/* =========================================================
   BOB THE BUILDER — landing page
   Palette matches the app (frontend/src/style.css) so the site
   and the product read as one thing.
   ========================================================= */

:root {
  --bg:       #0f0f1e;
  --bg-soft:  #12132453;
  --panel:    #14162a;
  --text:     #e8ebff;
  --muted:    #9aa0c8;
  --accent:   #4ecdc4;
  --accent-2: #7b6cff;
  --pink:     #f0a8cf;
  --sand:     #e8dc9a;
  --border:   #2a2d4a;

  --maxw: 1312px;
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 16px;

  --ease: cubic-bezier(.22, .61, .36, 1);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Ambient glow behind the hero — pure CSS, no images. */
body::before {
  content: "";
  position: fixed;
  inset: -20% -10% auto -10%;
  height: 70vh;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(45% 55% at 30% 0%, rgba(123, 108, 255, .20), transparent 70%),
    radial-gradient(40% 50% at 72% 8%, rgba(78, 205, 196, .16), transparent 70%);
  filter: blur(10px);
}

main, .footer { position: relative; z-index: 1; }
/* Above main, or the open mobile menu gets painted over by page content. */
.nav { z-index: 50; }

h1, h2, h3 { margin: 0; letter-spacing: -.02em; }
p { margin: 0; }
code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .92em;
  background: rgba(255, 255, 255, .06);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: .1em .4em;
  color: #cfd6ff;
}

/* ---------------- Buttons ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 0;
  border-radius: var(--r-md);
  padding: 14px 26px;
  font: inherit;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease), filter .18s var(--ease);
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(100deg, var(--accent-2), var(--accent));
  color: #0f0f1e;
  box-shadow: 0 8px 26px rgba(123, 108, 255, .32);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 34px rgba(123, 108, 255, .42); filter: brightness(1.06); }
.btn-primary:active { transform: translateY(0); }
.btn-primary.lg { padding: 17px 34px; font-size: 16px; }

.btn-ghost {
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
}
.btn-ghost:hover { border-color: rgba(78, 205, 196, .55); transform: translateY(-1px); }

/* ---------------- Nav ---------------- */
.nav {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  gap: 32px;
  padding: 18px clamp(20px, 4vw, 64px);
  backdrop-filter: blur(14px);
  background: rgba(15, 15, 30, .72);
  border-bottom: 1px solid transparent;
  transition: border-color .25s var(--ease), background .25s var(--ease);
}
.nav.scrolled { border-bottom-color: var(--border); background: rgba(15, 15, 30, .9); }

.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand-mark {
  width: 28px; height: 28px; border-radius: var(--r-sm);
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 18px rgba(78, 205, 196, .45);
}
.brand-name { font-size: 15px; font-weight: 800; letter-spacing: .12em; color: var(--text); }

.nav-links { margin-left: auto; display: flex; gap: 32px; }
.nav-links a {
  position: relative;
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  padding: 4px 0;
  transition: color .2s var(--ease);
}
.nav-links a::after {
  content: "";
  position: absolute; left: 0; bottom: 0;
  height: 1.5px; width: 0;
  background: var(--accent);
  transition: width .25s var(--ease);
}
.nav-links a:hover { color: var(--text); }
.nav-links a:hover::after { width: 100%; }

.only-collapsed { display: none; }

.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; margin: 4px 0; background: var(--text); border-radius: 2px; transition: .2s var(--ease); }

/* ---------------- Hero ---------------- */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: clamp(56px, 8vw, 96px) clamp(20px, 4vw, 64px) 72px;
  max-width: var(--maxw);
  margin: 0 auto;
}

.pill {
  display: inline-block;
  padding: 7px 14px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--accent);
  background: rgba(78, 205, 196, .10);
  border: 1px solid rgba(78, 205, 196, .35);
}

.hero h1 {
  margin: 22px 0 0;
  font-size: clamp(38px, 6.4vw, 76px);
  line-height: 1.06;
  font-weight: 800;
}
.grad {
  background: linear-gradient(100deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lede {
  margin-top: 22px;
  max-width: 720px;
  font-size: clamp(15px, 1.7vw, 19px);
  line-height: 1.68;
  color: var(--muted);
}

.repo-form { display: flex; gap: 10px; margin-top: 34px; flex-wrap: wrap; justify-content: center; }
.repo-form input {
  width: min(480px, 78vw);
  padding: 16px 20px;
  border-radius: var(--r-md);
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, .35);
  color: var(--text);
  font: inherit;
  font-size: 15px;
  outline: none;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.repo-form input::placeholder { color: #6f76a0; }
.repo-form input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(78, 205, 196, .14);
}
.hint { margin-top: 14px; font-size: 13px; color: var(--muted); }
.hint.err { color: #ff8f8f; }

/* ---------------- App window ---------------- */
.window {
  width: 100%;
  max-width: 1180px;
  margin-top: 56px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border);
  background: var(--panel);
  overflow: hidden;
  box-shadow: 0 32px 70px rgba(0, 0, 0, .55);
}

.titlebar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: rgba(0, 0, 0, .25);
  border-bottom: 1px solid var(--border);
}
.dot { width: 11px; height: 11px; border-radius: 50%; display: inline-block; }
.dot.r { background: #ff5f57; } .dot.y { background: #febc2e; } .dot.g { background: #28c840; }
.url { margin-left: auto; font-size: 12px; color: var(--muted); }

/* The city itself — plates and buildings are generated by script.js,
   but every bit of the animation lives here in CSS. */
.city {
  position: relative;
  height: clamp(240px, 42vw, 560px);
  background: linear-gradient(160deg, #dfe4ec, #aeb5c0);
  overflow: hidden;
}

