:root {
  --ink: #061c1d;
  --canvas: #061b1c;
  --panel: #0b292a;
  --panel-2: #102f30;
  --panel-3: #163838;
  --line: rgba(125, 237, 220, .18);
  --line-soft: rgba(125, 237, 220, .10);
  --text: #f1f8f5;
  --muted: #84a7a4;
  --muted-2: #4e7a77;
  --mint: #6de8d4;
  --mint-2: #a0f7e8;
  --gold: #ffbd45;
  --orange: #f39d42;
  --violet: #b9a5ff;
  --danger: #ff7f7f;
  --radius: 11px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; background: var(--ink); color: var(--text); }
body { min-width: 320px; overflow-x: hidden; }
button, textarea, input { font: inherit; }
button { cursor: pointer; }
button:focus-visible, input:focus-visible, textarea:focus-visible { outline: 2px solid var(--mint); outline-offset: 3px; }

.login-shell { min-height: 100vh; display: grid; grid-template-columns: minmax(320px, 1fr) minmax(400px, 1.03fr); background: radial-gradient(circle at 19% 24%, rgba(79, 214, 197, .09), transparent 30%), var(--ink); position: relative; overflow: hidden; }
.login-shell::before { content: ""; position: absolute; inset: 0; opacity: .16; pointer-events: none; background-image: linear-gradient(rgba(105, 228, 208, .11) 1px, transparent 1px), linear-gradient(90deg, rgba(105, 228, 208, .11) 1px, transparent 1px); background-size: 48px 48px; mask-image: linear-gradient(90deg, #000, transparent 78%); }
.login-card { align-self: center; justify-self: center; width: min(510px, calc(100% - 56px)); padding: 40px 0; position: relative; z-index: 1; }
.brand { display: flex; gap: 14px; align-items: center; letter-spacing: .22em; color: var(--text); }
.brand strong { display: block; font-size: 15px; font-weight: 700; letter-spacing: .3em; }
.brand small { display: block; color: var(--muted); font-size: 8px; letter-spacing: .27em; margin-top: 5px; }
.brand-mark { width: 40px; height: 28px; position: relative; display: inline-flex; flex-direction: column; justify-content: space-between; padding: 2px 0; }
.brand-mark i { display: block; height: 5px; border-radius: 9px; background: var(--mint); box-shadow: 0 0 15px rgba(109, 232, 212, .5); }
.brand-mark i:nth-child(1) { width: 40px; }
.brand-mark i:nth-child(2) { width: 29px; }
.brand-mark i:nth-child(3) { width: 20px; }
.brand-large { margin-bottom: 78px; }
.eyebrow, .nav-label, .view-tab, .composer-note, .preview-head, .model-pill, .unit-code { font-size: 10px; letter-spacing: .24em; text-transform: uppercase; }
.eyebrow { color: var(--mint); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
.login-card h1, .landing-copy h1, .page-heading h1, .result-title-row h1 { font-size: clamp(44px, 5.3vw, 80px); line-height: .96; letter-spacing: -.065em; margin: 26px 0 21px; font-weight: 700; }
h1 em, .landing-copy em, .page-heading em { font-family: Georgia, "Times New Roman", serif; color: var(--gold); font-weight: 400; }
.login-copy { max-width: 455px; color: var(--muted); line-height: 1.7; font-size: 15px; margin-bottom: 33px; }
.login-form { display: grid; gap: 15px; max-width: 390px; }
.login-form label, .composer-form label { color: var(--muted); display: grid; gap: 8px; font-size: 12px; letter-spacing: .05em; }
.login-form input { width: 100%; background: rgba(14, 45, 45, .76); border: 1px solid var(--line); color: var(--text); border-radius: 8px; padding: 15px 16px; }
.login-form input::placeholder, textarea::placeholder { color: var(--muted-2); }
.primary-button, .secondary-button, .small-button, .tiny-button, .ghost-button, .new-problem, .example-chip, .nav-item, .profile-chip, .history-item, .step-item { border: 0; color: inherit; }
.primary-button { background: var(--mint); color: #062121; border-radius: 8px; padding: 14px 19px; font-weight: 700; letter-spacing: .02em; display: inline-flex; align-items: center; justify-content: center; gap: 23px; transition: transform .18s ease, filter .18s ease; }
.primary-button:hover { transform: translateY(-2px); filter: brightness(1.07); }
