@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@200;300;400;500&display=swap');

/* Dark is the default theme (no data-theme attribute needed).
   [data-theme="light"] below overrides every token for light mode. */
:root {
  --bg: #000;
  --fg: rgba(255,255,255,0.92);
  --fg-dim: rgba(255,255,255,0.5);
  --fg-faint: rgba(255,255,255,0.32);
  --fg-soft: rgba(255,255,255,0.8);
  --line: rgba(255,255,255,0.09);
  --grid-line: rgba(255,255,255,0.14);
  --overlay-bg: rgba(0,0,0,0.97);
  --input-bg: var(--bg);
  --input-border: rgba(255,255,255,0.16);
  --input-border-focus: rgba(255,255,255,0.5);
  --sheet-edge: rgba(255,255,255,0.08);
  --logo-filter: drop-shadow(0 0 6px rgba(0,0,0,0.35));
  --error: #e0534f; /* same shade in both themes — readable on black or white */
}

:root[data-theme="light"] {
  --bg: #fff;
  --fg: rgba(0,0,0,0.92);
  --fg-dim: rgba(0,0,0,0.55);
  --fg-faint: rgba(0,0,0,0.38);
  --fg-soft: rgba(0,0,0,0.78);
  --line: rgba(0,0,0,0.1);
  --grid-line: rgba(0,0,0,0.12);
  --overlay-bg: rgba(255,255,255,0.97);
  --input-bg: var(--bg);
  --input-border: rgba(0,0,0,0.18);
  --input-border-focus: rgba(0,0,0,0.45);
  --sheet-edge: rgba(0,0,0,0.12);
  /* logo-full.png is drawn white; invert it back to dark on a light page. */
  --logo-filter: invert(1) drop-shadow(0 0 6px rgba(0,0,0,0.15));
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  font-weight: 300;
  min-height: 100%;
}

a { color: inherit; }
[hidden] { display: none !important; }

/* Grid texture used on interior pages */
.grid-bg {
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 42px 42px;
  background-position: -1px -1px;
}

/* ---------- Brand mark (clickable, returns home) ---------- */
.brand-link {
  position: fixed;
  top: 32px;
  left: 32px;
  z-index: 70;
  display: block;
  line-height: 0;
}
.brand-logo {
  /* The PNG has transparent padding; the negative margins keep the
     visible wordmark's top-left corner at 32px / 32px. */
  height: 52px;
  margin: -10.5px 0 0 -10px;
  width: auto;
  display: block;
  filter: var(--logo-filter);
  transition: opacity 0.25s ease;
}
.brand-link:hover .brand-logo { opacity: 0.7; }

/* ---------- Menu button ----------
   Icon is the "E" from the wordmark, measured from logo-full.png:
   three equal bars, 95x141 units, stroke 11.5, round caps, white.
   The button itself is a 44px tap target centred on the logo. */
.menu-btn {
  position: fixed;
  top: 25px;
  right: 17px;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  z-index: 70;
}
.menu-btn svg {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  overflow: visible;
  transition: opacity 0.3s ease;
}
.menu-btn .icon-menu { width: 13.5px; height: 20px; }
.menu-btn .icon-close { width: 14px; height: 14px; opacity: 0; }
.menu-btn svg line {
  stroke: var(--fg);
  stroke-width: 11.5;
  stroke-linecap: round;
}
.menu-btn .icon-close line { stroke-width: 14; }
/* The actual open/close state is driven purely by .menu-open (JS toggles
   it on click) so it works the same everywhere. The :hover preview is
   extra, and kept to real mouse hover only — on touch, tapping can leave
   an element "stuck" in :hover with no way to un-hover it, which left the
   X showing after the menu was closed on mobile. */
.menu-btn.menu-open .icon-menu { opacity: 0; }
.menu-btn.menu-open .icon-close { opacity: 1; }
@media (hover: hover) and (pointer: fine) {
  .menu-btn:hover .icon-menu { opacity: 0; }
  .menu-btn:hover .icon-close { opacity: 1; }
}

