:root {
  --navy: #17366B; --teal: #13868C; --teal-dark: #0F6E73; --green: #3FAE6A; --orange: #D9711C;
  --ink: #1E2733; --ink2: #39434F; --muted: #59636E; --line: #D5DEE6; --panel: #FAFCFD; --mint: #EEF6F6; --white: #ffffff;
  --radius: 10px; --max: 1120px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--white); color: var(--ink); font: 17px/1.55 'Source Sans 3', 'Segoe UI', system-ui, sans-serif; }
h1, h2, h3 { font-family: Lexend, 'Segoe UI', sans-serif; color: var(--navy); margin: 0; line-height: 1.15; }
h2 { font-size: clamp(26px, 3.2vw, 34px); font-weight: 700; }
h3 { font-size: 18px; font-weight: 600; }
p { margin: 0; }
a { color: var(--teal); }
a:hover { color: var(--navy); }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.stripe { height: 8px; display: flex; }
.stripe span:nth-child(1) { flex: 3; background: var(--navy); } .stripe span:nth-child(2) { flex: 2; background: var(--teal); } .stripe span:nth-child(3) { flex: 1; background: var(--green); }

/* header */
header { position: sticky; top: 0; z-index: 10; background: rgba(255,255,255,0.96); border-bottom: 1px solid var(--line); backdrop-filter: saturate(1.2) blur(6px); }
header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 68px; }
header img { height: 40px; width: auto; display: block; }
nav { display: flex; align-items: center; gap: 22px; flex-wrap: wrap; }
nav a { color: var(--ink2); text-decoration: none; font-weight: 600; font-size: 15px; }
nav a:hover { color: var(--navy); }
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 10px 20px; border-radius: 8px; font-weight: 700; text-decoration: none; border: 2px solid var(--navy); font-size: 16px; cursor: pointer; font-family: inherit; }
.btn.primary { background: var(--navy); color: #fff; }
.btn.primary:hover { background: var(--teal-dark); border-color: var(--teal-dark); color: #fff; }
.btn.ghost { background: transparent; color: var(--navy); }
.btn.ghost:hover { background: var(--mint); }
nav .btn { min-height: 40px; padding: 6px 16px; font-size: 15px; color: #fff; }

/* hero */
.hero { padding: 64px 0 40px; }
.hero .top { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr); gap: 48px; align-items: center; }
.hero h1 { font-size: clamp(38px, 5.2vw, 60px); letter-spacing: -0.01em; font-weight: 700; }
.hero h1 span { color: var(--teal); }
.hero p.lead { margin-top: 18px; font-size: 19px; color: var(--ink2); max-width: 34em; }
.hero .cta { margin-top: 28px; display: flex; gap: 12px; flex-wrap: wrap; }
.card { border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); padding: 18px 20px 14px; }
.card .head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; margin-bottom: 8px; }
.card .head strong { font-family: Lexend, sans-serif; color: var(--navy); font-weight: 600; }
.card .head span { color: var(--muted); font-size: 14px; }
.card p.sub { color: var(--ink2); font-size: 15px; margin: -2px 0 10px; }

/* stats */
.stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin-top: 8px; }
.stat { border-radius: var(--radius); padding: 20px 22px; }
.stat b { display: block; font-family: Lexend, sans-serif; font-size: 38px; line-height: 1.1; }
.stat:nth-child(1) { background: var(--navy); color: #fff; }
.stat:nth-child(2) { background: var(--teal-dark); color: #fff; }
.stat:nth-child(3) { background: #EAF6EF; border: 1px solid #BFE3CC; color: var(--ink); }
.stat:nth-child(3) b { color: var(--navy); }
.note { color: var(--muted); font-size: 14px; margin-top: 12px; }

section { padding: 56px 0; }
section[id] { scroll-margin-top: 70px; }
section.alt { background: var(--panel); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.intro { max-width: 46em; margin: 10px 0 30px; color: var(--ink2); font-size: 18px; }

/* finds */
.finds { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 28px 32px; }
.finds div h3 { margin-bottom: 6px; }
.finds div p { color: var(--ink2); }
.finds svg { width: 28px; height: 28px; margin-bottom: 8px; color: var(--teal); }