.primary-button.wide { width: 100%; margin-top: 6px; }
.primary-button.compact { padding: 10px 14px; gap: 9px; font-size: 12px; }
.login-foot { display: flex; align-items: center; gap: 8px; color: var(--muted-2); font-size: 10px; margin-top: 32px; letter-spacing: .04em; }
.lock-note { margin-left: auto; }
.status-dot { display: inline-block; width: 9px; height: 9px; border-radius: 50%; background: var(--mint); box-shadow: 0 0 15px var(--mint); flex: 0 0 auto; }
.login-preview { position: relative; margin: 7vh 4vw 7vh 0; padding: 18px; border: 1px solid var(--line); border-radius: 15px; background: linear-gradient(145deg, rgba(16, 57, 57, .8), rgba(5, 26, 27, .76)); box-shadow: 0 24px 100px rgba(0, 0, 0, .25); align-self: center; }
.login-preview::before { content: ""; position: absolute; inset: 18% -14% -15% 16%; z-index: -1; background: rgba(95, 225, 206, .1); filter: blur(55px); }
.preview-head { display: flex; justify-content: space-between; color: var(--muted); padding: 3px 6px 16px; }
.preview-tag { color: var(--mint); letter-spacing: .12em; }
.mini-drawing { padding: 10px; border-top: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft); background: #061b1c; min-height: 410px; display: grid; align-items: center; }
.mini-drawing .diagram-svg { width: 100%; height: auto; }
.preview-caption { display: grid; gap: 7px; padding: 17px 7px 1px; }
.preview-caption strong { font-size: 16px; }
.preview-caption span { color: var(--muted); font-size: 12px; }
.login-orbit { position: absolute; border: 1px solid rgba(109, 232, 212, .15); border-radius: 50%; pointer-events: none; }
.orbit-one { width: 480px; height: 480px; left: 56%; top: 7%; }
.orbit-two { width: 290px; height: 290px; right: 12%; bottom: 6%; border-color: rgba(255, 189, 69, .15); }

.app-shell { display: grid; grid-template-columns: 380px minmax(0, 1fr); min-height: 100vh; background: var(--ink); }
.sidebar { border-right: 1px solid var(--line); display: flex; flex-direction: column; padding: 47px 33px 24px; background: linear-gradient(180deg, rgba(5, 26, 27, .98), rgba(5, 25, 26, .88)); }
.sidebar .brand { margin-left: 4px; margin-bottom: 68px; }
.new-problem { background: rgba(11, 48, 48, .88); border: 1px solid var(--mint); color: var(--mint); border-radius: 10px; padding: 17px 22px; display: flex; align-items: center; gap: 14px; font-weight: 600; font-size: 16px; text-align: left; }
.new-problem span { font-size: 27px; font-weight: 300; line-height: .5; }
.nav-group { margin-top: 44px; }
.nav-label { color: var(--muted-2); margin: 0 15px 12px; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
.nav-item { width: 100%; display: flex; align-items: center; gap: 13px; text-align: left; padding: 14px 15px; background: transparent; color: var(--muted); border-radius: 10px; font-size: 16px; margin-bottom: 3px; }
.nav-item.active { background: rgba(19, 62, 62, .84); color: var(--text); box-shadow: inset 4px 0 var(--mint); }
.nav-item:hover { color: var(--text); background: rgba(19, 62, 62, .6); }
.nav-icon { color: var(--mint); font-size: 23px; width: 22px; text-align: center; }
.nav-count { margin-left: auto; font-size: 11px; color: var(--muted-2); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
.sidebar-bottom { margin-top: auto; }
.engine-status { display: flex; align-items: center; gap: 14px; border-top: 1px solid var(--line); padding: 31px 14px 23px; }
.engine-status strong, .engine-status small { display: block; }
.engine-status strong { font-size: 13px; color: var(--mint); }
.engine-status small { color: var(--muted-2); margin-top: 5px; font-size: 11px; }
.profile-chip { width: 100%; min-height: 68px; padding: 10px 12px; border-radius: 10px; background: rgba(11, 48, 48, .8); display: grid; grid-template-columns: 38px 1fr; grid-template-rows: 1fr 1fr; gap: 0 10px; text-align: left; color: var(--text); }
