:root {
  color-scheme: dark;
  --bg: #07090d;
  --bg-2: #0a0d13;
  --text: #e8eef4;
  --muted: #8b98a6;
  --faint: #5b6672;
  --frame-bg: #080b10;
  --border: #1c232c;
  --border-soft: #141a21;

  /* Flatte brand palette */
  --flatte-teal: #30c2b8;
  --flatte-pink: #ef227d;
  --flatte-magenta: #852467;
  --flatte-purple: #3c0956;
  --flatte-blue: #49819a;

  --accent: var(--flatte-teal);
  --accent-2: var(--flatte-pink);
  --accent-glow: rgb(48 194 184 / 40%);
  --mono:
    "JetBrains Mono", "Berkeley Mono", ui-monospace, SFMono-Regular, Menlo,
    Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --edge: 12px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--mono);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

::selection {
  background: color-mix(in srgb, var(--accent) 32%, transparent);
  color: #fff;
}

/* ---------------------------------------------------------------- backdrop */

.backdrop {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}

/* drifting cell-buffer grid — evokes the terminal cell matrix */
.backdrop-grid {
  position: absolute;
  inset: -40% -20% -20%;
  background-image:
    linear-gradient(color-mix(in srgb, var(--accent) 9%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--accent) 9%, transparent) 1px, transparent 1px);
  background-size: 30px 24px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 8%, #000 0%, transparent 72%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 8%, #000 0%, transparent 72%);
  animation: grid-drift 32s linear infinite;
  opacity: 0.7;
}

/* slow aurora glow behind the hero */
.backdrop-aurora {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(38rem 24rem at 22% -6%, color-mix(in srgb, var(--accent) 22%, transparent), transparent 60%),
    radial-gradient(34rem 22rem at 84% 4%, color-mix(in srgb, var(--accent-2) 16%, transparent), transparent 62%),
    radial-gradient(50rem 34rem at 50% 40%, color-mix(in srgb, var(--flatte-purple) 50%, transparent), transparent 70%);
  filter: blur(8px);
  animation: aurora-shift 18s ease-in-out infinite alternate;
}

/* fine film grain to kill banding and add texture */
.backdrop-grain {
  position: absolute;
  inset: 0;
  opacity: 0.05;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

@keyframes grid-drift {
  to {
    transform: translateY(24px);
  }
}

@keyframes aurora-shift {
  from {
    transform: translate3d(-2%, -1%, 0) scale(1);
    opacity: 0.9;
  }
  to {
    transform: translate3d(3%, 2%, 0) scale(1.08);
    opacity: 1;
  }
}

/* ------------------------------------------------------------------- page */

.page {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  width: min(100%, 108ch);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 40px;
  padding: 24px 24px 40px;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 44px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  color: var(--text);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.brand-logo {
  width: 26px;
  height: 26px;
  align-self: center;
  display: block;
  margin-right: 6px;
}

.brand-cursor {
  width: 8px;
  height: 15px;
  background: var(--accent);
  box-shadow: 0 0 10px var(--accent-glow);
  animation: blink 1.1s steps(1) infinite;
}

@keyframes blink {
  50% {
    opacity: 0;
  }
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  height: 38px;
  padding: 0 14px;
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 9px;
  transition:
    color 0.18s ease,
    border-color 0.18s ease,
    background 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--text);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
  background: rgb(255 255 255 / 3%);
}

.nav-link--icon {
  width: 38px;
  padding: 0;
  justify-content: center;
  color: var(--text);
  border-color: var(--border);
  background: rgb(255 255 255 / 3%);
}

.nav-link--icon:hover,
.nav-link--icon:focus-visible {
  color: var(--accent);
}

.nav-link svg {
  width: 18px;
  height: 18px;
}

:is(.nav-link, .cta, .frame, .brand):focus-visible {
  outline: 2px solid var(--accent-2);
  outline-offset: 3px;
}

/* ------------------------------------------------------------------- intro */

.intro {
  max-width: 80ch;
  padding-top: 8px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent);
  font-size: 12.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "// ";
  color: var(--faint);
}

.intro h1 {
  margin: 0;
  color: #f6faff;
  font-size: clamp(40px, 8.2vw, 82px);
  font-weight: 700;
  line-height: 0.98;
  letter-spacing: -0.03em;
}