/* steps */
.steps { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 20px; counter-reset: s; }
.steps div { border-top: 4px solid var(--navy); padding-top: 14px; }
.steps div:nth-child(2) { border-color: #1F5E8C; } .steps div:nth-child(3) { border-color: var(--teal); } .steps div:nth-child(4) { border-color: var(--green); }
.steps h3 { margin-bottom: 6px; }
.steps p { color: var(--ink2); }
/* features */
#features { border-top: 1px solid var(--line); }
.features { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 28px 32px; }
.features h3 { margin-bottom: 6px; }
.features ul { margin: 0; padding-left: 20px; color: var(--ink2); }
.features li { margin: 6px 0; }

/* proof */
.pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }

/* field */
.field { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 36px; align-items: start; }
.field ul { margin: 14px 0 0; padding-left: 20px; color: var(--ink2); }
.field li { margin: 8px 0; }
.box { background: var(--mint); border-radius: var(--radius); padding: 22px 24px; }
.box h3 { margin-bottom: 8px; }
.box p { color: var(--ink2); }

/* form */
.demo { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr); gap: 40px; align-items: start; }
form { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px 16px; }
label { display: flex; flex-direction: column; gap: 5px; font-weight: 600; font-size: 15px; color: var(--ink); }
label span.opt { font-weight: 400; color: var(--muted); }
input, select, textarea { font: inherit; font-size: 16px; padding: 10px 12px; border: 1px solid #A9B6C2; border-radius: 8px; background: #fff; color: var(--ink); min-height: 44px; }
input:focus, select:focus, textarea:focus, .btn:focus-visible, a:focus-visible { outline: 3px solid #8FC9CC; outline-offset: 1px; }
textarea { min-height: 120px; resize: vertical; }
form .full { grid-column: 1 / -1; }
.hp { position: absolute; left: -9999px; }
.privacy { color: var(--muted); font-size: 14px; }

/* about */
.about-stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin-bottom: 30px; }
.about-stats div { background: #fff; border: 1px solid var(--line); border-top: 4px solid var(--teal); border-radius: var(--radius); padding: 16px 20px; color: var(--ink2); }
.about-stats b { display: block; font-family: Lexend, sans-serif; font-size: 28px; line-height: 1.15; color: var(--navy); margin-bottom: 4px; }
.about { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 36px; align-items: start; }
.about h3 { margin-bottom: 8px; }
.about ul { margin: 0; padding-left: 20px; color: var(--ink2); }
.about li { margin: 8px 0; }
.why { margin: 0; }
.why .lead-why { margin: 4px 0 14px; font-family: Lexend, sans-serif; font-weight: 500; font-size: 18px; line-height: 1.4; color: var(--navy); }
/* faq */
.faq { max-width: 52em; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 16px; padding: 16px 2px; font-family: Lexend, sans-serif; font-weight: 600; color: var(--navy); font-size: 17px; min-height: 44px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; font-size: 24px; line-height: 1; color: var(--teal); flex: none; }
.faq details[open] summary::after { content: '\2212'; }
.faq summary:focus-visible { outline: 3px solid #8FC9CC; outline-offset: 1px; }
.faq details p { color: var(--ink2); padding: 0 2px 18px; max-width: 46em; }
footer { border-top: 1px solid var(--line); padding: 26px 0 34px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; justify-content: space-between; gap: 18px; flex-wrap: wrap; }

@media (max-width: 900px) {
  .hero .top, .field, .demo, .pair, .about { grid-template-columns: minmax(0, 1fr); }
  .finds { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .steps, .features { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  nav a:not(.btn) { display: none; }
}
@media (max-width: 600px) {
  body { font-size: 16px; }
  .wrap { padding: 0 16px; }
  .stats, .about-stats, .finds, .steps, .features, form { grid-template-columns: minmax(0, 1fr); }
  header img { height: 32px; }
  .hero { padding-top: 40px; }
}