.profile-chip > span { grid-row: 1 / span 2; width: 34px; height: 34px; border-radius: 50%; background: var(--gold); color: #18312f; display: grid; place-items: center; font-weight: 700; font-size: 16px; }
.profile-chip b { align-self: end; font-size: 13px; }
.profile-chip em { align-self: start; color: var(--muted); font-size: 10px; font-style: normal; margin-top: 3px; }
.main-column { min-width: 0; }
.topbar { min-height: 108px; padding: 0 5.4%; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line-soft); }
.breadcrumbs { display: flex; gap: 17px; align-items: center; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 11px; letter-spacing: .18em; }
.breadcrumbs span { color: var(--muted-2); }.breadcrumbs b { color: var(--muted-2); font-weight: 400; }.breadcrumbs strong { color: var(--text); font-weight: 500; }
.top-actions { display: flex; align-items: center; gap: 22px; }
.private { color: var(--muted); font-size: 13px; display: flex; align-items: center; gap: 10px; }
.model-pill { border: 1px solid var(--line); border-radius: 5px; padding: 8px 10px; color: var(--mint); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .13em; }
.icon-button { background: transparent; color: var(--muted); font-size: 20px; }
.content { max-width: 1590px; padding: 49px 5.4% 70px; margin: 0 auto; }
.solver-landing { padding: 24px 0; }.landing-copy { max-width: 1060px; margin: 0 auto 42px; }.landing-copy h1 { margin-top: 21px; font-size: clamp(56px, 6vw, 92px); }.landing-copy p { max-width: 920px; color: var(--muted); line-height: 1.75; font-size: 17px; margin: 0; }
.problem-card { border: 1px solid rgba(121, 232, 216, .38); border-radius: 11px; background: linear-gradient(145deg, rgba(15, 54, 54, .94), rgba(8, 34, 35, .8)); padding: 25px 27px 21px; max-width: 1180px; margin: 0 auto; box-shadow: 0 22px 80px rgba(0, 0, 0, .12); }
.composer-head { display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--line); padding-bottom: 22px; }.composer-note { color: var(--muted); letter-spacing: .05em; text-transform: none; }.problem-card textarea { display: block; width: 100%; resize: vertical; min-height: 156px; background: transparent; border: 0; padding: 22px 0 18px; color: var(--text); font-size: 18px; line-height: 1.65; }
.composer-foot { display: flex; align-items: center; gap: 22px; border-top: 1px solid var(--line-soft); padding-top: 17px; }.attach-label { color: var(--muted); font-size: 13px; cursor: pointer; }.attach-label:hover { color: var(--mint); }.parser-note { display: flex; align-items: center; gap: 9px; font-size: 11px; color: var(--muted); flex: 1; }.parser-note .status-dot { width: 7px; height: 7px; box-shadow: none; }
.image-attachment { display: flex; align-items: center; gap: 12px; padding: 10px; margin: 0 0 17px; background: rgba(3, 24, 25, .5); border: 1px solid var(--line-soft); border-radius: 8px; }.image-attachment img { width: 56px; height: 45px; object-fit: cover; border-radius: 4px; }.image-attachment .edge-preview { filter: contrast(1.2); opacity: .86; border: 1px solid rgba(109, 232, 212, .35); }.image-attachment strong, .image-attachment span { display: block; }.image-attachment strong { font-size: 12px; }.image-attachment span { font-size: 10px; color: var(--mint); margin-top: 4px; }.image-attachment button { margin-left: auto; background: transparent; color: var(--muted); font-size: 18px; }
.examples-row { max-width: 1180px; margin: 17px auto 0; display: flex; align-items: center; gap: 9px; flex-wrap: wrap; color: var(--muted-2); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 10px; letter-spacing: .16em; }.example-chip { border: 1px solid var(--line-soft); padding: 9px 13px; background: rgba(11, 44, 44, .76); border-radius: 20px; color: var(--mint); font-size: 12px; letter-spacing: 0; }.example-chip:hover { border-color: var(--mint); }
