@layer reset, base, layout, components, utilities;

@layer reset {
  *, *::before, *::after { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body, h1, h2, h3, h4, p, ul, ol, fieldset { margin: 0; }
  img, iframe { display: block; max-width: 100%; }
  button, textarea, input { font: inherit; }
}

@layer base {
  :root {
    --ink: #17211b;
    --ink-soft: #465048;
    --paper: #f3efe4;
    --paper-deep: #e8e1d1;
    --white: #fffdf7;
    --signal: #e5522f;
    --signal-dark: #a82e19;
    --acid: #cbd94c;
    --rule: #b9b2a3;
    --correct: #24704a;
    --wrong: #a53022;
    --display: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Palatino, Georgia, serif;
    --body: "Avenir Next", Avenir, "Segoe UI", Helvetica, sans-serif;
    --shadow: 0 18px 50px rgb(23 33 27 / 10%);
  }

  body {
    min-width: 300px;
    color: var(--ink);
    background:
      linear-gradient(90deg, rgb(23 33 27 / 3%) 1px, transparent 1px) 0 0 / 28px 28px,
      var(--paper);
    font-family: var(--body);
    font-size: 16px;
    line-height: 1.6;
  }

  body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    opacity: .25;
    z-index: 20;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 140 140' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.08'/%3E%3C/svg%3E");
  }

  a { color: inherit; }
  button { color: inherit; }
  :focus-visible { outline: 3px solid var(--signal); outline-offset: 4px; }
  ::selection { color: var(--ink); background: var(--acid); }
}

@layer layout {
  .masthead {
    position: sticky;
    top: 0;
    z-index: 10;
    min-height: 78px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    padding: 12px clamp(20px, 4vw, 64px);
    color: var(--paper);
    background: var(--ink);
    border-bottom: 4px solid var(--signal);
  }

  .site-shell {
    width: min(1560px, 100%);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 310px minmax(0, 1fr);
  }

  .course-rail {
    position: sticky;
    top: 82px;
    align-self: start;
    height: calc(100vh - 82px);
    overflow: auto;
    padding: 34px 24px 28px clamp(20px, 4vw, 54px);
    border-right: 1px solid var(--rule);
  }

  main { min-width: 0; }
  main:focus { outline: none; }
  #app { min-height: calc(100vh - 82px); }
  .page { padding: clamp(34px, 6vw, 88px) clamp(24px, 7vw, 110px) 100px; }
  .lesson-page { max-width: 1120px; }
  .reading-grid { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(260px, .6fr); gap: clamp(30px, 5vw, 72px); }
  .lesson-body { min-width: 0; }
  .lesson-margin { min-width: 0; }
  .site-footer {
    display: flex;
    justify-content: space-between;
    gap: 24px;
    padding: 30px clamp(20px, 4vw, 64px);
    color: var(--paper-deep);
    background: var(--ink);
    border-top: 1px solid #39423c;
    font-size: .78rem;
  }

  @media (max-width: 900px) {
    .site-shell { display: block; }
    .course-rail {
      position: static;
      height: auto;
      padding: 14px 20px;
      overflow-x: auto;
      overscroll-behavior-x: contain;
      scrollbar-color: var(--signal) var(--paper-deep);
      border-right: 0;
      border-bottom: 1px solid var(--rule);
    }
    .rail-heading, .rail-tools { display: none; }
    .course-nav-list { display: flex; width: max-content; }
    .course-nav-list::after { content: "Swipe through lessons →"; min-width: 150px; display: grid; place-items: center; padding: 12px; color: var(--signal-dark); font-size: .62rem; font-weight: 850; letter-spacing: .1em; text-transform: uppercase; }
    .course-nav-link { min-width: 205px; border-bottom: 0; border-right: 1px solid var(--rule); }
    .reading-grid { grid-template-columns: 1fr; }
    .lesson-margin { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
  }

  @media (min-width: 901px) and (max-height: 950px) {
    .course-rail { padding-top: 20px; padding-bottom: 18px; }
    .rail-heading { margin-bottom: 12px; padding-bottom: 10px; }
    .course-nav-link { padding: 9px 4px; }
    .rail-tools { margin-top: 14px; }
  }

