:root{--ink:#172337;--primary:#1b64a5;--primary-dark:#124a7c;--secondary:#187b68;--paper:#fff;--canvas:#f5f7fa;--border:#d7e0e9;--muted:#62738a;--ring:#80b5e9;--shadow:0 12px 30px rgba(25,55,90,.06);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;color:var(--ink);background:var(--canvas);font-synthesis:none}*{box-sizing:border-box}body{margin:0;line-height:1.55}button,input,select{font:inherit}button{cursor:pointer}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--ring);outline-offset:3px}img{max-width:100%;height:auto}button:disabled{opacity:.52;cursor:not-allowed}.container{max-width:1320px;margin:auto;padding:0 28px}.site-header{background:#fff;border-bottom:1px solid var(--border)}.header-inner{min-height:74px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:inline-flex;align-items:center;gap:12px;font-weight:780;letter-spacing:-.035em;font-size:1.13rem;color:var(--ink)}.brand:hover{text-decoration:none}.brand-mark{width:38px;height:38px;background:#eaf3fb;border:1px solid #c8dfef;color:var(--primary);display:grid;place-items:center;border-radius:12px;font-weight:800;font-family:Georgia,serif;font-size:1.35rem}.header-nav{display:flex;align-items:center;gap:20px;flex-wrap:wrap}.header-nav a{color:#4d6178;font-size:.91rem;font-weight:560}.nav-pill{background:#eef5fb;border-radius:999px;padding:8px 13px;color:var(--primary)!important}.hero{padding:44px 0 28px}.eyebrow{font-size:.76rem;letter-spacing:.12em;text-transform:uppercase;color:var(--secondary);font-weight:760;display:inline-block;margin-bottom:12px}.hero h1{font-size:clamp(2rem,4.4vw,3.35rem);line-height:1.13;letter-spacing:-.055em;font-weight:790;max-width:840px;margin:0 0 15px}.hero p{font-size:1.05rem;color:var(--muted);max-width:750px;margin:0}.hero-compact{padding:34px 0 25px}.hero-compact h1{font-size:clamp(1.9rem,3.5vw,2.75rem)}.crumb{font-size:.82rem;color:var(--muted);margin-bottom:11px}.crumb a{color:var(--muted)}.workspace{display:grid;grid-template-columns:minmax(290px,340px) minmax(0,1fr);gap:22px;align-items:start;margin:18px 0 34px}.panel{background:#fff;border:1px solid var(--border);border-radius:18px;box-shadow:var(--shadow)}.settings{padding:25px;position:sticky;top:16px}.mobile-jump{display:none}.panel-title{font-size:1.12rem;font-weight:750;letter-spacing:-.022em;margin:0 0 5px}.panel-sub{font-size:.87rem;color:var(--muted);margin:0 0 22px}.field{display:block;margin:17px 0}.field label{font-size:.85rem;font-weight:700;display:flex;justify-content:space-between;margin-bottom:7px}.field select,.field input{width:100%;border:1px solid #c7d4e1;border-radius:10px;height:44px;padding:0 12px;background:#fff;color:var(--ink)}.field .hint{font-size:.76rem;color:var(--muted);margin:6px 0 0}.field-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.actions{display:flex;flex-direction:column;gap:10px;margin:20px 0 0}.btn{border:1px solid var(--border);background:#fff;border-radius:11px;min-height:46px;display:inline-flex;justify-content:center;align-items:center;gap:9px;padding:10px 16px;font-weight:700;color:var(--ink);transition:transform .16s ease,background .16s ease,border-color .16s ease}.btn:hover:not(:disabled){transform:translateY(-1px);border-color:#adc4da;text-decoration:none}.btn-primary{background:var(--primary);color:#fff;border-color:var(--primary)}.btn-primary:hover:not(:disabled){background:var(--primary-dark)}.btn-soft{background:#eff6fc;color:var(--primary);border-color:#d3e4f2}.btn-secondary{background:#f1f7f5;color:var(--secondary);border-color:#c8e1d9}.download-grid{display:grid;grid-template-columns:1fr 1fr;gap:9px}.controls-foot{font-size:.79rem;color:var(--muted);border-top:1px solid var(--border);padding-top:16px;margin-top:19px}.preview-panel{min-width:0;padding:22px;background:#ebf0f5}.preview-head{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:17px}.preview-head strong{font-size:.98rem}.preview-head small{color:var(--muted)}.preview-tools{display:flex;align-items:center;gap:7px;flex-wrap:wrap}.toggle{border:1px solid #d4dfe9;background:#fff;padding:7px 12px;min-height:36px;font-size:.82rem;border-radius:8px;color:var(--muted)}.toggle[aria-pressed=true]{background:var(--ink);color:#fff}.sheet-outer{max-height:730px;overflow:auto;border-radius:11px;background:#dfe7ef;padding:16px;display:grid;place-items:start center}.print-sheet{background:#fff;color:#172337;width:min(100%,635px);min-height:760px;padding:38px 39px 58px;box-shadow:0 14px 45px #283a5321;border:1px solid #d5dbe1;font-family:Arial,Helvetica,sans-serif}.sheet-top{display:flex;justify-content:space-between;gap:10px;align-items:start;border-bottom:2px solid #1d2c40;padding-bottom:18px}.sheet-top h2{font-size:1.18rem;line-height:1.25;margin:0 0 6px;letter-spacing:-.018em}.sheet-top p{font-size:.72rem;color:#546171;margin:0}.sheet-top .sheet-logo{font-size:.76rem;color:#285b85;font-weight:800}.sheet-name{font-size:.8rem;margin:16px 0 22px;display:flex;justify-content:space-between}.problems-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:15px;row-gap:16px}.problems-grid.with-diagrams{grid-template-columns:1fr}.problem{min-height:90px;border-bottom:1px