/* Sail Academy — design system. Tokens + components shared by every page, the game and the knots module. */
@font-face { font-family: "Source Serif 4"; src: url("../fonts/source-serif-4-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "Source Serif 4"; src: url("../fonts/source-serif-4-latin-400-italic.woff2") format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "Source Serif 4"; src: url("../fonts/source-serif-4-latin-600-normal.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "Source Serif 4"; src: url("../fonts/source-serif-4-latin-600-italic.woff2") format("woff2"); font-weight: 600; font-style: italic; font-display: swap; }
@font-face { font-family: "Source Serif 4"; src: url("../fonts/source-serif-4-latin-700-normal.woff2") format("woff2"); font-weight: 700; font-display: swap; }
@font-face { font-family: "Inter"; src: url("../fonts/inter-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "Inter"; src: url("../fonts/inter-latin-500-normal.woff2") format("woff2"); font-weight: 500; font-display: swap; }
@font-face { font-family: "Inter"; src: url("../fonts/inter-latin-600-normal.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "Inter"; src: url("../fonts/inter-latin-700-normal.woff2") format("woff2"); font-weight: 700; font-display: swap; }
@font-face { font-family: "JetBrains Mono"; src: url("../fonts/jetbrains-mono-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "JetBrains Mono"; src: url("../fonts/jetbrains-mono-latin-600-normal.woff2") format("woff2"); font-weight: 600; font-display: swap; }

:root {
  --paper: #F3EEE2; --paper-2: #EAE3D2; --paper-3: #E1D8C3;
  --ink: #14213D; --ink-2: #3A4660; --ink-3: #6B7488;
  --sea: #2E6F95; --sea-deep: #1F5274; --shallows: #CFE3E8;
  --magenta: #B0307A; --port: #C8442F; --stbd: #2E7D4F;
  --buoy-yellow: #E8B400; --sail: #FFFDF7; --wind: #7FA7B8;
  --rule: rgba(20, 33, 61, .18); --rule-strong: rgba(20, 33, 61, .42);
  --display: "Source Serif 4", Georgia, serif;
  --body: "Inter", system-ui, -apple-system, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
  --col: 42rem; --rail: 13.5rem; --margin: 15rem;
  --r: 4px;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 1.0625rem/1.65 var(--body); }
img, svg, video { max-width: 100%; display: block; }
a { color: var(--sea-deep); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--ink); }
:focus-visible { outline: 2px solid var(--magenta); outline-offset: 2px; }
.mono, .fig { font-family: var(--mono); font-feature-settings: "zero" 1; letter-spacing: -.01em; }
.skip { position: absolute; left: -999px; } .skip:focus { left: 1rem; top: 1rem; background: var(--paper); padding: .5rem; z-index: 10; }

/* ---------- Masthead ---------- */
.mast { display: flex; align-items: center; gap: 1.5rem; padding: .9rem clamp(1rem, 3vw, 2.5rem); border-bottom: 1px solid var(--rule); background: var(--paper); position: sticky; top: 0; z-index: 5; }
.wordmark { display: flex; align-items: center; gap: .6rem; color: var(--ink); text-decoration: none; font: italic 600 1.35rem/1 var(--display); letter-spacing: -.01em; white-space: nowrap; }
.wordmark svg { width: 30px; height: 30px; flex: none; }
.mast nav { margin-left: auto; display: flex; gap: 1.4rem; font: 500 .92rem/1 var(--body); }
.mast nav a { color: var(--ink-2); text-decoration: none; padding: .35rem 0; border-bottom: 2px solid transparent; }
.mast nav a[aria-current="page"], .mast nav a:hover { color: var(--ink); border-bottom-color: var(--magenta); }
@media (max-width: 720px) {
  .mast { flex-wrap: wrap; gap: .5rem 1rem; }
  .mast nav { margin-left: 0; width: 100%; gap: 1.1rem; overflow-x: auto; font-size: .88rem; scrollbar-width: none; }
}

