/* Landing page. Builds on style.css tokens (+ spring2027.css for tags/pills). */

.home {
  --text-2: #52525b;
  --wrap: 1120px;
  --shadow-window: 0 1px 2px rgba(24, 24, 27, .04), 0 8px 24px -12px rgba(24, 24, 27, .08), 0 32px 64px -32px rgba(24, 24, 27, .14);
  --ease: cubic-bezier(.2, .7, .2, 1);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .home {
    --text-2: #a1a1aa;
    --shadow-window: 0 0 0 1px rgba(255, 255, 255, .02), 0 32px 64px -32px rgba(0, 0, 0, .8);
  }
}
.home main { display: block; padding: 0; max-width: none; }
.home main > section { max-width: var(--wrap); margin: 0 auto; padding-left: 24px; padding-right: 24px; }

/* ---- Header -------------------------------------------------------------- */
.site-header { position: sticky; top: 0; z-index: 20; max-width: none; padding: 0; background: color-mix(in srgb, var(--bg) 88%, transparent); border-bottom: 1px solid var(--border); }
@supports (backdrop-filter: blur(8px)) { .site-header { backdrop-filter: saturate(1.4) blur(8px); } }
.home .site-header .nav { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; height: 60px; border-bottom: 0; margin-bottom: 0; gap: 6px; }
.home .nav a:not(.brand):not(.nav-cta) { transition: color .15s, background .15s; }
.nav-cta {
  margin-left: 6px;
  padding: 6px 12px !important;
  border-radius: 8px !important;
  background: #18181b !important;
  color: #fff !important;
  font-weight: 500;
  white-space: nowrap;
  transition: opacity .15s;
}
.nav-cta:hover { opacity: .86; text-decoration: none; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .nav-cta { background: #fafafa !important; color: #18181b !important; } }

/* ---- Hero ---------------------------------------------------------------- */
.hero { position: relative; text-align: center; padding-top: 96px; }
.hero-bg {
  position: absolute;
  top: -1px;
  left: 50%;
  width: 100vw;
  height: 620px;
  transform: translateX(-50%);
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--border) 1px, transparent 1px),
    linear-gradient(to bottom, var(--border) 1px, transparent 1px);
  background-size: 56px 56px;
  background-position: center top;
  opacity: .5;
  -webkit-mask-image: radial-gradient(ellipse 55% 70% at 50% 0%, #000 0%, transparent 72%);
  mask-image: radial-gradient(ellipse 55% 70% at 50% 0%, #000 0%, transparent 72%);
}
.home { overflow-x: clip; }

.pill-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 30px;
  padding: 0 12px 0 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-size: 12.5px;
  font-weight: 500;
  box-shadow: 0 1px 2px rgba(24, 24, 27, .04);
  transition: border-color .15s;
}
.pill-tag:hover { border-color: var(--border-strong); text-decoration: none; }
.pill-tag .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 0 3px color-mix(in srgb, var(--blue) 18%, transparent); }
.pill-sep { width: 1px; height: 12px; background: var(--border); }
.pill-meta { color: var(--muted); font-weight: 400; font-variant-numeric: tabular-nums; }

.hero h1 {
  margin: 28px auto 0;
  max-width: 14em;
  font-size: clamp(36px, 6.4vw, 64px);
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: -0.035em;
  color: var(--text);
  text-wrap: balance;
}
 .hero h1 .nw { display: inline-block; white-space: nowrap; }
:lang(zh-CN) .hero h1 { letter-spacing: -0.02em; line-height: 1.15; }
.hero .lede {
  margin: 22px auto 0;
  max-width: 32em;
  font-size: 17.5px;
  line-height: 1.65;
  color: var(--text-2);
  text-wrap: balance;
}

.cta-row { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  padding: 0 20px;
  border-radius: 10px;
  font: inherit;
  font-size: 14.5px;
  font-weight: 500;
  white-space: nowrap;
  transition: background .18s var(--ease), border-color .18s var(--ease), transform .18s var(--ease);
}
.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn .arrow { transition: transform .18s var(--ease); }
.btn:hover .arrow { transform: translateX(3px); }
.btn-primary { background: #18181b; color: #fff; box-shadow: 0 1px 2px rgba(0, 0, 0, .1), inset 0 1px 0 rgba(255, 255, 255, .08); }
.btn-primary:hover { background: #27272a; }
.btn-ghost, .btn-secondary { background: var(--surface); color: var(--text); border: 1px solid var(--border); box-shadow: 0 1px 2px rgba(24, 24, 27, .04); }
.btn-ghost:hover, .btn-secondary:hover { border-color: var(--border-strong); background: var(--subtle); }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .btn-primary { background: #fafafa; color: #18181b; }
  :root:not([data-theme="light"]) .btn-primary:hover { background: #e4e4e7; }
}