.showcase-callout { max-width: 1180px; margin: 16px auto 0; display: flex; justify-content: space-between; align-items: center; gap: 22px; padding: 16px 18px; border: 1px solid rgba(255, 189, 69, .34); border-radius: 9px; background: linear-gradient(100deg, rgba(84, 57, 18, .32), rgba(15, 54, 54, .38)); }.showcase-callout > div { display: grid; gap: 5px; }.showcase-callout strong { font-size: 14px; }.showcase-callout small { color: var(--muted); font-size: 11px; }.showcase-callout .secondary-button { flex: 0 0 auto; }
.feature-strip { max-width: 1180px; margin: 58px auto 0; display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }.feature-strip > div { padding: 25px 24px; min-height: 98px; display: grid; grid-template-columns: 30px 1fr; grid-template-rows: 1fr 1fr; border-right: 1px solid var(--line); }.feature-strip > div:last-child { border-right: 0; }.feature-strip span { grid-row: 1 / span 2; color: var(--mint); font-size: 26px; }.feature-strip b { font-size: 14px; }.feature-strip small { color: var(--muted); font-size: 12px; }
.solver-result { max-width: 1470px; margin: 0 auto; }.result-kicker { display: flex; gap: 15px; align-items: center; flex-wrap: wrap; }.engine-badge { color: var(--mint); border: 1px solid var(--line); border-radius: 4px; padding: 7px 10px; font: 10px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .14em; }.gate-badge { display: inline-flex; align-items: center; gap: 8px; border-radius: 4px; padding: 7px 10px; font: 10px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .12em; }.gate-badge .status-dot { width: 7px; height: 7px; box-shadow: none; }.gate-badge.passed { color: var(--mint); border: 1px solid rgba(109, 232, 212, .32); background: rgba(109, 232, 212, .08); }.gate-badge.preview { color: var(--gold); border: 1px solid rgba(255, 189, 69, .32); background: rgba(255, 189, 69, .08); }.result-title-row { display: flex; justify-content: space-between; gap: 40px; align-items: end; margin: 25px 0 36px; }.result-title-row h1 { font-size: clamp(36px, 4vw, 65px); margin: 0 0 12px; }.result-title-row p { color: var(--muted); font-size: 14px; margin: 0; max-width: 950px; line-height: 1.55; }.result-meta { display: flex; flex-wrap: wrap; gap: 9px 18px; margin-top: 17px; color: var(--mint); font: 10px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .12em; }.result-meta span + span { color: var(--muted); }.export-actions { display: flex; align-items: end; gap: 9px; flex: 0 0 auto; }.small-button { min-width: 58px; min-height: 55px; border: 1px solid var(--line); background: rgba(10, 46, 46, .82); color: var(--mint); border-radius: 7px; display: grid; place-items: center; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 18px; }.small-button span { font-size: 9px; letter-spacing: .13em; }.small-button:hover, .tiny-button:hover { border-color: var(--mint); }
.workbench { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(330px, .7fr); border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: var(--canvas); min-height: 620px; }.workbench-main { min-width: 0; }.view-toolbar { display: flex; justify-content: space-between; align-items: center; padding: 0 21px; min-height: 60px; border-bottom: 1px solid var(--line); }.view-tabs { display: flex; gap: 25px; height: 60px; align-items: center; }.view-tab { height: 60px; padding: 0 1px; background: transparent; color: var(--muted); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; position: relative; }.view-tab.active { color: var(--mint); }.view-tab.active::after { content: ""; position: absolute; left: 0; right: 0; bottom: -1px; height: 2px; background: var(--mint); }.view-actions { display: flex; align-items: center; gap: 8px; }.view-actions > span { color: var(--muted-2); font: 9px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .12em; margin-right: 7px; }.tiny-button { background: transparent; color: var(--muted); padding: 7px 11px; border: 1px solid var(--line); border-radius: 5px; font-size: 11px; }
