/* UCL Linguistics Short Courses — site styles */

:root {
  --bg: #ffffff;
  --bg-soft: #f3f5f9;
  --surface: #ffffff;
  --ink: #1a1f27;
  --ink-2: #4d5765;
  --line: #dde2ea;
  --navy: #0d2a52;
  --link: #0b5cad;
  --link-hover: #083f78;
  --accent-soft: #e6eef9;
  --btn: #0d2a52;
  --notice: #fff6d6;
  --notice-line: #e2c25a;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .05), 0 1px 4px rgba(16, 24, 40, .05);
  --shadow-hover: 0 6px 20px rgba(16, 24, 40, .10);
  --font: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-serif: "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  color-scheme: light;
}

/* Dark theme: set by the toggle, or by the device setting until the toggle is used */
:root[data-theme="dark"] {
  --bg: #10141a;
  --bg-soft: #161c24;
  --surface: #1a212b;
  --ink: #e7eaf0;
  --ink-2: #a6afbd;
  --line: #2a3340;
  --link: #8ab8f0;
  --link-hover: #b5d2f6;
  --accent-soft: #1d3150;
  --btn: #2f62ad;
  --notice: #3a3115;
  --notice-line: #7a6522;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3);
  --shadow-hover: 0 6px 20px rgba(0, 0, 0, .45);
  color-scheme: dark;
}
/* Avoid a white flash before the script has picked the theme */
@media (prefers-color-scheme: dark) { html:not([data-theme]) { background: #10141a; } }

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 84px; }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.6 var(--font); transition: background-color .2s, color .2s; }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--link); text-underline-offset: 2px; transition: color .15s; }
a:hover { color: var(--link-hover); }
:focus-visible { outline: 2px solid var(--link); outline-offset: 2px; border-radius: 4px; }
h1, h2, h3 { font-family: var(--font-serif); font-weight: 700; line-height: 1.25; color: var(--ink); }
h1 { font-size: 2.1rem; margin: 0 0 .5rem; }
h2 { font-size: 1.55rem; margin: 2.2rem 0 .9rem; }
h3 { font-size: 1.2rem; margin: 1.6rem 0 .6rem; }
h4 { font-size: 1rem; margin: 0; }
p { margin: 0 0 1em; }
.wrap { max-width: 1100px; margin: 0 auto; padding: 0 20px; }
.muted { color: var(--ink-2); }
.tba { color: var(--ink-2); font-style: italic; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--bg); padding: 8px 12px; z-index: 30; }
.skip:focus { left: 8px; }
.ic { width: 1.1em; height: 1.1em; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- buttons ---------- */

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: .62em 1.15em; border-radius: 8px; border: 1.5px solid transparent;
  background: var(--btn); color: #fff; font-weight: 600; text-decoration: none;
  transition: background-color .15s, transform .15s, box-shadow .15s;
}
.btn:hover { color: #fff; transform: translateY(-1px); box-shadow: var(--shadow-hover); }
.btn-light { background: #fff; color: var(--navy); }
.btn-light:hover { background: #eaf1fb; color: var(--navy); }
.btn-outline { background: transparent; color: #fff; border-color: rgba(255, 255, 255, .65); }
.btn-outline:hover { background: rgba(255, 255, 255, .12); }

/* ---------- masthead ---------- */

.topbar { background: #000; font-size: .82rem; }
.topbar .wrap { padding-top: 5px; padding-bottom: 5px; }
.topbar a { color: #fff; text-decoration: none; font-weight: 600; }
.topbar a:hover { color: #fff; text-decoration: underline; }

.masthead {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--navy) 94%, transparent);
  backdrop-filter: saturate(1.3) blur(8px);
  box-shadow: 0 2px 12px rgba(0, 0, 0, .12);
}
.masthead .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 20px; min-height: 64px; }
.site-title { margin-right: auto; color: #fff; text-decoration: none; font-family: var(--font-serif); line-height: 1.2; font-size: 1.35rem; }
.site-title:hover { color: #fff; }
.site-title span { font-weight: 400; color: #b9c8de; }
.masthead nav ul { list-style: none; display: flex; gap: 4px; margin: 0; padding: 0; }
.masthead nav a {
  display: block; padding: 7px 12px; border-radius: 6px;
  color: #dbe4f0; text-decoration: none; transition: background-color .15s, color .15s;
}
.masthead nav a:hover { color: #fff; background: rgba(255, 255, 255, .09); }
.masthead nav a[aria-current="page"] { color: #fff; background: rgba(255, 255, 255, .15); font-weight: 600; }
.theme-toggle {
  display: grid; place-items: center; width: 36px; height: 36px; padding: 0; cursor: pointer;
  border: 1px solid rgba(255, 255, 255, .28); border-radius: 8px; background: transparent; color: #fff; font-size: 1.05rem;
  transition: background-color .15s;
}
.theme-toggle:hover { background: rgba(255, 255, 255, .1); }

