:root {
  /* White and blue (CEO 2026-10-20); light only. */
  --ink: #14213d; --ink-soft: #4a5a78; --heading: #0c3b8c; --paper: #ffffff; --paper-raised: #f4f7fc;
  --line: #dce4f0; --accent: #1d5fd1; --accent-soft: #e8f0fc; --accent-ink: #ffffff;
  color-scheme: light;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.55; padding: 0 16px 56px; }
.wrap { max-width: 720px; margin: 0 auto; }
header.top { border-bottom: 3px solid var(--accent); margin-bottom: 8px; display: flex; align-items: center; justify-content: space-between; padding: 18px 0; gap: 12px; }
.mark { display: inline-flex; align-items: center; gap: 10px; font-size: 20px; letter-spacing: -.01em; color: var(--heading); font-weight: 800; text-decoration: none; }
.mark::before { content: ""; width: 36px; height: 36px; background: url("img/logo.svg") center / contain no-repeat; display: inline-block; }
nav a { color: var(--ink-soft); text-decoration: none; font-size: 14px; margin-left: 16px; }
nav a:hover { color: var(--accent); }
h1 { color: var(--heading); font-family: Georgia, "Times New Roman", serif; font-size: clamp(30px, 6vw, 44px); line-height: 1.12; margin: 28px 0 14px; text-wrap: balance; }
/* Home headline: sized so "Looking to join a CSST network?" stays on one line from a 375 px phone up (the middle line is the longest). */
h1.hero { font-size: clamp(17px, 5.4vw, 42px); }
h2 { color: var(--heading); font-family: Georgia, "Times New Roman", serif; font-size: clamp(21px, 4vw, 26px); margin: 40px 0 10px; }
h3 { color: var(--heading); font-size: 15px; margin: 18px 0 6px; }
p { margin: 0 0 12px; }
.sub { font-size: 17px; color: var(--ink-soft); max-width: 56ch; margin-bottom: 24px; }
nav a.login { background: var(--accent-soft); color: var(--accent); padding: 6px 12px; border-radius: 8px; font-weight: 600; }
.btn { display: inline-block; background: var(--accent); color: var(--accent-ink); padding: 12px 18px; border-radius: 8px; font-weight: 600; text-decoration: none; }
.btn.ghost { background: var(--accent-soft); color: var(--accent); }
.btn + .btn { margin-left: 10px; }
.card { background: var(--paper-raised); border: 1px solid var(--line); border-radius: 10px; padding: 18px 20px; margin: 14px 0; }
.card h3 { margin-top: 0; }
.grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
@media (max-width: 520px) { .grid { grid-template-columns: 1fr; } .btn + .btn { margin-left: 0; margin-top: 10px; } }
.steps { counter-reset: s; padding: 0; margin: 0 0 22px; list-style: none; }
.steps li { counter-increment: s; display: flex; gap: 14px; padding: 10px 0; border-bottom: 1px solid var(--line); }
.steps li::before { content: counter(s); flex: none; width: 28px; height: 28px; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 700; display: inline-flex; align-items: center; justify-content: center; }
.sample { background: var(--accent-soft); border-radius: 12px; padding: 14px 16px; font-size: 15px; max-width: 46ch; }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
td, th { padding: 9px 4px; border-bottom: 1px solid var(--line); text-align: left; }
td:last-child, th:last-child { text-align: right; }
.muted { color: var(--ink-soft); font-size: 14px; }
.notice { border-left: 4px solid var(--accent); padding: 10px 14px; background: var(--paper-raised); border-radius: 0 8px 8px 0; margin: 14px 0; font-size: 15px; }
footer { margin-top: 48px; padding-top: 18px; border-top: 1px solid var(--line); font-size: 13px; color: var(--ink-soft); }
footer a { color: var(--accent); }
details summary { cursor: pointer; font-weight: 600; padding: 8px 0; }
ul { padding-left: 20px; }

/* About page */
.goals li { margin-bottom: 8px; }
.founder { display: flex; gap: 18px; align-items: flex-start; }
.photo { flex: none; width: 112px; height: 112px; border-radius: 50%; background: var(--accent-soft); color: var(--heading); display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 32px; border: 3px solid var(--accent); }
.photo.small { width: 52px; height: 52px; font-size: 18px; border-width: 2px; }
.founder h3 { margin-top: 4px; font-size: 18px; }
.ethos { margin: 12px 0 0; padding: 10px 14px; border-left: 4px solid var(--accent); background: var(--paper-raised); color: var(--ink-soft); font-style: italic; }
.profile-card .pc-head { display: flex; gap: 12px; align-items: center; margin-bottom: 10px; }
.badge { display: inline-block; background: var(--accent); color: var(--accent-ink); font-size: 12px; font-weight: 700; padding: 2px 8px; border-radius: 999px; margin-left: 6px; }
.pc-rows { display: grid; grid-template-columns: 7em 1fr; gap: 4px 12px; margin: 0; }
.pc-rows dt { color: var(--ink-soft); } .pc-rows dd { margin: 0; }
@media (max-width: 520px) { .founder { flex-direction: column; align-items: center; text-align: center; } }

/* Top bar on phones: four items fit beside the logo; nothing breaks across lines. */
nav a { white-space: nowrap; }
@media (max-width: 520px) {
  header.top { flex-wrap: wrap; gap: 8px; }
  .mark { font-size: 18px; }
  .mark::before { width: 30px; height: 30px; }
  nav a { margin-left: 10px; font-size: 13px; }
  nav a.login { padding: 5px 10px; }
}