.canvas-stage { min-height: 559px; position: relative; display: grid; place-items: center; padding: 22px; overflow: hidden; }.canvas-stage.no-grid .diagram-svg .grid-line { opacity: 0; }.diagram-svg { width: 100%; height: auto; max-height: 560px; }.diagram-bg { fill: #061b1c; }.grid-line { stroke: rgba(94, 217, 203, .12); stroke-width: 1; }.shape-fill { fill: rgba(52, 147, 139, .38); stroke: none; }.shape-line { fill: none; stroke: #c6f7ee; stroke-width: 2.1; }.hidden-line { fill: none; stroke: var(--muted); stroke-dasharray: 7 6; stroke-width: 1.2; }.center-line { stroke: var(--mint); stroke-dasharray: 11 5 2 5; stroke-width: 1; opacity: .75; }.reference-line { stroke: var(--gold); stroke-width: 1.8; }.projector { stroke: var(--mint); stroke-dasharray: 6 5; stroke-width: 1.2; }.point-mark { fill: var(--gold); stroke: #fff1be; stroke-width: 1.3; }.point-mark.secondary { fill: var(--mint); }.dimension-line line { stroke: var(--gold); stroke-width: 1.2; }.dimension-text { fill: var(--gold); font: 12px ui-monospace, SFMono-Regular, Consolas, monospace; }.arrow-fill { fill: var(--gold); }.svg-label { fill: var(--text); font-size: 13px; }.view-label { fill: var(--mint); font: 11px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .14em; }.micro-label, .axis-text { fill: var(--muted); font: 9px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .12em; }.section-label { fill: var(--orange); font: 10px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .08em; }.section-hatch { stroke: var(--orange); opacity: .55; stroke-width: 1.1; }.solid-canvas { display: block; width: 100%; height: 100%; min-height: 515px; border-radius: 7px; touch-action: none; }.canvas-overlay { position: absolute; top: 23px; left: 25px; color: var(--muted); font: 11px ui-monospace, SFMono-Regular, Consolas, monospace; display: grid; gap: 8px; }.canvas-overlay strong { color: var(--mint); font-size: 13px; font-weight: 500; }.canvas-footer { position: absolute; left: 25px; right: 25px; bottom: 18px; display: flex; justify-content: space-between; color: var(--mint); font: 11px ui-monospace, SFMono-Regular, Consolas, monospace; }.canvas-footer span:last-child { color: var(--muted); }
.conic-guide { fill: none; stroke: rgba(109, 232, 212, .48); stroke-width: 1; stroke-dasharray: 5 5; }.construction-circle { fill: none; stroke: rgba(255, 189, 69, .38); stroke-width: 1; stroke-dasharray: 4 5; }.curve-path { fill: none; stroke: #e9fff8; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }.locus-line, .locus-circle { fill: none; stroke: rgba(185, 165, 255, .72); stroke-width: 1.4; stroke-dasharray: 8 5; }.reference-circle { fill: none; stroke: rgba(255, 189, 69, .58); stroke-width: 1.5; }.tangent-line { fill: none; stroke: var(--gold); stroke-width: 2.1; }.normal-line { fill: none; stroke: var(--orange); stroke-width: 1.6; stroke-dasharray: 8 5; }.tangent-point { fill: var(--gold); stroke: #fff1be; stroke-width: 1.3; }.conic-label { fill: var(--text); font: 10px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .05em; }
.inspector { border-left: 1px solid var(--line); min-width: 0; display: flex; flex-direction: column; }.inspector-tabs { display: flex; border-bottom: 1px solid var(--line); min-height: 60px; }.inspector-tab { flex: 1; background: transparent; color: var(--muted); border: 0; font: 11px ui-monospace, SFMono-Regular, Consolas, monospace; }.inspector-tab.active { color: var(--mint); border-bottom: 2px solid var(--mint); }.step-list { flex: 1; overflow: auto; }.step-item { width: 100%; display: grid; grid-template-columns: 28px 1fr; gap: 8px; text-align: left; padding: 25px 21px; background: transparent; border-bottom: 1px solid var(--line-soft); color: var(--text); }.step-item:hover, .step-item.current { background: rgba(30, 99, 94, .18); }.step-number { color: var(--gold); font: 11px ui-monospace, SFMono-Regular, Consolas, monospace; padding-top: 