  @media (max-width: 620px) {
    .masthead { position: static; align-items: flex-start; gap: 12px; padding: 14px 18px; }
    .wordmark small { display: none; }
    .progress-summary { width: 118px; flex: 0 0 118px; }
    .progress-summary span { font-size: .58rem; }
    .page { padding: 34px 18px 72px; }
    .source-line { gap: 10px 12px; }
    .source-line a { flex-basis: 100%; margin-top: 2px; }
    .video-launch { padding: 18px; }
    .video-launch::before { inset: 8px; }
    .video-launch .play-mark { width: 50px; height: 50px; }
    .video-launch small { font-size: .58rem; }
    .lesson-margin { display: block; }
    .site-footer { display: block; }
    .site-footer p + p { margin-top: 12px; }
  }
}

@layer components {
  .skip-link { position: fixed; top: 8px; left: 8px; z-index: 100; padding: 10px 14px; color: var(--white); background: var(--signal); transform: translateY(-150%); }
  .skip-link:focus { transform: none; }
  .wordmark { display: flex; align-items: center; gap: 12px; text-decoration: none; line-height: 1.1; }
  .wordmark-mark { width: 44px; height: 44px; display: grid; place-items: center; border: 1px solid var(--paper); font-family: var(--display); font-size: 1.15rem; transform: rotate(-3deg); }
  .wordmark strong { display: block; font-family: var(--display); font-size: clamp(1rem, 2vw, 1.3rem); letter-spacing: .02em; }
  .wordmark small { margin-top: 5px; display: block; color: #aab2ab; font-size: .62rem; letter-spacing: .16em; text-transform: uppercase; }
  .progress-summary { width: min(260px, 35vw); align-self: stretch; display: flex; flex-direction: column; justify-content: center; color: #e1e5e1; font-size: .72rem; line-height: 1.2; letter-spacing: .08em; text-transform: uppercase; }
  .progress-track { height: 5px; margin-top: 9px; overflow: hidden; background: #3b443e; }
  .progress-track span { display: block; width: 0; height: 100%; background: var(--acid); transition: width .45s ease; }
  .rail-heading { margin-bottom: 22px; padding-bottom: 16px; border-bottom: 3px double var(--ink); }
  .rail-heading span { display: block; color: var(--signal-dark); font-size: .67rem; font-weight: 800; letter-spacing: .18em; text-transform: uppercase; }
  .rail-heading strong { font-family: var(--display); font-size: 1.2rem; }
  .course-nav-list { padding: 0; list-style: none; }
  .course-nav-link { position: relative; display: grid; grid-template-columns: 31px 1fr 14px; gap: 8px; align-items: start; padding: 14px 4px; text-decoration: none; border-bottom: 1px solid var(--rule); }
  .course-nav-link:hover, .course-nav-link[aria-current="page"] { color: var(--signal-dark); }
  .course-nav-link[aria-current="page"]::before { content: ""; position: absolute; left: -24px; top: 0; bottom: 0; width: 5px; background: var(--signal); }
  .nav-number { font-family: var(--display); font-size: .8rem; font-style: italic; }
  .nav-title { font-size: .78rem; font-weight: 750; line-height: 1.25; }
  .nav-title small { display: block; margin-top: 4px; color: var(--ink-soft); font-size: .63rem; font-weight: 500; }
  .nav-status { width: 10px; height: 10px; margin-top: 3px; border: 1px solid var(--ink); border-radius: 50%; }
  .nav-status.done { border-color: var(--correct); background: var(--correct); box-shadow: inset 0 0 0 2px var(--paper); }
  .rail-tools { margin-top: 30px; }
  .rail-tools p { margin-top: 8px; color: var(--ink); font-size: .68rem; line-height: 1.4; }
  .text-button { padding: 0; color: var(--signal-dark); background: transparent; border: 0; border-bottom: 1px solid currentColor; cursor: pointer; font-size: .75rem; font-weight: 800; text-transform: uppercase; letter-spacing: .1em; }

