/* YDL Capsule — base stylesheet
   Plain CSS, no framework, no external font requests (fast + crawlable) */

:root {
  --ink: #0f2438;
  --ink-2: #4a5b6b;
  --brand: #14507a;
  --brand-dk: #0d3a5c;
  --accent: #17a398;
  --bg: #ffffff;
  --bg-2: #f5f8fa;
  --line: #dde5ec;
  --max: 1180px;
  --radius: 3px;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

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

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.94);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex; align-items: center; gap: 28px;
  height: 68px;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; letter-spacing: .02em; color: var(--ink);
  font-size: 17px;
}
.logo-mark {
  width: 26px; height: 26px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  position: relative; flex: 0 0 26px;
}
.logo-mark::after {
  content: ""; position: absolute; inset: 7px 3px;
  border-radius: 999px; background: #fff; opacity: .9;
}
.nav { display: flex; gap: 22px; margin-left: auto; align-items: center; }
.nav a { font-size: 14.5px; color: var(--ink-2); font-weight: 500; }
.nav a:hover { color: var(--brand); }
.nav .btn { padding: 9px 16px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: var(--radius);
  font-size: 15px; font-weight: 600; border: 1px solid transparent;
  background: var(--brand); color: #fff; transition: background .15s ease, color .15s ease;
}
.btn:hover { background: var(--accent); color: #fff; }
.btn-ghost {
  background: transparent; color: var(--brand); border-color: var(--line);
}
.btn-ghost:hover { background: var(--bg-2); color: var(--brand); }

/* ---------- hero ---------- */
.hero {
  background: linear-gradient(180deg, var(--bg-2), #fff);
  border-bottom: 1px solid var(--line);
  padding: 72px 0 56px;
}
.hero h1 {
  font-size: clamp(30px, 4.4vw, 46px);
  line-height: 1.15; margin: 0 0 18px; letter-spacing: -.015em;
  max-width: 15em;
}
.hero p.lead {
  font-size: clamp(16px, 1.8vw, 19px);
  color: var(--ink-2); max-width: 44em; margin: 0 0 28px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

.eyebrow {
  display: inline-block; margin-bottom: 14px;
  font-size: 12px; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--accent);
}

/* ---------- stats ---------- */
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  background: #fff;
}
.stat { padding: 22px 20px; border-left: 1px solid var(--line); }
.stat:first-child { border-left: none; }
.stat b { display: block; font-size: 30px; font-weight: 300; line-height: 1.1; }
.stat span { font-size: 13px; color: var(--ink-2); }

/* ---------- sections ---------- */
section { padding: 64px 0; }
section.tight { padding: 48px 0; }
.section-head { max-width: 46em; margin-bottom: 34px; }
.section-head h2 {
  font-size: clamp(23px, 2.8vw, 30px);
  margin: 0 0 12px; line-height: 1.25; letter-spacing: -.01em;
}
.section-head p { margin: 0; color: var(--ink-2); font-size: 16px; }
.alt { background: var(--bg-2); }

/* ---------- cards ---------- */
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }

.card {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px;
  transition: border-color .15s ease, transform .2s ease;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; font-size: 14.5px; color: var(--ink-2); }
.card .tag {
  display: inline-block; margin-top: 14px; padding: 3px 9px;
  font-size: 11.5px; font-weight: 600; letter-spacing: .06em;
  background: #e8f5f4; color: #0f7d74; border-radius: 2px;
}

/* ---------- table ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; font-size: 14.5px; background: #fff; }
thead th {
  text-align: left; padding: 13px 14px; background: var(--brand); color: #fff;
  font-weight: 600; font-size: 13px; letter-spacing: .02em; white-space: nowrap;
}
tbody td { padding: 12px 14px; border-top: 1px solid var(--line); vertical-align: top; }
tbody tr:nth-child(even) td { background: #fafcfd; }
tbody tr:hover td { background: #f0f7f7; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
.note { font-size: 13px; color: var(--ink-2); margin-top: 12px; }

/* ---------- formula ---------- */
.formula {
  font-family: var(--mono); font-size: 14px;
  background: var(--ink); color: #d7e6f2;
  padding: 18px 20px; border-radius: var(--radius);
  overflow-x: auto; margin: 18px 0;
}
.formula b { color: #7ee0d5; font-weight: 600; }

/* ---------- calculator ---------- */
.calc {
  border: 1px solid var(--line); border-radius: var(--radius);
  background: #fff; padding: 26px; margin: 22px 0;
}
.calc-fields { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: 13px; font-weight: 600; color: var(--ink-2); }
.field input, .field select, .field textarea {
  padding: 10px 12px; border: 1px solid var(--line); border-radius: 2px;
  font: inherit; font-size: 15px; color: var(--ink); background: #fff;
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(23,163,152,.12);
}
.calc-result {
  margin-top: 20px; padding: 16px 18px; background: var(--bg-2);
  border-left: 3px solid var(--accent); border-radius: 2px; font-size: 15px;
}
.calc-result strong { font-size: 18px; }

/* ---------- faq ---------- */
.faq { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  cursor: pointer; list-style: none; padding: 20px 0;
  font-weight: 600; font-size: 16.5px; display: flex;
  justify-content: space-between; gap: 20px; align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; color: var(--accent); font-size: 22px; font-weight: 300;
  flex: 0 0 auto; transition: transform .2s ease;
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq p { margin: 0 0 20px; color: var(--ink-2); font-size: 15px; max-width: 66em; }

/* ---------- cta band ---------- */
.cta-band {
  background: var(--ink); color: #e6eef5; padding: 52px 0;
}
.cta-band h2 { color: #fff; margin: 0 0 10px; font-size: clamp(22px, 2.6vw, 28px); }
.cta-band p { margin: 0 0 22px; color: #b8c9d8; max-width: 42em; }

/* ---------- form ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-grid .full { grid-column: 1 / -1; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }

/* ---------- breadcrumb ---------- */
.crumb { font-size: 13px; color: var(--ink-2); padding: 18px 0 0; }
.crumb a { color: var(--ink-2); }
.crumb span { margin: 0 6px; opacity: .5; }

/* ---------- footer ---------- */
.site-footer {
  background: #0b1c2b; color: #9fb3c4; padding: 48px 0 32px; font-size: 14px;
}
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 28px; }
.site-footer h4 { color: #fff; font-size: 13px; letter-spacing: .1em; text-transform: uppercase; margin: 0 0 12px; }
.site-footer a { color: #9fb3c4; display: block; padding: 3px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom {
  margin-top: 34px; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.1);
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13px;
}

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .grid-4, .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(3) { border-left: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .calc-fields { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .nav { display: none; }
  .header-inner { height: 60px; }
  .grid-4, .grid-3, .grid-2, .form-grid, .calc-fields { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; }
  .stat { border-left: none; border-top: 1px solid var(--line); }
  .stat:first-child { border-top: none; }
  section { padding: 46px 0; }
  .hero { padding: 48px 0 40px; }
  .footer-grid { grid-template-columns: 1fr; }
}