/* ---------- Generic type ---------- */
h1, h2, h3, h4 { font-family: var(--display); font-weight: 600; letter-spacing: -.015em; line-height: 1.12; margin: 0; color: var(--ink); }
h1 { font-size: clamp(2.2rem, 5.2vw, 3.9rem); }
h1 em, h2 em { font-style: italic; color: var(--sea); }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-top: 3.2rem; }
h3 { font-size: 1.32rem; margin-top: 2.2rem; }
p { margin: 1rem 0 0; }
.eyebrow { font: 600 .74rem/1.2 var(--body); letter-spacing: .2em; text-transform: uppercase; color: var(--sea); }
.lede { font: 400 1.25rem/1.55 var(--display); color: var(--ink-2); max-width: 38rem; }
hr { border: 0; border-top: 1px solid var(--rule); margin: 3rem 0; }

/* ---------- Module page: thumb index rail + pilot-book column + margin ---------- */
.book { display: grid; grid-template-columns: var(--rail) minmax(0, var(--col)) var(--margin); gap: 0 clamp(1.5rem, 3vw, 3.5rem); max-width: 84rem; margin: 0 auto; padding: 0 clamp(1rem, 3vw, 2.5rem) 6rem; }
.rail { position: sticky; top: 4.4rem; align-self: start; padding-top: 2.4rem; max-height: calc(100vh - 4.4rem); overflow-y: auto; scrollbar-width: thin; }
.rail h4 { font: 600 .7rem/1 var(--body); letter-spacing: .2em; text-transform: uppercase; color: var(--ink-3); margin: 0 0 .8rem; }
.rail ol { list-style: none; margin: 0; padding: 0; border-left: 1px dashed var(--rule-strong); }
.rail li a { display: grid; grid-template-columns: 2.1rem 1fr; gap: .2rem; padding: .32rem 0 .32rem .7rem; margin-left: -1px; border-left: 3px solid transparent; color: var(--ink-2); text-decoration: none; font-size: .84rem; line-height: 1.3; }
.rail li a .n { font: 600 .78rem/1.3 var(--mono); color: var(--ink-3); }
.rail li a:hover { color: var(--ink); }
.rail li a[aria-current="page"] { border-left-color: var(--magenta); color: var(--ink); font-weight: 600; background: linear-gradient(90deg, rgba(176,48,122,.07), transparent); }
.rail li.soon a { color: var(--ink-3); }
.rail li.soon a::after { content: "soon"; grid-column: 2; font: 500 .66rem/1 var(--body); letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3); }
.page { grid-column: 2; padding-top: 2.6rem; min-width: 0; }
.page > header .eyebrow { display: flex; gap: .8rem; align-items: center; }
.page > header .eyebrow .mono { color: var(--magenta); letter-spacing: .05em; }
.page > header h1 { margin-top: .7rem; }
.page > header .lede { margin-top: 1rem; }
.meta { display: flex; flex-wrap: wrap; gap: .4rem 1.4rem; margin-top: 1.4rem; font: 500 .82rem/1.3 var(--body); color: var(--ink-3); }
.meta b { color: var(--ink-2); font-weight: 600; }
.aside-col { grid-column: 3; padding-top: 2.6rem; }
.sidenote { font-size: .86rem; line-height: 1.5; color: var(--ink-2); border-top: 1px solid var(--rule); padding-top: .7rem; margin-bottom: 1.6rem; }
.sidenote b { display: block; font: 600 .7rem/1.2 var(--body); letter-spacing: .16em; text-transform: uppercase; color: var(--ink-3); margin-bottom: .3rem; }
@media (max-width: 1180px) {
  .book { grid-template-columns: var(--rail) minmax(0, 1fr); }
  .aside-col { grid-column: 2; padding-top: 0; }
}
@media (max-width: 860px) {
  .book { display: block; padding: 0 1rem 5rem; }
  .rail { position: static; max-height: none; padding-top: 1rem; overflow: visible; }
  .rail ol { display: flex; gap: .4rem; overflow-x: auto; border-left: 0; padding-bottom: .5rem; scrollbar-width: none; }
  .rail li a { display: flex; gap: .4rem; white-space: nowrap; border: 1px solid var(--rule); border-radius: 999px; padding: .3rem .7rem; margin: 0; }
  .rail li a[aria-current="page"] { border-color: var(--magenta); background: rgba(176,48,122,.07); }
  .rail li.soon { display: none; }
  .rail h4 { display: none; }
  .page { padding-top: 1.4rem; }
}