/* ---------- Theme toggle (sun / moon, left of the menu button) ---------- */
.theme-toggle {
  position: fixed;
  top: 27px;
  right: 71px;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  z-index: 70;
  transition: opacity 0.25s ease;
}
.theme-toggle:hover { opacity: 0.7; }
.theme-toggle svg {
  position: absolute;
  width: 19px;
  height: 19px;
  transition: opacity 0.25s ease, transform 0.35s ease;
}
.theme-toggle svg circle,
.theme-toggle svg line { stroke: var(--fg); stroke-width: 1.6; stroke-linecap: round; fill: none; }
.theme-toggle .icon-moon path { fill: var(--fg); stroke: none; }
.theme-toggle .icon-sun { opacity: 0; transform: scale(0.6) rotate(-45deg); }
.theme-toggle .icon-moon { opacity: 1; transform: scale(1) rotate(0deg); }
:root[data-theme="light"] .theme-toggle .icon-sun { opacity: 1; transform: scale(1) rotate(0deg); }
:root[data-theme="light"] .theme-toggle .icon-moon { opacity: 0; transform: scale(0.6) rotate(45deg); }

/* ---------- Tooltip popup ----------
   Reusable on any icon-only control: add class="tip" and an aria-label,
   the label text itself becomes the popup. Used on the menu and theme
   buttons here, which are already position:fixed (their own positioning
   context) — if you drop .tip on an element that isn't already
   positioned, give it its own position:relative/fixed/absolute/sticky
   too, since .tip itself intentionally sets no position (that clobbered
   .menu-btn / .theme-toggle's position:fixed last time, knocking both
   buttons out of their fixed top-right spot and into normal flow). */
.tip::after {
  content: attr(aria-label);
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  background: var(--fg);
  color: var(--bg);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.03em;
  white-space: nowrap;
  padding: 6px 10px;
  opacity: 0;
  transform: translateY(-4px);
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
  z-index: 80;
}
.tip:focus-visible::after { opacity: 1; transform: translateY(0); }
@media (hover: hover) and (pointer: fine) {
  /* Real mouse hover only — same "stuck :hover on touch" reasoning as the
     menu icon above, so a tap can't leave this popup stuck open on mobile. */
  .tip:hover::after { opacity: 1; transform: translateY(0); }
}

/* ---------- Full-screen nav overlay ---------- */
.nav-overlay {
  position: fixed;
  inset: 0;
  background: var(--overlay-bg);
  z-index: 60;
  display: flex;
  align-items: center;
  padding: 0 48px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.4s ease, visibility 0s linear 0.4s;
}
.nav-overlay.open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition: opacity 0.4s ease;
}
/* Groups the sign-in box and the link list as one vertically-centered
   unit inside .nav-overlay (which centers its single flex child). */
.nav-menu {
  display: flex;
  flex-direction: column;
  gap: 36px;
}

/* Sign-in box at the top of the menu — content is invite-only, so the
   links below it don't go anywhere yet; this is where you actually get in. */
.nav-signin {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  max-width: 420px;
  padding: 18px 22px;
  border: 1px solid var(--line);
}
.nav-signin-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.nav-signin-label {
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-faint);
}
.nav-signin-sub {
  font-size: 13px;
  color: var(--fg-dim);
}
.nav-signin-btn {
  flex: none;
  background: var(--fg);
  color: var(--bg);
  text-decoration: none;
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 11px 20px;
  transition: opacity 0.25s ease;
}
.nav-signin-btn:hover { opacity: 0.85; }

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.nav-list a {
  text-decoration: none;
  font-size: clamp(30px, 5.5vw, 52px);
  font-weight: 200;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--fg);
  opacity: 0.78;
  transition: opacity 0.25s ease;
}
.nav-list a:hover, .nav-list a:focus { opacity: 1; }
/* Locked: nothing to browse yet, so clicking shows .nav-lock-msg instead
   of navigating (wired in nav.js) rather than pretending there's a page there. */
.nav-list a[aria-current="page"] {
  opacity: 1;
  font-weight: 400;
  border-bottom: 2px solid var(--fg);
  padding-bottom: 4px;
}
.nav-lock-msg {
  font-size: 13px;
  color: var(--fg-dim);
  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transition: opacity 0.25s ease;
  margin: 0;
}
.nav-lock-msg.show { opacity: 1; max-height: 2em; margin-top: 4px; }

