/* Morning briefing — mobile first, light/dark via prefers-color-scheme, no frameworks. */

/* ---------- Tokens ---------- */

:root {
  color-scheme: light dark;

  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-serif: ui-serif, "New York", "Iowan Old Style", "Charter", "Georgia", "Times New Roman", serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", Menlo, Consolas, monospace;

  --bg: #f7f5f0;
  --surface: #ffffff;
  --surface-sunken: #f1ede4;
  --text: #1b1a17;
  --text-muted: #5b574f;
  --border: #e3ddd1;
  --border-strong: #cfc7b8;
  --link: #1d4ed8;
  --focus: #2563eb;
  --shadow: 0 1px 2px rgb(40 30 10 / 0.05), 0 4px 16px rgb(40 30 10 / 0.04);

  --accent-must-know: #c2410c;
  --accent-ai: #6d28d9;
  --accent-videos: #be123c;
  --accent-engineering: #1d4ed8;
  --accent-learn: #047857;
  --accent-discovery: #a16207;
  --accent-skip: #6b7280;
  --accent-default: #44403c;

  --radius: 14px;
  --radius-sm: 8px;
  --max-width: 1100px;
  --gutter: max(1rem, env(safe-area-inset-left), env(safe-area-inset-right));
  --measure: 68ch;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #131417;
    --surface: #1b1c20;
    --surface-sunken: #222329;
    --text: #ecebe6;
    --text-muted: #a9a69e;
    --border: #2d2e35;
    --border-strong: #3d3f47;
    --link: #93b4ff;
    --focus: #93b4ff;
    --shadow: 0 1px 2px rgb(0 0 0 / 0.3);

    --accent-must-know: #fb923c;
    --accent-ai: #b8a1ff;
    --accent-videos: #fb7185;
    --accent-engineering: #7fb0ff;
    --accent-learn: #4ade9f;
    --accent-discovery: #f5c451;
    --accent-skip: #9ca3af;
    --accent-default: #d6d3d1;
  }
}

/* ---------- Base ---------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: 4.5rem;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  font-kerning: normal;
  font-feature-settings: "kern", "liga";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1,
h2,
h3,
p,
ul {
  margin: 0;
}

h1,
h2,
h3 {
  text-wrap: balance;
}

p,
li {
  text-wrap: pretty;
  overflow-wrap: break-word;
}

a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration-thickness: 2px;
}

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: 4px;
}

.wrap {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3rem;
  z-index: 10;
  padding: 0.5rem 0.9rem;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  top: 1rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- Masthead ---------- */

.masthead {
  padding-block: max(2rem, env(safe-area-inset-top)) 1.5rem;
}

.masthead-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.lang-switch {
  display: inline-flex;
  flex: none;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
}

.lang-switch button {
  min-width: 2.75rem;
  min-height: 2rem;
  padding: 0.2rem 0.7rem;
  font: inherit;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  background: none;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
}

.lang-switch button + button {
  box-shadow: -1px 0 0 var(--border);
}

.lang-switch button[aria-pressed="true"] {
  color: var(--bg);
  background: var(--text);
  box-shadow: none;
}

.lang-switch button[aria-pressed="true"] + button {
  box-shadow: none;
}

.eyebrow {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.masthead h1 {
  margin-top: 0.35rem;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(2.25rem, 1.6rem + 3.2vw, 3.5rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
}

.masthead-date {
  margin-top: 0.6rem;
  font-size: 1.125rem;
  color: var(--text);
}

.masthead-stats {
  margin-top: 0.25rem;
  font-size: 0.9375rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.masthead-stats:empty {
  display: none;
}

.masthead-intro {
  margin-top: 1rem;
  max-width: var(--measure);
  font-size: 1.0625rem;
}

.stale-note {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.35rem 0.75rem;
  font-size: 0.875rem;
  border: 1px solid var(--accent-discovery);
  border-radius: 999px;
  color: var(--text);
}

/* ---------- Section nav ---------- */

.section-nav {
  position: sticky;
  top: 0;
  z-index: 5;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  -webkit-backdrop-filter: saturate(1.4) blur(10px);
  backdrop-filter: saturate(1.4) blur(10px);
  border-bottom: 1px solid var(--border);
}