dashed #e0e6ed;break-inside:avoid;padding:4px 0 12px;overflow-wrap:anywhere}.problem .no{font-size:.78rem;font-weight:800;color:#697789}.problem .q{font-size:.93rem;line-height:1.6;margin-top:6px;font-weight:550;white-space:pre-wrap}.problem .answer-text{font-size:.83rem;color:#284e72;margin-top:9px}.problem .steps{font-size:.74rem;color:#415166;margin:9px 0 0 15px;padding:0}.problem .steps li{margin-bottom:3px}.problem svg:not(.protractor-vector){width:100%;max-height:145px;margin-top:8px}.problem svg.protractor-vector{max-width:100%;height:auto}.sheet-footer{font-size:.68rem;margin-top:28px;display:flex;justify-content:space-between;border-top:1px solid #dde4ec;padding-top:8px;color:#697789}.status{min-height:22px;margin-top:14px;font-size:.83rem;color:var(--secondary)}.status.error{color:#a52d35}.topic-section{margin:32px 0 65px}.section-header{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-bottom:20px}.section-header h2{font-size:1.7rem;letter-spacing:-.035em;line-height:1.15;margin:0}.section-header p{margin:7px 0 0;color:var(--muted)}.topic-group{margin:24px 0 30px}.topic-group h3{font-size:1rem;margin:0 0 13px;color:#38526b}.topic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.topic-card{display:flex;flex-direction:column;gap:7px;border:1px solid var(--border);background:#fff;border-radius:14px;padding:17px 18px;transition:box-shadow .17s ease,transform .17s ease}.topic-card:hover{box-shadow:var(--shadow);text-decoration:none;transform:translateY(-2px)}.topic-card strong{font-size:.95rem;color:var(--ink);line-height:1.3}.topic-card small{color:var(--muted)}.topic-card .topic-link{font-size:.77rem;color:var(--secondary);font-weight:720;margin-top:auto;padding-top:6px}.info-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:35px 0 60px}.info-panel{padding:25px}.info-panel h2{font-size:1.25rem;letter-spacing:-.025em;margin:0 0 13px}.info-panel p,.info-panel li{color:#53657a;font-size:.91rem}.info-panel ol{padding-left:22px}.sample-img{border-radius:12px;border:1px solid var(--border);display:block;margin-top:15px;width:100%;aspect-ratio:16/9;object-fit:cover}.site-footer{background:#fff;border-top:1px solid var(--border);padding:28px 0;color:var(--muted);font-size:.86rem}.footer-inner{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap}.footer-links{display:flex;flex-wrap:wrap;gap:16px}.footer-links a{color:#57708a}.notice{border-left:3px solid #aecde4;padding:10px 14px;background:#eff5fa;color:#52657b;border-radius:0 8px 8px 0;font-size:.86rem}.empty{padding:24px;color:var(--muted);background:#fff;border:1px solid var(--border);border-radius:12px}.link-back{display:inline-flex;gap:6px;margin:17px 0;color:var(--muted);font-size:.86rem}.simple-copy{max-width:800px;background:#fff;border:1px solid var(--border);border-radius:16px;padding:33px;margin:35px 0 60px}.simple-copy p{color:#52657b}.simple-copy h2{font-size:1.16rem;margin-top:25px}.simple-copy a{overflow-wrap:anywhere}@media(max-width:960px){.workspace{grid-template-columns:1fr}.settings{position:static}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.preview-panel{padding:15px}.sheet-outer{max-height:620px}}@media(max-width:630px){.settings{order:2;scroll-margin-top:16px}.preview-panel{order:1}.mobile-jump{display:inline-flex;margin-top:6px;font-size:.78rem;font-weight:750;text-decoration:underline}.container{padding:0 16px}.header-inner{min-height:65px}.header-nav{gap:12px}.header-nav a:nth-child(2){display:none}.hero{padding:30px 0 18px}.hero h1{font-size:2rem}.hero p{font-size:.96rem}.workspace{margin-top:12px;gap:13px}.settings{padding:19px}.panel-sub{margin-bottom:12px}.preview-panel{padding:11px;border-radius:12px}.sheet-outer{padding:5px;max-height:570px}.print-sheet{padding:19px 15px 30px;min-height:550px}.sheet-name{font-size:.68rem}.sheet-top h2{font-size:.91rem}.problem .q{font-size:.76rem}.problems-grid{gap:8px}.problem{min-height:72px}.topic-grid{grid-template-columns:1fr}.topic-section{margin-bottom:35px}.info-grid{grid-template-columns:1fr;margin-top:18px}.info-panel{padding:20px}.section-header h2{font-size:1.4rem}.header-nav .nav-pill{padding:6px 9px}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation-duration:.001ms!important;transition-duration:.001ms!important;scroll-behavior:auto!important}}@page{size:letter;margin:12.7mm}@media print{html,body{background:#fff!important}.site-header,.hero,.settings,.preview-head,.status,.topic-section,.info-grid,.site-footer,.notice,.crumb,.link-back{display:none!important}.container{padding:0!important;max-width:none!important}.workspace,.panel,.preview-panel,.sheet-outer{display:block!important;margin:0!important;padding:0!important;border:0!important;background:#fff!important;box-shadow:none!important;max-height:none!important;overflow:visible!important}.print-sheet{width:100%!important;min-height:auto!important;border:0!important;padding:0!important;box-shadow:none!important}.problem{break-inside:avoid}.sheet-footer{margin-top:15px}.problems-grid.with-diagrams .problem{min-height:155px}}