/* Keyboard focus for everything interactive on the page */
.home a:focus-visible, .home button:focus-visible, .home input:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}

/* ---- Product preview window --------------------------------------------- */
.window {
  max-width: 1040px;
  margin: 72px auto 0;
  text-align: left;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow-window);
  overflow: hidden;
}
.window-bar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  height: 42px;
  padding: 0 14px;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--subtle) 60%, var(--surface));
}
.lights { display: inline-flex; gap: 6px; }
.lights i { width: 10px; height: 10px; border-radius: 50%; background: var(--border-strong); opacity: .7; }
.window-title { font-size: 12.5px; color: var(--muted); font-weight: 500; }
.live { justify-self: end; display: inline-flex; align-items: center; gap: 6px; font-size: 12px; color: var(--muted); }
.live-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--green); }

.window-body { display: grid; grid-template-columns: 208px minmax(0, 1fr); min-height: 452px; }
.pv-side { padding: 18px 12px; border-right: 1px solid var(--border); background: color-mix(in srgb, var(--subtle) 35%, var(--surface)); }
.pv-side-title { margin: 0 8px 10px; font-size: 11.5px; font-weight: 500; color: var(--faint); letter-spacing: .04em; }
.pv-cats { display: flex; flex-direction: column; gap: 2px; }
.pv-cat {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  width: 100%;
  height: 32px;
  padding: 0 10px;
  border: 0;
  border-radius: 7px;
  background: transparent;
  color: var(--text-2);
  font: inherit;
  font-size: 13px;
  text-align: left;
  cursor: pointer;
  transition: background .15s, color .15s;
}
.pv-cat:hover { background: var(--subtle); color: var(--text); }
.pv-cat[aria-pressed="true"] { background: var(--surface); color: var(--text); font-weight: 500; box-shadow: 0 0 0 1px var(--border), 0 1px 2px rgba(24, 24, 27, .05); }
.pv-cat .n { font-size: 12px; color: var(--faint); font-variant-numeric: tabular-nums; font-weight: 400; }

.pv-main { padding: 18px 20px 14px; display: flex; flex-direction: column; min-width: 0; }
.pv-search input[type="search"] { height: 38px; width: 100%; padding-left: 36px; font-size: 14px; border-radius: 9px; }
.pv-search svg { left: 12px; }

.pv-head, .pv-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 128px 132px 72px 48px;
  align-items: center;
  gap: 12px;
}
.pv-head { margin-top: 16px; padding: 0 10px 8px; font-size: 11.5px; color: var(--faint); border-bottom: 1px solid var(--border); }
.pv-head .num, .pv-row .num { text-align: right; }
.pv-list { list-style: none; margin: 0; padding: 4px 0 0; flex: 1; }
.pv-row { padding: 8px 10px; border-radius: 8px; color: var(--text); transition: background .12s; }
.pv-row:hover { background: var(--subtle); text-decoration: none; }
.pv-row .r-title { min-width: 0; }
.pv-row .r-code { font-weight: 600; font-size: 13.5px; }
.pv-row .r-name { margin-left: 8px; font-size: 13px; color: var(--text-2); }
.pv-row .r-meta { display: block; font-size: 12px; color: var(--faint); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.pv-row .r-gened { display: flex; flex-wrap: wrap; gap: 4px; }
.pv-row .r-gened .tag { margin: 0; font-size: 11px; line-height: 18px; padding: 0 6px; }
.pv-row .r-fmt { font-size: 12.5px; color: var(--text-2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.pv-row .r-fmt .eight { color: var(--amber-text); }
.pv-row .num { font-size: 13.5px; font-weight: 600; font-variant-numeric: tabular-nums; }
.pv-row .num.gpa { font-weight: 500; color: var(--text-2); }
.pv-empty { padding: 40px 10px; color: var(--muted); font-size: 13px; text-align: center; }
.pv-foot { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 12px 10px 0; margin-top: 6px; border-top: 1px solid var(--border); font-size: 12.5px; color: var(--faint); }
.pv-foot a { color: var(--text); font-weight: 500; white-space: nowrap; }
.pv-foot a:hover { color: var(--blue-text); text-decoration: none; }

/* ---- Notice under the preview: independence disclaimer + contact -------- */
.notice {
  max-width: 720px;
  margin: 28px auto 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}
.notice p { margin: 0; }
.notice .fun { margin-bottom: 4px; color: var(--text-2); }
.notice .contact { margin-top: 4px; color: var(--text-2); }
.notice .contact a { color: var(--text); font-weight: 500; text-decoration: underline; text-decoration-color: var(--border-strong); text-underline-offset: 3px; }
@media (prefers-reduced-motion: no-preference) { .notice.reveal { animation-delay: .3s; } }