3px; }.step-item strong, .step-item small { display: block; }.step-item strong { font-size: 16px; margin-bottom: 8px; }.step-item small { color: var(--muted); line-height: 1.55; font-size: 12px; }.step-item:not(.done) { opacity: .45; }.step-item.current { opacity: 1; box-shadow: inset 3px 0 var(--mint); }.spec-footer { display: flex; align-items: center; gap: 9px; padding: 15px 20px; border-top: 1px solid var(--line); color: var(--muted); font-size: 11px; }.spec-footer .status-dot { width: 7px; height: 7px; box-shadow: none; }.spec-footer strong { color: var(--mint); margin-left: auto; font-weight: 500; }.rerun-row { display: flex; align-items: center; gap: 17px; color: var(--muted); font-size: 12px; margin-top: 14px; }.ghost-button { background: transparent; color: var(--mint); padding: 0; }.confidence { margin-left: auto; color: var(--muted-2); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 10px; }
.spec-panel, .check-panel { flex: 1; overflow: auto; padding: 20px; }.spec-title { color: var(--gold); font: 10px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .16em; margin: 7px 0 13px; }.spec-row { display: flex; justify-content: space-between; gap: 15px; padding: 10px 0; border-bottom: 1px solid var(--line-soft); font-size: 12px; }.spec-row span { color: var(--muted); }.spec-row strong { color: var(--mint); font-weight: 500; text-align: right; }.check-row { display: grid; grid-template-columns: 24px 1fr; gap: 9px; padding: 15px 0; border-bottom: 1px solid var(--line-soft); }.check-row > span { color: var(--mint); font-size: 17px; }.check-row strong, .check-row small { display: block; }.check-row strong { font-size: 13px; }.check-row small { color: var(--muted); line-height: 1.5; margin-top: 5px; font-size: 11px; }

.page-view { max-width: 1290px; margin: 0 auto; }.page-heading { display: flex; justify-content: space-between; align-items: end; gap: 30px; }.page-heading h1 { font-size: clamp(50px, 5vw, 76px); margin-bottom: 0; }.page-count { color: var(--muted); font: 11px ui-monospace, SFMono-Regular, Consolas, monospace; margin-bottom: 10px; }.page-intro { max-width: 730px; color: var(--muted); line-height: 1.7; margin: 26px 0 39px; }.unit-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }.unit-card { border: 1px solid var(--line); border-radius: 10px; padding: 24px; background: rgba(10, 41, 41, .62); min-height: 270px; }.unit-card:hover { border-color: rgba(125, 237, 220, .45); }.unit-card.gold { box-shadow: inset 3px 0 var(--gold); }.unit-card.cyan { box-shadow: inset 3px 0 var(--mint); }.unit-card.violet { box-shadow: inset 3px 0 var(--violet); }.unit-card.orange { box-shadow: inset 3px 0 var(--orange); }.unit-card.mint { box-shadow: inset 3px 0 var(--mint-2); }.unit-top { display: flex; justify-content: space-between; color: var(--muted); font: 11px ui-monospace, SFMono-Regular, Consolas, monospace; }.unit-code { color: var(--gold); font-size: 16px; }.unit-card h2 { font-size: 22px; line-height: 1.15; margin: 31px 0 11px; letter-spacing: -.03em; }.unit-card p { color: var(--muted); line-height: 1.55; font-size: 13px; min-height: 42px; }.topic-row { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 16px; }.topic-row span { color: var(--mint); font-size: 10px; padding: 6px 8px; background: rgba(109, 232, 212, .07); border-radius: 4px; }.progress-line { height: 3px; background: rgba(109, 232, 212, .12); margin-top: 23px; }.progress-line span { display: block; height: 100%; background: var(--mint); }.unit-foot { display: flex; justify-content: space-between; align-items: center; margin-top: 12px; color: var(--muted); font-size: 11px; }.unit-foot button { background: transparent; color: var(--mint); font-size: 11px; }.reference-note { display: flex; justify-content: space-between; gap: 30px; margin-top: 42px; padding: 24px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }.reference-note h2 { margin: 11px 0 8px; font-size: 24px; }.reference-note p { max-width: 720px; margin: 0; color: var(--muted); line-height: 1.55; font-size: 13px; }.reference-stats { display: flex; gap: 22px; align-items: center; }.reference-stats span { display: grid; gap: 4px; color: var(--muted); font-size: 11px; }.reference-stats b { color: var(--mint); font-size: 18px; font-weight: 500; }
