*{box-sizing:border-box} [hidden]{display:none!important}
:root{--paper:#f4f5ef;--ink:#182b24;--muted:#4f625a;--green:#14533c;--deep:#112b22;--line:#d5dfd5;--white:#fff;--lime:#d1ec9c}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.6 "Instrument Sans","Segoe UI",sans-serif}
.shell{width:min(1200px,calc(100% - 64px));margin-inline:auto}
.top{background:var(--white);border-bottom:1px solid var(--line)}.masthead{min-height:76px;display:flex;align-items:center;justify-content:space-between;gap:24px}
a{color:var(--green);text-underline-offset:4px}a:hover{text-decoration-thickness:2px}
.brand{display:flex;gap:13px;align-items:center;font-weight:750;text-decoration:none;line-height:1.25;color:var(--ink)}
small{display:block;font-size:.79rem;color:var(--muted)}.chip{display:grid;place-items:center;width:38px;height:38px;background:var(--deep);color:var(--lime);border-radius:8px;font-size:24px}
nav{display:flex;gap:23px}nav a,.login-link{text-decoration:none;font-weight:600;font-size:.91rem}.login-link{border:1px solid var(--line);padding:7px 14px;border-radius:6px}
.hero{margin:34px 0 0;display:grid;grid-template-columns:1.04fr 1fr;gap:28px;padding:48px;background:var(--deep);color:#f4faef;border-radius:15px;align-items:center}
.hero p:not(.kicker){color:#d6e4db;max-width:470px;font-size:1.06rem}
.kicker{color:var(--green);font-weight:750;letter-spacing:.13em;font-size:.71rem;margin:0 0 10px}.hero .kicker{color:var(--lime)}
h1,h2,h3{line-height:1.14;margin:0;font-weight:750;letter-spacing:-.03em}h1{font-size:clamp(2.5rem,5vw,4.65rem)}h2{font-size:clamp(1.9rem,3.5vw,2.8rem)}h3{font-size:1.24rem;margin-bottom:12px}
.actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:18px}
button,.button,.secondary{appearance:none;border:1px solid transparent;border-radius:6px;padding:10px 14px;font:inherit;font-weight:650;font-size:.9rem;text-decoration:none;cursor:pointer;display:inline-block;background:var(--green);color:white}
.hero .button{background:var(--lime);color:var(--deep)}.hero .secondary{background:transparent;border-color:#709082;color:white}
button:hover,.button:hover,.secondary:hover{filter:brightness(.92)}button:disabled{opacity:.45;cursor:default}.muted{background:#ebf2eb;border-color:var(--line);color:var(--green)}
.hero-art{margin:0;border:1px solid #416157;border-radius:10px;padding:14px;background:#15352a}.hero-art img,.circuit{display:block;width:100%;border-radius:7px}.hero-art figcaption{font-size:.8rem;color:#d6e4db;padding:10px 2px 0}
main section:not(.hero){margin:50px 0;scroll-margin-top:20px}.section-head{display:flex;justify-content:space-between;align-items:end;gap:15px;margin-bottom:18px}.section-head a{font-size:.92rem;font-weight:650}
.grid{display:grid;gap:16px}.two{grid-template-columns:repeat(2,minmax(0,1fr))}.sim-grid{grid-template-columns:1fr 1.15fr}.panel,details{background:var(--white);border:1px solid var(--line);border-radius:10px;padding:22px;min-width:0}.panel p{margin:8px 0 14px}.meta{font-size:.82rem;font-weight:650;color:var(--green);margin:0 0 8px!important}
details{margin:12px 0}summary{cursor:pointer;font-weight:700}details[open] summary{margin-bottom:16px}ol{padding-left:22px}li{margin-bottom:7px}
label{display:block;font-weight:650}input:not([type=checkbox],[type=range]){width:100%;display:block;margin:6px 0 12px;border:1px solid #a8beb1;border-radius:5px;padding:8px;color:var(--ink);background:white;font:inherit}
