:root {
  --accent: #2f3fe0;
  --accent-light: #eef0ff;
  --text: #14151a;
  --muted: #6b7280;
  --border: #e7e8ee;
  --bg-hero-start: #eef2ff;
  --bg-hero-end: #ffffff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--text);
  background: #fff;
}

a { color: inherit; text-decoration: none; }

/* ---------- nav ---------- */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 40px;
  border-bottom: 1px solid var(--border);
}

.nav .logo {
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -0.02em;
}

.nav .logo .dot { color: var(--accent); }

.nav .links {
  display: flex;
  gap: 32px;
}

.nav .links a {
  font-weight: 600;
  font-size: 14.5px;
  color: var(--text);
}

.nav .links a:hover { color: var(--accent); }

/* ---------- hero ---------- */
.hero {
  background: linear-gradient(180deg, var(--bg-hero-start) 0%, var(--bg-hero-end) 100%);
  padding: 90px 20px 100px;
  text-align: center;
}

.hero .wordmark {
  font-size: 44px;
  font-weight: 800;
  margin-bottom: 28px;
  letter-spacing: -0.02em;
}

.hero .wordmark .dot { color: var(--accent); }

.hero h1 {
  max-width: 760px;
  margin: 0 auto 20px;
  font-size: 44px;
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.hero p.sub {
  max-width: 620px;
  margin: 0 auto 34px;
  font-size: 17px;
  line-height: 1.6;
  color: var(--muted);
}

.hero .cta {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.btn {
  padding: 14px 26px;
  border-radius: 9px;
  font-weight: 700;
  font-size: 15px;
  cursor: pointer;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover { opacity: 0.92; }

.btn-secondary {
  background: #fff;
  color: var(--text);
  border-color: var(--border);
}

.btn-secondary:hover { border-color: var(--accent); }

/* ---------- feature columns ---------- */
.features {
  max-width: 1040px;
  margin: 0 auto;
  padding: 70px 20px 100px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
}

@media (max-width: 720px) {
  .features { grid-template-columns: 1fr; }
  .nav .links { gap: 18px; }
  .hero h1 { font-size: 32px; }
}

.features h2 {
  font-size: 20px;
  font-weight: 800;
  color: var(--accent);
  margin: 0 0 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.feature-item {
  display: flex;
  gap: 14px;
  margin-bottom: 26px;
}

.feature-icon {
  flex: 0 0 34px;
  height: 34px;
  width: 34px;
  border-radius: 8px;
  background: var(--accent-light);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
}

.feature-item h3 {
  font-size: 15.5px;
  margin: 0 0 4px;
}

.feature-item p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.55;
}

/* ---------- app page ---------- */
.app-wrap {
  max-width: 640px;
  margin: 0 auto;
  padding: 60px 20px;
}

.app-wrap h1 {
  font-size: 24px;
  margin: 0 0 6px;
}

.app-wrap p.lead {
  color: var(--muted);
  margin: 0 0 28px;
  font-size: 14.5px;
}

.row { display: flex; gap: 8px; }

input[type=text] {
  flex: 1;
  padding: 13px 14px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 9px;
  color: var(--text);
  font-size: 15px;
}

input[type=text]:focus { outline: 2px solid var(--accent); border-color: transparent; }

.addr {
  margin-top: 18px;
  padding: 13px 16px;
  background: var(--accent-light);
  border: 1px solid var(--border);
  border-radius: 9px;
  font-size: 15px;
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.addr code { color: var(--accent); font-weight: 700; }

.addr button {
  padding: 7px 12px;
  font-size: 12px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: #fff;
  cursor: pointer;
  font-weight: 600;
}

.status { margin-top: 10px; font-size: 12px; color: var(--muted); }

.messages { margin-top: 24px; display: flex; flex-direction: column; gap: 10px; }

.msg {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
  cursor: pointer;
}

.msg .top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 4px;
}

.msg .subject { font-size: 15px; font-weight: 700; }

.msg .body {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  font-size: 14px;
  white-space: pre-wrap;
  color: var(--text);
  display: none;
}

.msg.open .body { display: block; }

.empty {
  margin-top: 40px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

/* ---------- docs page ---------- */
.docs-wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 60px 20px 100px;
}

.docs-wrap h1 { font-size: 28px; margin-bottom: 6px; }
.docs-wrap p.lead { color: var(--muted); margin: 0 0 40px; }

.docs-wrap h2 {
  font-size: 19px;
  margin-top: 40px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

.docs-wrap pre {
  background: #14151a;
  color: #e6e8ec;
  padding: 16px 18px;
  border-radius: 9px;
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.6;
}

.docs-wrap code {
  background: var(--accent-light);
  color: var(--accent);
  padding: 2px 6px;
  border-radius: 5px;
  font-size: 13.5px;
}

.docs-wrap pre code { background: none; color: inherit; padding: 0; }

.docs-wrap table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 12px;
  font-size: 14px;
}

.docs-wrap th, .docs-wrap td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
}

.docs-wrap th { color: var(--muted); font-weight: 600; }