:root{--dir-ink:#0d1622;--dir-ink-2:#132133;--dir-paper:#f8faf7;--dir-card:#ffffff;--dir-muted:#667085;--dir-line:rgba(13, 22, 34, .12);--dir-green:#176b4c;--dir-teal:#0f766e;--dir-gold:#d6a93e;--dir-blue:#315f8c}.dir-wrap{background:var(--dir-paper);color:var(--dir-ink)}.dir-shell{margin:0 auto;max-width:1180px;padding:0 24px}.dir-command{background:linear-gradient(135deg,rgba(7,19,31,.98),rgba(16,37,29,.96) 58%,rgba(24,60,77,.94)),linear-gradient(90deg,var(--dir-green),var(--dir-blue));color:#fff;overflow:hidden;padding:62px 0 38px;position:relative;text-align:center}.dir-command::before{background-image:linear-gradient(rgba(255,255,255,.055) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.045) 1px,transparent 1px);background-size:58px 58px;content:"";inset:0;opacity:.38;pointer-events:none;position:absolute}.dir-command::after{background:linear-gradient(180deg,transparent,#f8faf7);bottom:0;content:"";height:74px;left:0;pointer-events:none;position:absolute;right:0}.dir-command-grid{align-items:stretch;display:grid;gap:18px;grid-template-columns:minmax(0,1.45fr)minmax(320px,.72fr);min-width:0;position:relative;z-index:1}.dir-hero-panel,.dir-command-card{background:rgba(255,255,255,.085);border:1px solid rgba(255,255,255,.15);border-radius:8px;box-shadow:0 22px 62px rgba(0,0,0,.24);min-width:0;padding:26px}.dir-hero-panel{display:grid;gap:18px;justify-items:center}.dir-command h1,.dir-hero-panel h1{color:#fff;font-size:3.2rem;font-weight:900;letter-spacing:0;line-height:1.04;margin:0 auto;max-width:900px}.dir-command-lede{color:#d7e5e2;font-size:1.08rem;line-height:1.72;margin:0 auto;max-width:780px}.dir-stat-row{display:grid;gap:10px;grid-template-columns:repeat(3,minmax(0,1fr));width:100%}.dir-stat{background:rgba(255,255,255,8%);border:1px solid rgba(255,255,255,.14);border-radius:8px;display:grid;gap:4px;min-height:74px;padding:12px}.dir-stat strong{color:#fff;font-size:1.25rem;font-weight:950;line-height:1}.dir-stat span{color:rgba(255,255,255,.74);font-size:.76rem;font-weight:850;letter-spacing:.08em;text-transform:uppercase}.dir-route-chips{display:flex;flex-wrap:wrap;gap:9px;justify-content:center;min-width:0;width:100%}.dir-route-chip{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.16);border-radius:999px;color:#fff;font-size:.84rem;font-weight:900;max-width:100%;overflow-wrap:anywhere;padding:9px 12px;text-decoration:none;transition:background .18s ease,transform .18s ease}.dir-route-chip:hover,.dir-route-chip:focus-visible{background:rgba(255,255,255,.18);color:#fff;transform:translateY(-1px)}.dir-command-card{align-content:center;display:grid;gap:12px;text-align:center}.dir-command-card h2{color:#fff;font-size:1.25rem;font-weight:950;letter-spacing:0;line-height:1.16;margin:0}.dir-command-card p{color:rgba(255,255,255,.72);line-height:1.58;margin:0}.dir-mini-list{display:grid;gap:8px;margin-top:4px}.dir-mini-list a,.dir-mini-list span{background:rgba(7,19,31,.38);border:1px solid rgba(95,216,181,.18);border-radius:8px;color:#eaf8f3;display:block;font-size:.9rem;font-weight:850;padding:10px 12px;text-decoration:none}.dir-mini-list a:hover{background:rgba(95,216,181,.14);color:#fff}.dir-hero{background:linear-gradient(135deg,rgba(13,22,34,.98),rgba(20,41,56,.95)),linear-gradient(90deg,var(--dir-green),var(--dir-blue));color:#fff;padding:70px 0 50px;text-align:center}.dir-kicker{color:#5fd6b5;font-size:.78rem;font-weight:900;letter-spacing:.14em;margin:0 0 12px;text-transform:uppercase}.dir-hero h1{color:#fff;font-size:3.2rem;font-weight:900;letter-spacing:0;line-height:1.05;margin:0 auto 16px;max-width:880px}.dir-hero