/* ============================================
   Sleep Lamp Flasher — tokens
   ============================================ */
:root {
  --bg: #0b0f14;
  --panel: #121821;
  --panel-border: #1f2a37;
  --text: #e7ecf2;
  --muted: #8b98a5;
  --accent-1: #6c8eff;
  --accent-2: #9b7fff;
  --accent-grad: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  --success: #3fb950;
  --warning: #d9a544;
  --danger: #f85149;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  --font-ui: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 20px;
}

/* subtle ambient glow behind the hero — one static radial gradient, no blur filter, cheap to paint */
.glow {
  position: fixed;
  inset: -20% -20% auto -20%;
  height: 480px;
  background: radial-gradient(closest-side, rgba(108, 142, 255, 0.16), transparent 70%);
  pointer-events: none;
  z-index: 0;
}

/* ============================================
   Header
   ============================================ */
.site-header {
  position: relative;
  z-index: 1;
  border-bottom: 1px solid var(--panel-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.brand-mark {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-grad);
  animation: pulse 3s ease-in-out infinite;
}

@media (prefers-reduced-motion: reduce) {
  .brand-mark { animation: none; }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.nav-link {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
}
.nav-link:hover { color: var(--text); }

/* ============================================
   Hero
   ============================================ */
.hero {
  position: relative;
  z-index: 1;
  padding: 64px 0 40px;
  text-align: center;
}

.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-1);
  margin-bottom: 12px;
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.subtitle {
  max-width: 480px;
  margin: 16px auto 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.board-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 20px;
  padding: 6px 14px;
  border: 1px solid var(--panel-border);
  border-radius: 999px;
  font-size: 0.85rem;
  color: var(--muted);
  background: var(--panel);
}

.board-chip .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--success);
}

/* ============================================
   Buttons
   ============================================ */
.cta-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-top: 32px;
  flex-wrap: wrap;
}

/* Style the REAL slotted ESP Web Tools button directly — functionality stays intact */
esp-web-install-button button.flash-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--accent-grad);
  color: #0b0f14;
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease, filter 0.15s ease;
}

esp-web-install-button button.flash-btn:hover {
  transform: translateY(-1px);
  filter: brightness(1.06);
}

esp-web-install-button button.flash-btn:active {
  transform: translateY(0);
  filter: brightness(0.96);
}

.flash-icon {
  width: 18px;
  height: 18px;
}

.unsupported-msg {
  display: block;
  max-width: 420px;
  margin: 0 auto;
  color: var(--warning);
  font-size: 0.9rem;
}

.tutorial-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.98rem;
  background: var(--panel);
  transition: border-color 0.15s ease, background 0.15s ease;
}
.tutorial-btn:hover {
  border-color: var(--accent-1);
  background: #161f2b;
}
.tutorial-btn svg { width: 16px; height: 16px; }

/* ============================================
   Cards
   ============================================ */
.card {
  position: relative;
  z-index: 1;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 20px;
}

.card h2 {
  margin: 0 0 18px;
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.card h3 {
  margin: 0 0 4px;
  font-size: 1rem;
  font-weight: 650;
}

.card p { color: var(--muted); margin: 0; }

.muted-note { color: var(--muted); font-size: 0.88rem; }

/* spec grid */
.spec-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.spec {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px;
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
}
.spec-label { font-size: 0.78rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.05em; }
.spec-value { font-weight: 650; }

/* steps */
.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.steps li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.step-num {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-1);
  padding-top: 2px;
}

/* warning card */
.warning-card { border-color: rgba(217, 165, 68, 0.35); }
.warning-list {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.warning-list strong { color: var(--warning); }

/* two column */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.plain-list {
  margin: 8px 0 0;
  padding-left: 20px;
  color: var(--muted);
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.plain-list a { color: var(--accent-1); }

/* FAQ / details */
.faq {
  border-top: 1px solid var(--panel-border);
  padding: 14px 0;
}
.faq:first-of-type { border-top: none; padding-top: 0; }
.faq summary {
  cursor: pointer;
  font-weight: 650;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before {
  content: "+";
  display: inline-block;
  width: 18px;
  color: var(--accent-1);
  font-weight: 700;
}
.faq[open] summary::before { content: "−"; }
.faq p, .faq ul { margin-top: 10px; }

code {
  font-family: var(--font-mono);
  background: rgba(108, 142, 255, 0.12);
  color: var(--accent-1);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.88em;
}

.code-block {
  background: #0d1218;
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
  padding: 16px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text);
}
.code-block code { background: none; padding: 0; color: inherit; }

/* ============================================
   Footer
   ============================================ */
.site-footer {
  border-top: 1px solid var(--panel-border);
  margin-top: 40px;
  padding: 28px 0 48px;
}
.footer-inner { text-align: center; }
.footer-inner p { margin: 4px 0; color: var(--muted); font-size: 0.88rem; }
.footer-inner a { color: var(--accent-1); text-decoration: none; }

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 640px) {
  .spec-grid { grid-template-columns: 1fr; }
  .two-col { grid-template-columns: 1fr; gap: 20px; }
  .card { padding: 20px; }
  .hero { padding: 44px 0 28px; }
}