/* ---------- Footer ---------- */
.site-footer {
  text-align: center;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--fg-dim);
  padding: 40px 20px 26px;
}
.site-footer.fixed {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 0 20px 22px;
  z-index: 5;
}
.footer-links {
  margin-top: 10px;
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}
.footer-links a {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--fg-faint);
  text-decoration: none;
  transition: color 0.25s ease;
}
.footer-links a:hover { color: var(--fg); }

/* ---------- Interior page header ---------- */
.page-header {
  padding: 150px 40px 44px;
  max-width: 1200px;
}
.eyebrow {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
  display: block;
  margin-bottom: 20px;
}
.page-title {
  font-size: clamp(34px, 6vw, 66px);
  font-weight: 200;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  margin: 0 0 16px;
}
.page-sub {
  color: var(--fg-dim);
  font-size: 15px;
  max-width: 540px;
  line-height: 1.65;
  margin: 0;
}

/* ---------- Featured entry ---------- */
.featured {
  display: block;
  text-decoration: none;
  margin: 0 40px;
  padding: 36px 0 40px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  max-width: 900px;
}
.featured .kicker {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
  display: block;
  margin-bottom: 18px;
}
.featured h2 {
  font-size: clamp(26px, 3.6vw, 40px);
  font-weight: 300;
  letter-spacing: 0.01em;
  margin: 0 0 16px;
}
.featured p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--fg-dim);
  margin: 0 0 20px;
  max-width: 720px;
}
.featured .more {
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--fg-faint);
  transition: color 0.25s ease;
}
.featured:hover .more { color: var(--fg); }

/* ---------- Entry list (papers / articles / research) ---------- */
.entry-list {
  margin: 0 40px 20px;
  max-width: 900px;
}
.entry {
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 4px 20px;
  padding: 30px 0;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
  transition: opacity 0.25s ease;
}
.entry:hover { opacity: 0.72; }
.entry .num {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--fg-faint);
  padding-top: 5px;
}
.entry h3 {
  font-size: 21px;
  font-weight: 400;
  letter-spacing: 0.01em;
  margin: 0 0 9px;
}
.entry p {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--fg-dim);
  margin: 0 0 12px;
}
.entry .topic {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-faint);
}

/* Card variant of .entry-list: a grid of thumbnail cards, used on papers.html
   to lay out "this week's papers" the way academy.dair.ai/papers does. */
.entry-list.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 38px 28px;
}
.entry-list.cards .entry {
  display: block;
  padding: 0;
  border-bottom: none;
}
.entry-list.cards .entry .sheet { margin-bottom: 16px; }
.entry-list.cards .entry h3 { font-size: 16.5px; margin: 0 0 8px; }
.entry-list.cards .entry p {
  font-size: 13.5px;
  line-height: 1.55;
  margin: 0 0 12px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.entry-list.cards .entry .meta-row {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--fg-faint);
}
.entry-list.cards .entry .meta-row .topic { color: var(--fg-dim); }

/* ---------- Papers listing: stats, search, sidebar ---------- */
.stats {
  display: flex;
  gap: 48px;
  margin: 34px 0 0;
}
.stats div { margin: 0; display: flex; flex-direction: column-reverse; }
.stats dd {
  margin: 0;
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 200;
  letter-spacing: 0.02em;
  line-height: 1;
}
.stats dt {
  margin-top: 10px;
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
}
.search {
  margin-top: 38px;
  max-width: 620px;
  position: relative;
}
.search input {
  width: 100%;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--fg);
  font: inherit;
  font-size: 15px;
  padding: 15px 18px;
  border-radius: 0;
  outline: none;
  transition: border-color 0.25s ease;
  -webkit-appearance: none;
}
.search input::placeholder { color: var(--fg-faint); }
.search input:focus { border-color: var(--input-border-focus); }