.assignment-toolbar { display: flex; justify-content: space-between; align-items: center; margin: 49px 0 16px; color: var(--muted); font-size: 12px; }.assignment-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 17px; }.assignment-card { border: 1px solid var(--line); border-radius: 10px; padding: 22px; background: rgba(10, 41, 41, .62); position: relative; }.assignment-card .assignment-number { position: absolute; top: 18px; right: 22px; color: var(--gold); font: 12px ui-monospace, SFMono-Regular, Consolas, monospace; }.assignment-card h2 { max-width: 500px; font-size: 20px; line-height: 1.25; margin: 13px 0 18px; }.assignment-preview { background: var(--canvas); border: 1px solid var(--line-soft); border-radius: 7px; overflow: hidden; margin-bottom: 16px; }.assignment-preview .diagram-svg { display: block; width: 100%; }.secondary-button { border: 1px solid var(--line); color: var(--mint); background: transparent; padding: 11px 14px; border-radius: 6px; font-size: 12px; display: inline-flex; gap: 18px; }.secondary-button:hover { border-color: var(--mint); background: rgba(109, 232, 212, .08); }
.history-list { margin-top: 50px; border-top: 1px solid var(--line); }.history-item { display: grid; grid-template-columns: 44px minmax(0, 1fr) 100px 25px; align-items: center; gap: 14px; width: 100%; padding: 20px 3px; background: transparent; text-align: left; border-bottom: 1px solid var(--line-soft); }.history-item:hover { background: rgba(18, 60, 60, .32); }.history-icon { width: 36px; height: 36px; display: grid; place-items: center; border: 1px solid var(--line); border-radius: 7px; color: var(--mint); font-size: 19px; }.history-item strong, .history-item small { display: block; }.history-item strong { font-size: 15px; }.history-item small { color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; margin-top: 6px; font-size: 12px; }.history-date { color: var(--muted-2); font: 10px ui-monospace, SFMono-Regular, Consolas, monospace; }.history-arrow { color: var(--mint); font-size: 19px; }.empty-state { border: 1px dashed var(--line); border-radius: 10px; margin-top: 48px; padding: 80px 30px; text-align: center; }.empty-state > span { color: var(--mint); font-size: 35px; }.empty-state h2 { margin: 18px 0 8px; }.empty-state p { color: var(--muted); margin-bottom: 23px; }

@media (max-width: 1150px) {
  .app-shell { grid-template-columns: 260px minmax(0, 1fr); }.sidebar { padding-left: 20px; padding-right: 20px; }.sidebar .brand strong { font-size: 12px; }.new-problem { font-size: 14px; }.workbench { grid-template-columns: minmax(0, 1fr) 320px; }.result-title-row { align-items: start; flex-direction: column; }.export-actions { align-self: stretch; }.result-title-row h1 { font-size: 48px; }.login-shell { grid-template-columns: 1fr; }.login-preview { display: none; }.login-card { width: min(570px, calc(100% - 56px)); }.brand-large { margin-bottom: 55px; }
}
@media (max-width: 860px) {
  .topbar { padding: 0 24px; }.content { padding-left: 24px; padding-right: 24px; }.private { display: none; }.workbench { grid-template-columns: 1fr; }.inspector { border-left: 0; border-top: 1px solid var(--line); max-height: 420px; }.unit-grid, .assignment-grid { grid-template-columns: 1fr; }.feature-strip { grid-template-columns: 1fr; }.feature-strip > div { border-right: 0; border-bottom: 1px solid var(--line); }.feature-strip > div:last-child { border-bottom: 0; }.page-heading { align-items: start; flex-direction: column; gap: 10px; }.page-count { margin: 0; }.reference-note { flex-direction: column; }.reference-stats { justify-content: space-between; }
