/* =========================================================
   After Effects Basics · Oliver Aemisegger
   Layout: sticky section index left, one reading column right;
   steps widen into text + media rows.
   ========================================================= */

@font-face { font-family: "IBM Plex Mono"; src: url("../fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url("../fonts/ibm-plex-mono-latin-500-normal.woff2") format("woff2"); font-weight: 500; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Mono"; src: url("../fonts/ibm-plex-mono-latin-600-normal.woff2") format("woff2"); font-weight: 600; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("../fonts/ibm-plex-sans-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("../fonts/ibm-plex-sans-latin-400-italic.woff2") format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("../fonts/ibm-plex-sans-latin-500-normal.woff2") format("woff2"); font-weight: 500; font-style: normal; font-display: swap; }
@font-face { font-family: "IBM Plex Sans"; src: url("../fonts/ibm-plex-sans-latin-600-normal.woff2") format("woff2"); font-weight: 600; font-style: normal; font-display: swap; }

/* ---------- Tokens ---------- */
:root {
  --bg: #fbfbfc;
  --surface: #f0f2f5;
  --line: #dde1e7;
  --fg: #16181d;
  --muted: #5c6370;
  --accent: #1f6fff;
  --accent-ink: #ffffff;
  --tint: #e8f0ff;
  --warn: #b25e00;
  --warn-tint: #fff3e3;
  --shape: #1f6fff;
  --shape-2: #16181d;

  /* After Effects UI is dark in both themes */
  --ae-bg: #232323;
  --ae-line: #3a3a3a;
  --ae-fg: #b9b9b9;
  --ae-blue: #3a8fff;

  --font-mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --font-sans: "IBM Plex Sans", -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;

  --text: 1.0625rem;
  --small: 0.875rem;
  --tiny: 0.75rem;
  --h1: clamp(2rem, 1.4rem + 2.6vw, 3rem);
  --h2: 1.5rem;
  --radius: 4px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111318; --surface: #1a1d24; --line: #2a2f38; --fg: #e6e8ec; --muted: #9aa1ad;
    --accent: #5b9bff; --accent-ink: #0b1020; --tint: #18233a; --warn: #ffb35c; --warn-tint: #2a2114;
    --shape: #5b9bff; --shape-2: #e6e8ec; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #111318; --surface: #1a1d24; --line: #2a2f38; --fg: #e6e8ec; --muted: #9aa1ad;
  --accent: #5b9bff; --accent-ink: #0b1020; --tint: #18233a; --warn: #ffb35c; --warn-tint: #2a2114;
  --shape: #5b9bff; --shape-2: #e6e8ec; color-scheme: dark;
}

/* ---------- Base ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img, video { max-width: 100%; display: block; }
a { color: var(--accent); text-underline-offset: 3px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 8px; z-index: 20; background: var(--bg); padding: 0.4rem 0.7rem; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.site-header .inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.75rem 16px;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.brand {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: var(--small);
  letter-spacing: 0.04em;
  color: var(--fg);
  text-decoration: none;
}
.crumb { font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); flex: 1; min-width: 0; }
.controls { display: flex; gap: 0.5rem; align-items: center; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.seg button, .theme-btn, .loop-btn {
  font-family: var(--font-mono);
  font-size: var(--tiny);
  background: transparent;
  color: var(--muted);
  border: 0;
  padding: 0.35rem 0.6rem;
  cursor: pointer;
}
.seg button[aria-pressed="true"] { background: var(--fg); color: var(--bg); }
.theme-btn { border: 1px solid var(--line); border-radius: var(--radius); }

/* ---------- Page grid ---------- */
.page {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 16px 4rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2rem;
}
@media (min-width: 1000px) {
  .page { grid-template-columns: 220px minmax(0, 1fr); gap: 3.5rem; }
}
main { min-width: 0; }
.prose { max-width: 66ch; }
.prose > :first-child { margin-top: 0; }
.prose ul, .prose ol { padding-left: 1.2rem; }
.prose li + li { margin-top: 0.2rem; }

