:root{--navy:#07192c;--navy2:#0d2946;--navy3:#123a60;--gold:#d4af37;--gold2:#f4c84f;--teal:#27c7c9;--ink:#10243e;--muted:#60748d;--line:#dbe5ef;--soft:#f5f8fc;--white:#fff;--shadow:0 14px 34px rgba(7,25,44,.11)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:#f6f9fd;font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}body.modal-open{overflow:hidden}a{color:inherit}
.site-header{min-height:72px;padding:0 5vw;display:flex;align-items:center;justify-content:space-between;gap:24px;position:sticky;top:0;z-index:1000;background:var(--navy);border-bottom:2px solid var(--gold);box-shadow:0 6px 20px rgba(7,25,44,.16)}
.brand{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;min-width:0}.brand img{width:58px;height:58px;object-fit:contain;border-radius:8px}.brand span{font-family:Georgia,"Times New Roman",serif;font-size:30px;line-height:1;white-space:nowrap}.brand b{color:#dbeaff}.brand strong{color:var(--gold2)}
.site-header nav{display:flex;align-items:center;gap:9px}.site-header nav a{color:#eaf3ff;text-decoration:none;font-weight:700;padding:10px 13px;border-radius:9px}.site-header nav a:hover,.site-header nav a.active{color:var(--gold2);background:rgba(255,255,255,.08)}.nav-toggle{display:none;border:1px solid rgba(255,255,255,.24);color:#fff;background:transparent;border-radius:9px;padding:8px 11px;font-size:22px}
.hero{padding:58px 5vw 46px;background:radial-gradient(circle at 85% 25%,rgba(39,199,201,.18),transparent 25%),radial-gradient(circle at 20% 5%,rgba(212,175,55,.18),transparent 30%),linear-gradient(135deg,#061625,#0c2b49 62%,#0b3651);color:#fff}.hero-copy{max-width:1050px;margin:auto}.eyebrow{display:inline-block;color:var(--gold2);font-size:12px;font-weight:900;letter-spacing:1.5px;margin-bottom:10px}.hero h1{margin:0;font-family:Georgia,"Times New Roman",serif;font-size:clamp(38px,5vw,64px);line-height:1.03}.hero p{max-width:880px;margin:16px 0 0;color:#c8d9ec;line-height:1.72;font-size:17px}.hero-stats{display:flex;flex-wrap:wrap;gap:12px;margin-top:27px}.hero-stats div{min-width:150px;padding:14px 18px;border:1px solid rgba(255,255,255,.16);background:rgba(255,255,255,.065);border-radius:13px;backdrop-filter:blur(7px)}.hero-stats strong{display:block;color:#fff;font-size:25px}.hero-stats span{display:block;color:#a9c3dd;font-size:12px;margin-top:2px;text-transform:uppercase;letter-spacing:.8px}
.library-shell{width:min(1450px,92vw);margin:-20px auto 50px;position:relative;z-index:2}.library-toolbar{display:flex;align-items:center;gap:12px;padding:17px;background:#fff;border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow)}.search-box{min-width:0;flex:1;display:flex;align-items:center;gap:9px;border:1px solid #cddaea;background:#f9fbfe;border-radius:11px;padding:0 14px}.search-box span{color:var(--navy3);font-size:25px}.search-box input{min-width:0;width:100%;height:48px;border:0;outline:0;background:transparent;color:var(--ink);font-size:15px}.filter-reset{border:1px solid #b9cbe0;border-radius:10px;background:var(--navy2);color:#fff;min-height:48px;padding:0 20px;font-weight:800;cursor:pointer}
.course-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px;margin-top:18px}.course-card{text-align:left;border:1px solid var(--line);background:#fff;border-radius:15px;padding:17px;cursor:pointer;transition:.18s ease;min-height:138px;color:var(--ink);box-shadow:0 7px 20px rgba(7,25,44,.055)}.course-card:hover{transform:translateY(-2px);border-color:#9dbde1;box-shadow:var(--shadow)}.course-card.active{color:#fff;border-color:var(--gold);background:linear-gradient(145deg,var(--navy),var(--navy3))}.course-symbol{display:inline-grid;place-items:center;min-width:48px;height:32px;padding:0 9px;border-radius:8px;color:var(--navy);background:#edf4fb;font-size:11px;font-weight:900;letter-spacing:.4px}.course-card.active .course-symbol{background:var(--gold2)}.course-card h3{font-size:17px;margin:12px 0 5px}.course-card p{font-size:12px;line-height:1.45;margin:0;color:var(--muted)}.course-card.active p{color:#bed2e7}.course-count{display:block;margin-top:10px;color:#0a7c6a;font-size:12px;font-weight:800}.course-card.active .course-count{color:#91f1dc}