.papers-layout {
  display: grid;
  grid-template-columns: 210px minmax(0, 1fr);
  gap: 64px;
  padding: 0 40px;
  max-width: 1200px;
}
/* Solid panel so the page's grid texture doesn't run behind the topic list. */
.papers-side { background: var(--bg); }
.papers-layout .featured,
.papers-layout .entry-list { margin: 0; max-width: none; }
.side-label {
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.side-block + .side-block { margin-top: 38px; }
.topic-list { list-style: none; margin: 0; padding: 0; }
.topic-list button,
.topic-list a {
  width: 100%;
  display: grid;
  grid-template-columns: 30px 1fr auto;
  align-items: baseline;
  padding: 11px 0;
  background: none;
  border: none;
  border-bottom: 1px solid var(--line);
  color: var(--fg-dim);
  font: inherit;
  font-size: 15px;
  text-align: left;
  text-decoration: none;
  cursor: pointer;
  transition: color 0.25s ease;
}
.topic-list button:hover, .topic-list a:hover,
.topic-list button.active { color: var(--fg); }
.topic-list .num, .topic-list .count {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--fg-faint);
}

/* Featured paper with a first-page thumbnail */
.featured-paper {
  display: grid;
  grid-template-columns: 170px 1fr;
  gap: 36px;
  align-items: start;
  padding-top: 0;
  border-top: none;
}
.list-head {
  display: flex;
  justify-content: space-between;
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
  padding: 44px 0 12px;
  border-bottom: 1px solid var(--line);
}
.no-results {
  color: var(--fg-dim);
  font-size: 15px;
  padding: 30px 0;
}

/* "First page" preview. Swap the .sheet div for
   <img class="sheet-img" src="..." alt="..."> once you have a page image. */
.sheet {
  aspect-ratio: 8.5 / 11;
  background: #f3f2ee;
  color: #111;
  padding: 11% 10%;
  box-shadow: 0 0 0 1px var(--sheet-edge);
  overflow: hidden;
  transition: opacity 0.25s ease;
}
.sheet-title {
  display: block;
  font-size: 11px;
  font-weight: 500;
  line-height: 1.3;
  text-align: center;
  margin-bottom: 9%;
}
.sheet::after {
  content: "";
  display: block;
  height: 100%;
  background: repeating-linear-gradient(#bbb 0 1.5px, transparent 1.5px 7px);
  opacity: 0.8;
}
.sheet-img {
  display: block;
  width: 100%;
  height: auto;
  box-shadow: 0 0 0 1px var(--sheet-edge);
}
.featured-paper:hover .sheet { opacity: 0.85; }

/* ---------- Detail page (a single paper / article) ---------- */
.detail-nav {
  padding: 140px 40px 0;
  max-width: 1200px;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-faint);
}
.detail-nav a { text-decoration: none; transition: color 0.25s ease; }
.detail-nav a:hover { color: var(--fg); }
.detail-nav .sep { margin: 0 12px; opacity: 0.6; }

.detail-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 72px;
  padding: 0 40px 40px;
  max-width: 1200px;
}
.detail-head { padding: 44px 0 36px; }
.detail-meta {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
  margin-bottom: 10px;
}
.detail-topics {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-dim);
  margin-bottom: 20px;
}
.detail-title {
  font-size: clamp(34px, 5.5vw, 62px);
  font-weight: 200;
  letter-spacing: 0.02em;
  line-height: 1.08;
  margin: 0;
}
.detail-byline {
  margin-top: 18px;
  font-size: 14px;
  color: var(--fg-dim);
}
.paper-preview {
  margin: 0 0 40px;
  max-width: 560px;
}
.paper-preview .sheet { padding: 9% 9%; }
.paper-preview .sheet-title { font-size: clamp(13px, 2vw, 18px); }
.paper-preview .sheet::after {
  background: repeating-linear-gradient(#c4c4c4 0 2px, transparent 2px 13px);
}
.section-label {
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
  padding-top: 34px;
  margin-bottom: 18px;
  border-top: 1px solid var(--line);
}
.detail-main .lede {
  font-size: clamp(18px, 2vw, 21px);
  font-weight: 300;
  line-height: 1.75;
  color: var(--fg-soft);
  margin: 0 0 40px;
}
.keypoints {
  list-style: none;
  margin: 0;
  padding: 0;
}
.keypoints li {
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 20px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}
.keypoints .num {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--fg-faint);
  padding-top: 4px;
}
.keypoints p {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--fg-soft);
}
.keypoints strong {
  font-weight: 400;
  color: var(--fg);
}