.zone {
  position: absolute;
  border-radius: 6px;
  opacity: 0;
  animation: zone-in .5s var(--ease) forwards;
}
.building {
  position: absolute;
  border-radius: 3px;
  background: #e6eaf0;
  border: 1px solid rgba(140, 148, 166, .55);
  box-shadow: 3px 5px 0 rgba(26, 28, 41, .18);
  transform-origin: 50% 100%;
  opacity: 0;
  animation: rise .42s var(--ease) forwards;
}
.building.tall { background: #f6f2ee; }

@keyframes zone-in { to { opacity: .85; } }
@keyframes rise {
  0%   { opacity: 0; transform: translateY(9px) scale(.55); }
  60%  { opacity: 1; }
  100% { opacity: 1; transform: translateY(0) scale(1); }
}

/* Scrubber under the city */
.scrubber {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background: rgba(0, 0, 0, .3);
  border-top: 1px solid var(--border);
}
.play {
  width: 34px; height: 34px;
  flex: none;
  border: 0; border-radius: 50%;
  background: var(--accent);
  color: #06121a;
  font-size: 12px;
  cursor: pointer;
  transition: transform .18s var(--ease), filter .18s var(--ease);
}
.play:hover { transform: scale(1.08); filter: brightness(1.08); }
.track { flex: 1; height: 4px; border-radius: 999px; background: rgba(255, 255, 255, .12); overflow: hidden; }
.fill { height: 100%; width: 0; border-radius: 999px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); }
.meta { font-size: 12px; color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }

/* ---------------- Sections ---------------- */
.section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(64px, 9vw, 96px) clamp(20px, 4vw, 64px);
  text-align: center;
}
.section.tight { padding-top: 0; }

.eyebrow { font-size: 11px; font-weight: 700; letter-spacing: .18em; }
.eyebrow.accent { color: var(--accent); }
.eyebrow.violet { color: var(--accent-2); }

.section h2, .footer h2 {
  margin: 16px auto 0;
  font-size: clamp(27px, 3.6vw, 42px);
  line-height: 1.2;
  font-weight: 800;
  max-width: 760px;
}

.grid { display: grid; gap: 20px; margin-top: 44px; text-align: left; }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

.card {
  padding: 28px;
  border-radius: 14px;
  background: var(--panel);
  border: 1px solid var(--border);
  transition: transform .25s var(--ease), border-color .25s var(--ease), box-shadow .25s var(--ease);
}
.card:hover {
  transform: translateY(-4px);
  border-color: rgba(123, 108, 255, .5);
  box-shadow: 0 18px 40px rgba(0, 0, 0, .4);
}
.card h3 { margin-top: 14px; font-size: 19px; font-weight: 600; line-height: 1.35; }
.card p { margin-top: 12px; font-size: 14px; line-height: 1.65; color: var(--muted); }

.chip { display: block; width: 38px; height: 38px; border-radius: 10px; }
.c-teal   { background: rgba(78, 205, 196, .18);  border: 1px solid rgba(78, 205, 196, .45); }
.c-violet { background: rgba(123, 108, 255, .18); border: 1px solid rgba(123, 108, 255, .45); }
.c-pink   { background: rgba(240, 168, 207, .18); border: 1px solid rgba(240, 168, 207, .45); }
.c-sand   { background: rgba(232, 220, 154, .18); border: 1px solid rgba(232, 220, 154, .45); }

.step .num { font-size: 30px; font-weight: 800; color: var(--accent-2); }

/* ---------------- Stats ---------------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 46px clamp(20px, 4vw, 64px);
  background: rgba(20, 22, 42, .55);
  border-block: 1px solid var(--border);
  text-align: center;
}
.stat b {
  display: block;
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 800;
  letter-spacing: -.02em;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.stat span { display: block; margin-top: 6px; font-size: 13px; color: var(--muted); }

/* ---------------- Footer ---------------- */
.footer {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(64px, 9vw, 96px) clamp(20px, 4vw, 64px) 72px;
  text-align: center;
}
.footer p { margin-top: 18px; font-size: 16px; line-height: 1.6; color: var(--muted); }
.footer .btn { margin-top: 30px; }
.footer hr { margin: 56px 0 22px; border: 0; border-top: 1px solid var(--border); }
.footer small { font-size: 12px; letter-spacing: .12em; color: var(--muted); }

/* ---------------- Scroll reveal ---------------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
.reveal.in { opacity: 1; transform: none; }

/* ---------------- Responsive ---------------- */
@media (max-width: 1080px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .stats  { grid-template-columns: repeat(2, 1fr); row-gap: 32px; }
}
@media (max-width: 760px) {
  /* Brand + button + burger don't fit side by side at phone widths, so the
     GitHub link moves into the collapsed menu instead of overflowing. */
  .nav { gap: 12px; }
  .nav-links {
    position: absolute;
    top: 100%; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    padding: 8px clamp(20px, 4vw, 64px) 18px;
    /* Fully opaque — the nav's backdrop-filter makes any alpha here let the
       hero headline ghost through the open menu. */
    background: #0f0f1e;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 18px 40px rgba(0, 0, 0, .55);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 0; }
  .nav .btn-ghost { display: none; }
  .only-collapsed { display: block; color: var(--accent) !important; }
  .nav-toggle { display: block; margin-left: auto; }
  .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .repo-form input { width: 100%; }
  .repo-form .btn { width: 100%; }
}

/* ---------------- Reduced motion ---------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
  .zone { opacity: .85; }
  .building { opacity: 1; }
}