/* ---------- Lesson blocks ---------- */
.film { margin: 2rem 0 0; }
.film .frame { position: relative; background: var(--ink); border-radius: var(--r); overflow: hidden; aspect-ratio: 16 / 9; }
.film video { width: 100%; height: 100%; object-fit: contain; background: var(--paper); }
.film figcaption { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .4rem 1rem; margin-top: .6rem; font-size: .84rem; color: var(--ink-3); }
.film figcaption a { font-weight: 500; }
.film.vertical .frame { aspect-ratio: 9 / 16; max-width: 22rem; margin: 0 auto; }
.diagram { margin: 2rem 0 0; padding: 1.2rem; border: 1px solid var(--rule); border-radius: var(--r); background: var(--paper); }
.diagram svg { width: 100%; height: auto; }
.diagram figcaption { margin-top: .7rem; font-size: .85rem; color: var(--ink-3); }
.remember { margin: 2.2rem 0 0; padding: 1.1rem 1.3rem 1.2rem; border-top: 3px solid var(--ink); border-bottom: 1px solid var(--rule); font: 600 1.35rem/1.35 var(--display); }
.remember::before { content: "Remember"; display: block; font: 600 .7rem/1 var(--body); letter-spacing: .2em; text-transform: uppercase; color: var(--magenta); margin-bottom: .55rem; }
.callout { margin: 1.8rem 0 0; padding: 1rem 1.15rem 1.1rem; border-radius: var(--r); font-size: .97rem; }
.callout > b:first-child { display: flex; align-items: center; gap: .5rem; font: 600 .74rem/1 var(--body); letter-spacing: .18em; text-transform: uppercase; margin-bottom: .45rem; }
.callout p:first-of-type { margin-top: 0; }
.callout.cat { background: var(--shallows); border-left: 4px solid var(--sea); }
.callout.cat > b:first-child { color: var(--sea-deep); }
.callout.cat > b:first-child::before { content: ""; width: 28px; height: 18px; flex: none; background: no-repeat center/contain url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 28 18'%3E%3Cpath d='M3 1c3 3 3 13 0 16M25 1c-3 3-3 13 0 16' fill='none' stroke='%231F5274' stroke-width='2.4' stroke-linecap='round'/%3E%3Cpath d='M4 6h20M4 12h20' stroke='%231F5274' stroke-width='1.6'/%3E%3C/svg%3E"); }
.callout.exam { background: var(--paper-2); border-left: 4px solid var(--magenta); }
.callout.exam > b:first-child { color: var(--magenta); }
.callout.safety { background: #F6E3DC; border-left: 4px solid var(--port); }
.callout.safety > b:first-child { color: var(--port); }
dl.terms { display: grid; grid-template-columns: minmax(8rem, 12rem) 1fr; gap: 0; margin: 1.4rem 0 0; border-top: 1px solid var(--rule); }
dl.terms dt, dl.terms dd { margin: 0; padding: .6rem 0; border-bottom: 1px solid var(--rule); }
dl.terms dt { font-weight: 600; padding-right: 1rem; }
@media (max-width: 560px) { dl.terms { grid-template-columns: 1fr; } dl.terms dt { border-bottom: 0; padding-bottom: 0; } }
table.data { width: 100%; border-collapse: collapse; margin-top: 1.4rem; font-size: .93rem; }
table.data th { text-align: left; font: 600 .72rem/1.2 var(--body); letter-spacing: .14em; text-transform: uppercase; color: var(--ink-3); padding: .5rem .6rem .5rem 0; border-bottom: 1.5px solid var(--ink); }
table.data td { padding: .6rem .6rem .6rem 0; border-bottom: 1px solid var(--rule); vertical-align: top; }
.scroll-x { overflow-x: auto; }
.chip { display: inline-block; font: 600 .7rem/1 var(--body); letter-spacing: .1em; text-transform: uppercase; padding: .3rem .5rem; border-radius: 3px; background: var(--paper-2); color: var(--ink-2); }