input[type=range]{width:100%;accent-color:var(--green)}input[type=checkbox]{accent-color:var(--green);width:18px;height:18px}.check{display:flex;align-items:center;gap:7px;margin-top:16px}.range-label,.controls>label:first-child{display:flex;justify-content:space-between}.range-label{color:var(--muted);font-size:.8rem}.controls h3{margin-top:22px}.telemetry{background:var(--deep);color:white}.telemetry small{color:#bfd2c7}.statusline{display:flex;gap:12px;align-items:center;margin-bottom:16px}.lamp{width:17px;height:17px;border:2px solid #83a396;border-radius:50%}.lamp.on{background:var(--lime);border-color:var(--lime)}.lamp.fault{border-color:#ffd0ad;background:#ad492b}.telemetry button:not(.muted){background:var(--lime);color:var(--ink)}
pre{white-space:pre;overflow:auto;background:#0d201a;color:#e7f8ee;border-radius:6px;padding:12px;font:14px/1.5 Consolas,monospace;margin:0;min-height:100px;max-height:310px}#journal{height:170px}
.fields{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}.result{display:block;margin-top:10px;font-weight:600}.feedback:empty{display:none}.pdf-reader{margin:14px 0}.reader-toolbar{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-bottom:12px}.reader-toolbar strong{margin-right:auto}#pdf-page{width:min(100%,780px);display:block;margin:auto;border:1px solid var(--line)}
#lecture-list{margin-top:12px}#reader>h3,#tools>h3{margin-top:22px}#login{display:flex;gap:12px;align-items:center;flex-wrap:wrap}#login input{margin-bottom:0}.table-scroll{overflow:auto}table{width:100%;border-collapse:collapse}th,td{padding:7px 10px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}footer{padding:25px 0;border-top:1px solid var(--line);color:var(--muted);font-size:.86rem}
:focus-visible{outline:3px solid #b26b20;outline-offset:4px}
@media(max-width:850px){.hero{padding:30px}.masthead{flex-wrap:wrap;padding:12px 0;gap:12px}.masthead nav{order:3;width:100%;gap:18px;flex-wrap:wrap}.sim-grid{grid-template-columns:1fr}}
@media(max-width:620px){.shell{width:calc(100% - 28px)}.hero,.two{grid-template-columns:1fr}.hero{gap:18px;padding:23px;margin-top:18px}.section-head{align-items:start;flex-direction:column;gap:8px}.panel,details{padding:15px}main section:not(.hero){margin:35px 0}.masthead nav{gap:13px}.brand small{font-size:.67rem}}


:root{--paper:#f1f4f7;--ink:#13243a;--muted:#435870;--green:#165380;--deep:#10273d;--line:#cfdae4;--white:#fff;--lime:#d5eef1}
body{font-family:"Segoe UI",sans-serif}
.shell{width:min(1240px,calc(100% - 72px))}
.top{position:sticky;top:0;z-index:3;box-shadow:0 3px 16px #10273d12}
.masthead{min-height:72px}
.masthead a[aria-current=page]:not(.brand){color:#0d6087;text-decoration:underline;text-underline-offset:.45em}
.skip{position:fixed;top:8px;left:8px;transform:translateY(-200%);z-index:5;background:white;padding:8px}
.skip:focus{transform:none}
:focus-visible{outline:3px solid #16749c;outline-offset:4px}
.hero{margin:0;min-height:380px;padding:46px 54px;background:linear-gradient(125deg,#112a45,#143d54);gap:44px}
.hero h1{font-size:clamp(3.2rem,7.4vw,6.2rem);letter-spacing:-.055em}
.hero p:not(.kicker){color:#e0ecf3}
.hero .kicker{font-size:.86rem;letter-spacing:.07em;text-transform:uppercase}
.hero .hero-art{background:#1b3c51;border-color:#557386;transform:rotate(-1deg);padding:12px}
.hero .hero-art figcaption{color:#edf5fb}
.hero .secondary{border-color:#acc4ce}
