/* ===== reset ===== */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, p, ul, ol, li, figure, blockquote { margin: 0; padding: 0; }
ul, ol { list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
img { max-width: 100%; display: block; }
table { border-collapse: collapse; width: 100%; }

:root {
  --ink-green: #081A14;
  --grass-deep: #12362A;
  --grass-mid: #1F5C45;
  --cyan: #64F0C4;
  --paper: #EDE5D2;
  --paper-light: #F7F2E5;
  --brown-ink: #241A13;
  --score-orange: #FF5A2B;
  --amber: #FFC24B;
  --mist: #8FA79C;

  --font-display: "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --font-data: "SFMono-Regular", "Menlo", "Consolas", "Liberation Mono", monospace;

  --shell: 1240px;
  --gap: 24px;
  --radius: 4px;
  --header-h: 72px;
  --shadow-panel: 0 24px 48px -32px rgba(0, 0, 0, .85);
  --ease: cubic-bezier(.22, .7, .3, 1);
}

html { font-size: 16px; }
body {
  background-color: var(--ink-green);
  background-image:
    repeating-linear-gradient(90deg, rgba(100, 240, 196, .045) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, rgba(100, 240, 196, .045) 0 1px, transparent 1px 96px);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: .01em;
  overflow-x: hidden;
}

.site-shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-inline: 20px;
}

/* ===== typography ===== */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1.14;
}
h1 { font-size: clamp(38px, 6.4vw, 80px); }
h2 { font-size: clamp(26px, 3.6vw, 36px); }
h3 { font-size: clamp(20px, 2.4vw, 26px); }
p { max-width: 68ch; }

.data-num {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: -.02em;
  line-height: .95;
}
.data-label {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--mist);
}
.annotation {
  font-size: 12.5px;
  font-weight: 300;
  letter-spacing: .22em;
  color: var(--mist);
}
.annotation-vertical {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 12.5px;
  font-weight: 300;
  letter-spacing: .32em;
  color: var(--mist);
}

/* ===== skip link ===== */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 200;
  padding: 12px 18px;
  background: var(--cyan);
  color: var(--ink-green);
  font-weight: 700;
  border-radius: var(--radius);
  transition: top .2s var(--ease);
}
.skip-link:focus { top: 14px; }

/* ===== header ===== */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 120;
  background: linear-gradient(180deg, rgba(8, 26, 20, .78), rgba(8, 26, 20, 0));
  border-bottom: 1px solid transparent;
  transition: background-color .18s var(--ease), border-color .18s var(--ease);
}
.site-header[data-scrolled="true"] {
  background: var(--ink-green);
  border-bottom-color: var(--grass-mid);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: var(--header-h);
}
.brand { display: flex; flex-direction: column; gap: 2px; }
.brand-mark {
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 800;
  letter-spacing: .06em;
  color: var(--paper);
  white-space: nowrap;
}
.brand-mark::after {
  content: "";
  display: inline-block;
  width: 26px;
  height: 3px;
  margin-left: 10px;
  vertical-align: middle;
  background: var(--score-orange);
  transform: skewX(-28deg);
}
.brand-tag {
  font-size: 11.5px;
  letter-spacing: .18em;
  color: var(--mist);
  white-space: nowrap;
}

.nav { display: flex; align-items: center; gap: 26px; }
.nav-list { display: flex; align-items: center; gap: 4px; }
.nav-link {
  position: relative;
  display: inline-block;
  padding: 10px 12px;
  font-size: 15px;
  font-weight: 600;
  color: var(--paper);
  transform: skewX(-6deg);
  transition: color .16s var(--ease);
}
.nav-link::before {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 6px;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .18s var(--ease);
}
.nav-link:hover { color: var(--cyan); }
.nav-link:hover::before { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--cyan); }
.nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 12px;
  bottom: 0;
  width: 22px;
  height: 3px;
  background: var(--score-orange);
}
.nav-actions { display: flex; align-items: center; gap: 10px; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border: 1px solid var(--grass-mid);
  border-radius: var(--radius);
  color: var(--paper);
}
.nav-toggle-bar {
  display: block;
  width: 16px;
  height: 2px;
  background: var(--cyan);
}
.nav-toggle-text { font-size: 13px; letter-spacing: .12em; }

