/* =========================================================
   BEPLAY主页 · 共享样式表  /assets/site.css
   深靛蓝枢纽 + 电光青脉冲 + 暖纸色阅读面
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd, ul, ol { margin: 0; }

ul, ol { padding: 0; }

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

button, input, select, textarea { font: inherit; color: inherit; }

a { color: inherit; }

[hidden] { display: none !important; }

/* ---------- 2. Design tokens ---------- */
:root {
  --ink:          #0B1020;
  --navy-950:     #0C1530;
  --navy-900:     #101B3B;
  --navy-700:     #1B2A5B;
  --navy-line:    #2C3E70;
  --cyan:         #35E0D6;
  --cyan-deep:    #0E7F7B;
  --orange:       #FF8A3D;
  --paper:        #F4EFE6;
  --paper-line:   #D8CFBE;
  --mist:         #9FB0D6;
  --mist-deep:    #5A6A8C;
  --vermilion:    #D9483B;
  --on-dark:      #DCE5FA;

  --rail-w:       240px;
  --shell-max:    1180px;
  --gutter:       20px;
  --radius:       14px;
  --shadow-lift:  0 16px 34px -20px rgba(4, 8, 22, .92);

  --font-display: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-body:    "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-serif:   "Noto Serif SC", "Songti SC", "SimSun", Georgia, "Times New Roman", serif;
  --font-mono:    ui-monospace, "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;
}

/* ---------- 3. Base ---------- */
body {
  min-height: 100vh;
  background-color: var(--navy-900);
  background-image:
    radial-gradient(62vw 48vh at 88% -8%, rgba(53, 224, 214, .11), transparent 62%),
    radial-gradient(54vw 46vh at 2% 104%, rgba(255, 138, 61, .10), transparent 60%),
    repeating-linear-gradient(90deg, rgba(255, 255, 255, .022) 0 1px, transparent 1px 92px);
  background-repeat: no-repeat;
  color: var(--on-dark);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.85;
  letter-spacing: .005em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -.01em;
  line-height: 1.3;
}

::selection {
  background: var(--cyan);
  color: #06231F;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  z-index: 90;
  pointer-events: none;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
  transition: width .1s linear;
}

/* ---------- 4. Focus & motion ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 4px;
}

.section--paper :focus-visible { outline-color: var(--cyan-deep); }

[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s ease, transform .5s ease;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  [data-reveal] { opacity: 1; transform: none; }
  .scroll-progress { transition: none; }
}

/* ---------- 5. Layout primitives ---------- */
.wrap {
  width: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.section { padding: 56px 0; }

.section--navy { background: var(--navy-950); }

.section--paper {
  background: var(--paper);
  color: var(--ink);
}

.section--paper .section-lede,
.section--paper .crumb-list,
.section--paper .crumb-list a { color: var(--mist-deep); }

.section--paper .prose a,
.section--paper .link { color: var(--cyan-deep); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: 1px;
  background: currentColor;
}

.section--paper .eyebrow { color: var(--cyan-deep); }

.section-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 3.4vw, 40px);
  line-height: 1.25;
  letter-spacing: -.01em;
  margin: .35em 0 .5em;
}

.section-lede {
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
  max-width: 46em;
}

.meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
}

.section--paper .meta { color: var(--mist-deep); }

/* ---------- 6. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: 10px;
  font-family: var(--font-display);
  font-size: 14.5px;
  font-weight: 700;
  line-height: 1.4;
  text-decoration: none;
  cursor: pointer;
  transition: transform .16s ease, background-color .16s ease, border-color .16s ease, color .16s ease;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--orange);
  border-color: var(--orange);
  color: #1A0C02;
}

.btn-primary:hover { background: #FFA063; border-color: #FFA063; }

.btn-cyan {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #06231F;
}

.btn-cyan:hover { background: #5CEAE2; border-color: #5CEAE2; }

.btn-ghost {
  background: transparent;
  border-color: var(--navy-line);
  color: var(--on-dark);
}