/* ---------- Course sidebar ---------- */
.sidebar { font-family: var(--font-mono); font-size: var(--small); min-width: 0; }
.side-toggle { display: none; }
.side-home {
  display: block;
  font-size: var(--tiny);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  text-decoration: none;
  margin: 0 0 0.75rem 0.5rem;
}
.side-home:hover { color: var(--fg); }
.side-list, .side-sub { list-style: none; margin: 0; padding: 0; }
.side-list { display: grid; gap: 0.1rem; }
.side-link {
  display: grid;
  grid-template-columns: 1.9rem minmax(0, 1fr) auto;
  align-items: baseline;
  padding: 0.35rem 0.5rem;
  border-radius: var(--radius);
  color: var(--fg);
  text-decoration: none;
}
.side-link:hover { background: var(--surface); }
.side-num { color: var(--muted); font-size: var(--tiny); }
.side-done { color: var(--accent); font-weight: 600; }
.is-current > .side-link { background: var(--surface); font-weight: 600; }
.is-current > .side-link .side-num { color: var(--accent); }
.side-sub { margin: 0.2rem 0 0.5rem 2.4rem; border-left: 1px solid var(--line); }
.side-sub a {
  display: block;
  padding: 0.22rem 0 0.22rem 0.75rem;
  margin-left: -1px;
  border-left: 2px solid transparent;
  color: var(--muted);
  text-decoration: none;
  font-size: var(--tiny);
}
.side-sub a:hover { color: var(--fg); }
.side-sub a.is-active { color: var(--fg); border-left-color: var(--accent); }

@media (min-width: 1000px) {
  .sidebar {
    position: sticky;
    top: 3.25rem;
    align-self: start;
    max-height: calc(100vh - 3.25rem);
    overflow-y: auto;
    padding-block: 3.5rem 2rem;
  }
}
@media (max-width: 999px) {
  .sidebar {
    position: sticky;
    top: 3.1rem;
    z-index: 5;
    margin: 0 -16px;
    padding: 0.5rem 16px;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
  }
  .side-toggle {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    font-family: var(--font-mono);
    font-size: var(--small);
    font-weight: 600;
    color: var(--fg);
    background: var(--surface);
    border: 0;
    border-radius: var(--radius);
    padding: 0.5rem 0.75rem;
    cursor: pointer;
  }
  .js .sidebar:not(.is-open) .side-nav { display: none; }
  .side-nav { padding-top: 0.75rem; max-height: 70vh; overflow-y: auto; }
  .page { gap: 0; }
}

/* ---------- Lesson header ---------- */
.lesson-head { padding-top: 3.5rem; display: grid; gap: 1.25rem; }
.chapter { font-family: var(--font-mono); font-size: var(--tiny); text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); }
.chapter b { color: var(--accent); font-weight: 600; }
h1 {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: var(--h1);
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 0;
  text-wrap: balance;
}
.squiggle { position: relative; white-space: nowrap; }
.squiggle svg { position: absolute; left: 0; right: 0; bottom: -0.32em; width: 100%; height: 0.38em; overflow: visible; }
.squiggle path { fill: none; stroke: var(--accent); stroke-width: 3; stroke-linecap: round; }
.meta { font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); }
.intro { font-size: 1.1875rem; line-height: 1.55; margin: 0; }
.outcomes { background: var(--surface); border-radius: var(--radius); padding: 1rem 1.25rem; }
.outcomes p { margin: 0 0 0.5rem; font-family: var(--font-mono); font-size: var(--tiny); text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); }
.outcomes ul { margin: 0; padding-left: 1.1rem; display: grid; gap: 0.2rem; }

/* ---------- Sections ---------- */
section.topic { padding-top: 3.5rem; scroll-margin-top: 4.5rem; }
h2 {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: var(--h2);
  line-height: 1.25;
  margin: 0 0 0.75rem;
  text-wrap: balance;
}
.topic > .prose { margin-bottom: 1.25rem; }
.topic > .prose p { margin: 0 0 0.75rem; }

/* ---------- Steps ---------- */
.steps { list-style: none; margin: 0 0 1.25rem; padding: 0; }
.step {
  display: grid;
  grid-template-columns: 2.75rem minmax(0, 1fr);
  column-gap: 1rem;
  padding: 1.1rem 0;
  border-top: 1px solid var(--line);
}
.step:last-child { border-bottom: 1px solid var(--line); }
.step-num { font-family: var(--font-mono); font-size: var(--small); font-weight: 600; color: var(--accent); padding-top: 0.15rem; }
.step-body { min-width: 0; display: grid; gap: 0.5rem; align-content: start; justify-items: start; }
.step-title { font-family: var(--font-mono); font-weight: 600; font-size: 1rem; margin: 0; }
.step-text { margin: 0; max-width: 60ch; }
.step-media { min-width: 0; margin-top: 0.75rem; grid-column: 2; }
@media (min-width: 760px) {
  .step.has-media { grid-template-columns: 2.75rem minmax(0, 1fr) minmax(0, 1.05fr); }
  .step.has-media .step-media { grid-column: 3; margin-top: 0; }
}