  .hero { position: relative; overflow: hidden; min-height: 530px; display: flex; align-items: flex-end; color: var(--paper); background: var(--ink); }
  .hero::before { content: "10"; position: absolute; right: -2vw; top: -100px; color: transparent; -webkit-text-stroke: 1px rgb(243 239 228 / 18%); font-family: var(--display); font-size: clamp(250px, 38vw, 560px); line-height: 1; }
  .hero-inner { position: relative; z-index: 1; width: min(940px, 100%); padding: clamp(55px, 8vw, 110px) clamp(24px, 7vw, 110px); }
  .eyebrow { display: flex; align-items: center; gap: 12px; margin-bottom: 24px; color: var(--acid); font-size: .7rem; font-weight: 850; letter-spacing: .2em; text-transform: uppercase; }
  .eyebrow::before { content: ""; width: 42px; height: 3px; background: currentColor; }
  .hero h1, .lesson-header h1 { max-width: 900px; font-family: var(--display); font-weight: 500; font-size: clamp(3.2rem, 8vw, 7.6rem); line-height: .87; letter-spacing: -.055em; }
  .hero-deck { max-width: 650px; margin-top: 34px; color: #cdd3ce; font-size: clamp(1rem, 2vw, 1.28rem); }
  .hero-meta { display: flex; flex-wrap: wrap; gap: 10px 24px; margin-top: 38px; font-size: .68rem; letter-spacing: .14em; text-transform: uppercase; }
  .hero-meta strong { color: var(--acid); }
  .start-link { display: inline-flex; align-items: center; gap: 12px; margin-top: 34px; padding: 12px 18px; color: var(--ink); background: var(--acid); text-decoration: none; font-size: .74rem; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; transform: rotate(-1deg); }
  .start-link:hover { background: var(--white); transform: rotate(0deg); }

  .method-strip { display: grid; grid-template-columns: repeat(3, 1fr); border-bottom: 1px solid var(--rule); }
  .method-item { min-height: 170px; padding: 28px clamp(20px, 3vw, 42px); border-right: 1px solid var(--rule); }
  .method-item:last-child { border-right: 0; }
  .method-item span { color: var(--signal-dark); font-family: var(--display); font-size: 2.5rem; font-style: italic; }
  .method-item h2 { margin: 8px 0; font-family: var(--display); font-size: 1.2rem; }
  .method-item p { color: var(--ink-soft); font-size: .8rem; }
  .audit-note { display: flex; gap: 24px; align-items: baseline; padding: 20px clamp(24px, 7vw, 110px); color: var(--paper); background: var(--signal-dark); border-bottom: 1px solid var(--ink); }
  .audit-note strong { flex: 0 0 auto; font-size: .68rem; letter-spacing: .14em; text-transform: uppercase; }
  .audit-note p { max-width: 920px; font-size: .78rem; }

  .lesson-list { padding: clamp(46px, 7vw, 90px) clamp(24px, 7vw, 110px); }
  .section-kicker { color: var(--signal-dark); font-size: .68rem; font-weight: 850; letter-spacing: .18em; text-transform: uppercase; }
  .lesson-list h2 { max-width: 720px; margin: 8px 0 30px; font-family: var(--display); font-size: clamp(2.2rem, 5vw, 4.4rem); font-weight: 500; line-height: .98; }
  .lesson-card { display: grid; grid-template-columns: 86px 1fr auto; gap: 22px; align-items: center; padding: 24px 0; border-top: 1px solid var(--rule); text-decoration: none; }
  .lesson-card:last-child { border-bottom: 1px solid var(--rule); }
  .lesson-card:hover .lesson-card-title { color: var(--signal-dark); transform: translateX(7px); }
  .lesson-card-number { color: var(--signal-dark); font-family: var(--display); font-size: 2.2rem; font-style: italic; }
  .lesson-card-title { font-family: var(--display); font-size: clamp(1.25rem, 3vw, 2rem); line-height: 1; transition: .2s ease; }
  .lesson-card-title small { display: block; margin-bottom: 6px; color: var(--ink-soft); font-family: var(--body); font-size: .64rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
  .lesson-card-meta { text-align: right; color: var(--ink-soft); font-size: .67rem; text-transform: uppercase; letter-spacing: .1em; }
  .status-stamp { display: inline-block; margin-top: 6px; padding: 3px 7px; color: var(--correct); border: 1px solid currentColor; font-weight: 850; transform: rotate(-2deg); }