.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan); }

.btn-block { width: 100%; }

/* ---------- 7. Chips & tags ---------- */
.chip,
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--navy-line);
  border-radius: 999px;
  background: rgba(255, 255, 255, .02);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--mist);
  text-decoration: none;
}

.tag { border-radius: 4px; }

.tag--live { border-color: var(--vermilion); color: #F3B9B3; }

.chip--cyan { border-color: var(--cyan); color: var(--cyan); }

.chip--orange {
  border-color: var(--orange);
  color: var(--orange);
  background: rgba(255, 138, 61, .10);
}

.chip--paper {
  border-color: var(--paper-line);
  background: #FBF7EF;
  color: var(--mist-deep);
}

/* ---------- 8. Header / vertical rail ---------- */
.site-header {
  position: relative;
  z-index: 40;
  padding: 16px var(--gutter) 18px;
  background: linear-gradient(180deg, #101B3B 0%, #0C1530 100%);
  border-bottom: 1px solid var(--navy-line);
  color: var(--on-dark);
}

.skip-link {
  position: absolute;
  left: 14px;
  top: -70px;
  z-index: 100;
  padding: 10px 16px;
  border-radius: 0 0 10px 10px;
  background: var(--cyan);
  color: #06231F;
  font-family: var(--font-display);
  font-weight: 700;
  text-decoration: none;
  transition: top .18s ease;
}

.skip-link:focus { top: 0; }

.rail-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  text-decoration: none;
  color: inherit;
}

.brand-mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--cyan);
  border-radius: 10px;
  background: rgba(53, 224, 214, .08);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  transition: background-color .18s ease, box-shadow .18s ease;
}

.brand:hover .brand-mark {
  background: rgba(53, 224, 214, .18);
  box-shadow: 0 0 0 4px rgba(53, 224, 214, .10);
}

.brand-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.35;
  color: #fff;
}

.brand-line {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .04em;
  line-height: 1.5;
  color: var(--mist);
}

.nav-toggle {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--navy-line);
  border-radius: 9px;
  background: transparent;
  color: var(--on-dark);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  cursor: pointer;
  transition: border-color .16s ease, color .16s ease;
}

.nav-toggle:hover,
.nav-toggle[aria-expanded="true"] {
  border-color: var(--cyan);
  color: var(--cyan);
}

.nav-toggle-icon {
  position: relative;
  display: inline-block;
  width: 16px;
  height: 12px;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 1.5px;
  background: currentColor;
  transition: transform .2s ease, top .2s ease;
}

.nav-toggle-icon::before { top: 2px; }
.nav-toggle-icon::after { top: 8px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before { top: 5px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after { top: 5px; transform: rotate(-45deg); }

.rail-note {
  margin-top: 12px;
  padding-left: 11px;
  border-left: 2px solid var(--navy-line);
  font-size: 12.5px;
  line-height: 1.75;
  color: var(--mist);
}

.site-nav {
  display: none;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--navy-line);
}

.site-nav[data-open] { display: block; }

.nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-left: 2px solid transparent;
  border-radius: 9px;
  color: var(--on-dark);
  font-family: var(--font-display);
  font-size: 14.5px;
  font-weight: 500;
  text-decoration: none;
  transition: background-color .18s ease, color .18s ease, border-color .18s ease;
}

.nav-list a::before {
  content: "";
  flex: 0 0 auto;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--navy-line);
  transition: background-color .18s ease;
}

.nav-list a:hover {
  background: rgba(53, 224, 214, .07);
  color: #fff;
}

.nav-list a:hover::before { background: var(--mist); }

.nav-list a[aria-current="page"] {
  background: rgba(53, 224, 214, .12);
  border-left-color: var(--cyan);
  color: #fff;
}

.nav-list a[aria-current="page"]::before { background: var(--cyan); }

.rail-foot {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 16px;
}

.update-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--orange);
}

.update-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 3px rgba(255, 138, 61, .18);
}

/* ---------- 9. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: 64px;
  padding: 46px var(--gutter) 28px;
  background: var(--navy-900);
  border-top: 1px solid var(--navy-line);
  color: var(--on-dark);
}

.site-footer::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--orange) 38%, transparent 78%);
}