/* Chip: the exact thing to click or type */
.chip {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--small);
  font-weight: 500;
  background: var(--accent);
  color: var(--accent-ink);
  border-radius: var(--radius);
  padding: 0.2rem 0.55rem;
  max-width: 100%;
  overflow-wrap: anywhere;
}
kbd {
  font-family: var(--font-mono);
  font-size: 0.85em;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: var(--radius);
  padding: 0.05rem 0.4rem;
  background: var(--bg);
  color: var(--fg);
  white-space: nowrap;
}
code { font-family: var(--font-mono); font-size: 0.9em; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 0 0.3rem; }

/* ---------- Media ---------- */
.media { margin: 0; display: grid; gap: 0.4rem; max-width: 100%; }
.media img, .media video { border-radius: var(--radius); width: 100%; height: auto; background: var(--ae-bg); }
.media-bar { display: flex; align-items: center; gap: 0.6rem; flex-wrap: wrap; font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); }
.loop-btn { border: 1px solid var(--line); border-radius: var(--radius); color: var(--fg); background: var(--bg); padding: 0.2rem 0.55rem; }

/* Missing screenshot or loop: clean placeholder, so pages work from day one */
.media-missing {
  aspect-ratio: 16 / 10;
  background: var(--ae-bg);
  border-radius: var(--radius);
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 0.35rem;
  padding: 1rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.media-missing::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(var(--ae-line) 1px, transparent 1px) 0 0 / 100% 22px;
  opacity: 0.6;
}
.media-missing span, .media-missing small {
  position: relative;
  font-family: var(--font-mono);
  color: var(--ae-fg);
  background: var(--ae-bg);
  padding: 0.15rem 0.5rem;
}
.media-missing span { font-size: var(--tiny); border: 1px dashed var(--ae-line); border-radius: var(--radius); }
.media-missing small { font-size: 0.6875rem; opacity: 0.7; }

/* ---------- Tip / warning ---------- */
.note {
  margin: 1.5rem 0 0;
  border-radius: var(--radius);
  padding: 0.85rem 1.1rem;
  background: var(--tint);
  display: grid;
  gap: 0.35rem;
  justify-items: start;
  max-width: 66ch;
}
.note-label { font-family: var(--font-mono); font-size: var(--tiny); font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--accent); }
.note p { margin: 0; }
.note.warning { background: var(--warn-tint); }
.note.warning .note-label { color: var(--warn); }

/* ---------- Exercise ---------- */
.exercise {
  margin-top: 4rem;
  scroll-margin-top: 4.5rem;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.5rem;
  display: grid;
  gap: 1.25rem;
}
@media (max-width: 520px) { .exercise { padding: 1.1rem; } }
.exercise-head { display: grid; gap: 0.35rem; }
.exercise h2 { margin: 0; }
.ex-meta { font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); margin: 0; }
.soon { border: 1px dashed var(--line); border-radius: var(--radius); padding: 0 0.35rem; margin-left: 0.25rem; }
.result { display: grid; gap: 0.5rem; }
.result-label { font-family: var(--font-mono); font-size: var(--tiny); text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); }
.result .media-missing { max-width: 36rem; }

.checklist { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.35rem; }
.checklist label {
  display: grid;
  grid-template-columns: 1.25rem 1.75rem minmax(0, 1fr);
  gap: 0.5rem;
  align-items: start;
  padding: 0.45rem 0.5rem;
  border-radius: var(--radius);
  cursor: pointer;
}
.checklist label:hover { background: var(--bg); }
.checklist input { margin: 0.35rem 0 0; accent-color: var(--accent); width: 1rem; height: 1rem; }
.checklist .n { font-family: var(--font-mono); font-size: var(--small); color: var(--muted); padding-top: 0.15rem; }
.checklist input:checked ~ .t { color: var(--muted); text-decoration: line-through; text-decoration-color: var(--line); }
.checklist code { background: var(--bg); }
.progress { font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); margin: 0; }

