@font-face {
  font-family: "Instrument Serif";
  src: url("assets/InstrumentSerif-Regular.ttf") format("truetype");
  font-display: swap;
}

:root {
  color-scheme: light;
  --paper: #f5f4ed;
  --ink: #1d322c;
  --muted: #52615a;
  --border: #dcded2;
  --mint: #c6f2d2;
  --sans: "Inter", "Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  --serif: "Instrument Serif", Georgia, serif;
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; }
a { color: inherit; text-decoration: none; }
p, h1, h2 { margin: 0; }
a, summary { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 2px solid #38865e; outline-offset: 5px; }
::selection { background: #c5edd1; color: #143627; }

.shell { width: min(100% - 80px, 1176px); margin-inline: auto; }
.site-header { border-bottom: 1px solid var(--border); }
.header-inner { min-height: 77px; display: flex; align-items: center; justify-content: space-between; }
.wordmark { display: inline-flex; align-items: center; gap: 12px; font: 32px / 1 var(--serif); letter-spacing: -.025em; }
.brand-mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: #dce9da;
  color: #246247;
}
.brand-mark i { position: absolute; width: 18px; height: 8px; border: 1px solid currentColor; border-radius: 100%; }
.brand-mark i:nth-child(2) { transform: rotate(60deg); }
.brand-mark i:nth-child(3) { transform: rotate(120deg); }
.brand-mark::after { content: ""; width: 3px; height: 3px; background: currentColor; border-radius: 50%; }
nav { display: flex; gap: clamp(20px, 3.2vw, 43px); font-size: 14px; }
nav a { color: var(--muted); padding-block: 8px; }
nav a:hover, .site-footer a:hover { color: #25734e; }
.skip-link {
  position: fixed;
  z-index: 3;
  top: 12px;
  left: 12px;
  transform: translateY(-150%);
  background: var(--mint);
  color: var(--ink);
  padding: 10px 14px;
  border-radius: 6px;
}
.skip-link:focus { transform: translateY(0); }

.hero {
  isolation: isolate;
  position: relative;
  display: flex;
  align-items: center;
  min-height: 508px;
  margin-top: 37px;
  overflow: hidden;
  border-radius: 17px;
  background: #112c2d;
  color: #f2f6ee;
}
.hero-image {
  position: absolute;
  inset: 0 0 0 auto;
  width: 68%;
  height: 100%;
  object-fit: cover;
  object-position: 60% 46%;
  z-index: -2;
}
.hero::before {
  position: absolute;
  z-index: -1;
  inset: 0;
  content: "";
  background: linear-gradient(90deg, #112c2d 1%, #112c2d 32%, #112c2d63 56%, transparent 78%);
}
.hero-copy { padding: 53px clamp(30px, 6vw, 84px) 62px; max-width: 57%; }
.overline { display: flex; align-items: center; gap: 11px; color: #bce4cb; font-size: 13px; letter-spacing: .23em; }
.overline > span { width: 6px; height: 6px; border-radius: 50%; background: #a6e8bb; }
.hero h1 { margin-top: 24px; font-size: clamp(24px, 3.35vw, 46px); font-weight: 500; letter-spacing: .025em; }
.hero h1 > span {
  display: block;
  font-family: var(--serif);
  font-size: clamp(87px, 10.2vw, 152px);
  line-height: .9;
  font-weight: 400;
  letter-spacing: -.044em;
  margin: 5px 0 18px -.025em;
  white-space: nowrap;
}
.hero-period { color: #a6e8bb; }
.hero-intro { width: min(100%, 340px); color: #c9d7cc; font-size: 15px; line-height: 1.85; }
.hero-links { display: flex; flex-wrap: wrap; align-items: center; gap: 14px 24px; margin-top: 27px; font-size: 14px; }
.primary-link, .quiet-link { display: inline-flex; align-items: center; gap: 14px; white-space: nowrap; }
.primary-link {
  padding: 12px 17px;
  color: #173b2b;
  background: var(--mint);
  border-radius: 6px;
  font-weight: 650;
  transition: background-color 160ms ease;
}
.primary-link:hover { background: #e1f9e6; }
.quiet-link { padding-block: 9px; color: #d5e6d9; }
.quiet-link:hover { color: #fff; }
.hero a:focus-visible { outline-color: #e4f8e8; }