/* ---- Stats --------------------------------------------------------------- */
.stats-row { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 96px !important; }
.stats-row > div { padding: 4px 24px; border-left: 1px solid var(--border); }
.stats-row > div:first-child { border-left: 0; padding-left: 0; }
.stats-row b { display: block; font-size: 34px; font-weight: 650; letter-spacing: -0.03em; line-height: 1.15; font-variant-numeric: tabular-nums; }
.stats-row span { font-size: 13.5px; color: var(--muted); }

/* ---- Shared section typography ------------------------------------------ */
.kicker { margin: 0 0 12px; font-size: 13px; font-weight: 500; color: var(--blue-text); }
.home h2 { margin: 0; font-size: clamp(26px, 3.4vw, 36px); line-height: 1.2; font-weight: 650; letter-spacing: -0.025em; text-wrap: balance; }
.section-head { max-width: 560px; }
.section-desc, .feature-desc { margin: 14px 0 0; font-size: 16px; line-height: 1.7; color: var(--text-2); }
.fine { margin: 16px 0 0; font-size: 12.5px; color: var(--faint); }
.text-link { display: inline-block; margin-top: 22px; font-weight: 500; color: var(--text); }
.text-link:hover { color: var(--blue-text); text-decoration: none; }

/* ---- Feature: course page ------------------------------------------------ */
.feature {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: 64px;
  align-items: center;
  margin-top: 140px !important;
}
.course-preview {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow-window);
  color: var(--text);
  transition: transform .25s var(--ease), border-color .25s var(--ease);
}
.course-preview:hover { transform: translateY(-2px); border-color: var(--border-strong); text-decoration: none; }
.course-preview .tags { margin-bottom: -6px; }
.cp-head h3 { margin: 0; font-size: 22px; font-weight: 650; letter-spacing: -0.02em; }
.cp-head h3 small { margin-left: 10px; font-size: 16px; font-weight: 500; letter-spacing: 0; }
.cp-head p { margin: 4px 0 0; color: var(--muted); font-size: 13.5px; }
.cp-teacher { padding-top: 12px; border-top: 1px solid var(--border); }
.cp-teacher .who { font-weight: 600; font-size: 13.5px; }
.cp-grading { padding-top: 12px; border-top: 1px solid var(--border); }
.cp-grading-title { margin: 0 0 10px; font-size: 12px; color: var(--faint); }
.cp-bars { display: flex; height: 8px; border-radius: 4px; overflow: hidden; gap: 2px; }
.cp-bars span { background: var(--ink); }
.cp-bars span:nth-child(2) { opacity: .75; }
.cp-bars span:nth-child(3) { opacity: .55; }
.cp-bars span:nth-child(4) { opacity: .38; }
.cp-bars span:nth-child(n + 5) { opacity: .22; }
.cp-legend { display: flex; flex-wrap: wrap; gap: 4px 14px; margin-top: 10px; font-size: 12px; color: var(--text-2); }
.cp-legend b { font-weight: 600; color: var(--text); font-variant-numeric: tabular-nums; margin-left: 4px; }

/* ---- Gen Ed list --------------------------------------------------------- */
.geneds { margin-top: 140px !important; scroll-margin-top: 84px; }
.ge-list {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: 48px;
  border-top: 1px solid var(--border);
}
.ge-list li { border-bottom: 1px solid var(--border); }
.ge-list a {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4px 16px;
  padding: 20px 4px;
  color: var(--text);
  transition: padding .2s var(--ease);
}
.ge-list a:hover { text-decoration: none; padding-left: 10px; padding-right: 0; }
.ge-name { font-size: 16px; font-weight: 600; letter-spacing: -0.01em; }
.ge-codes { margin-left: 8px; font-size: 12px; font-weight: 400; color: var(--faint); letter-spacing: .02em; }
.ge-req { grid-column: 1; font-size: 13.5px; line-height: 1.6; color: var(--text-2); }
.ge-count { grid-row: 1 / span 2; grid-column: 2; align-self: center; font-size: 13px; font-weight: 500; color: var(--muted); white-space: nowrap; transition: color .15s; }
.ge-list a:hover .ge-count { color: var(--blue-text); }

/* ---- Data sources (asymmetric: heading left, items right) ---------------- */
.sources {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  gap: 64px;
  margin-top: 140px !important;
}
.how { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 36px 40px; }
.how-n { font-size: 12px; color: var(--faint); font-variant-numeric: tabular-nums; }
.how h3 { margin: 8px 0 6px; font-size: 15.5px; font-weight: 600; }
.how p { margin: 0; color: var(--text-2); line-height: 1.7; font-size: 14px; }
.how-featured h3 { font-size: 17px; font-weight: 700; }
.how-featured p { color: var(--text); font-weight: 600; }
.how a { color: var(--text); text-decoration: underline; text-decoration-color: var(--border-strong); text-underline-offset: 3px; }

