/* SPARKBYTE — clean indie SaaS */
:root {
  --bg: #0b0f14;
  --bg-elev: #121820;
  --bg-card: #161d27;
  --border: #243041;
  --text: #e8eef6;
  --muted: #9aabbd;
  --accent: #5b9fff;
  --accent-hover: #7ab0ff;
  --accent-soft: rgba(91, 159, 255, 0.12);
  --ok: #3dd68c;
  --warn: #f0b429;
  --radius: 12px;
  --max: 960px;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

img {
  max-width: 100%;
  height: auto;
}

.wrap {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

/* Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 15, 20, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
  flex-wrap: wrap;
}
.logo {
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text);
  text-decoration: none;
  font-size: 1.05rem;
}
.logo:hover {
  text-decoration: none;
  color: var(--text);
}
.nav-links {
  display: flex;
  gap: 1.1rem;
  align-items: center;
  flex-wrap: wrap;
  font-size: 0.92rem;
}
.nav-links a {
  color: var(--muted);
  text-decoration: none;
}
.nav-links a:hover {
  color: var(--text);
}

/* Buttons / CTA */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, opacity 0.15s;
}
.btn:hover {
  text-decoration: none;
}
.btn-primary {
  background: var(--accent);
  color: #061018;
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: #061018;
}
.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}
.btn-ghost:hover {
  border-color: var(--muted);
  color: var(--text);
}
.cta-disabled,
.btn[aria-disabled="true"] {
  opacity: 0.55;
  cursor: not-allowed;
  pointer-events: none;
  background: #2a3544;
  color: var(--muted);
}

/* Hero */
.hero {
  padding: 3.5rem 0 2.5rem;
}
.hero-badge {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  margin-bottom: 1rem;
}
.hero h1 {
  font-size: clamp(1.85rem, 4.5vw, 2.75rem);
  line-height: 1.15;
  margin: 0 0 1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.hero .lead {
  font-size: 1.15rem;
  color: var(--muted);
  max-width: 36rem;
  margin: 0 0 1.75rem;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}
.hero-note {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 1rem;
}

/* Sections */
section {
  padding: 2.75rem 0;
  border-top: 1px solid var(--border);
}
section h2 {
  font-size: clamp(1.35rem, 3vw, 1.65rem);
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}
.section-lead {
  color: var(--muted);
  margin: 0 0 1.5rem;
  max-width: 36rem;
}

.grid-3 {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}
.grid-2 {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
}
.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}
.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}
.card ol,
.card ul {
  margin: 0.5rem 0 0;
  padding-left: 1.2rem;
  color: var(--muted);
  font-size: 0.95rem;
}

/* Steps */
.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1rem;
}
@media (min-width: 720px) {
  .steps {
    grid-template-columns: repeat(3, 1fr);
  }
}
.steps li {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  position: relative;
}
.steps li::before {
  counter-increment: step;
  content: counter(step);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}
.steps strong {
  display: block;
  margin-bottom: 0.35rem;
}
.steps p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

/* Pricing */
.price-card {
  background: linear-gradient(160deg, var(--bg-elev), var(--bg-card));
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 4px);
  padding: 1.75rem;
  max-width: 28rem;
}
.price-card .amount {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin: 0.25rem 0;
}
.price-card .amount span {
  font-size: 1rem;
  font-weight: 500;
  color: var(--muted);
}
.price-warn {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  border-radius: 8px;
  background: rgba(240, 180, 41, 0.1);
  border: 1px solid rgba(240, 180, 41, 0.35);
  color: #e8d5a0;
  font-size: 0.9rem;
}

/* FAQ */
.faq details {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1.1rem;
  margin-bottom: 0.65rem;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}
.faq summary::-webkit-details-marker {
  display: none;
}
.faq details[open] summary {
  margin-bottom: 0.5rem;
}
.faq details p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

/* CTA band */
.cta-band {
  text-align: center;
  background: var(--bg-elev);
  border-radius: calc(var(--radius) + 4px);
  padding: 2.25rem 1.5rem;
  border: 1px solid var(--border);
}
.cta-band h2 {
  margin-bottom: 0.5rem;
}
.cta-band p {
  color: var(--muted);
  margin: 0 0 1.25rem;
}
.waitlist-form {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  max-width: 28rem;
  margin: 0 auto 0.75rem;
}
.waitlist-form input[type="email"] {
  flex: 1 1 12rem;
  padding: 0.7rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
}
.waitlist-form input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.toast {
  font-size: 0.85rem;
  color: var(--ok);
  margin-top: 0.5rem;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem 0 3rem;
  margin-top: 1rem;
  font-size: 0.88rem;
  color: var(--muted);
}
.footer-grid {
  display: grid;
  gap: 1.5rem;
}
@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr;
  }
}
.site-footer h4 {
  margin: 0 0 0.5rem;
  color: var(--text);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.site-footer li {
  margin-bottom: 0.35rem;
}
.site-footer a {
  color: var(--muted);
}
.site-footer a:hover {
  color: var(--text);
}
.disclaimer {
  margin-top: 1.75rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  line-height: 1.55;
  max-width: 48rem;
}

/* Legal pages */
.legal {
  padding: 2.5rem 0 3rem;
}
.legal h1 {
  font-size: 1.85rem;
  margin: 0 0 0.5rem;
}
.legal .meta {
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 2rem;
}
.legal h2 {
  font-size: 1.15rem;
  margin: 1.75rem 0 0.5rem;
}
.legal p,
.legal li {
  color: var(--muted);
}
.legal ul {
  padding-left: 1.25rem;
}

/* Product page hero tweak */
.product-hero {
  padding-top: 2.5rem;
}

/* zh WeChat block */
.wechat-block {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}
.wechat-placeholder {
  width: 140px;
  height: 140px;
  border-radius: 8px;
  background: var(--bg-elev);
  border: 1px dashed var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0.75rem;
  font-size: 0.8rem;
  color: var(--muted);
}
.wechat-qr {
  width: 140px;
  height: 140px;
  border-radius: 8px;
  object-fit: cover;
  border: 1px solid var(--border);
}
.wechat-id {
  font-family: ui-monospace, monospace;
  font-size: 1.05rem;
  color: var(--text);
}

/* Utility */
.muted {
  color: var(--muted);
}
.mt-0 {
  margin-top: 0;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}