:root {
  --bg: #0b0d10;
  --bg-elev: #14181d;
  --bg-elev-2: #1b2026;
  --border: #232a31;
  --text: #e6edf3;
  --text-dim: #9aa4ad;
  --accent: #7c5cff;
  --accent-2: #5eead4;
  --danger: #ff6b6b;
  --good: #22c55e;
  --radius: 10px;
  --radius-lg: 14px;
  --maxw: 760px;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Inter, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "JetBrains Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-2); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 28px 20px 80px;
}

header.site {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  background: rgba(11,13,16,0.85);
  backdrop-filter: saturate(140%) blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}

header.site .brand {
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.2px;
  color: var(--text);
}

header.site .brand .dot {
  display: inline-block;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent);
  margin-right: 8px;
  vertical-align: 1px;
}

header.site nav a {
  color: var(--text-dim);
  margin-left: 18px;
  font-size: 14px;
}
header.site nav a:hover { color: var(--text); text-decoration: none; }

h1 {
  font-size: 30px;
  line-height: 1.2;
  margin: 8px 0 8px;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 20px;
  margin: 32px 0 10px;
  letter-spacing: -0.005em;
}

h3 { font-size: 16px; margin: 18px 0 6px; }

p { color: var(--text); }
p.lede {
  color: var(--text-dim);
  font-size: 17px;
  margin: 0 0 22px;
}

.card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.calc {
  display: grid;
  gap: 14px;
}

.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
@media (max-width: 520px) {
  .row { grid-template-columns: 1fr; }
}

label {
  display: block;
  font-size: 13px;
  color: var(--text-dim);
  margin-bottom: 6px;
}

input[type="number"],
input[type="text"] {
  width: 100%;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 12px;
  font-size: 15px;
  border-radius: var(--radius);
  font-family: var(--mono);
  outline: none;
  transition: border-color 0.15s;
}
input:focus { border-color: var(--accent); }

button {
  background: var(--accent);
  color: #fff;
  border: 0;
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: filter 0.15s;
}
button:hover { filter: brightness(1.08); }
button.ghost {
  background: transparent;
  color: var(--text-dim);
  border: 1px solid var(--border);
}
button.ghost:hover { color: var(--text); border-color: var(--text-dim); }

.results {
  display: grid;
  gap: 10px;
  margin-top: 6px;
}

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 12px 14px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.result-row .k { color: var(--text-dim); font-size: 14px; }
.result-row .v { font-family: var(--mono); font-size: 17px; font-weight: 500; }
.result-row.primary .v { color: var(--accent-2); font-size: 19px; }
.result-row .v.pos { color: var(--good); }
.result-row .v.neg { color: var(--danger); }

.error {
  background: rgba(255,107,107,0.08);
  border: 1px solid rgba(255,107,107,0.3);
  color: #ffb4b4;
  padding: 10px 12px;
  border-radius: var(--radius);
  font-size: 14px;
}

.cta {
  margin-top: 28px;
  background: linear-gradient(135deg, rgba(124,92,255,0.12), rgba(94,234,212,0.08));
  border: 1px solid rgba(124,92,255,0.35);
  border-radius: var(--radius-lg);
  padding: 18px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.cta p { margin: 0; font-size: 15px; color: var(--text); }
.cta a.btn {
  background: var(--accent);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
}
.cta a.btn:hover { text-decoration: none; filter: brightness(1.1); }
@media (max-width: 560px) {
  .cta { flex-direction: column; align-items: stretch; }
  .cta a.btn { text-align: center; }
}

.related {
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}
.related h2 { margin-top: 0; font-size: 16px; color: var(--text-dim); font-weight: 500; }
.related ul { list-style: none; padding: 0; margin: 10px 0 0; display: grid; gap: 10px; }
.related li a {
  display: block;
  padding: 12px 14px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
}
.related li a:hover { border-color: var(--accent); text-decoration: none; }
.related li a span { display: block; color: var(--text-dim); font-size: 13px; margin-top: 2px; }

.tool-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 24px;
}
.tool-grid a {
  display: block;
  padding: 18px 20px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  color: var(--text);
  transition: border-color 0.15s, transform 0.15s;
}
.tool-grid a:hover { border-color: var(--accent); text-decoration: none; transform: translateY(-1px); }
.tool-grid a h3 { margin: 0 0 4px; font-size: 17px; }
.tool-grid a p { margin: 0; color: var(--text-dim); font-size: 14px; }

.faq details {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  margin-bottom: 8px;
  background: var(--bg-elev);
}
.faq details[open] { border-color: var(--accent); }
.faq summary {
  cursor: pointer;
  font-weight: 500;
  list-style: none;
  color: var(--text);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; float: right; color: var(--text-dim); }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin: 10px 0 2px; color: var(--text-dim); font-size: 15px; }

.row-stack { display: grid; gap: 10px; }
.buy-row {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 10px;
  align-items: end;
}
.buy-row .remove {
  background: transparent;
  color: var(--text-dim);
  border: 1px solid var(--border);
  padding: 10px 12px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 14px;
}
.buy-row .remove:hover { color: var(--danger); border-color: var(--danger); }
.buy-row .remove[disabled] { opacity: 0.3; cursor: not-allowed; }

.muted { color: var(--text-dim); font-size: 14px; }

footer.site {
  margin-top: 60px;
  padding: 24px 20px;
  border-top: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 13px;
  text-align: center;
}
footer.site a { color: var(--text-dim); }
footer.site a:hover { color: var(--text); }