/* ---- All courses band ---------------------------------------------------- */
.all-courses { display: flex; justify-content: space-between; align-items: center; gap: 32px; margin-top: 140px !important; }
.all-courses > div { max-width: 560px; }
.home .all-courses h2 { font-size: clamp(22px, 2.6vw, 28px); }
.all-courses p { margin: 10px 0 0; color: var(--text-2); line-height: 1.7; }

/* ---- Footer -------------------------------------------------------------- */
.home-footer {
  max-width: calc(var(--wrap) - 48px);
  width: calc(100% - 48px);
  margin: 120px auto 0;
  padding: 32px 0 48px;
  border-top: 1px solid var(--border);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--faint);
}
.home-footer p { margin: 0; max-width: 680px; }
.foot-brand { margin-bottom: 12px; font-size: 13px; }
.home-footer .contact { color: var(--muted); }
.home-footer .contact a { color: var(--text); }

/* ---- Entrance animation (short; off with reduced motion) ----------------- */
@media (prefers-reduced-motion: no-preference) {
  .reveal { animation: rise .45s var(--ease) both; }
  .hero h1.reveal { animation-delay: .04s; }
  .hero .lede.reveal { animation-delay: .08s; }
  .cta-row.reveal { animation-delay: .12s; }
  .window.reveal { animation: rise-window .6s var(--ease) .16s both; }
  html { scroll-behavior: smooth; }
}
@keyframes rise { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
@keyframes rise-window { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }

/* ---- Responsive ---------------------------------------------------------- */
@media (max-width: 960px) {
  .pv-head, .pv-row { grid-template-columns: minmax(0, 1fr) 120px 68px 44px; }
  .c-gened, .r-gened { display: none !important; }
  .feature, .sources { grid-template-columns: minmax(0, 1fr); gap: 36px; }
}
@media (max-width: 760px) {
  .home main > section { padding-left: 16px; padding-right: 16px; }
  .home .site-header .nav { padding: 0 16px; height: 56px; }
  .nav-cta { display: none; }
  .hero { padding-top: 56px; }
  .hero h1 { margin-top: 22px; }
  .hero .lede { font-size: 16px; }
  .cta-row { flex-direction: column; align-items: stretch; max-width: 360px; margin: 28px auto 0; }
  .window { margin-top: 44px; border-radius: 14px; }
  .window-bar { grid-template-columns: auto 1fr; gap: 12px; }
  .window-title { text-align: right; }
  .live { display: none; }
  .window-body { grid-template-columns: minmax(0, 1fr); min-height: 0; }
  .pv-side { border-right: 0; border-bottom: 1px solid var(--border); padding: 10px 12px; }
  .pv-side-title { display: none; }
  .pv-cats { flex-direction: row; overflow-x: auto; gap: 4px; scrollbar-width: none; }
  .pv-cats::-webkit-scrollbar { display: none; }
  .pv-cat { width: auto; flex: none; height: 30px; gap: 6px; }
  .pv-main { padding: 12px; }
  .pv-head, .pv-row { grid-template-columns: minmax(0, 1fr) 76px 38px; gap: 8px; }
  .pv-head span { white-space: nowrap; }
  .pv-list li:nth-child(n + 6) { display: none; }
  .c-fmt, .r-fmt { display: none !important; }
  .pv-head { padding: 0 6px 8px; }
  .pv-row { padding: 9px 6px; }
  .pv-row .r-name { display: block; margin: 1px 0 0; }
  .pv-foot { flex-direction: column; align-items: flex-start; gap: 4px; padding: 10px 6px 0; }
  .stats-row { grid-template-columns: repeat(2, 1fr); margin-top: 64px !important; row-gap: 24px; }
  .stats-row > div { padding: 0 16px; }
  .stats-row > div:nth-child(3) { border-left: 0; padding-left: 0; }
  .stats-row b { font-size: 28px; }
  .feature, .geneds, .sources, .all-courses { margin-top: 88px !important; }
  .course-preview { padding: 18px; }
  .ge-list { grid-template-columns: minmax(0, 1fr); margin-top: 28px; }
  .how { grid-template-columns: minmax(0, 1fr); gap: 24px; }
  .all-courses { flex-direction: column; align-items: flex-start; }
  .home-footer { margin-top: 80px; padding: 28px 0 40px; width: calc(100% - 32px); }
}