #f1f8e9 100%); border-left-color:#2b8c5e; font-weight:bold; }
.footer-note { text-align:center; color:#666; margin:20px 0 30px; }