main{min-height:70vh}
main section.view{margin:38px 0 72px;scroll-margin-top:102px}
section.view>.section-head h1{font-size:clamp(2.2rem,5vw,4rem)}
.overview-title{margin-top:37px}
.overview-title h2{font-size:clamp(1.55rem,3vw,2.3rem)}
.overview-grid{grid-template-columns:repeat(4,minmax(0,1fr))}
.route-card{display:block;background:white;border:1px solid var(--line);border-radius:10px;padding:20px 22px;position:relative;text-decoration:none;color:var(--ink);box-shadow:0 2px 4px #10273d07}
.route-card:hover{border-color:#6892aa}
.route-card small{margin-bottom:8px}
.route-card p{margin:0;color:var(--muted);line-height:1.45;font-size:.92rem}
.route-card span{position:absolute;right:12px;top:10px;color:var(--green)}
.lede{max-width:77ch;color:var(--muted);font-size:1.05rem}
.reading-list{max-width:1000px}
.reading-item,.book-card,.panel{box-shadow:0 3px 8px #10273d07}
.reading-item{scroll-margin-top:102px;padding:17px 22px}
.reading-item summary{display:flex;gap:14px;align-items:baseline}
.reading-item summary::before{content:"+";color:var(--green)}
.reading-item[open]>summary::before{content:"−"}
.reading-item .ordinal{font-size:.82rem;min-width:3.25rem;color:var(--green);font-variant-numeric:tabular-nums}
.reading-content{max-width:78ch;padding:6px 0 12px 25px}
.reading-content h4{font-size:1.1rem;margin:1.5em 0 .4em}
.reading-content p{margin:.55em 0 1em}
.reading-content li{margin:.45em 0}
.panel h2{font-size:clamp(1.25rem,2vw,1.65rem);margin-bottom:12px}
.account-entry{margin-bottom:18px}
.metrics{grid-template-columns:repeat(3,minmax(0,1fr));margin:18px 0}
.metric{display:grid;background:#e1edf6;border-radius:8px;padding:16px 20px}
.metric strong{font-size:1.85rem;font-variant-numeric:tabular-nums}
.metric span,.hint{color:var(--muted)}
.record{border-top:1px solid var(--line);padding:12px 0}
.record h4,.record h5{margin:4px 0}
.preserve-lines{white-space:pre-wrap;overflow-wrap:anywhere}
.study-controls{margin-top:12px}
.study-controls .actions{margin-top:0}
.note-box{padding:10px 12px}
textarea,select{font:inherit;color:var(--ink);background:#fff;border:1px solid #8ca6b8;border-radius:6px;width:100%;padding:8px;display:block;margin:6px 0 13px}
textarea{resize:vertical}
input[type=file]{width:100%}
.book-card{display:grid;grid-template-columns:minmax(64px,120px) 1fr;gap:18px;align-items:center}
.book-card img{width:100%;border:1px solid var(--line);box-shadow:3px 4px 9px #10273d2c}
.pdf-reader{scroll-margin-top:92px;padding:16px;background:#dce5ed;border:1px solid var(--line);border-radius:12px}
.book-spread{position:relative;display:flex;justify-content:center;max-width:1120px;margin:auto;perspective:1400px;filter:drop-shadow(0 6px 12px #10273d35)}
.book-spread img,#pdf-page{display:block;margin:0;width:min(50%,560px);height:auto;object-fit:contain;border:1px solid #b9c5d0;background:white}
.book-spread img:first-child{border-radius:4px 1px 1px 4px}
.book-spread img:nth-child(2){border-radius:1px 4px 4px 1px;transform-origin:left center;animation:page-turn .32s ease-out}
.book-spread:has(#pdf-facing[hidden]) #pdf-page{width:min(100%,650px);border-radius:3px}
.book-spread:has(#pdf-facing:not([hidden]))::after{content:"";position:absolute;top:0;bottom:0;left:calc(50% - 8px);width:16px;pointer-events:none;background:linear-gradient(90deg,transparent,#16263b2a,transparent)}
@keyframes page-turn{from{transform:rotateY(-17deg);opacity:.64}to{transform:rotateY(0);opacity:1}}
