:root {
  color-scheme: light;
  --bg: #ffffff;
  --panel: #f7f8fa;
  --line: #e6e8ec;
  --txt: #15181d;
  --dim: #666e7b;
  --acc: #1a5fd0;
  --brand1: #5b9bff;
  --brand2: #8b5cf6;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--txt);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--acc); text-underline-offset: 2px; }
.mark {
  width: 40px; height: 40px; border-radius: 11px; flex: 0 0 auto;
  background: linear-gradient(135deg, var(--brand1), var(--brand2));
}

/* --- nav --------------------------------------------------------------- */
nav {
  max-width: 980px; margin: 0 auto; padding: 24px;
  display: flex; align-items: center; gap: 11px;
}
nav .mark { width: 28px; height: 28px; border-radius: 8px; display: block; }
nav .brand { display: flex; align-items: center; gap: 11px; text-decoration: none; color: var(--txt); }
nav b { font-size: 15px; font-weight: 600; letter-spacing: -0.01em; }
nav .spacer { flex: 1; }
nav a { color: var(--dim); font-size: 14px; text-decoration: none; }
nav a:hover { color: var(--txt); }
nav .brand:hover b { color: var(--acc); }

/* --- hero -------------------------------------------------------------- */
.hero { max-width: 980px; margin: 0 auto; padding: 64px 24px 8px; text-align: center; }
.hero h1 {
  font-size: clamp(30px, 4.6vw, 42px); line-height: 1.1; margin: 0;
  letter-spacing: -0.03em; font-weight: 700;
}
.hero .tagline {
  margin: 10px auto 0; font-size: clamp(24px, 3.6vw, 34px); line-height: 1.15;
  letter-spacing: -0.028em; font-weight: 700;
  background: linear-gradient(115deg, var(--brand1), var(--brand2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero .lead {
  max-width: 560px; margin: 22px auto 0;
  font-size: 17.5px; line-height: 1.55; color: var(--dim);
}
.hero .meta { margin-top: 14px; color: var(--dim); font-size: 13px; }
.cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 32px; }
.btn {
  display: inline-block; padding: 11px 22px; border-radius: 10px;
  font-size: 15px; font-weight: 600; text-decoration: none;
  border: 1px solid transparent; transition: transform .12s ease, box-shadow .12s ease;
}
.btn.primary {
  color: #fff; background: linear-gradient(120deg, var(--brand1), var(--brand2));
  box-shadow: 0 6px 18px rgba(91, 155, 255, .28);
}
.btn.primary:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(91, 155, 255, .34); }
.btn.ghost { color: var(--txt); border-color: var(--line); background: var(--bg); }
.btn.ghost:hover { background: var(--panel); }

/* --- the chunk visual -------------------------------------------------- */
.demo {
  max-width: 520px; margin: 56px auto 0; padding: 20px 22px;
  background: var(--panel); border: 1px solid var(--line); border-radius: 14px;
  text-align: left;
}
.demo .file { display: flex; align-items: baseline; gap: 10px; font-size: 14px; }
.demo .file b { font-weight: 600; }
.demo .file i { font-style: normal; color: var(--dim); margin-left: auto; font-variant-numeric: tabular-nums; }
.bars { display: grid; grid-template-columns: repeat(6, 1fr); gap: 5px; margin-top: 14px; }
.bars i {
  display: block; height: 7px; border-radius: 4px;
  background: #dfe3ea; overflow: hidden;
}
.bars i::after {
  content: ""; display: block; height: 100%; border-radius: 4px;
  background: linear-gradient(90deg, var(--brand1), var(--brand2));
}
.bars i:nth-child(1)::after { width: 100%; }
.bars i:nth-child(2)::after { width: 72%; }
.bars i:nth-child(3)::after { width: 90%; }
.bars i:nth-child(4)::after { width: 45%; }
.bars i:nth-child(5)::after { width: 83%; }
.bars i:nth-child(6)::after { width: 61%; }
.demo .legend {
  margin-top: 11px; color: var(--dim); font-size: 12.5px;
  display: flex; justify-content: space-between;
}

/* --- features ---------------------------------------------------------- */
.features {
  max-width: 980px; margin: 0 auto; padding: 96px 24px 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.grid-head { grid-column: 1 / -1; margin: 0 0 -4px; }
.feat { padding: 22px; border: 1px solid var(--line); border-radius: 14px; }
.feat h3 { margin: 0 0 7px; font-size: 15.5px; letter-spacing: -0.01em; }
.feat p { margin: 0; font-size: 14.5px; line-height: 1.55; color: var(--dim); }
@media (max-width: 820px) { .features { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .features { grid-template-columns: 1fr; } }

/* --- plain sections ---------------------------------------------------- */
.section { max-width: 660px; margin: 0 auto; padding: 96px 24px 0; }
.section h2 {
  font-size: 13px; margin: 0 0 14px; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--dim); font-weight: 600;
}
.section p { margin: 0 0 14px; }
.section p:last-child { margin-bottom: 0; }
code {
  background: var(--panel); border: 1px solid var(--line);
  padding: 1px 6px; border-radius: 6px; font-size: 14px;
}

footer {
  max-width: 980px; margin: 96px auto 0; padding: 22px 24px 56px;
  border-top: 1px solid var(--line); color: var(--dim); font-size: 14px;
}
footer .spacer { flex: 1; }

/* --- privacy.html ------------------------------------------------------ */
.wrap { max-width: 660px; margin: 0 auto; padding: 24px 24px 96px; }
.wrap header { display: flex; align-items: center; gap: 14px; margin-bottom: 40px; }
.wrap h1 { font-size: 26px; margin: 0; letter-spacing: -0.02em; }
.wrap header p { margin: 2px 0 0; color: var(--dim); font-size: 14px; }
.wrap h2 {
  font-size: 13px; margin: 44px 0 12px; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--dim); font-weight: 600;
}
.wrap ul { padding-left: 20px; }
.wrap li { margin: 8px 0; }
.lead { font-size: 18px; line-height: 1.55; color: var(--dim); }
.wrap footer { margin-top: 56px; padding-left: 0; padding-right: 0; max-width: none; }

/* --- lists, figures, FAQ ---------------------------------------------- */
.section ul { padding-left: 20px; margin: 0; }
.section li { margin: 9px 0; }
.section.wide { max-width: 900px; }
figure { margin: 0 0 26px; }
figure img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--line); border-radius: 12px; background: var(--panel);
}
figcaption { margin-top: 9px; color: var(--dim); font-size: 13.5px; }

.qa { border-bottom: 1px solid var(--line); }
.qa:first-of-type { border-top: 1px solid var(--line); }
.qa summary {
  cursor: pointer; padding: 15px 28px 15px 0; position: relative;
  list-style: none;
}
.qa summary::-webkit-details-marker { display: none; }
.qa summary h3 { display: inline; margin: 0; font-size: 15.5px; font-weight: 600; }
.qa summary::after {
  content: "+"; position: absolute; right: 4px; top: 13px;
  color: var(--dim); font-size: 19px; line-height: 1;
}
.qa[open] summary::after { content: "\2212"; }
.qa summary:hover h3 { color: var(--acc); }
.qa > p { margin: 0 0 18px; color: var(--dim); font-size: 15px; }

/* --- footer ----------------------------------------------------------- */
footer .frow { display: flex; gap: 16px; flex-wrap: wrap; align-items: baseline; }
footer .disclaimer {
  margin: 14px 0 0; font-size: 12.5px; line-height: 1.5; color: var(--dim);
  max-width: 620px;
}