.footer-inner {
  display: grid;
  gap: 34px;
  max-width: var(--shell-max);
  margin: 0 auto;
}

.footer-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 21px;
  letter-spacing: -.01em;
  color: #fff;
}

.footer-tagline {
  margin-top: 6px;
  font-family: var(--font-serif);
  font-size: 15px;
  line-height: 1.7;
  color: var(--mist);
}

.footer-blurb {
  margin-top: 12px;
  max-width: 32em;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 24px;
}

.footer-heading {
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer-list a {
  display: inline-block;
  border-bottom: 1px solid transparent;
  color: var(--on-dark);
  font-size: 14.5px;
  text-decoration: none;
  transition: color .16s ease, border-color .16s ease;
}

.footer-list a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.contact-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.contact-list li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
}

.contact-key {
  min-width: 34px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .1em;
  color: var(--mist);
}

.contact-value {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--on-dark);
}

.copy-chip {
  padding: 3px 8px;
  border: 1px dashed var(--navy-line);
  border-radius: 7px;
  background: transparent;
  color: var(--on-dark);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .03em;
  cursor: pointer;
  transition: border-color .16s ease, color .16s ease, background-color .16s ease;
}

.copy-chip:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.copy-chip[data-copied="true"] {
  border-style: solid;
  border-color: var(--cyan);
  background: rgba(53, 224, 214, .10);
  color: var(--cyan);
}

.copy-chip[data-copied="true"]::after { content: " · 已复制"; }

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  max-width: var(--shell-max);
  margin: 38px auto 0;
  padding-top: 18px;
  border-top: 1px solid var(--navy-line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--mist);
}

.footer-footnote {
  flex-basis: 100%;
  color: rgba(159, 176, 214, .72);
}

/* ---------- 10. Breadcrumbs ---------- */
.crumbs { margin-bottom: 18px; }

.crumb-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--mist);
}

.crumb-list li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.crumb-list li + li::before {
  content: "/";
  color: var(--navy-line);
}

.crumb-list a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s ease, border-color .16s ease;
}

.crumb-list a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.crumb-list [aria-current="page"] { color: var(--on-dark); }

/* ---------- 11. Cards, grids, media ---------- */
.grid {
  display: grid;
  gap: var(--gutter);
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.bento {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

@media (min-width: 720px) {
  .bento { grid-template-columns: repeat(6, 1fr); }
  .span-2 { grid-column: span 2; }
  .span-3 { grid-column: span 3; }
  .span-4 { grid-column: span 4; }
  .span-6 { grid-column: span 6; }
}

.card {
  padding: 20px;
  border: 1px solid var(--navy-line);
  border-radius: var(--radius);
  background: var(--navy-700);
  transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease;
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(53, 224, 214, .55);
  box-shadow: var(--shadow-lift);
}

.card--paper {
  background: #FBF7EF;
  border-color: var(--paper-line);
  color: var(--ink);
}

.media-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border: 1px solid var(--navy-line);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(53, 224, 214, .18), rgba(255, 138, 61, .12) 55%, transparent 100%),
    #16234A;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background: repeating-linear-gradient(45deg, rgba(255, 255, 255, .05) 0 1px, transparent 1px 11px);
  pointer-events: none;
}

.media-frame > img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-caption {
  margin-top: 9px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--mist);
}

.section--paper .media-caption { color: var(--mist-deep); }

/* ---------- 12. Prose ---------- */
.prose {
  max-width: 44em;
  font-size: 16px;
  line-height: 1.9;
}

.prose p { margin-bottom: 1.1em; }

.prose h2 {
  margin: 1.9em 0 .6em;
  font-family: var(--font-display);
  font-size: 26px;
  line-height: 1.4;
}

.prose h3 {
  margin: 1.5em 0 .5em;
  font-family: var(--font-display);
  font-size: 19px;
  line-height: 1.5;
}

.prose ul,
.prose ol { margin: 0 0 1.1em 1.3em; }

.prose li { margin-bottom: .4em; }

.prose a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose blockquote {
  margin: 1.4em 0;
  padding: 4px 0 4px 16px;
  border-left: 2px solid var(--navy-line);
  color: var(--mist);
}