.intro h1 .accent {
  color: var(--accent);
  text-shadow: 0 0 32px var(--accent-glow);
}

.lede {
  max-width: 66ch;
  margin: 24px 0 0;
  color: #b9c4cf;
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.7;
}

.lede code,
.pillar code,
.site-footer code {
  padding: 1px 6px;
  color: var(--accent);
  font-family: inherit;
  font-size: 0.9em;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 22%, transparent);
  border-radius: 5px;
}

.reasons {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  color: #aeb9c4;
  font-size: 13px;
}

.reasons li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px 6px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: rgb(255 255 255 / 2%);
}

.reasons-key {
  color: var(--accent);
  font-weight: 700;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 46px;
  padding: 0 22px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 11px;
  transition:
    transform 0.15s ease,
    box-shadow 0.2s ease,
    border-color 0.18s ease,
    background 0.18s ease;
}

.cta--primary {
  color: #04120d;
  background: linear-gradient(180deg, color-mix(in srgb, var(--accent) 60%, #fff), var(--accent));
  box-shadow: 0 12px 34px -12px var(--accent-glow);
}

.cta--primary:hover,
.cta--primary:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 18px 40px -12px var(--accent-glow);
}

.cta--ghost {
  color: var(--text);
  border: 1px solid var(--border);
  background: rgb(255 255 255 / 3%);
}

.cta--ghost:hover,
.cta--ghost:focus-visible {
  border-color: color-mix(in srgb, var(--accent) 42%, var(--border));
  color: var(--accent);
}

/* ---------------------------------------------------------------- terminal */

.terminal {
  position: relative;
  border: 1px solid var(--border);
  border-radius: var(--edge);
  background: color-mix(in srgb, var(--frame-bg) 88%, transparent);
  box-shadow:
    0 1px 0 rgb(255 255 255 / 4%) inset,
    0 40px 120px -40px rgb(0 0 0 / 80%),
    0 0 0 1px rgb(0 0 0 / 20%);
  overflow: hidden;
  backdrop-filter: blur(6px);
}

.terminal-bar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 11px 16px;
  border-bottom: 1px solid var(--border-soft);
  background: linear-gradient(180deg, rgb(255 255 255 / 4%), transparent);
}

.dots {
  display: inline-flex;
  gap: 7px;
}

.dots i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #2a323b;
}

.dots i:nth-child(1) {
  background: #ff5f57;
}
.dots i:nth-child(2) {
  background: #febc2e;
}
.dots i:nth-child(3) {
  background: #28c840;
}

.terminal-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--faint);
  font-size: 12px;
  letter-spacing: 0.02em;
}

.live-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 3px 10px;
  color: var(--accent);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: 1px solid color-mix(in srgb, var(--accent) 32%, transparent);
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 10%, transparent);
}

.live-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0 var(--accent-glow);
  animation: pulse 2s ease-out infinite;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 var(--accent-glow);
  }
  70% {
    box-shadow: 0 0 0 8px transparent;
  }
  100% {
    box-shadow: 0 0 0 0 transparent;
  }
}

/* IMPORTANT: padding / font-size / line-height here are read by the WASM app
   (main_js.go browserMetrics) to size the cell grid. Keep them real px. */
.frame {
  width: 100%;
  min-height: 34rem;
  margin: 0;
  padding: 24px;
  overflow: auto;
  white-space: pre;
  line-height: 1.2;
  font-size: clamp(11px, 1.15vw, 15px);
  color: var(--text);
  background:
    radial-gradient(120% 80% at 50% 0%, color-mix(in srgb, var(--accent) 5%, transparent), transparent 60%),
    var(--frame-bg);
}

.frame:focus {
  outline: none;
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--accent) 45%, transparent);
}

/* boot / loading state shown until the WASM app takes over the frame */
.boot {
  color: var(--muted);
}

.boot-line {
  color: var(--text);
}

.boot-sub {
  color: var(--faint);
}

.boot-cursor {
  display: inline-block;
  width: 0.6em;
  height: 1em;
  translate: 0 0.14em;
  background: var(--accent);
  box-shadow: 0 0 10px var(--accent-glow);
  animation: blink 1.1s steps(1) infinite;
}

.boot-dots::after {
  content: "";
  animation: boot-dots 1.4s steps(4, end) infinite;
}