@media(prefers-reduced-motion:reduce){.book-spread img:nth-child(2){animation:none}}
#book-actions{display:flex;gap:8px;justify-content:center;margin-bottom:10px;flex-wrap:wrap}
#projects article{scroll-margin-top:102px}
@media(max-width:940px){.overview-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.hero{padding:30px;gap:24px}.masthead{flex-wrap:wrap}}
@media(max-width:700px){.shell{width:calc(100% - 30px)}.masthead{padding:8px 0;gap:7px}.masthead nav{order:3;width:100%;justify-content:space-between;gap:5px;overflow:auto}.masthead nav a{font-size:.82rem;white-space:nowrap;padding:6px 0}.login-link{font-size:.83rem}.hero{grid-template-columns:1fr;padding:22px}.hero h1{font-size:3.45rem}.hero .hero-art{transform:none}.overview-grid{gap:10px}.route-card{padding:12px}.route-card h3{font-size:1.08rem}.route-card p{font-size:.82rem}.reading-content{padding-left:0}.reading-item{padding:12px}.reading-item summary{gap:8px}.metrics{gap:7px}.metric{padding:9px}.metric strong{font-size:1.3rem}.metric span{font-size:.78rem}.pdf-reader{padding:8px}.panel{padding:16px}.book-card{grid-template-columns:minmax(55px,88px) 1fr}}

.assignments-panel{margin-bottom:18px}.assignments-panel fieldset{border:1px solid var(--line);border-radius:6px;margin:12px 0;padding:0 12px 12px}.assignments-panel .check{margin-top:8px}

.auth-page{min-height:100svh;display:grid;align-items:center;background:#10273d}
.auth-layout{width:min(980px,calc(100% - 40px));min-height:0;margin:42px auto;display:grid;grid-template-columns:1fr minmax(320px,.82fr);gap:54px;align-items:center}
.auth-identity{color:#f2f8fc}
.auth-identity .chip{color:#132b42;background:#d5eef1;margin-bottom:24px}
.auth-identity h1{font-size:clamp(2.65rem,7vw,5.6rem);line-height:1.03}
.auth-identity p{color:#d5e5ee}
.auth-card{padding:32px;background:#fff;border-radius:12px;border:1px solid #cfdae4}
.auth-card h2{font-size:1.9rem;margin-bottom:25px}
.auth-card button[type=submit]{width:100%;margin-top:8px}
@media(max-width:730px){.auth-layout{grid-template-columns:1fr;gap:22px;margin:28px auto}.auth-identity .chip{margin-bottom:12px}.auth-card{padding:20px}}

.lecture-equation{font:1.15rem Cambria,serif;text-align:center;background:#e7eff5;border-radius:5px;padding:12px;overflow-wrap:anywhere}.lecture-fraction{display:inline-grid;grid-template-rows:auto auto;vertical-align:middle;line-height:1.25;text-align:center;margin-inline:.14em}.lecture-fraction span{padding-inline:.2em}.lecture-fraction span:first-child{border-bottom:1px solid currentColor}.lecture-figure{margin:18px 0 25px}.lecture-figure img{display:block;width:100%;height:auto;border:1px solid #cfdae4}.lecture-figure figcaption{font-size:.88rem;color:var(--muted);margin-top:6px}.reading-content h5{font-size:1rem;margin:1.25em 0 .4em}

.study-heading{font-size:1.55rem;margin:32px 0 14px}

.reader-jump{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:14px;align-items:end;margin:10px 0 15px}.reader-jump form{display:flex;gap:8px;align-items:end}.reader-jump input:not([type=checkbox],[type=range]),.reader-jump select{margin:4px 0 0}.reader-jump input{max-width:7ch}.reader-jump label{min-width:0}.reader-jump button{white-space:nowrap}@media(max-width:690px){.reader-jump{grid-template-columns:1fr}.reader-jump form{justify-content:start}}


.tool-toolbar{display:flex;align-items:end;justify-content:space-between;gap:16px;margin:20px 0 6px}