.result-summary{margin:23px 0 9px}.result-summary p{margin:0;color:var(--muted);font-size:14px}.course-section{margin:22px 0;background:#fff;border:1px solid var(--line);border-radius:17px;box-shadow:0 8px 28px rgba(7,25,44,.055);overflow:hidden}.course-section-head{padding:20px 22px;display:flex;justify-content:space-between;gap:16px;align-items:center;background:linear-gradient(90deg,#f8fbff,#fff);border-bottom:1px solid var(--line)}.course-section-head h2{margin:0;font-family:Georgia,"Times New Roman",serif;font-size:25px;color:var(--navy)}.course-section-head p{margin:5px 0 0;color:var(--muted);font-size:13px}.section-count{flex:none;color:#755b00;background:#fff6d7;border:1px solid #ead687;border-radius:999px;padding:7px 11px;font-size:12px;font-weight:800}
.topic-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;padding:18px}.ppt-card{border:1px solid #dce6ef;border-radius:14px;overflow:hidden;background:#fff;box-shadow:0 8px 22px rgba(7,25,44,.055);display:flex;flex-direction:column;min-width:0;transition:.18s ease}.ppt-card:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:#b9cfe5}.preview-media{position:relative;aspect-ratio:16/9;background:linear-gradient(135deg,#07192c,#123a60);overflow:hidden}.preview-media img{width:100%;height:100%;display:block;object-fit:cover}.preview-media::after{content:"";position:absolute;inset:auto 0 0;height:28%;background:linear-gradient(transparent,rgba(0,0,0,.3));pointer-events:none}.preview-badge{position:absolute;left:10px;top:10px;z-index:2;padding:5px 8px;border-radius:999px;background:rgba(7,25,44,.88);color:#f4c84f;border:1px solid rgba(244,200,79,.45);font-size:9px;font-weight:900;letter-spacing:.6px}.preview-fallback{position:absolute;inset:0;display:grid;place-items:center;padding:22px;color:#fff;text-align:center;font-weight:900}.ppt-card-body{padding:14px 15px 15px;display:flex;flex-direction:column;gap:10px;flex:1}.ppt-card h3{margin:0;font-size:15px;line-height:1.35;color:#10243e}.ppt-meta{display:flex;flex-wrap:wrap;gap:6px}.badge{display:inline-flex;align-items:center;min-height:23px;padding:0 8px;border-radius:999px;background:#f0f4f8;color:#506780;font-size:10px;font-weight:800;letter-spacing:.3px;text-transform:uppercase}.badge.premium{background:#fff4c8;color:#745700}.ppt-file{font-size:10px;color:#8698ab;overflow-wrap:anywhere}.card-actions{display:grid;grid-template-columns:1fr 1.25fr;gap:8px;margin-top:auto}.preview-btn,.secondary-btn{border:1px solid #b8cbe0;border-radius:9px;background:#fff;color:#123a60;min-height:40px;padding:0 12px;font-weight:850;cursor:pointer}.preview-btn:hover,.secondary-btn:hover{background:#f1f6fb}.download-btn{display:inline-flex;align-items:center;justify-content:center;min-height:40px;padding:0 14px;border-radius:9px;color:#07192c;background:linear-gradient(135deg,var(--gold2),#f1b720);border:1px solid #d8a715;text-decoration:none;font-weight:900;font-size:12px;box-shadow:0 5px 12px rgba(212,175,55,.18)}.download-btn:hover{filter:brightness(1.035);transform:translateY(-1px)}
