/*
 * The layout of the introduction page only. The components and every colour, radius and size
 * come from the Atelier web kit (atelier/atelier.css), so the page follows the application's
 * Glass themes; nothing here names a colour.
 */

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
}

body.at-root {
  /* The backdrop shows through; sections that hold reading sit on cards. */
  background: transparent;
  font-size: var(--at-size-lg);
  line-height: 1.6;
}

a {
  color: var(--at-accent-text);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

a.at-button:hover {
  text-decoration: none;
}

code {
  font-family: var(--at-font-mono);
  font-size: 0.9em;
}

/* One language at a time; `data-lang` on <html> decides which. */
html[data-lang="en"] [data-l="ja"],
html[data-lang="ja"] [data-l="en"] {
  display: none !important;
}

/* ---------------------------------------------------------------- navigation */

.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: var(--at-space-lg);
  height: 56px;
  padding: 0 var(--at-space-xl);
  border-bottom: 1px solid var(--at-border);
  font-size: var(--at-size-md);
}

.nav__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--at-space-sm);
  color: var(--at-text);
  font-weight: var(--at-heading-weight);
  font-size: var(--at-size-lg);
}

.nav__brand:hover {
  text-decoration: none;
}

.nav__brand img {
  border-radius: 6px;
}

.nav__links {
  display: flex;
  gap: var(--at-space-lg);
  margin-left: var(--at-space-lg);
}

.nav__links a {
  color: var(--at-text-muted);
}

.nav__links a:hover {
  color: var(--at-text);
  text-decoration: none;
}

.nav__tools {
  display: flex;
  align-items: center;
  gap: var(--at-space-sm);
  margin-left: auto;
}

/* ---------------------------------------------------------------- hero */

main {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 var(--at-space-xl);
}

.hero {
  position: relative;
  isolation: isolate;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 96px 0 56px;
  text-align: center;
}

/* The aurora is brightest exactly where the smaller text sits, so a soft pool of the page's own
   background is laid under the hero. It fades out well before the edges, leaving the scene
   visible around the words rather than boxing them in. */
.hero::before {
  content: "";
  position: absolute;
  inset: 0 -8%;
  z-index: -1;
  background: radial-gradient(
    ellipse 60% 55% at 50% 62%,
    color-mix(in srgb, var(--at-background) 62%, transparent),
    transparent 100%
  );
  pointer-events: none;
}

.hero__lead,
.hero__platforms,
.hero__note {
  text-shadow: 0 1px 10px color-mix(in srgb, var(--at-background) 85%, transparent),
    0 0 2px color-mix(in srgb, var(--at-background) 70%, transparent);
}

.hero__badge {
  height: 26px;
  padding: 0 10px;
  font-size: var(--at-size-sm);
}

.hero__title {
  margin: var(--at-space-xl) 0 var(--at-space-lg);
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.02em;
}

.hero__lead {
  max-width: 680px;
  margin: 0;
  /* Not --at-text-muted: grey on the aurora read as faded rather than secondary. */
  color: color-mix(in srgb, var(--at-text) 88%, transparent);
  font-size: clamp(16px, 2vw, 19px);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--at-space-md);
  margin-top: var(--at-space-xxl);
}

.hero__platforms {
  margin: var(--at-space-lg) 0 0;
  color: color-mix(in srgb, var(--at-text) 85%, transparent);
  font-size: var(--at-size-md);
}

.hero__platforms a {
  font-weight: 600;
}

.hero__version {
  margin-left: var(--at-space-xs);
  color: color-mix(in srgb, var(--at-text) 70%, transparent);
}

.hero__note {
  margin: var(--at-space-sm) 0 0;
  color: color-mix(in srgb, var(--at-text) 75%, transparent);
  font-size: var(--at-size-sm);
}

.icon-down {
  transform: rotate(180deg);
}

/* ---------------------------------------------------------------- screenshots */

.shot {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--at-border-strong);
  border-radius: var(--at-radius-lg);
  background: var(--at-background);
  line-height: 0;
}