.tool-toolbar label{width:min(100%,480px)}
.tool-toolbar input[type=search]{margin-bottom:0}
.tool-toolbar>a{margin-bottom:8px;font-weight:650}
.tool-group{margin-top:28px}
.tool-group h2{font-size:1.35rem;margin-bottom:12px}
.tool-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));align-items:start;gap:12px}
.tool-grid details{margin:0;padding:0;scroll-margin-top:140px}
.tool-card summary{position:relative;display:grid;gap:4px;padding:16px 44px 16px 18px;list-style:none}
.tool-card summary::-webkit-details-marker{display:none}
.tool-card summary::after{content:"+";position:absolute;right:17px;top:15px;color:var(--green);font-size:1.2rem}
.tool-card[open] summary{margin:0;border-bottom:1px solid var(--line)}
.tool-card[open] summary::after{content:"−"}
.tool-card summary strong{font-size:1.05rem}
.tool-card summary span,.tool-method,.tool-references{color:var(--muted);font-size:.86rem;font-weight:400}
.tool-card form,.tool-method,.tool-references{margin:12px 18px}
.tool-card form label{line-height:1.3;font-size:.89rem;min-width:0}
.tool-fields{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:12px}
.tool-fields input:not([type=checkbox]),.tool-fields select{margin-top:5px;margin-bottom:9px}
.tool-fields select{width:100%;min-width:0}
.tool-method{border-top:1px solid var(--line);padding-top:12px}
.tool-references{display:flex;gap:12px;flex-wrap:wrap}
.tool-result p{padding:8px 10px;border-radius:4px;margin:10px 0 0}
.tool-result .tool-pass{color:#144b3a;background:#e8f4ed}
.tool-result .tool-check{color:#7a390e;background:#fcf0e3}
.tool-result dl{margin:10px 0 0;font-size:.89rem}
.tool-result dl>div{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:10px;border-top:1px solid var(--line);padding:6px 0}
.tool-result dd{margin:0;font-weight:650;overflow-wrap:anywhere}
#boards{scroll-margin-top:140px}
@media(max-width:780px){.tool-grid{grid-template-columns:1fr}}
@media(max-width:520px){.tool-toolbar{align-items:start;flex-direction:column;gap:6px}}


.board-filters { display:grid; grid-template-columns:minmax(0,2fr) minmax(0,1fr); gap:1rem; margin-top:1.2rem; }
.board-filters label { margin:0; }
.board-count { min-height:1.5em; color:var(--muted); }
.board-catalog { display:grid; grid-template-columns:repeat(auto-fit,minmax(min(100%,315px),1fr)); gap:1rem; }
.board-card { display:flex; flex-direction:column; min-width:0; overflow-wrap:anywhere; }
.board-card[hidden] { display:none; }
.board-card h3 { margin:.55rem 0 .15rem; }
.board-chip { margin:0 0 .8rem; color:var(--muted); font-size:.88rem; }
.board-photo { aspect-ratio: 16/9; margin:0; border:1px solid var(--line); border-radius:.65rem; background:white; }
.board-photo img { width:100%; height:100%; object-fit:contain; padding:.85rem; display:block; }
.board-facts { display:grid; grid-template-columns:1fr 1fr; gap:.35rem .75rem; margin:.2rem 0 .75rem; padding-left:1.1rem; font-size:.9rem; }
.board-card details { margin:.4rem 0 .65rem; }
.board-card details p:last-child { margin-bottom:0; }
.board-links { display:flex; flex-wrap:wrap; gap:.35rem .75rem; align-items:center; margin-top:auto; font-size:.91rem; }
.board-credit { margin:.65rem 0 0; color:var(--muted); font-size:.77rem; }
.board-photo-link { height:100%; display:grid; place-content:center; padding:1rem; text-align:center; }
@media(max-width:560px) { .board-filters { grid-template-columns:1fr; } }