p{color:#d7e5e2;font-size:1.08rem;line-height:1.7;margin:0 auto;max-width:760px}.dir-meta-row{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-top:24px}.dir-meta-row span,.dir-back-link{background:rgba(255,255,255,9%);border:1px solid rgba(255,255,255,.16);border-radius:999px;color:#fff;font-size:.84rem;font-weight:850;padding:9px 12px;text-decoration:none}.dir-back-link:hover{background:rgba(255,255,255,.16);color:#fff}.dir-content{padding:58px 0 72px}.dir-section{margin:0 auto 48px}.dir-section:last-child{margin-bottom:0}.dir-section-head{margin:0 auto 22px;max-width:820px;text-align:center}.dir-section-head h2{color:var(--dir-ink);font-size:2.2rem;font-weight:950;letter-spacing:0;line-height:1.08;margin:0 0 10px}.dir-section-head p{color:var(--dir-muted);line-height:1.68;margin:0 auto;max-width:760px}.dir-feature-grid{display:grid;gap:14px;grid-template-columns:repeat(3,minmax(0,1fr))}.dir-feature-card{background:linear-gradient(180deg,rgba(255,255,255,.98),rgba(248,250,247,.98));border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 16px 34px rgba(13,22,34,7%);color:var(--dir-ink);display:grid;gap:10px;min-height:172px;padding:22px;text-align:center;text-decoration:none;transition:border-color .2s ease,box-shadow .2s ease,transform .2s ease}.dir-feature-card:hover,.dir-feature-card:focus-visible{border-color:rgba(23,107,76,.28);box-shadow:0 22px 46px rgba(13,22,34,.12);color:var(--dir-ink);transform:translateY(-3px)}.dir-feature-card strong{color:var(--dir-ink);font-size:1.08rem;font-weight:950;line-height:1.18}.dir-feature-card span{color:var(--dir-muted);font-size:.94rem;line-height:1.55}.dir-feature-card em{color:var(--dir-green);font-size:.78rem;font-style:normal;font-weight:950;letter-spacing:.08em;text-transform:uppercase}.dir-index-tools{align-items:center;display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin:0 auto 22px}.dir-index-tools span,.dir-index-tools a{background:#fff;border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 10px 24px rgba(13,22,34,5%);color:var(--dir-ink);font-size:.84rem;font-weight:900;padding:9px 11px;text-decoration:none}.dir-index-tools a:hover{background:var(--dir-ink);color:#fff}.dir-prose{background:#fff;border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 16px 34px rgba(13,22,34,6%);color:var(--dir-muted);line-height:1.75;margin:0 auto 34px;max-width:860px;padding:26px 30px;text-align:center}.dir-prose>*:first-child{margin-top:0}.dir-prose>*:last-child{margin-bottom:0}.dir-prose a{color:var(--dir-green);font-weight:850}.dir-grid{display:grid;gap:18px;grid-template-columns:repeat(3,minmax(0,1fr))}.dir-card{background:var(--dir-card);border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 16px 34px rgba(13,22,34,7%);color:var(--dir-ink);display:grid;overflow:hidden;text-decoration:none;transition:box-shadow .2s ease,transform .2s ease,border-color .2s ease}.dir-card:hover{border-color:rgba(23,107,76,.28);box-shadow:0 22px 46px rgba(13,22,34,.13);color:var(--dir-ink);transform:translateY(-3px)}.dir-card-media{aspect-ratio:16/9;background:radial-gradient(circle at 24% 18%,rgba(214,169,62,.35),transparent 28%),linear-gradient(135deg,var(--dir-ink-2),var(--dir-green));display:block;overflow:hidden;position:relative}.dir-card-media img{display:block;height:100%;object-fit:cover;width:100%}.dir-card-media::after{background:linear-gradient(180deg,transparent 28%,rgba(0,0,0,.62));content:"";inset:0;pointer-events:none;position:absolute}.dir-fallback{align-items:center;color:#fff;display:flex;font-size:1.15rem;font-weight:900;height:100%;justify-content:center;line-height:1.25;padding:22px;text-align:center;width:100%}.dir-card-body{display:grid;gap:10px;padding:20px}.dir-card-body