@keyframes boot-dots {
  0% {
    content: "";
  }
  25% {
    content: ".";
  }
  50% {
    content: "..";
  }
  75% {
    content: "...";
  }
}

.frame--error {
  color: #ffb4a8;
}

.frame--error .boot-sub {
  color: #ffb4a8;
}

.hint-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  padding: 12px 18px;
  border-top: 1px solid var(--border-soft);
  color: var(--muted);
  font-size: 12px;
  background: rgb(0 0 0 / 22%);
}

.hint {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.hint--note {
  margin-left: auto;
  color: var(--faint);
  font-style: italic;
}

kbd {
  min-width: 20px;
  padding: 2px 6px;
  color: var(--text);
  font-family: inherit;
  font-size: 11px;
  text-align: center;
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 6px;
  background: #10151b;
}

/* ----------------------------------------------------------------- pillars */

.pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.pillar {
  position: relative;
  padding: 22px 20px 20px;
  border: 1px solid var(--border);
  border-radius: 11px;
  background: linear-gradient(180deg, rgb(255 255 255 / 3%), transparent);
  transition:
    border-color 0.2s ease,
    transform 0.2s ease;
}

.pillar:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--accent) 38%, var(--border));
}

.pillar-index {
  color: var(--accent);
  font-size: 12px;
  letter-spacing: 0.1em;
}

.pillar h2 {
  margin: 8px 0 10px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.pillar p {
  margin: 0;
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.6;
}

.pillar code {
  padding: 0 4px;
  font-size: 0.92em;
}

/* ----------------------------------------------------------------- compare */

.compare-head {
  max-width: 64ch;
  margin-bottom: 22px;
}

.compare-head h2 {
  margin: 0;
  font-size: clamp(24px, 3.4vw, 34px);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.compare-head p {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.65;
}

.compare-head code {
  padding: 1px 5px;
  color: var(--accent);
  font-size: 0.88em;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 20%, transparent);
  border-radius: 5px;
}

.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  align-items: stretch;
}

.code {
  margin: 0;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border);
  border-radius: 11px;
  overflow: hidden;
  background: var(--frame-bg);
}

.code--after {
  border-color: color-mix(in srgb, var(--accent) 34%, var(--border));
  box-shadow: 0 24px 60px -30px var(--accent-glow);
}

.code figcaption {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border-soft);
  background: linear-gradient(180deg, rgb(255 255 255 / 3%), transparent);
}

.code-tag {
  padding: 2px 9px;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: 1px solid var(--border);
  border-radius: 999px;
}

.code-tag--accent {
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  background: color-mix(in srgb, var(--accent) 12%, transparent);
}

.code-file {
  color: var(--faint);
  font-size: 12px;
}

.code pre {
  margin: 0;
  padding: 16px 18px;
  overflow-x: auto;
  font-size: clamp(11px, 1.05vw, 13px);
  line-height: 1.62;
  tab-size: 2;
}

.code code {
  color: #c4cfd9;
  font-family: inherit;
}

/* lightweight token colors for the hand-tagged snippets */
.code .k {
  color: var(--accent-2);
}
.code .t {
  color: var(--accent-2);
}
.code .fn {
  color: #e6c07b;
}
.code .s {
  color: var(--accent);
}
.code .c {
  color: var(--faint);
  font-style: italic;
}
.code .o {
  color: var(--accent-2);
}
.code .nil {
  color: var(--accent-2);
}

.compare-notes {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  color: var(--muted);
  font-size: 13px;
}

.compare-notes li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.compare-notes span {
  display: inline-grid;
  place-items: center;
  width: 18px;
  height: 18px;
  color: var(--accent-2);
  border-radius: 5px;
  background: color-mix(in srgb, var(--accent-2) 14%, transparent);
}

.compare-notes .plus {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 14%, transparent);
}

.compare-notes code {
  padding: 0 5px;
  color: var(--text);
  font-size: 0.9em;
  background: rgb(255 255 255 / 4%);
  border: 1px solid var(--border);
  border-radius: 5px;
}

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

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 20px;
  padding-top: 8px;
  color: var(--faint);
  font-size: 12.5px;
}

.site-footer code {
  padding: 1px 6px;
  color: var(--muted);
  background: rgb(255 255 255 / 4%);
  border-color: var(--border);
}