.notice { background: var(--notice); border-bottom: 1px solid var(--notice-line); }
.notice .wrap { padding-top: 10px; padding-bottom: 10px; }

/* ---------- hero (home) ---------- */

.hero { position: relative; isolation: isolate; background: var(--navy); color: #fff; overflow: hidden; }
.hero > img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: center 30%; z-index: -2; }
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background: linear-gradient(180deg, rgba(8, 22, 45, .05) 0%, rgba(8, 22, 45, .3) 40%, rgba(8, 22, 45, .88) 100%);
}
.hero .wrap { min-height: clamp(320px, 36vw, 440px); display: flex; flex-direction: column; justify-content: flex-end; padding-top: 48px; padding-bottom: 36px; }
.hero .eyebrow { font-size: .8rem; letter-spacing: .12em; text-transform: uppercase; font-weight: 600; color: #c9d7ec; margin: 0 0 6px; }
.hero h1 { color: #fff; font-size: clamp(2rem, 4.4vw, 3rem); margin: 0 0 8px; text-shadow: 0 2px 16px rgba(0, 0, 0, .35); }
.hero-status { font-size: 1.1rem; color: #e3eaf4; max-width: 42em; margin-bottom: 18px; text-shadow: 0 1px 8px rgba(0, 0, 0, .45); }
.hero a:not(.btn) { color: #fff; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.credit { font-size: .75rem; color: var(--ink-2); text-align: right; margin: 0; padding-top: 6px; padding-bottom: 6px; }

/* ---------- layout ---------- */

main { padding-bottom: 64px; }
.page { padding-top: 32px; }
.page-title { padding-top: 36px; }
.with-aside { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 48px; align-items: start; }
.with-aside > :first-child > :first-child { margin-top: 0; }
.lead { font-size: 1.12rem; color: var(--ink-2); }

.box {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 20px; margin-bottom: 16px; box-shadow: var(--shadow);
}
.box h2 { font-size: 1.12rem; margin: 0 0 8px; }
.box p:last-child, .box ul:last-child { margin-bottom: 0; }
.plain { list-style: none; margin: 0; padding: 0; }
.plain li + li { margin-top: 5px; }
.ticks li { display: flex; gap: 8px; align-items: baseline; }
.ticks li::before { content: "✓"; color: var(--link); font-weight: 700; }

.contents { background: var(--bg-soft); border-radius: var(--radius); padding: 16px 20px; margin: 0 0 8px; }
.contents h2 { font-size: .85rem; margin: 0 0 8px; font-family: var(--font); text-transform: uppercase; letter-spacing: .08em; color: var(--ink-2); }
.contents ul ul { margin: 2px 0 6px; padding-left: 1.2em; }
.contents li > span { font-weight: 600; }

/* ---------- tables ---------- */

.table-wrap { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--surface); box-shadow: var(--shadow); margin: 0 0 1.4rem; }
table { width: 100%; border-collapse: collapse; font-size: .95rem; }
th, td { text-align: left; vertical-align: top; padding: 11px 14px; border-bottom: 1px solid var(--line); }
tbody tr:last-child td { border-bottom: 0; }
thead th { background: var(--bg-soft); font-size: .76rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2); white-space: nowrap; }
tbody tr { transition: background-color .12s; }
tbody tr:hover { background: var(--bg-soft); }
td.nowrap { white-space: nowrap; }
td small { display: block; color: var(--ink-2); margin-top: 2px; }
tr.is-past td, tr.is-past a { color: var(--ink-2); }
tr.is-next { background: var(--accent-soft); }
tr.is-next:hover { background: var(--accent-soft); }
tr.is-next td { font-weight: 600; }
tr.is-next td:first-child { box-shadow: inset 3px 0 var(--link); }
.label-next {
  display: inline-block; font: 700 .68rem/1.6 var(--font); text-transform: uppercase; letter-spacing: .06em;
  color: #fff; background: var(--link); padding: 0 7px; margin-left: 6px; border-radius: 999px; vertical-align: 1px;
}
:root[data-theme="dark"] .label-next { color: #0e1a2b; }

table.info { max-width: 760px; margin-bottom: 1.2rem; }
table.info th, table.info td { padding: 8px 12px 8px 0; }
table.info tr:hover { background: none; }
table.info th { width: 9.5em; color: var(--ink-2); font-weight: 600; }
table.info tbody tr:last-child th, table.info tbody tr:last-child td { border-bottom: 0; }