  .lesson-header { position: relative; margin-bottom: 34px; padding-bottom: 34px; border-bottom: 4px solid var(--ink); }
  .lesson-header h1 { max-width: 860px; font-size: clamp(3rem, 7vw, 6.7rem); color: var(--ink); }
  .lesson-number { position: absolute; right: 0; top: -12px; color: var(--signal); font-family: var(--display); font-size: clamp(3rem, 8vw, 8rem); font-style: italic; opacity: .22; }
  .lesson-deck { max-width: 770px; margin-top: 24px; color: var(--ink-soft); font-family: var(--display); font-size: clamp(1.05rem, 2vw, 1.35rem); }
  .source-line { display: flex; flex-wrap: wrap; gap: 8px 18px; align-items: center; margin-top: 25px; font-size: .7rem; font-weight: 750; letter-spacing: .08em; text-transform: uppercase; }
  .verified-badge { display: inline-flex; align-items: center; gap: 6px; padding: 5px 8px; color: var(--correct); border: 1px solid currentColor; }
  .verified-badge::before { content: "✓"; font-weight: 900; }
  .source-line a { color: var(--signal-dark); }
  .video-frame { position: relative; margin: 0 0 46px; padding-top: 56.25%; overflow: hidden; background: #050706; box-shadow: var(--shadow); }
  .video-frame iframe, .video-launch { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
  .video-launch { display: grid; place-items: center; align-content: center; gap: 16px; padding: 30px; overflow: hidden; color: var(--white); background: linear-gradient(rgb(5 7 6 / 48%), rgb(5 7 6 / 84%)), var(--video-poster) center / cover; cursor: pointer; text-align: center; }
  .video-launch::before { content: ""; position: absolute; inset: 14px; border: 1px solid rgb(255 253 247 / 48%); pointer-events: none; }
  .video-launch > * { position: relative; z-index: 1; }
  .video-launch .play-mark { width: 62px; height: 62px; display: grid; place-items: center; padding-left: 4px; color: var(--ink); background: var(--acid); border-radius: 50%; box-shadow: 0 0 0 8px rgb(203 217 76 / 18%); font-size: 1.25rem; transition: transform .2s ease; }
  .video-launch:hover .play-mark { transform: scale(1.08); }
  .video-launch strong { display: block; font-family: var(--display); font-size: clamp(1.4rem, 3vw, 2.4rem); font-weight: 500; }
  .video-launch small { display: block; margin-top: 4px; color: #d7ddd7; font-size: .68rem; letter-spacing: .09em; text-transform: uppercase; }
  .source-note { margin: -34px 0 44px; color: var(--ink-soft); font-size: .7rem; }
  .source-note strong { color: var(--ink); }
  .content-section { margin: 0 0 50px; }
  .content-section > h2 { margin-bottom: 20px; font-family: var(--display); font-size: clamp(1.9rem, 4vw, 3rem); font-weight: 500; line-height: 1; }
  .objective-list { padding: 0; counter-reset: objective; list-style: none; border-top: 1px solid var(--rule); }
  .objective-list li { position: relative; padding: 15px 10px 15px 46px; border-bottom: 1px solid var(--rule); }
  .objective-list li::before { counter-increment: objective; content: "0" counter(objective); position: absolute; left: 4px; color: var(--signal-dark); font-family: var(--display); font-style: italic; }
  .topic-block { margin: 24px 0; padding: 22px; background: rgb(255 253 247 / 58%); border-left: 5px solid var(--ink); }
  .topic-block h3 { margin-bottom: 10px; font-family: var(--display); font-size: 1.35rem; }
  .topic-block ul { padding-left: 18px; }
  .topic-block li + li { margin-top: 7px; }
  .takeaway-card { margin-bottom: 18px; padding: 22px; background: var(--ink); color: var(--paper); box-shadow: 7px 7px 0 var(--acid); }
  .takeaway-card h3 { margin-bottom: 10px; color: var(--acid); font-size: .68rem; letter-spacing: .16em; text-transform: uppercase; }
  .takeaway-card ul { padding-left: 18px; }
  .takeaway-card li + li { margin-top: 10px; }
  .margin-card { margin-bottom: 20px; padding: 18px; border: 1px solid var(--rule); background: rgb(255 253 247 / 45%); }
  .margin-card h3 { margin-bottom: 8px; color: var(--signal-dark); font-size: .67rem; letter-spacing: .16em; text-transform: uppercase; }
  .margin-card p { color: var(--ink-soft); font-size: .78rem; }