p{max-width:100%}.dir-card-kicker{color:var(--dir-teal);font-size:.72rem;font-weight:900;letter-spacing:.1em;text-transform:uppercase}.dir-card h2,.dir-card h3{color:var(--dir-ink);font-size:1.15rem;font-weight:900;letter-spacing:0;line-height:1.25;margin:0}.dir-card h2 a,.dir-card h3 a{color:inherit;text-decoration:none}.dir-card p{color:var(--dir-muted);font-size:.94rem;line-height:1.58;margin:0}.book-dir-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:4px}.book-dir-actions a{background:#fffaf0;border:1px solid rgba(214,169,62,.42);border-radius:999px;color:var(--dir-ink);font-size:.82rem;font-weight:900;padding:8px 11px;text-decoration:none}.book-dir-actions a:first-child{background:var(--dir-ink);border-color:var(--dir-ink);color:#fff}.book-dir-actions a:hover{transform:translateY(-1px)}.dir-card-link{color:var(--dir-green);font-size:.86rem;font-weight:900;margin-top:4px}.dir-empty{background:#fff;border:1px solid var(--dir-line);border-radius:8px;color:var(--dir-muted);padding:28px;text-align:center}.dir-pagination{margin-top:36px}.dir-pagination .pagination{justify-content:center}.dir-terms-grid{display:grid;gap:14px;grid-template-columns:repeat(4,minmax(0,1fr))}.dir-term-card{background:#fff;border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 14px 28px rgba(13,22,34,6%);color:var(--dir-ink);display:grid;gap:8px;min-height:150px;padding:20px;text-align:center;text-decoration:none;transition:transform .2s ease,box-shadow .2s ease}.dir-term-card:hover{box-shadow:0 20px 38px rgba(13,22,34,.12);color:var(--dir-ink);transform:translateY(-3px)}.dir-term-card strong{font-size:1.05rem;line-height:1.25}.dir-term-card span{color:var(--dir-green);font-size:.82rem;font-weight:900;text-transform:uppercase}.ai-study-layout{background:var(--dir-paper);color:var(--dir-ink);padding:58px 0 72px}.ai-hub-flow{background:linear-gradient(180deg,#f8faf7 0,#eef5f1 45%,#f8faf7 100%);padding:58px 0 76px}.ai-hub-tabs{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin:0 auto 42px;max-width:920px}.ai-hub-tabs a{background:#fff;border:1px solid var(--dir-line);border-radius:999px;box-shadow:0 12px 26px rgba(13,22,34,6%);color:var(--dir-ink);font-size:.86rem;font-weight:900;padding:11px 15px;text-decoration:none}.ai-hub-tabs a:hover{background:var(--dir-ink);color:#fff}.ai-hub-section{margin:0 auto 54px}.ai-hub-section:last-child{margin-bottom:0}.ai-hub-heading{margin:0 auto 24px;max-width:790px;text-align:center}.ai-hub-heading .dir-kicker{color:var(--dir-green)}.ai-hub-heading h2{color:var(--dir-ink);font-size:2.2rem;font-weight:900;letter-spacing:0;line-height:1.08;margin:0 0 12px}.ai-hub-section,.ai-study-layout .dir-shell>*{position:relative}.ai-hub-heading p{color:var(--dir-muted);font-size:1rem;line-height:1.7;margin:0 auto}.ai-hub-teacher-grid{display:grid;gap:18px;grid-template-columns:repeat(3,minmax(0,1fr))}.ai-hub-teacher-card{background:#fff;border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 16px 34px rgba(13,22,34,7%);color:var(--dir-ink);display:grid;overflow:hidden;text-decoration:none;transition:border-color .2s ease,box-shadow .2s ease,transform .2s ease}.ai-hub-teacher-card:hover{border-color:rgba(23,107,76,.28);box-shadow:0 22px 46px rgba(13,22,34,.13);color:var(--dir-ink);transform:translateY(-3px)}.ai-hub-teacher-media{aspect-ratio:16/9;background:radial-gradient(circle at 24% 18%,rgba(214,169,62,.28),transparent 30%),linear-gradient(135deg,var(--dir-ink-2),var(--dir-teal));display:block;overflow:hidden}.ai-hub-teacher-media img{display:block;height:100%;object-fit:cover;width:100%}.ai-hub-teacher-media