.detail-side {
  padding-top: 44px;
  align-self: start;
  position: sticky;
  top: 110px;
}
.link-list, .more-list { list-style: none; margin: 0; padding: 0; }
.link-list a,
.more-list a {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
  font-size: 15px;
  color: var(--fg-dim);
  text-decoration: none;
  transition: color 0.25s ease;
}
.more-list a { justify-content: flex-start; }
.link-list a:hover, .more-list a:hover { color: var(--fg); }
.link-list .arrow, .more-list .num {
  font-size: 12px;
  color: var(--fg-faint);
}
.more-list .num { width: 30px; flex: none; padding-top: 2px; letter-spacing: 0.06em; }

/* ---------- About: editorial, research-institute tone ----------
   Large statements outside any card, generous vertical rhythm, hairline
   dividers between sections instead of boxes. Each section is its own
   max-width:1200px block so they all share the page's side margins. */
.about-hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 150px 40px 0;
}
.about-statement {
  margin: 34px 0 0;
  max-width: 760px;
  font-size: clamp(30px, 4.4vw, 52px);
  font-weight: 200;
  line-height: 1.28;
  letter-spacing: 0.005em;
}

.about-columns {
  max-width: 1200px;
  margin: 90px auto 0;
  padding: 60px 40px 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px 60px;
}
.about-columns p {
  margin: 0;
  max-width: 480px;
  font-size: 17px;
  line-height: 1.8;
  color: var(--fg-soft);
}

.about-philosophy,
.about-explore,
.about-work,
.about-audience {
  max-width: 1200px;
  margin: 120px auto 0;
  padding: 0 40px;
}
.about-substatement {
  margin: 0 0 28px;
  max-width: 640px;
  font-size: clamp(26px, 3.6vw, 40px);
  font-weight: 200;
  line-height: 1.3;
}
.about-philosophy > p:not(.about-substatement):not(.about-ask-lead),
.about-work > p:not(.about-substatement) {
  max-width: 640px;
  font-size: 17px;
  line-height: 1.8;
  color: var(--fg-soft);
  margin: 0 0 34px;
}
.about-ask-lead {
  margin: 0 0 18px;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
}
.about-questions {
  list-style: none;
  margin: 0 0 40px;
  padding: 0;
  max-width: 680px;
}
.about-questions li {
  padding: 18px 0;
  font-size: clamp(19px, 2.4vw, 26px);
  font-weight: 300;
  line-height: 1.3;
  border-bottom: 1px solid var(--line);
}
.about-questions li:first-child { border-top: 1px solid var(--line); }

.explore-grid {
  margin-top: 34px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 60px;
}
.explore-item {
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}
.explore-item .num {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--fg-faint);
}
.explore-item h3 {
  margin: 10px 0 10px;
  font-size: 19px;
  font-weight: 400;
  letter-spacing: 0.005em;
}
.explore-item p {
  margin: 0;
  max-width: 420px;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--fg-dim);
}

.about-list {
  list-style: none;
  margin: 20px 0 34px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 30px;
}
.about-list li {
  position: relative;
  padding-left: 16px;
  font-size: 15px;
  color: var(--fg-dim);
}
.about-list li::before {
  content: "\2014";
  position: absolute;
  left: 0;
  color: var(--fg-faint);
}
.about-list-stack {
  flex-direction: column;
  gap: 14px;
  max-width: 640px;
}
.about-list-stack li { font-size: 16px; line-height: 1.6; }
.about-emphasis {
  max-width: 640px;
  margin: 0 !important;
  font-size: 19px !important;
  font-weight: 300;
  line-height: 1.6 !important;
  color: var(--fg) !important;
}