  .notes-panel { margin-top: 44px; padding: clamp(20px, 4vw, 34px); background: var(--paper-deep); border-top: 5px solid var(--signal); }
  .notes-panel h2 { font-family: var(--display); font-size: 2rem; font-weight: 500; }
  .notes-prompt { margin: 6px 0 16px; color: var(--ink-soft); }
  .notes-panel label { display: block; margin-bottom: 7px; font-size: .7rem; font-weight: 850; letter-spacing: .12em; text-transform: uppercase; }
  .notes-panel textarea { width: 100%; min-height: 180px; resize: vertical; padding: 16px; color: var(--ink); background: var(--white); border: 1px solid var(--ink); line-height: 1.55; }
  .save-state { min-height: 1.4em; margin-top: 7px; color: var(--correct); font-size: .7rem; }

  .quiz-panel { margin-top: 56px; padding-top: 30px; border-top: 4px solid var(--ink); }
  .quiz-heading { display: flex; justify-content: space-between; align-items: end; gap: 20px; margin-bottom: 26px; }
  .quiz-heading h2 { font-family: var(--display); font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 500; line-height: 1; }
  .quiz-heading span { color: var(--ink-soft); font-size: .66rem; font-weight: 850; letter-spacing: .14em; text-transform: uppercase; }
  .question { margin: 0 0 28px; padding: 0 0 26px; border: 0; border-bottom: 1px solid var(--rule); }
  .question legend { width: 100%; margin-bottom: 13px; font-family: var(--display); font-size: 1.2rem; font-weight: 650; }
  .option { position: relative; display: block; margin: 8px 0; padding: 11px 14px 11px 42px; background: rgb(255 253 247 / 58%); border: 1px solid transparent; cursor: pointer; }
  .option:hover { border-color: var(--rule); }
  .option input { position: absolute; left: 14px; top: 16px; accent-color: var(--signal); }
  .option.correct { color: var(--correct); border-color: var(--correct); background: #e8f2ea; }
  .option.wrong { color: var(--wrong); border-color: var(--wrong); background: #f7e9e4; }
  .explanation { display: none; margin-top: 10px; padding: 12px 14px; color: var(--ink-soft); background: var(--paper-deep); border-left: 4px solid var(--ink); font-size: .8rem; }
  .explanation.visible { display: block; }
  .primary-button, .secondary-button { border: 0; cursor: pointer; font-size: .72rem; font-weight: 900; letter-spacing: .12em; text-transform: uppercase; }
  .primary-button { padding: 13px 18px; color: var(--paper); background: var(--signal-dark); box-shadow: 4px 4px 0 var(--ink); }
  .primary-button:hover { background: var(--ink); box-shadow: 4px 4px 0 var(--acid); }
  .secondary-button { padding: 12px 17px; color: var(--ink); background: transparent; border: 1px solid var(--ink); }
  .quiz-result { display: none; margin-top: 24px; padding: 22px; background: var(--ink); color: var(--paper); }
  .quiz-result.visible { display: block; }
  .quiz-result strong { display: block; color: var(--acid); font-family: var(--display); font-size: 1.65rem; }
  .quiz-result p { margin: 4px 0 16px; }
  .quiz-result .secondary-button { color: var(--paper); border-color: var(--paper); }
  .quiz-result .secondary-button:hover { color: var(--ink); background: var(--acid); border-color: var(--acid); }
  .lesson-complete { margin-top: 20px; color: var(--correct); font-size: .8rem; font-weight: 800; }
  .notice { margin: 50px; padding: 30px; border: 2px solid var(--ink); }

  @media (max-width: 720px) {
    .method-strip { grid-template-columns: 1fr; }
    .method-item { min-height: 0; border-right: 0; border-bottom: 1px solid var(--rule); }
    .lesson-card { grid-template-columns: 52px 1fr; }
    .lesson-card-meta { grid-column: 2; text-align: left; }
    .quiz-heading { display: block; }
    .quiz-heading span { display: block; margin-top: 8px; }
    .audit-note { display: block; }
    .audit-note p { margin-top: 8px; }
  }
}

@layer utilities {
  .sr-only { position: absolute !important; width: 1px !important; height: 1px !important; padding: 0 !important; margin: -1px !important; overflow: hidden !important; clip: rect(0, 0, 0, 0) !important; white-space: nowrap !important; border: 0 !important; }
  @media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; }
  }
}