.filter-bar { display: flex; align-items: center; gap: 10px; margin: 0 0 8px; }
.filter-bar select {
  font: inherit; padding: 7px 10px; border: 1px solid var(--line); border-radius: 8px;
  background: var(--surface); color: var(--ink); flex: 0 1 auto; min-width: 0; width: 26em; max-width: 100%;
}

/* ---------- courses ---------- */

.course {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 30px; margin-top: 22px; box-shadow: var(--shadow);
}
.course h2 { margin-top: 0; }
.sessions { list-style: none; margin: 0; padding: 0; }
.sessions > li { display: flex; gap: 14px; padding: 13px 0; border-top: 1px solid var(--line); }
.session-n {
  flex: none; width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--link); font-weight: 700; font-size: .9rem; margin-top: 1px;
}
.sessions .is-past .session-n { background: var(--bg-soft); color: var(--ink-2); }
.sessions .when { font-size: .9rem; color: var(--ink-2); margin: 2px 0 0; }
.sessions .is-past h4, .sessions .is-past .when { color: var(--ink-2); }
.sessions .detail { margin-top: 6px; }
.sessions .detail p, .sessions .detail ul { margin: 0 0 6px; }
.sessions ul.readings { padding-left: 1.2em; font-size: .95rem; }
.term-heading {
  font-size: .95rem; text-transform: uppercase; letter-spacing: .1em; font-family: var(--font);
  color: var(--ink-2); border-bottom: 2px solid var(--line); padding-bottom: 8px; margin-top: 44px;
}
.person + .person { margin-top: 14px; }
.person p { margin: 0; }

/* ---------- about ---------- */

figure.figure { float: right; width: min(380px, 45%); margin: 4px 0 16px 28px; }
figure.figure img { border-radius: 8px; box-shadow: var(--shadow-hover); }
figure.figure figcaption { margin-top: 8px; font-size: .78rem; color: var(--ink-2); }
.faq h3 { font-family: var(--font); font-size: 1rem; margin: 1.2rem 0 .3rem; }
.clear { clear: both; }

/* ---------- footer ---------- */

.site-footer { background: var(--navy); color: #c3cfe0; font-size: .9rem; }
.site-footer a { color: #fff; }
.site-footer a:hover { color: #cfe0f7; }
.site-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px; padding-top: 22px; padding-bottom: 22px; }

/* ---------- data.js problems ---------- */

.fatal, .dev-warn { max-width: 860px; margin: 24px auto; padding: 16px 20px; border-radius: 8px; font: 15px/1.5 var(--font); }
.fatal { background: #fde8e8; color: #7a1010; border: 2px solid #e05252; }
.dev-warn { background: #fff4cc; color: #4d3800; border: 1px solid #e6c34d; }
.dev-warn ul { margin: 6px 0 0; padding-left: 1.2em; }

/* ---------- small screens ---------- */

@media (max-width: 900px) {
  .with-aside { grid-template-columns: 1fr; gap: 8px; }
  figure.figure { float: none; width: 100%; margin: 0 0 16px; }
}

@media (max-width: 640px) {
  html { scroll-padding-top: 120px; }
  h1 { font-size: 1.7rem; }
  .masthead .wrap { padding-top: 10px; padding-bottom: 4px; }
  .site-title { font-size: 1.05rem; flex: 1; min-width: 0; }
  .hero::before { background: linear-gradient(180deg, rgba(8, 22, 45, .3) 0%, rgba(8, 22, 45, .65) 45%, rgba(8, 22, 45, .92) 100%); }
  .masthead nav { order: 3; width: 100%; overflow-x: auto; }
  .masthead nav ul { margin-left: -12px; }
  .course { padding: 20px 18px; }
  /* Stack data tables into labelled rows */
  table.stack thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  table.stack tr { display: block; padding: 10px 14px; border-bottom: 1px solid var(--line); }
  table.stack tbody tr:last-child { border-bottom: 0; }
  table.stack td { display: flex; gap: 10px; border: 0; padding: 2px 0; }
  table.stack td::before { content: attr(data-label); flex: 0 0 5.2em; color: var(--ink-2); font-size: .78rem; text-transform: uppercase; letter-spacing: .04em; padding-top: 2px; }
  table.stack td.nowrap { white-space: normal; }
  table.stack tr.is-next { box-shadow: inset 3px 0 var(--link); }
  table.stack tr.is-next td:first-child { box-shadow: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; }
}