.scroll-progress {
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--cyan), var(--score-orange));
  transition: width .1s linear;
}

/* ===== buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  font-size: 14.5px;
  font-weight: 700;
  letter-spacing: .04em;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: transform .16s var(--ease), background-color .16s var(--ease), color .16s var(--ease), border-color .16s var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--score-orange); color: #180A04; }
.btn-primary:hover { background: #FF7549; }
.btn-ghost { border-color: var(--cyan); color: var(--cyan); background: rgba(100, 240, 196, .06); }
.btn-ghost:hover { background: rgba(100, 240, 196, .16); }

/* ===== layout primitives ===== */
.section { position: relative; padding: clamp(52px, 8vw, 112px) 0; }
.section-dark { background: var(--ink-green); color: var(--paper); }
.section-deep { background: var(--grass-deep); color: var(--paper); }
.section-paper { background: var(--paper); color: var(--brown-ink); }
.section-paper-light { background: var(--paper-light); color: var(--brown-ink); }
.section-paper a, .section-paper-light a { color: var(--brown-ink); }

.panel {
  position: relative;
  background: var(--grass-deep);
  border: 1px solid var(--grass-mid);
  border-radius: var(--radius);
  padding: clamp(22px, 3.4vw, 40px);
  box-shadow: var(--shadow-panel);
}
.panel::before {
  content: "";
  position: absolute;
  inset: 8px 8px auto auto;
  width: 42px;
  height: 10px;
  background-image: repeating-linear-gradient(90deg, var(--mist) 0 1px, transparent 1px 5px);
  opacity: .55;
}
.panel-paper { background: var(--paper); color: var(--brown-ink); border-color: #D6CB B0; }
.panel-tilt { transform: translateX(0); }
.panel-tilt-left { margin-left: -32px; }
.panel-tilt-right { margin-left: 32px; }

.grid-12 { display: grid; grid-template-columns: repeat(12, 1fr); gap: var(--gap); }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

.stack { display: flex; flex-direction: column; gap: 18px; }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.rule {
  height: 1px;
  background: linear-gradient(90deg, var(--grass-mid), transparent);
  border: 0;
}
.section-paper .rule { background: linear-gradient(90deg, #C9BBA0, transparent); }

/* ===== breadcrumb ===== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--mist);
  padding: 14px 0;
}
.breadcrumb-link { color: inherit; border-bottom: 1px solid transparent; }
.breadcrumb-link:hover { color: var(--cyan); border-bottom-color: var(--cyan); }
.breadcrumb-sep { color: var(--grass-mid); }

/* ===== prose ===== */
.prose { max-width: 72ch; }
.prose-wide { max-width: 88ch; }
.prose h2 { margin-top: 1.8em; margin-bottom: .6em; }
.prose h3 { margin-top: 1.4em; margin-bottom: .5em; }
.prose p+p { margin-top: 1em; }
.prose ul { margin: 1em 0; padding-left: 1.1em; list-style: none; }
.prose li { position: relative; padding-left: 18px; margin-bottom: .5em; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 9px;
  height: 2px;
  background: var(--score-orange);
}

/* ===== filter bar ===== */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 10px;
  background: rgba(31, 92, 69, .28);
  border: 1px dashed var(--grass-mid);
  border-radius: var(--radius);
}
.filter-btn {
  padding: 8px 16px;
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--paper);
  border: 1px solid transparent;
  border-radius: var(--radius);
  transition: background-color .16s var(--ease), color .16s var(--ease), border-color .16s var(--ease);
}
.filter-btn:hover { border-color: var(--cyan); color: var(--cyan); }
.filter-btn[aria-pressed="true"] { background: var(--cyan); color: var(--ink-green); }
.filter-count {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  color: var(--mist);
  align-self: center;
}
.is-hidden { display: none !important; }

/* ===== reveal ===== */
.reveal { opacity: 0; transform: translateY(12px); transition: opacity .32s var(--ease), transform .32s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }

/* ===== toc ===== */
.toc { position: sticky; top: calc(var(--header-h) + 18px); }
.toc-link {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--mist);
  border-left: 2px solid var(--grass-mid);
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.toc-link:hover { color: var(--paper); }
.toc-link[aria-current="true"] { color: var(--cyan); border-left-color: var(--score-orange); }