.section { scroll-margin-top: 24px; }
.notes { padding-top: 65px; }
.section-heading {
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 15px;
}
.section-heading h2, .about h2 { font-size: clamp(24px, 3vw, 32px); font-weight: 650; letter-spacing: .025em; }
.note {
  background: #fbfaf5;
  border: 1px solid var(--border);
  border-radius: 10px;
  transition: border-color 160ms ease, background-color 160ms ease;
}
.note:hover, .note[open] { background: #fffef8; border-color: #99b3a3; }
.note summary { display: block; padding: 19px 21px 21px; cursor: pointer; list-style: none; border-radius: inherit; }
.note summary::-webkit-details-marker { display: none; }
.note-meta { display: flex; align-items: center; justify-content: space-between; margin-bottom: 9px; }
.category { display: inline-flex; align-items: center; gap: 7px; color: #426754; font-size: 12px; }
.topic { display: block; width: 7px; height: 7px; border-radius: 50%; background: #619b76; }
.note-toggle {
  position: relative;
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid #d4ddce;
  color: #315b46;
}
.note-toggle::before, .note-toggle::after { position: absolute; content: ""; width: 9px; height: 1px; background: currentColor; }
.note-toggle::after { transform: rotate(90deg); transition: transform 160ms ease; }
.note[open] .note-toggle::after { transform: rotate(0); }
.note-title { display: block; margin-bottom: 8px; font-weight: 650; font-size: clamp(16px, 1.65vw, 20px); }
.note-description, .note-body { color: var(--muted); font-size: 13px; line-height: 1.8; }
.note-description { display: block; }
.note-body { padding: 0 21px 21px; }
.note-body p { border-top: 1px solid var(--border); padding-top: 13px; }
code { color: #2d5b47; font-size: .97em; }

.about { padding-block: 53px 54px; }
.about-card {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  align-items: start;
  gap: 20px 34px;
  padding: 31px clamp(20px, 5vw, 54px);
  border-radius: 10px;
  background: #e7ede1;
}
.about-card p { color: #344c40; font-size: 15px; line-height: 1.85; }
.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding-block: 19px 26px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 13px;
}
.footer-dot, .site-footer a span { margin-inline: 4px; }

@media (max-width: 840px) {
  .shell { width: calc(100% - 48px); }
  .hero { min-height: 458px; }
  .hero-copy { max-width: 63%; }
  .note summary { padding-inline: 16px; }
  .note-body { padding-inline: 16px; }
}
@media (max-width: 650px) {
  .shell { width: calc(100% - 32px); }
  .header-inner { min-height: 63px; }
  .wordmark { font-size: 29px; gap: 8px; }
  .brand-mark { width: 26px; height: 26px; }
  nav { gap: 17px; font-size: 13px; }
  .hero { align-items: flex-start; min-height: 0; margin-top: 21px; flex-direction: column; border-radius: 12px; }
  .hero-image { position: static; order: 2; width: 100%; height: auto; aspect-ratio: 1.62; object-position: 60% 42%; }
  .hero::before { display: none; }
  .hero-copy { max-width: none; padding: 30px 24px 18px; }
  .hero h1 { margin-top: 18px; }
  .hero h1 > span { font-size: clamp(74px, 16vw, 107px); margin-bottom: 15px; }
  .hero-links { margin-top: 18px; }
  .hero-intro { font-size: 14px; }
  .notes { padding-top: 37px; }
  .section-heading { margin-bottom: 14px; }
  .about { padding-block: 36px; }
  .about-card { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; }
}