:root{color-scheme:light;--paper:#f6f1e8;--surface:#fffdf7;--ink:#243236;--muted:#586660;--teal:#006f7c;--line:#d7d9cd;--soft:#e8eee6}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:24px}
body{margin:0;background:var(--paper);color:var(--ink);font-family:Montserrat,Arial,sans-serif;font-size:15px;line-height:1.75}
a{color:var(--teal);text-underline-offset:4px}
a:hover{text-decoration-thickness:2px}
a:focus-visible,summary:focus-visible{outline:3px solid var(--teal);outline-offset:5px}
h1,h2,h3,p,figure{margin:0}
h1,h2,h3{line-height:1.2;text-wrap:balance}
h1{font-family:Cinzel,Georgia,serif;font-size:clamp(2.2rem,5vw,4rem);font-weight:600;letter-spacing:-.045em;margin:14px 0 24px;max-width:900px}
h2{font-size:clamp(1.3rem,3vw,1.8rem);letter-spacing:-.035em}
h3{font-size:1.3rem;letter-spacing:-.025em}
p+p{margin-top:12px}
.skip-link{position:absolute;left:16px;top:-100px;padding:10px 16px;background:var(--ink);color:white;z-index:10}
.skip-link:focus{top:12px}
.site-header{background:var(--surface);border-bottom:1px solid var(--line)}
.header-inner{max-width:1160px;margin:auto;min-height:100px;padding:22px 30px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{display:flex;align-items:center;gap:14px;color:var(--ink);text-decoration:none;font-weight:700;font-size:17px;line-height:1.4}
.brand small{display:block;font-size:11px;font-weight:500;color:var(--muted);margin-top:4px}
.brand-mark{display:grid;place-items:center;width:46px;height:46px;background:var(--teal);color:var(--surface);font-size:36px;line-height:1;border-radius:4px}
.site-header nav{display:flex;gap:26px;font-size:12px;font-weight:600}
.site-header nav a{color:var(--ink);text-decoration:none}
.site-header nav a:hover,.site-header nav a[aria-current]{color:var(--teal);text-decoration:underline}
.page{max-width:1160px;margin:auto;padding:30px 30px 80px}
.breadcrumb{display:flex;flex-wrap:wrap;gap:12px;font-size:12px;color:var(--muted)}
.intro{padding:55px 0 36px}
.eyebrow{display:block;color:var(--teal);text-transform:uppercase;letter-spacing:.13em;font-size:11px;font-weight:700}
.lead{max-width:770px;color:var(--muted);font-size:17px;line-height:1.9}
.section-nav{display:flex;flex-wrap:wrap;gap:12px 28px;padding:18px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);font-size:12px;font-weight:600}
.section-nav a{text-decoration:none}
.section-nav a:hover{text-decoration:underline}
.reading-guide{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center;padding:38px 0 44px}
.reading-guide h2{margin:8px 0 15px}
.reading-guide p:not(.eyebrow){font-size:13px;color:var(--muted)}
.legend{display:grid;grid-template-columns:repeat(4,1fr);gap:7px}
.legend>span{text-align:center;font-size:10px;color:var(--muted)}
.legend b{display:block;background:var(--soft);border:1px solid var(--line);color:var(--teal);font-size:32px;padding:8px;border-radius:4px;margin-bottom:8px}
.legend strong{display:block;font-size:13px;color:var(--ink)}
.section-heading{display:flex;justify-content:space-between;align-items:end;gap:24px;margin:24px 0}
.section-heading h2{margin-top:8px}
.section-heading>p,.count{max-width:260px;font-size:12px;color:var(--muted)}
.pattern-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.pattern-card{padding:28px;background:var(--surface);border:1px solid var(--line);border-radius:8px;scroll-margin-top:24px}
.card-heading{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:14px}
.badge{font-size:10px;font-weight:600;background:var(--soft);color:#285546;border-radius:20px;padding:3px 10px}
.pattern-card>p{font-size:13px;color:var(--muted);margin:14px 0 24px;min-height:70px}
.mosaic{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:5px;background:#d3d8c9;border:5px solid #d3d8c9;border-radius:4px;max-width:360px;margin:auto}
.tile{display:flex;position:relative;flex-direction:column;align-items:center;justify-content:center;aspect-ratio:1;background:#f7f1df;color:#12565e;overflow:hidden}
.tile::before{content:"";position:absolute;inset:5px;border:1px solid #c6ccb8;pointer-events:none}
.tile-arrow{font-family:Arial,sans-serif;font-size:clamp(23px,4vw,35px);font-weight:700;line-height:1;display:block;margin-bottom:6px}
.angle-90{background:#e4ece1}.angle-180{background:#e6e4d2}.angle-270{background:#d9e6df}
.angle-90 .tile-arrow{transform:rotate(90deg)}.angle-180 .tile-arrow{transform:rotate(180deg)}.angle-270 .tile-arrow{transform:rotate(270deg)}
.tile-angle{font-size:10px;line-height:1;font-weight:600;z-index:1}