/* ===== image frames ===== */
.img-frame,
.img-frame-wide,
.img-frame-tall {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, var(--grass-mid) 0%, var(--grass-deep) 52%, var(--ink-green) 100%);
  border: 1px solid var(--grass-mid);
}
.img-frame::after,
.img-frame-wide::after,
.img-frame-tall::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(45deg, rgba(100, 240, 196, .08) 0 2px, transparent 2px 14px);
  pointer-events: none;
}
.img-frame { aspect-ratio: 4 / 3; }
.img-frame-wide { aspect-ratio: 16 / 9; }
.img-frame-tall { aspect-ratio: 3 / 4; }
.img-frame img,
.img-frame-wide img,
.img-frame-tall img { width: 100%; height: 100%; object-fit: cover; }

/* ===== to top ===== */
.to-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 130;
  padding: 11px 16px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .1em;
  background: var(--cyan);
  color: var(--ink-green);
  border-radius: var(--radius);
  box-shadow: 0 12px 26px -14px rgba(0, 0, 0, .9);
}
.to-top:hover { background: var(--paper); }

/* ===== footer ===== */
.site-footer {
  background: var(--grass-deep);
  border-top: 1px solid var(--grass-mid);
  color: var(--paper);
  padding: clamp(44px, 6vw, 76px) 0 26px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr 1.2fr;
  gap: 28px;
}
.footer-brand-mark {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: .06em;
  color: var(--paper);
}
.footer-brand-mark::after {
  content: "";
  display: block;
  width: 46px;
  height: 3px;
  margin-top: 10px;
  background: var(--score-orange);
  transform: skewX(-28deg);
}
.footer-note { margin-top: 12px; font-size: 14px; color: var(--mist); max-width: 34ch; }
.footer-title {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--cyan);
  margin-bottom: 14px;
  font-family: var(--font-data);
}
.footer-list { display: flex; flex-direction: column; gap: 9px; }
.footer-link { font-size: 14.5px; color: var(--paper); border-bottom: 1px solid transparent; }
.footer-link:hover { color: var(--cyan); border-bottom-color: var(--cyan); }
.footer-contact-line {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 13.5px;
  color: var(--paper);
  margin-bottom: 8px;
  word-break: break-all;
}
.footer-contact .footer-contact-line:last-child { color: var(--mist); font-family: var(--font-body); }
.footer-bottom {
  margin-top: clamp(28px, 4vw, 48px);
  padding-top: 18px;
  border-top: 1px solid var(--grass-mid);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
}
.footer-service { font-size: 13px; color: var(--mist); max-width: 74ch; }
.footer-legal {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--mist);
}

/* ===== focus ===== */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ===== responsive ===== */
@media (max-width: 1080px) {
  .footer-grid { grid-template-columns: 1fr 1fr 1fr; }
  .col-8, .col-6 { grid-column: span 12; }
  .col-4 { grid-column: span 12; }
  .nav { gap: 16px; }
  .nav-link { padding: 10px 8px; font-size: 14px; }
  .nav-actions .btn { padding: 10px 14px; font-size: 13.5px; }
}

@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 18px 20px 26px;
    background: var(--ink-green);
    border-bottom: 1px solid var(--grass-mid);
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }
  .site-header[data-open="true"] .nav { display: flex; }
  .nav-list { flex-direction: column; align-items: stretch; gap: 0; }
  .nav-link {
    transform: none;
    padding: 14px 4px;
    border-bottom: 1px solid rgba(31, 92, 69, .6);
    font-size: 16px;
  }
  .nav-link::before { display: none; }
  .nav-link[aria-current="page"]::after { left: 4px; bottom: 8px; }
  .nav-actions { flex-direction: column; align-items: stretch; margin-top: 18px; gap: 12px; }
  .nav-actions .btn { width: 100%; padding: 13px 18px; font-size: 15px; }
  .brand-tag { display: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .panel-tilt-left, .panel-tilt-right { margin-left: 0; }
}

@media (max-width: 560px) {
  html { font-size: 15px; }
  .footer-grid { grid-template-columns: 1fr; gap: 22px; }
  .to-top { right: 12px; bottom: 12px; }
  .footer-bottom { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}