}
@media (max-width: 620px) {
  .app-shell { display: block; }.sidebar { min-height: auto; padding: 20px 16px 12px; border-right: 0; border-bottom: 1px solid var(--line); }.sidebar .brand { margin-bottom: 17px; }.new-problem { padding: 11px 14px; }.nav-group { margin-top: 17px; }.nav-label { display: none; }.nav-item { display: inline-flex; width: auto; margin-right: 4px; padding: 9px 10px; font-size: 12px; }.nav-item .nav-count { display: none; }.sidebar-bottom { display: none; }.topbar { min-height: 68px; padding: 0 16px; }.breadcrumbs { font-size: 9px; gap: 8px; }.model-pill { font-size: 8px; }.content { padding: 32px 16px 48px; }.landing-copy h1 { font-size: 47px; }.landing-copy p { font-size: 14px; }.problem-card { padding: 18px 16px; }.composer-head { align-items: start; gap: 10px; }.composer-note { font-size: 9px; }.problem-card textarea { font-size: 15px; min-height: 180px; }.composer-foot { flex-wrap: wrap; gap: 13px; }.parser-note { order: 3; flex-basis: 100%; }.composer-foot .primary-button { width: 100%; }.examples-row { font-size: 9px; }.example-chip { font-size: 10px; }.showcase-callout { align-items: stretch; flex-direction: column; }.showcase-callout .secondary-button { width: 100%; }.result-title-row h1 { font-size: 37px; }.result-meta { line-height: 1.6; }.export-actions { flex-wrap: wrap; }.export-actions .small-button { flex: 1; min-width: 56px; }.export-actions .primary-button { flex: 1; }.view-toolbar { padding: 0 13px; align-items: start; min-height: 96px; flex-direction: column; }.view-tabs, .view-tab { height: 55px; }.view-actions { width: 100%; justify-content: flex-end; padding-bottom: 10px; flex-wrap: wrap; }.view-actions > span { margin-right: auto; }.canvas-stage { padding: 8px; min-height: 340px; }.canvas-footer { font-size: 9px; bottom: 9px; left: 13px; right: 13px; }.canvas-footer span:last-child { display: none; }.solid-canvas { min-height: 335px; }.inspector-tabs { min-height: 48px; }.inspector-tab { font-size: 9px; }.step-item { padding: 18px 13px; }.step-item strong { font-size: 14px; }.step-item small { font-size: 11px; }.rerun-row { flex-wrap: wrap; }.confidence { margin-left: 0; }.history-item { grid-template-columns: 38px minmax(0, 1fr) 20px; }.history-date { display: none; }.login-card { width: calc(100% - 36px); }.login-card h1 { font-size: 48px; }.login-copy { font-size: 13px; }.login-foot { flex-wrap: wrap; }.lock-note { margin-left: 0; flex-basis: 100%; }.page-heading h1 { font-size: 50px; }.assignment-card h2 { font-size: 18px; }
}
@media print {
  .sidebar, .topbar, .view-toolbar, .inspector, .rerun-row, .export-actions { display: none !important; }.content { padding: 0; }.workbench { display: block; border: 0; }.canvas-stage { min-height: auto; }.diagram-svg { max-height: none; }
}

/* Isometric construction layers. These classes are referenced by the SVG
   geometry kernel; keeping them explicit makes axes and box/offset guides
   visible instead of silently inheriting browser defaults. */
.axis-iso { fill: none; stroke: rgba(109, 232, 212, .62); stroke-width: 1.15; stroke-dasharray: 8 6; opacity: .9; }
.construction-line { fill: none; stroke: rgba(109, 232, 212, .42); stroke-width: 1.05; stroke-dasharray: 6 5; }
.construction-line.secondary { stroke: rgba(109, 232, 212, .22); stroke-dasharray: 4 6; }
.shape-line.secondary { stroke: rgba(198, 247, 238, .52); stroke-width: 1.45; }
.shape-fill.secondary { fill: rgba(40, 116, 111, .22); stroke: none; }
.lettering-main { fill: #e9fff8; font: 700 28px ui-monospace, SFMono-Regular, Consolas, monospace; letter-spacing: .16em; }
.hole-fill { fill: rgba(2, 19, 20, .86); stroke: none; }
.hole-line { fill: none; stroke: #8ef8e5; stroke-width: 1.5; }
.hole-line.hidden-line { stroke: var(--muted); stroke-dasharray: 6 5; stroke-width: 1.1; }