/* ---------- Quiz ---------- */
.quiz { margin-top: 3.2rem; padding-top: 1.6rem; border-top: 3px double var(--ink); }
.quiz .qhead { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; flex-wrap: wrap; }
.quiz .score { font: 600 .95rem/1 var(--mono); color: var(--ink-2); }
.q { margin-top: 1.6rem; padding: 1.1rem 1.2rem 1.2rem; background: var(--paper-2); border-radius: var(--r); }
.q legend, .q .stem { font-weight: 600; font-size: 1.02rem; line-height: 1.45; padding: 0; }
.q .stem .n { font-family: var(--mono); color: var(--magenta); margin-right: .5rem; }
.q fieldset { border: 0; margin: 0; padding: 0; min-width: 0; }
.q .opts { display: grid; gap: .5rem; margin-top: .9rem; }
.q button.opt { all: unset; box-sizing: border-box; cursor: pointer; display: grid; grid-template-columns: 1.8rem 1fr; gap: .4rem; padding: .65rem .8rem; border: 1px solid var(--rule-strong); border-radius: var(--r); background: var(--paper); font-size: .97rem; line-height: 1.4; }
.q button.opt .k { font: 600 .85rem/1.4 var(--mono); color: var(--ink-3); }
.q button.opt:hover:not([disabled]) { border-color: var(--ink); }
.q button.opt:focus-visible { outline: 2px solid var(--magenta); outline-offset: 1px; }
.q button.opt[disabled] { cursor: default; }
.q button.opt.right { border-color: var(--stbd); background: #E3EFE6; }
.q button.opt.wrong { border-color: var(--port); background: #F6E3DC; }
.q .why { margin-top: .8rem; font-size: .93rem; color: var(--ink-2); display: none; }
.q.answered .why { display: block; }
.q .why b { color: var(--ink); }
.q figure { margin: .9rem 0 0; max-width: 22rem; }
.btn { display: inline-flex; align-items: center; gap: .5rem; font: 600 .95rem/1 var(--body); padding: .8rem 1.15rem; border-radius: var(--r); border: 1.5px solid var(--ink); background: var(--ink); color: var(--paper); text-decoration: none; cursor: pointer; }
.btn:hover { background: var(--sea-deep); border-color: var(--sea-deep); color: var(--paper); }
.btn.ghost { background: transparent; color: var(--ink); }
.btn.ghost:hover { background: var(--ink); color: var(--paper); }

/* ---------- Pager + footer ---------- */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 3.5rem; }
.pager a { display: block; padding: 1rem; border: 1px solid var(--rule-strong); border-radius: var(--r); text-decoration: none; color: var(--ink); }
.pager a span { display: block; font: 600 .7rem/1 var(--body); letter-spacing: .16em; text-transform: uppercase; color: var(--ink-3); margin-bottom: .4rem; }
.pager a.next { text-align: right; grid-column: 2; }
.foot { border-top: 1px solid var(--rule); padding: 2rem clamp(1rem, 3vw, 2.5rem) 3rem; font-size: .84rem; color: var(--ink-3); display: flex; flex-wrap: wrap; gap: .6rem 2rem; justify-content: space-between; }
.foot a { color: var(--ink-2); }

@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; } }
.rail li.exam-stop { margin-top: .5rem; padding-top: .5rem; border-top: 1px dashed var(--rule-strong); }
.rail li.exam-stop a .n { color: var(--magenta); }

/* ---------- Account layer (account.js): mast links, film lock, per-account watermark ---------- */
.mast .acct { display: flex; gap: 1rem; align-items: center; font: 500 .92rem/1 var(--body); }
.mast .acct a { text-decoration: none; color: var(--ink-2); }
.mast .acct .acct-link { color: var(--paper); background: var(--ink); padding: .5rem .8rem; border-radius: var(--r); }
.mast .acct .acct-link:hover { background: var(--magenta); color: #fff; }
@media (max-width: 720px) { .mast .acct { margin-left: auto; } .mast nav { order: 3; } }
.film-locked { position: absolute; inset: 0; display: grid; place-content: center; gap: .9rem; text-align: center; padding: 1.2rem;
  background: rgba(20, 33, 61, .9); color: var(--paper); }
.film-locked p { margin: 0; max-width: 26rem; font-size: .98rem; }
.film-locked .btn { justify-self: center; }
.wm { position: absolute; right: .6rem; bottom: .5rem; pointer-events: none; user-select: none; z-index: 3;
  font: 500 .72rem/1 var(--mono); color: rgba(20, 33, 61, .34); text-shadow: 0 0 2px rgba(255, 253, 247, .7); letter-spacing: .02em; }
.film .frame .wm { bottom: auto; top: .55rem; color: rgba(255, 253, 247, .42); text-shadow: 0 0 2px rgba(20, 33, 61, .6); }
.foot b { font-weight: 600; }