@import url('https://fonts.googleapis.com/css2?family=Syne:wght@400;500;700;800&family=DM+Mono:ital,wght@0,300;0,400;0,500;1,300&display=swap');

/* ── Reset ──────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Tokens ─────────────────────────────────────────────────────── */
:root {
  --bg:           #09090f;
  --surface:      #111118;
  --border:       rgba(255, 255, 255, 0.07);
  --border-hover: rgba(255, 255, 255, 0.12);
  --border-active:rgba(184, 244, 66, 0.25);
  --text:         #e2ddd4;
  --muted:        #4f4d5c;
  --dim:          #2e2c3a;
  --accent:       #b8f442;
  --accent-glow:  rgba(184, 244, 66, 0.18);
  --accent-subtle:rgba(184, 244, 66, 0.06);
  --ff-display:   'Syne', sans-serif;
  --ff-mono:      'DM Mono', monospace;
}

/* ── Base ───────────────────────────────────────────────────────── */
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--ff-display);
  min-height: 100vh;
  overflow-x: hidden;
  /* subtle grain */
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
}

/* ── Site header ────────────────────────────────────────────────── */
.site-header {
  padding: clamp(2.5rem, 6vw, 5rem) clamp(1.5rem, 6vw, 5rem) clamp(2rem, 4vw, 3.5rem);
  border-bottom: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}

.site-header::after {
  content: '';
  position: absolute;
  bottom: -1px; left: 0;
  width: 120px; height: 1px;
  background: var(--accent);
}

.header-eyebrow {
  font-family: var(--ff-mono);
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
  opacity: 0;
  animation: fadeUp 0.5s ease 0.1s forwards;
}

.header-title {
  font-size: clamp(2.2rem, 5vw, 4.5rem);
  font-weight: 800;
  line-height: 0.88;
  letter-spacing: -0.04em;
  color: var(--text);
  opacity: 0;
  animation: fadeUp 0.6s ease 0.2s forwards;
}

.header-title em {
  font-style: normal;
  color: var(--accent);
}

.header-meta {
  margin-top: clamp(1.25rem, 3vw, 2rem);
  display: flex;
  align-items: center;
  gap: 2rem;
  opacity: 0;
  animation: fadeUp 0.6s ease 0.35s forwards;
}

.header-meta-item {
  font-family: var(--ff-mono);
  font-size: 0.68rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--muted);
}

.header-meta-sep {
  width: 1px;
  height: 14px;
  background: var(--dim);
}

/* ── Challenge list ─────────────────────────────────────────────── */
.challenges-list {
  list-style: none;
}

/* each item */
.c-item {
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background 0.25s;
  position: relative;
  opacity: 0;
  animation: fadeUp 0.5s ease forwards;
}

.c-item::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--accent);
  transform: scaleY(0);
  transform-origin: bottom;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.c-item.open::before   { transform: scaleY(1); }
.c-item.open           { background: var(--accent-subtle); }
.c-item:hover:not(.open) { background: rgba(255,255,255,0.015); }

/* header row */
.c-header {
  display: grid;
  grid-template-columns: 3.5rem 1fr auto auto;
  align-items: center;
  gap: 1.5rem;
  padding: clamp(1.25rem, 3vw, 2rem) clamp(1.5rem, 6vw, 5rem);
  user-select: none;
}

.c-num {
  font-family: var(--ff-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--dim);
  transition: color 0.25s;
  padding-top: 0.15em;
  align-self: start;
}

.c-item.open .c-num { color: var(--accent); }

.c-title {
  font-size: clamp(1.4rem, 3.5vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1;
  color: var(--text);
  transition: color 0.2s;
}

.c-item.open .c-title { color: var(--accent); }

.c-tag {
  font-family: var(--ff-mono);
  font-size: 0.6rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 0.3rem 0.75rem;
  border-radius: 100px;
  white-space: nowrap;
  transition: border-color 0.2s, color 0.2s;
}

.c-item.open .c-tag {
  border-color: var(--border-active);
  color: rgba(184, 244, 66, 0.65);
}

.c-arrow {
  color: var(--dim);
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1), color 0.2s;
  display: flex;
  align-items: center;
}

.c-item.open .c-arrow {
  transform: rotate(45deg);
  color: var(--accent);
}

/* expandable body */
.c-body {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.38s cubic-bezier(0.4, 0, 0.2, 1);
}

.c-body.open { grid-template-rows: 1fr; }

.c-body-inner { overflow: hidden; }

.c-body-content {
  padding: 0 clamp(1.5rem, 6vw, 5rem) clamp(1.75rem, 4vw, 3rem);
  padding-left: calc(clamp(1.5rem, 6vw, 5rem) + 3.5rem + 1.5rem);
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 3rem;
}

.c-desc {
  max-width: 540px;
}

.c-desc p {
  font-size: clamp(0.9rem, 1.5vw, 1.05rem);
  line-height: 1.7;
  color: rgba(226, 221, 212, 0.6);
  margin-bottom: 1.25rem;
}

.c-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.c-chip {
  font-family: var(--ff-mono);
  font-size: 0.58rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  padding: 0.22rem 0.55rem;
  border-radius: 3px;
}

/* Launch button */
.c-launch {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--accent);
  color: #09090f;
  font-family: var(--ff-display);
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-decoration: none;
  padding: 0.95rem 2rem;
  border-radius: 3px;
  white-space: nowrap;
  flex-shrink: 0;
  position: relative;
  overflow: hidden;
  transition: box-shadow 0.2s, transform 0.15s;
}

.c-launch::after {
  content: '';
  position: absolute;
  inset: 0;
  background: white;
  opacity: 0;
  transition: opacity 0.15s;
}

.c-launch:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--accent-glow), 0 0 0 1px var(--accent);
}

.c-launch:hover::after { opacity: 0.1; }

.c-launch:active { transform: translateY(0); }

.c-launch svg {
  width: 13px; height: 13px;
  flex-shrink: 0;
}

/* ── Footer ─────────────────────────────────────────────────────── */
.site-footer {
  padding: 3rem clamp(1.5rem, 6vw, 5rem);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 4rem;
}

.footer-label {
  font-family: var(--ff-mono);
  font-size: 0.65rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ── Animations ─────────────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* stagger list items */
.c-item:nth-child(1) { animation-delay: 0.40s; }
.c-item:nth-child(2) { animation-delay: 0.48s; }
.c-item:nth-child(3) { animation-delay: 0.56s; }
.c-item:nth-child(4) { animation-delay: 0.64s; }
.c-item:nth-child(5) { animation-delay: 0.72s; }
.c-item:nth-child(6) { animation-delay: 0.80s; }
.c-item:nth-child(7) { animation-delay: 0.88s; }
.c-item:nth-child(8) { animation-delay: 0.96s; }

/* ── Responsive ─────────────────────────────────────────────────── */
@media (max-width: 680px) {
  .c-header {
    grid-template-columns: 2.2rem 1fr auto;
    gap: 1rem;
  }

  /* hide category tag on small screens */
  .c-tag { display: none; }

  .c-body-content {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.5rem;
    padding-left: clamp(1.5rem, 6vw, 5rem);
  }

  .c-launch { width: 100%; justify-content: center; }

  .site-footer { flex-direction: column; gap: 0.5rem; }
}