figcaption{text-align:center;color:var(--muted);font-size:10px;margin:12px 0 20px}
details{border-top:1px solid var(--line);font-size:12px}
summary{cursor:pointer;font-weight:600;color:var(--teal);padding:13px 0}
.angle-table{width:100%;border-collapse:collapse;margin:4px 0 10px;font-variant-numeric:tabular-nums}
.angle-table caption{font-size:11px;color:var(--muted);text-align:left;margin:0 0 10px}
.angle-table td{width:25%;padding:7px;text-align:center;border:1px solid var(--line)}
.assignment{margin-top:60px;padding-top:36px;border-top:1px solid var(--line)}
.assignment h2{margin:10px 0 18px}
.assignment>p{max-width:880px;color:var(--muted)}
code{font-family:ui-monospace,Consolas,monospace;font-size:.9em;background:var(--soft);padding:2px 5px;border-radius:3px;overflow-wrap:anywhere;color:#244e45}
.steps{list-style:none;counter-reset:step;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px;padding:0;margin:32px 0}
.steps li{counter-increment:step;border-top:2px solid var(--teal);padding-top:16px;font-size:13px}
.steps li::before{content:"0" counter(step);display:block;color:var(--teal);font-size:12px;font-weight:700;margin-bottom:10px}
.steps strong,.steps span{display:block}.steps span{color:var(--muted);margin-top:8px}
.note{background:var(--soft);border-left:3px solid var(--teal);padding:20px 24px;font-size:13px;margin:30px 0}
.note p{margin-top:6px}
.technical p{max-width:900px;margin-bottom:14px;color:var(--muted)}
.site-footer{display:flex;justify-content:space-between;gap:20px;max-width:1100px;margin:auto;padding:24px 0 32px;border-top:1px solid var(--line);font-size:11px;color:var(--muted)}
.index-page .intro{padding-top:55px;padding-bottom:50px}
.guide-link{display:flex;gap:35px;padding:32px;background:var(--surface);border:1px solid var(--line);border-radius:8px;color:var(--ink);text-decoration:none;align-items:center}
.guide-link:hover{border-color:var(--teal);background:#fbfcf4}
.guide-link+.guide-link{margin-top:24px}
.keyboard-art>span{font-size:24px}
kbd{display:inline-block;font-family:inherit;font-size:.9em;font-weight:600;line-height:1.5;background:var(--surface);color:var(--ink);border:1px solid var(--line);border-bottom-width:3px;border-radius:5px;padding:2px 8px}
.shortcut-list{display:grid;gap:20px;margin:24px 0}
.shortcut-card{padding:24px;background:var(--surface);border:1px solid var(--line);border-radius:8px}
.shortcut-card h3{margin-bottom:14px}
.shortcut-card p{color:var(--muted);font-size:14px}
.guide-art{flex:0 0 156px;display:grid;grid-template-columns:1fr 1fr;gap:4px;padding:4px;background:#cdd5c5;transform:rotate(-3deg)}
.guide-art>span{display:grid;place-items:center;aspect-ratio:1;background:#f4efd9;font-family:Arial,sans-serif;font-size:40px;line-height:1;color:var(--teal)}
.guide-art>span:nth-child(2),.guide-art>span:nth-child(3){background:#dce8da}
.guide-copy{display:block;max-width:650px}.guide-copy h3{margin:10px 0 12px;font-size:24px}
.guide-copy>span:not(.eyebrow){display:block;font-size:14px;color:var(--muted)}
.guide-copy .guide-cta{color:var(--teal)!important;font-weight:600;margin-top:18px}
.index-note{margin-top:42px;padding:32px 0}.index-note h2{font-size:21px}.index-note p{color:var(--muted);margin:12px 0 22px;max-width:600px}
.button{display:inline-block;background:var(--teal);color:white;border-radius:4px;padding:10px 18px;font-size:12px;font-weight:600;text-decoration:none}
.button:hover{background:#005965}
@media(max-width:760px){.header-inner{padding:20px;flex-wrap:wrap;gap:18px}.site-header nav{font-size:11px;gap:24px}.page{padding:24px 20px 50px}.intro,.index-page .intro{padding-top:35px}.lead{font-size:15px}.reading-guide{grid-template-columns:1fr;gap:24px}.legend{max-width:420px;width:100%}.pattern-grid{grid-template-columns:1fr}.section-heading{align-items:start;flex-direction:column;gap:12px}.section-heading>p{max-width:none}.pattern-card{padding:22px}.pattern-card>p{min-height:0}.tile-arrow{font-size:32px}.steps{grid-template-columns:1fr;gap:18px}.assignment{margin-top:40px}.site-footer{margin:0 20px;flex-wrap:wrap}.guide-link{align-items:start;flex-direction:column;padding:24px;gap:26px}.guide-art{flex-basis:auto;width:140px}.guide-copy h3{font-size:21px}.eyebrow{font-size:10px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
@media print{body{background:white}.site-header nav,.section-nav,.site-footer,.skip-link{display:none}.page{padding:0}.intro{padding:24px 0}h1{font-size:32px}.pattern-card{break-inside:avoid}.pattern-grid{gap:16px}.tile{print-color-adjust:exact}.assignment{margin-top:24px}}