.about-closing {
  max-width: 1200px;
  margin: 130px auto 0;
  padding: 60px 40px 110px;
  border-top: 1px solid var(--line);
}
.about-closing p {
  margin: 0 0 14px;
  max-width: 760px;
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 200;
  line-height: 1.4;
}
.about-closing-brand {
  color: var(--fg-faint) !important;
  font-size: 13px !important;
  font-weight: 400 !important;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ---------- Sign in page ----------
   UI only for now — see the <script> at the bottom of login.html. There's
   no backend yet, so submitting just shows .login-status instead of
   pretending to sign anyone in. */
.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 120px 24px 60px;
}
.login-card {
  width: 100%;
  max-width: 380px;
}
.login-card .eyebrow { text-align: center; }
.login-card h1 {
  font-size: clamp(28px, 5vw, 38px);
  font-weight: 200;
  letter-spacing: 0.02em;
  text-align: center;
  margin: 0 0 14px;
}
.login-sub {
  font-size: 14px;
  line-height: 1.6;
  color: var(--fg-dim);
  text-align: center;
  max-width: 320px;
  margin: 0 auto 40px;
}
.login-form { display: flex; flex-direction: column; gap: 20px; }
.field { display: flex; flex-direction: column; gap: 8px; }
.field label {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-faint);
}
.field input {
  width: 100%;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--fg);
  font: inherit;
  font-size: 15px;
  padding: 13px 14px;
  border-radius: 0;
  outline: none;
  transition: border-color 0.25s ease;
  -webkit-appearance: none;
}
.field input:focus { border-color: var(--input-border-focus); }
.login-submit {
  margin-top: 4px;
  width: 100%;
  background: var(--fg);
  color: var(--bg);
  border: none;
  font: inherit;
  font-size: 14px;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 14px;
  cursor: pointer;
  transition: opacity 0.25s ease;
}
.login-submit:hover { opacity: 0.85; }
.login-status {
  margin-top: 18px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--error);
  text-align: center;
  min-height: 1.6em;
}
.login-form.has-error .field input { border-color: var(--error); }
.login-note {
  margin-top: 34px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--fg-faint);
  text-align: center;
}

@media (max-width: 640px) {
  .brand-link { top: 20px; left: 20px; }
  .brand-logo { height: 40px; margin: -8px 0 0 -7.7px; }
  .menu-btn { top: 10px; right: 4px; }
  .menu-btn .icon-menu { width: 11.5px; height: 17px; }
  .menu-btn .icon-close { width: 12px; height: 12px; }
  .theme-toggle { top: 11px; right: 50px; width: 36px; height: 36px; }
  .theme-toggle svg { width: 16px; height: 16px; }
  .nav-overlay { padding: 0 28px; }
  .page-header { padding: 108px 22px 32px; }
  .featured, .entry-list { margin-left: 22px; margin-right: 22px; }
  .papers-layout, .detail-nav, .detail-layout { padding-left: 22px; padding-right: 22px; }
  .papers-layout .featured, .papers-layout .entry-list { margin-left: 0; margin-right: 0; }
  .detail-nav { padding-top: 100px; }
  .entry, .keypoints li { grid-template-columns: 40px 1fr; gap: 14px; }
  .featured-paper { grid-template-columns: 1fr; }
  .featured-paper .sheet { width: 150px; }
  .stats { gap: 32px; }

  .about-hero { padding: 108px 22px 0; }
  .about-columns,
  .about-philosophy,
  .about-explore,
  .about-work,
  .about-audience,
  .about-closing {
    padding-left: 22px;
    padding-right: 22px;
  }
  .about-columns { grid-template-columns: 1fr; gap: 30px; margin-top: 64px; padding-top: 44px; }
  .about-philosophy, .about-explore, .about-work, .about-audience { margin-top: 80px; }
  .explore-grid { grid-template-columns: 1fr; }
  .explore-item:first-child { border-top: 1px solid var(--line); }
  .about-closing { margin-top: 90px; padding-top: 44px; padding-bottom: 80px; }
}

@media (max-width: 900px) {
  .papers-layout, .detail-layout { grid-template-columns: 1fr; gap: 0; }
  .papers-side { display: none; }
  .detail-side { position: static; padding-top: 10px; }
}