.site-footer-note {
  color: var(--faint);
}

/* -------------------------------------------------------------- responsive */

@media (max-width: 760px) {
  .page {
    gap: 30px;
    padding: 16px 14px 28px;
  }

  .intro h1 {
    line-height: 1.02;
  }

  .pillars,
  .compare-grid {
    grid-template-columns: 1fr;
  }

  .hint--note {
    display: none;
  }

  .frame {
    min-height: 30rem;
    padding: 16px;
    font-size: 11px;
  }

  .site-footer-note {
    flex-basis: 100%;
  }
}

/* --------------------------------------------------------- reduced motion */

@media (prefers-reduced-motion: reduce) {
  .backdrop-grid,
  .backdrop-aurora,
  .brand-cursor,
  .live-dot {
    animation: none;
  }

  html {
    scroll-behavior: auto;
  }

  .cta,
  .pillar {
    transition: none;
  }
}

/* ---- Snake leaderboard overlay (browser-only; see leaderboard_js.go) ---- */

.lb-open {
  position: absolute;
  right: 12px;
  bottom: 12px;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font:
    600 12px/1 var(--mono);
  letter-spacing: 0.02em;
  color: var(--accent);
  background: color-mix(in srgb, var(--frame-bg) 80%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 45%, var(--border));
  border-radius: 999px;
  cursor: pointer;
  backdrop-filter: blur(4px);
  transition:
    color 0.15s,
    border-color 0.15s,
    background 0.15s;
}

.lb-open:hover {
  color: var(--text);
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 16%, var(--frame-bg));
}

/* The badge floats over the bottom-right hint. When it's showing (Game tab),
   hide the "click the pane, then type" note it would otherwise overlap. */
.terminal:has(> .lb-open:not([hidden])) .hint--note {
  display: none;
}

.lb {
  position: absolute;
  inset: 0;
  z-index: 4;
  display: grid;
  place-items: center;
  padding: 18px;
  background: rgb(4 6 9 / 68%);
  backdrop-filter: blur(3px);
}

.lb[hidden],
.lb-open[hidden],
.lb-submit[hidden] {
  display: none;
}

.lb-card {
  width: min(420px, 100%);
  max-height: 100%;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 16px 18px 18px;
  color: var(--text);
  font: 13px/1.5 var(--mono);
  background: linear-gradient(180deg, var(--bg-2), var(--frame-bg));
  border: 1px solid color-mix(in srgb, var(--accent) 30%, var(--border));
  border-radius: 10px;
  box-shadow: 0 30px 80px -30px rgb(0 0 0 / 85%);
  overflow: hidden;
}

.lb-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lb-title {
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--accent);
}

.lb-close {
  padding: 2px 8px;
  font: 14px/1 var(--mono);
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
}

.lb-close:hover {
  color: var(--text);
  border-color: var(--accent-2);
}

.lb-score {
  margin: 0;
  color: var(--text);
}

.lb-form {
  display: flex;
  gap: 8px;
}

.lb-name {
  flex: 1;
  min-width: 0;
  padding: 8px 10px;
  color: var(--text);
  font: 13px/1 var(--mono);
  background: var(--frame-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
}

.lb-name:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-glow);
}

.lb-send {
  padding: 8px 14px;
  font:
    600 13px/1 var(--mono);
  color: var(--bg);
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 6px;
  cursor: pointer;
  transition: filter 0.15s;
}

.lb-send:hover {
  filter: brightness(1.1);
}

.lb-send:disabled {
  filter: grayscale(0.6) brightness(0.8);
  cursor: default;
}

.lb-status {
  margin: 0;
  min-height: 1.2em;
  color: var(--accent-2);
  font-size: 12px;
}

.lb-list {
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-y: auto;
  border-top: 1px solid var(--border-soft);
}

.lb-list li {
  display: grid;
  grid-template-columns: 2.2em 1fr auto;
  align-items: baseline;
  gap: 10px;
  padding: 6px 2px;
  border-bottom: 1px solid var(--border-soft);
}

.lb-rank {
  color: var(--faint);
  text-align: right;
}

.lb-who {
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lb-pts {
  color: var(--accent);
  font-weight: 700;
}

.lb-empty {
  display: block;
  padding: 12px 2px;
  color: var(--muted);
  text-align: center;
}