.empty-state{text-align:center;margin:34px 0;padding:48px 20px;background:#fff;border:1px dashed #b8cbe0;border-radius:16px}.empty-icon{width:62px;height:62px;display:grid;place-items:center;margin:auto;border-radius:16px;background:var(--navy);color:var(--gold2);font-weight:900}.empty-state h2{margin:16px 0 5px}.empty-state p{color:var(--muted)}.empty-state button{border:0;border-radius:9px;background:var(--navy2);color:#fff;padding:11px 17px;font-weight:800;cursor:pointer}
.site-footer{display:grid;grid-template-columns:1.3fr auto auto;align-items:center;gap:24px;padding:28px 5vw;color:#cbd9e8;background:#061625;border-top:2px solid var(--gold)}.site-footer strong{color:#fff;font-size:20px}.site-footer p{margin:4px 0 0;font-size:12px}.site-footer nav{display:flex;gap:16px}.site-footer a{color:#d8e7f7;text-decoration:none;font-size:13px;font-weight:700}
.ppt-modal[hidden]{display:none}.ppt-modal{position:fixed;inset:0;z-index:3000;display:grid;place-items:center;padding:18px}.ppt-modal-backdrop{position:absolute;inset:0;background:rgba(4,14,25,.74);backdrop-filter:blur(4px)}.ppt-modal-card{position:relative;z-index:1;width:min(930px,96vw);max-height:92vh;overflow:auto;display:grid;grid-template-columns:minmax(0,1.35fr) minmax(300px,.85fr);background:#fff;border-radius:18px;border:1px solid rgba(212,175,55,.6);box-shadow:0 24px 70px rgba(0,0,0,.35)}.modal-preview{background:#061625;min-height:310px;display:grid;place-items:center}.modal-preview img{width:100%;height:100%;max-height:520px;object-fit:contain;display:block}.modal-copy{padding:30px}.modal-copy h2{margin:0 0 14px;font-family:Georgia,"Times New Roman",serif;color:#07192c;font-size:28px;line-height:1.15}.modal-meta{display:flex;gap:8px;flex-wrap:wrap}.modal-meta span{padding:6px 9px;border-radius:999px;background:#eef4fa;color:#35506e;font-size:11px;font-weight:800}.modal-filename{margin:18px 0;color:#73859a;font-size:11px;overflow-wrap:anywhere}.modal-actions{display:flex;gap:9px;flex-wrap:wrap}.modal-actions .download-btn{min-height:44px}.modal-actions .secondary-btn{min-height:44px}.modal-close{position:absolute;right:12px;top:12px;z-index:4;width:36px;height:36px;border-radius:50%;border:1px solid #d0dce8;background:#fff;color:#07192c;font-size:24px;line-height:1;cursor:pointer;box-shadow:0 4px 14px rgba(0,0,0,.15)}
.toast{position:fixed;left:50%;bottom:22px;z-index:3500;transform:translate(-50%,20px);opacity:0;pointer-events:none;background:#07192c;color:#fff;border:1px solid rgba(212,175,55,.55);border-radius:10px;padding:10px 14px;transition:.2s ease;box-shadow:0 10px 30px rgba(0,0,0,.2)}.toast.show{opacity:1;transform:translate(-50%,0)}
@media(max-width:1100px){.course-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.topic-list{grid-template-columns:repeat(2,minmax(0,1fr))}.site-footer{grid-template-columns:1fr auto}.site-footer>p{grid-column:1/-1}}
@media(max-width:760px){.site-header{min-height:64px;padding:0 14px}.brand img{width:48px;height:48px}.brand span{font-size:24px}.nav-toggle{display:block}.site-header nav{display:none;position:absolute;top:64px;left:0;right:0;padding:11px 14px 15px;background:#07192c;border-bottom:1px solid rgba(255,255,255,.12);flex-direction:column;align-items:stretch}.site-header nav.open{display:flex}.site-header nav a{text-align:center}.hero{padding:38px 18px 42px}.hero p{font-size:15px}.library-shell{width:calc(100% - 22px);margin-top:-18px}.library-toolbar{flex-direction:column;align-items:stretch}.course-grid,.topic-list{grid-template-columns:1fr}.course-card{min-height:auto}.course-section-head{align-items:flex-start}.site-footer{grid-template-columns:1fr;text-align:center}.site-footer nav{justify-content:center;flex-wrap:wrap}.ppt-modal-card{grid-template-columns:1fr}.modal-preview{min-height:auto}.modal-copy{padding:22px}.modal-copy h2{font-size:23px}}