/* sub-pages (2026-10-21) */
[hidden] { display: none !important; }
.page-head { padding: 48px 0 8px; }
.page-head h1 { font-size: clamp(30px, 4vw, 44px); font-weight: 700; }
.page-head .lead { margin-top: 12px; font-size: 19px; color: var(--ink2); max-width: 44em; }
.crumbs { font-size: 14px; color: var(--muted); margin-bottom: 12px; }
.crumbs a { color: var(--muted); }
/* tool cards */
.tool-cards { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.tool-card { display: flex; flex-direction: column; gap: 8px; border: 1px solid var(--line); border-top: 4px solid var(--teal); border-radius: var(--radius); background: #fff; padding: 20px 22px; text-decoration: none; color: var(--ink2); }
.tool-card:hover { border-color: var(--teal); color: var(--ink2); }
.tool-card h2, .tool-card h3 { font-size: 20px; }
.tool-card span.go { margin-top: auto; font-weight: 700; color: var(--teal); }
/* calculators */
.calc { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 32px; align-items: start; }
.calc form { display: block; }
.calc fieldset { border: 1px solid var(--line); border-radius: var(--radius); background: #fff; padding: 18px 20px 20px; margin: 0 0 18px; }
.calc legend { font-family: Lexend, sans-serif; font-weight: 600; color: var(--navy); padding: 0 6px; }
.calc .grid2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px 16px; }
.calc label small { font-weight: 400; color: var(--muted); font-size: 13px; }
.calc .unit { display: flex; align-items: center; gap: 8px; }
.calc .unit input { flex: 1; min-width: 0; }
.calc .unit span { color: var(--muted); font-size: 15px; white-space: nowrap; }
.calc .radios { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-bottom: 12px; }
.calc .radios label { flex-direction: row; align-items: center; gap: 8px; font-weight: 600; min-height: 44px; }
.calc .radios input { min-height: 0; width: 20px; height: 20px; }
.calc table { width: 100%; border-collapse: collapse; font-size: 16px; }
.calc th, .calc td { text-align: left; padding: 6px 8px; border-bottom: 1px solid var(--line); }
.calc th { color: var(--muted); font-weight: 600; font-size: 14px; }
.calc td.num, .calc th.num { text-align: right; font-variant-numeric: tabular-nums; }
.calc td input { width: 90px; min-height: 40px; }
.result { position: sticky; top: 84px; border-radius: var(--radius); background: var(--navy); color: #fff; padding: 22px 24px; }
.result h2 { color: #fff; font-size: 20px; margin-bottom: 14px; }
.result .big { font-family: Lexend, sans-serif; font-size: 40px; font-weight: 700; line-height: 1.1; }
.result .label { color: #C9D6E6; font-size: 15px; margin-bottom: 14px; }
.result dl { display: grid; grid-template-columns: auto auto; gap: 6px 16px; margin: 12px 0 0; padding-top: 12px; border-top: 1px solid rgba(255,255,255,0.25); }
.result dt { color: #C9D6E6; }
.result dd { margin: 0; text-align: right; font-weight: 600; font-variant-numeric: tabular-nums; }
.result .warn { margin-top: 12px; color: #FFD9B8; font-size: 15px; }
.explain { max-width: 46em; }
.explain h2 { font-size: 24px; margin: 28px 0 10px; }
.explain p, .explain li { color: var(--ink2); }
.explain p + p { margin-top: 10px; }
.explain ul { padding-left: 20px; }
.cta-box { margin-top: 32px; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; background: var(--mint); border-radius: var(--radius); padding: 22px 24px; }
.cta-box p { color: var(--ink2); max-width: 36em; }
.cta-box strong { display: block; font-family: Lexend, sans-serif; color: var(--navy); font-size: 19px; margin-bottom: 4px; }
.sources { font-size: 14px; color: var(--muted); margin-top: 18px; }
@media (max-width: 900px) {
  .calc, .tool-cards { grid-template-columns: minmax(0, 1fr); }
  .result { position: static; }
}
@media (max-width: 600px) {
  .calc .grid2 { grid-template-columns: minmax(0, 1fr); }
}
/* examples (2026-10-21) */
.page-head .note { margin-top: 10px; }
.example { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.6fr); gap: 36px; align-items: start; padding: 36px 0; border-top: 1px solid var(--line); }
.example:first-child { border-top: 0; padding-top: 8px; }
.ex-text { position: sticky; top: 96px; }
.ex-text h2 { font-size: 24px; margin-bottom: 10px; }
.ex-text p { color: var(--ink2); }
.shot { display: block; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: #fff; box-shadow: 0 1px 2px rgba(23,54,107,0.06), 0 8px 24px rgba(23,54,107,0.06); }
.shot img { display: block; width: 100%; height: auto; }
.shot:hover { border-color: var(--teal); }
.ex-strip { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.ex-strip a { display: flex; flex-direction: column; gap: 10px; text-decoration: none; color: var(--ink2); }
.ex-strip .shot { aspect-ratio: 4 / 3; }
.ex-strip .shot img { height: 100%; object-fit: cover; object-position: top left; }
.ex-strip strong { font-family: Lexend, sans-serif; color: var(--navy); font-weight: 600; }
@media (max-width: 900px) {
  .example { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .ex-text { position: static; }
  .ex-strip { grid-template-columns: minmax(0, 1fr); }
}