.section--paper .prose blockquote {
  border-left-color: var(--paper-line);
  color: var(--mist-deep);
}

/* ---------- 13. Tabs ---------- */
.tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--navy-line);
}

.section--paper .tablist { border-bottom-color: var(--paper-line); }

[role="tab"] {
  appearance: none;
  padding: 8px 15px;
  border: 1px solid transparent;
  border-radius: 999px;
  background: transparent;
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .05em;
  cursor: pointer;
  transition: background-color .16s ease, border-color .16s ease, color .16s ease;
}

[role="tab"]:hover {
  border-color: var(--navy-line);
  color: var(--on-dark);
}

[role="tab"][aria-selected="true"] {
  border-color: var(--cyan);
  background: rgba(53, 224, 214, .12);
  color: var(--cyan);
}

.section--paper [role="tab"] { color: var(--mist-deep); }

.section--paper [role="tab"]:hover {
  border-color: var(--paper-line);
  color: var(--ink);
}

.section--paper [role="tab"][aria-selected="true"] {
  border-color: var(--cyan-deep);
  background: rgba(14, 127, 123, .10);
  color: var(--cyan-deep);
}

[role="tabpanel"] { padding-top: 18px; }

/* ---------- 14. Accordion ---------- */
.accordion { border-top: 1px solid var(--navy-line); }

.section--paper .accordion { border-top-color: var(--paper-line); }

.accordion details { border-bottom: 1px solid var(--navy-line); }

.section--paper .accordion details { border-bottom-color: var(--paper-line); }

.accordion summary {
  padding: 15px 0;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}

.accordion summary::-webkit-details-marker { display: none; }

.accordion summary::after {
  content: "+";
  float: right;
  margin-left: 12px;
  color: var(--cyan);
  font-family: var(--font-mono);
  font-weight: 400;
}

.accordion details[open] summary::after { content: "–"; }

.accordion .accordion-body {
  padding: 0 0 18px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist);
}

.section--paper .accordion .accordion-body { color: var(--mist-deep); }

/* ---------- 15. Timeline ---------- */
.timeline {
  position: relative;
  list-style: none;
  padding: 0;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--navy-line);
}

.timeline > li {
  position: relative;
  padding: 0 0 22px 30px;
}

.timeline > li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 8px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--navy-line);
  border-radius: 50%;
  background: var(--navy-900);
  transition: background-color .3s ease, border-color .3s ease, box-shadow .3s ease;
}

.timeline > li.is-lit::before {
  border-color: var(--cyan);
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(53, 224, 214, .16);
}

.timeline--paper::before { background: var(--paper-line); }

.timeline--paper > li::before {
  border-color: var(--paper-line);
  background: var(--paper);
}

.timeline--paper > li.is-lit::before {
  border-color: var(--cyan-deep);
  background: var(--cyan-deep);
  box-shadow: 0 0 0 4px rgba(14, 127, 123, .14);
}

.timeline-title {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.6;
}

/* ---------- 16. Responsive shell ---------- */
@media (min-width: 1080px) {
  body { padding-left: var(--rail-w); }

  .site-header {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--rail-w);
    display: flex;
    flex-direction: column;
    gap: 18px;
    padding: 26px 18px 22px;
    border-right: 1px solid var(--navy-line);
    border-bottom: 0;
    overflow-y: auto;
  }

  .nav-toggle { display: none; }

  .site-nav {
    display: block;
    margin-top: 2px;
    padding-top: 0;
    border-top: 0;
  }

  .site-nav[data-open] { display: block; }

  .rail-note { margin-top: 16px; }

  .rail-foot { margin-top: auto; }

  .scroll-progress { left: var(--rail-w); }

  .section { padding: 72px 0; }

  .footer-inner {
    grid-template-columns: 1.05fr 1.9fr 1.15fr;
    gap: 40px;
  }
}

@media (max-width: 519px) {
  :root { --gutter: 16px; }

  .brand-line { display: none; }

  .section { padding: 44px 0; }

  .site-footer { padding-top: 38px; }
}