.section-nav-list {
  display: flex;
  gap: 0.4rem;
  padding: 0.6rem 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  /* Keep the first/last chip reachable next to the gutters. */
  scroll-padding-inline: var(--gutter);
}

.section-nav-list::-webkit-scrollbar {
  display: none;
}

.section-nav-list a {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  min-height: 2.25rem;
  padding: 0.3rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-decoration: none;
  white-space: nowrap;
}

.section-nav-list a::before {
  content: "";
  width: 0.5em;
  height: 0.5em;
  border-radius: 50%;
  background: var(--accent, var(--accent-default));
}

.section-nav-list a[aria-current="true"] {
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--accent);
}

/* ---------- Sections ---------- */

main {
  padding-block: 1.5rem 3rem;
}

main:focus {
  outline: none;
}

.section {
  --accent: var(--accent-default);
  padding-block: 1.75rem;
}

.section + .section {
  border-top: 1px solid var(--border);
}

[data-section="must-know"] { --accent: var(--accent-must-know); }
[data-section="ai"] { --accent: var(--accent-ai); }
[data-section="videos"] { --accent: var(--accent-videos); }
[data-section="engineering"] { --accent: var(--accent-engineering); }
[data-section="learn-one-thing"] { --accent: var(--accent-learn); }
[data-section="discovery"] { --accent: var(--accent-discovery); }
[data-section="skip-the-noise"] { --accent: var(--accent-skip); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.25rem 1rem;
  margin-bottom: 1rem;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}

.section-title::before {
  content: "";
  width: 1.5rem;
  height: 3px;
  border-radius: 2px;
  background: var(--accent);
}

.section-meta {
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.section-desc {
  flex: 0 0 100%;
  color: var(--text-muted);
  font-size: 0.9375rem;
}

.cards {
  display: grid;
  gap: 1rem;
  grid-template-columns: minmax(0, 1fr);
  list-style: none;
  padding: 0;
}

.section-empty {
  color: var(--text-muted);
  font-style: italic;
}

/* ---------- Card ---------- */

.card {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  height: 100%;
  padding: 1.15rem 1.15rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  list-style: none;
  padding: 0;
}

.card-tags li {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.card-tags li + li::before {
  content: "·";
  margin-right: 0.35rem;
  color: var(--text-muted);
}

.card-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.card-title a {
  color: inherit;
  text-decoration: none;
}

.card-title a:hover {
  text-decoration: underline;
  text-decoration-color: var(--accent);
}

.card-summary {
  max-width: var(--measure);
}

.card-takeaways {
  display: grid;
  gap: 0.35rem;
  max-width: var(--measure);
  padding-left: 1.2rem;
}

.card-takeaways li::marker {
  color: var(--accent);
}

.card-why {
  max-width: var(--measure);
  padding: 0.7rem 0.9rem;
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--surface-sunken);
  font-size: 0.9375rem;
}

.card-why-label {
  margin-bottom: 0.15rem;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}

.card-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem 0.5rem;
  margin-top: auto;
  padding-top: 0.2rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.card-meta > * + *::before {
  content: "·";
  margin-right: 0.5rem;
}

.card-meta a {
  color: inherit;
}

.card-source {
  font-weight: 600;
}

/* Video card: thumbnail with a play icon; the title link covers the whole card. */
.card-video {
  position: relative;
}

.card-video .card-title a::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
}

.card-video:has(.card-title a:focus-visible) {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

.card-video .card-title a:focus-visible {
  outline: none;
}

.card-video .card-meta a {
  position: relative;
  z-index: 1;
}

.card-thumb {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border-radius: var(--radius-sm);
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--accent) 22%, transparent), transparent 70%),
    var(--surface-sunken);
}

.card-thumb img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-thumb-play {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 3.5rem;
  height: 3.5rem;
  translate: -50% -50%;
  border-radius: 50%;
  background: rgb(0 0 0 / 0.6);
  box-shadow: 0 2px 12px rgb(0 0 0 / 0.3);
  transition: background-color 0.15s ease, scale 0.15s ease;
}

.card-thumb-play::before {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  width: 1.1rem;
  height: 1.3rem;
  translate: 12% 0;
  background: #fff;
  clip-path: polygon(0 0, 100% 50%, 0 100%);
}