/* ---------- Tables, shortcuts, more ---------- */
.block { padding-top: 3.5rem; scroll-margin-top: 4.5rem; }
.table-wrap, .prose table { overflow-x: auto; max-width: 40rem; }
table { border-collapse: collapse; width: 100%; font-size: var(--small); }
th, td { text-align: left; padding: 0.55rem 0.75rem 0.55rem 0; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-family: var(--font-mono); font-size: var(--tiny); font-weight: 500; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); }
.more { max-width: 66ch; }
.more ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.6rem; }

/* ---------- Pager / footer ---------- */
.pager { margin-top: 4rem; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 0.75rem; }
.pager a { border: 1px solid var(--line); border-radius: var(--radius); padding: 0.85rem 1rem; text-decoration: none; color: var(--fg); display: grid; gap: 0.15rem; }
.pager a:hover { border-color: var(--accent); }
.pager .dir { font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); }
.pager .name { font-family: var(--font-mono); font-weight: 600; font-size: var(--small); }
.pager .next { text-align: right; }
.site-footer { border-top: 1px solid var(--line); padding-block: 1.5rem; font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); }
.site-footer .inner { max-width: 1120px; margin: 0 auto; padding: 0 16px; display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.site-footer a { color: var(--muted); }

/* ---------- Start page ---------- */
.how { list-style: none; margin: 0 0 1.75rem; padding: 0; max-width: 66ch; }
.how li { display: grid; grid-template-columns: 2.75rem minmax(0, 1fr); column-gap: 1rem; padding: 1rem 0; border-top: 1px solid var(--line); }
.how li:last-child { border-bottom: 1px solid var(--line); }
.how-num { font-family: var(--font-mono); font-size: var(--small); font-weight: 600; color: var(--accent); padding-top: 0.1rem; }
.start {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: var(--small);
  background: var(--accent);
  color: var(--accent-ink);
  border-radius: var(--radius);
  padding: 0.55rem 0.9rem;
  text-decoration: none;
}
.start:hover { filter: brightness(1.08); }
.home-foot { margin-top: 3rem; color: var(--muted); max-width: 66ch; }

/* ---------- Demos (shared) ---------- */
.demo { position: relative; }
.is-paused, .is-paused * { animation-play-state: paused !important; }
.demo-missing { font-family: var(--font-mono); font-size: var(--tiny); color: var(--muted); border: 1px dashed var(--line); border-radius: var(--radius); padding: 1rem; margin: 0; }
@media (max-width: 520px) { .crumb { display: none; } .controls { margin-left: auto; } }

/* ---------- Folder trees ---------- */
.trees { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 14rem), 1fr)); gap: 0.75rem; margin: 1.25rem 0; }
.tree {
  margin: 1.25rem 0;
  padding: 0.9rem 1rem 1rem;
  background: var(--surface);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: var(--small);
  line-height: 1.5;
  min-width: 0;
}
.trees .tree { margin: 0; }
.tree figcaption { font-size: var(--tiny); text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 0.6rem; }
.prose .tree ul, .tree ul { list-style: none; margin: 0; padding: 0; }
.prose .tree ul ul, .tree ul ul { margin-left: 0.45rem; padding-left: 1.05rem; border-left: 1px solid var(--line); }
.prose .tree li + li, .tree li + li { margin-top: 0; }
.tree li { padding-top: 0.15rem; }
.tree .node { display: inline-flex; align-items: center; gap: 0.5rem; overflow-wrap: anywhere; }
.tree svg { width: 1em; height: 1em; flex: none; }
.ic-dir { fill: var(--accent); }
.ic-file { fill: none; stroke: var(--muted); stroke-width: 1.2; }

/* Standalone media in a section */
.topic > .media { max-width: 48rem; margin: 1.25rem 0; }

/* Long file names in inline code may wrap on small screens */
code { overflow-wrap: anywhere; }

/* Text that follows a tip or warning needs breathing room */
.note + .prose, .note + .media, .note + .steps { margin-top: 1.5rem; }

/* Small screenshots keep their size instead of stretching */
.media img { width: auto; max-width: 100%; }