span{align-items:center;color:#fff;display:flex;font-weight:900;height:100%;justify-content:center;padding:20px;text-align:center}.ai-hub-teacher-body{display:grid;gap:9px;padding:20px}.ai-hub-teacher-body strong{color:var(--dir-ink);display:block;font-size:1.14rem;font-weight:900;line-height:1.2}.ai-hub-teacher-body span:last-child{color:var(--dir-muted);font-size:.94rem;line-height:1.55}.ai-hub-topic-grid,.ai-hub-lesson-grid{display:grid;gap:14px;grid-template-columns:repeat(3,minmax(0,1fr))}.ai-hub-topic-card,.ai-hub-lesson-card{background:#fff;border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 14px 28px rgba(13,22,34,6%);color:var(--dir-ink);display:grid;gap:9px;min-height:170px;padding:22px;text-align:center;text-decoration:none}.ai-hub-topic-card:hover{box-shadow:0 20px 38px rgba(13,22,34,.12);color:var(--dir-ink);transform:translateY(-3px)}.ai-hub-topic-card strong,.ai-hub-lesson-card strong{color:var(--dir-ink);font-size:1.08rem;font-weight:900;line-height:1.2}.ai-hub-topic-card span,.ai-hub-lesson-card p{color:var(--dir-muted);font-size:.94rem;line-height:1.55;margin:0}.ai-study-grid{display:grid;gap:18px;grid-template-columns:repeat(2,minmax(0,1fr));margin:0 auto 34px;max-width:980px}.ai-study-panel{background:linear-gradient(180deg,#fff,#fbfdfb);border:1px solid var(--dir-line);border-top:5px solid var(--dir-green);border-radius:8px;box-shadow:0 16px 34px rgba(13,22,34,7%);padding:24px;text-align:center}.ai-study-panel:nth-child(2n){border-top-color:var(--dir-gold)}.ai-study-panel h2,.ai-study-panel h3{color:var(--dir-ink);font-size:1.24rem;letter-spacing:0;margin:0 0 10px}.ai-study-panel p,.ai-study-panel li{color:var(--dir-muted);line-height:1.65}.ai-study-panel ul{display:inline-grid;gap:8px;list-style-position:inside;margin:0 auto;max-width:620px;padding-left:0;text-align:center}.ai-teacher-strip{display:grid;gap:14px;grid-template-columns:repeat(2,minmax(0,1fr));margin:0 auto;max-width:980px}.ai-teacher-link{align-items:center;background:#fff;border:1px solid var(--dir-line);border-radius:8px;box-shadow:0 14px 28px rgba(13,22,34,6%);color:var(--dir-ink);display:grid;gap:14px;grid-template-columns:86px 1fr;padding:16px;text-decoration:none;text-align:left}.ai-teacher-link:hover{color:var(--dir-ink);transform:translateY(-2px)}.ai-teacher-link img,.ai-teacher-thumb-fallback{aspect-ratio:1;border-radius:8px;object-fit:cover;width:86px}.ai-teacher-thumb-fallback{align-items:center;background:linear-gradient(135deg,var(--dir-green),var(--dir-blue));color:#fff;display:flex;font-weight:900;justify-content:center}.ai-teacher-link strong{display:block;margin-bottom:4px}.ai-teacher-link span{color:var(--dir-muted);font-size:.9rem;line-height:1.45;margin-left:0;margin-right:0}@media(max-width:980px){.dir-grid,.dir-terms-grid,.dir-feature-grid,.ai-hub-teacher-grid,.ai-hub-topic-grid,.ai-hub-lesson-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.dir-command-grid{grid-template-columns:1fr}}@media(max-width:720px){.dir-shell{padding:0 18px}.dir-hero,.dir-command{padding:48px 0 40px}.dir-command h1,.dir-hero-panel h1,.dir-hero h1{font-size:2.25rem}.dir-section-head h2,.ai-hub-heading h2{font-size:1.75rem}.dir-hero-panel,.dir-command-card{padding:20px}.dir-stat-row{grid-template-columns:1fr}.dir-content,.ai-study-layout,.ai-hub-flow{padding:42px 0 56px}.dir-grid,.dir-terms-grid,.dir-feature-grid,.ai-study-grid,.ai-teacher-strip,.ai-hub-teacher-grid,.ai-hub-topic-grid,.ai-hub-lesson-grid{grid-template-columns:1fr}.dir-prose{padding:22px}.ai-teacher-link{grid-template-columns:68px 1fr}.ai-teacher-link img,.ai-teacher-thumb-fallback{width:68px}}