.card-video:hover .card-thumb-play {
  background: var(--accent-videos);
  scale: 1.08;
}

.card-thumb-duration {
  position: absolute;
  right: 0.5rem;
  bottom: 0.5rem;
  padding: 0.1rem 0.4rem;
  border-radius: 4px;
  background: rgb(0 0 0 / 0.75);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  line-height: 1.4;
}

.card-channel {
  font-weight: 600;
  color: var(--text);
}

.card-meta > .card-action {
  margin-left: auto;
  padding: 0.2rem 0.75rem;
  border: 1px solid color-mix(in srgb, var(--accent) 50%, var(--border));
  border-radius: 999px;
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
}

.card-meta > .card-action::before {
  content: none;
}

.card-meta > .card-action::after {
  content: " ▸";
}

.card-meta > .card-action:hover {
  background: color-mix(in srgb, var(--accent) 10%, transparent);
}

@media (prefers-reduced-motion: reduce) {
  .card-thumb-play {
    transition: none;
  }
}

/* Learn one thing: a single, larger feature card. */
.layout-feature .card {
  padding: 1.4rem 1.25rem 1.2rem;
  border-color: color-mix(in srgb, var(--accent) 35%, var(--border));
}

.layout-feature .card-title {
  font-size: clamp(1.4rem, 1.2rem + 1vw, 1.85rem);
}

.layout-feature .card-summary {
  font-size: 1.0625rem;
}

/* Skip the noise: quiet, compact cards. */
.layout-compact .card {
  gap: 0.5rem;
  padding: 0.9rem 1rem;
  background: transparent;
  box-shadow: none;
  border-style: dashed;
}

.layout-compact .card-title {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.35;
  letter-spacing: 0;
  color: var(--text-muted);
}

.layout-compact .card-summary,
.layout-compact .card-why {
  font-size: 0.875rem;
}

.layout-compact .card-why {
  padding: 0;
  border: 0;
  background: none;
}

/* ---------- States & footer ---------- */

.state {
  padding: 2rem 1.25rem;
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius);
  color: var(--text-muted);
  text-align: center;
}

.state-error {
  color: var(--text);
}

.state button {
  margin-top: 1rem;
  padding: 0.55rem 1.1rem;
  font: inherit;
  font-weight: 600;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  cursor: pointer;
}

.state-error code {
  font-family: var(--font-mono);
  font-size: 0.875em;
}

.site-footer {
  padding-block: 0 max(2rem, env(safe-area-inset-bottom));
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* ---------- Tablet ---------- */

@media (min-width: 720px) {
  .masthead {
    padding-top: max(3rem, env(safe-area-inset-top));
  }

  .layout-grid .cards,
  .layout-compact .cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .card {
    padding: 1.35rem 1.4rem 1.15rem;
  }
}

/* ---------- Desktop ---------- */

@media (min-width: 1000px) {
  .layout-compact .cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  /* Full-width cards: text on the left, "why" on the right. */
  .layout-list .card,
  .layout-feature .card {
    display: grid;
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    grid-template-areas:
      "tags   why"
      "title  why"
      "summary why"
      "takeaways why"
      "meta   meta";
    grid-template-rows: auto auto auto 1fr auto;
    column-gap: 2rem;
  }

  .layout-list .card-tags,
  .layout-feature .card-tags { grid-area: tags; }
  .layout-list .card-title,
  .layout-feature .card-title { grid-area: title; }
  .layout-list .card-summary,
  .layout-feature .card-summary { grid-area: summary; }
  .layout-list .card-takeaways,
  .layout-feature .card-takeaways { grid-area: takeaways; }
  .layout-list .card-meta,
  .layout-feature .card-meta { grid-area: meta; }

  .layout-list .card-why,
  .layout-feature .card-why {
    grid-area: why;
    align-self: start;
  }

  /* Video cards keep the stacked layout in full-width sections. */
  .layout-list .card-video,
  .layout-feature .card-video {
    display: flex;
  }
}

/* ---------- Print ---------- */

@media print {
  .section-nav,
  .skip-link,
  .lang-switch,
  .card-thumb-play {
    display: none;
  }

  .card {
    box-shadow: none;
    break-inside: avoid;
  }
}