.shot img {
  width: 100%;
  height: auto;
}

.shot--hero {
  box-shadow: var(--at-shadow-high);
}

/* ---------------------------------------------------------------- sections */

.section {
  padding: 96px 0 0;
}

.section__head {
  max-width: 720px;
  margin: 0 auto var(--at-space-xxl);
  text-align: center;
}

.section__title {
  margin: 0 0 var(--at-space-md);
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.section__lead {
  margin: 0;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--at-space-lg);
}

.grid > *,
.section--pair > * {
  /* A grid item is as wide as its longest line by default; let the code blocks scroll instead. */
  min-width: 0;
}

.grid--two {
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
}

.grid--three {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.at-card {
  background: color-mix(in srgb, var(--at-elevated) 82%, transparent);
  backdrop-filter: blur(var(--at-chrome-blur));
  -webkit-backdrop-filter: blur(var(--at-chrome-blur));
}

.at-card p {
  margin: 0;
  font-size: var(--at-size-md);
}

.feature__icon {
  display: inline-flex;
  width: 36px;
  height: 36px;
  padding: 8px;
  border-radius: var(--at-radius-sm);
  background: var(--at-accent-wash);
  color: var(--at-accent-text);
}

.feature__icon--agent {
  background: var(--at-agent-wash);
  color: var(--at-agent);
}

.door > .at-icon {
  width: 22px;
  height: 22px;
  color: var(--at-text-muted);
}

.section--pair {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: var(--at-space-lg);
}

.pair {
  margin: 0;
  overflow: hidden;
}

.pair .shot {
  border: none;
  border-bottom: 1px solid var(--at-border);
  border-radius: 0;
}

.pair figcaption {
  display: flex;
  flex-direction: column;
  gap: var(--at-space-xs);
  padding: var(--at-panel-padding);
}

/* ---------------------------------------------------------------- install */

.download {
  display: flex;
  flex-direction: column;
  gap: var(--at-space-md);
}

.download > p {
  margin: 0;
}

.download__button {
  align-self: flex-start;
}

.download__meta:not(:empty) {
  opacity: 0.8;
  font-weight: 400;
}

.steps {
  margin: 0;
  padding-left: 1.4em;
  color: var(--at-text-muted);
  line-height: 1.6;
}

.steps li + li {
  margin-top: var(--at-space-xs);
}

.steps strong {
  color: var(--at-text);
}

.downloads__more {
  margin: var(--at-space-lg) 0 var(--at-space-xxl);
}

.code {
  position: relative;
}

.code .at-code {
  padding-right: 44px;
  white-space: pre;
}

.code__copy {
  position: absolute;
  top: 8px;
  right: 8px;
}

/* ---------------------------------------------------------------- docs */

.links {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  padding: var(--at-space-xs);
}

.link {
  display: flex;
  align-items: center;
  gap: var(--at-space-md);
  padding: var(--at-space-md);
  border-radius: var(--at-radius-sm);
  color: var(--at-text);
  font-size: var(--at-size-md);
}

.link:hover {
  background: var(--at-hover);
  text-decoration: none;
}

.link > .at-icon {
  width: 16px;
  height: 16px;
  color: var(--at-text-muted);
}

.link__chevron {
  margin-left: auto;
}

/* ---------------------------------------------------------------- community */

.community {
  flex-direction: row;
  align-items: center;
  gap: var(--at-space-lg);
}

.community__text {
  flex: 1;
}

.community__text p {
  margin: var(--at-space-xs) 0 0;
}

.community__button {
  flex: none;
}

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

.footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--at-space-md);
  max-width: 1120px;
  margin: 96px auto 0;
  padding: var(--at-space-xl);
  border-top: 1px solid var(--at-separator);
  font-size: var(--at-size-sm);
}

@media (max-width: 720px) {
  .nav {
    padding: 0 var(--at-space-lg);
  }
  .nav__links {
    display: none;
  }
  main {
    padding: 0 var(--at-space-lg);
  }
  .hero {
    padding-top: 56px;
  }
  .section {
    padding-top: 64px;
  }
  .grid,
  .grid--two,
  .section--pair,
  .links {
    grid-template-columns: 1fr;
  }
  .community {
    flex-direction: column;
    align-items: flex-start;
  }
}