/* ==========================================================================
   YOUBEI / TOUCHLINE — grid.css
   Layer 2 of 4: page shell — top strip, header, nav, sections, footer
   ========================================================================== */

@layer shell {
  /* ------------------------------------------------------------------ top */
  .yb-top {
    background: var(--turf-950);
    color: var(--chalk-2);
    font-size: 0.76rem;
  }
  .yb-top__in {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    min-height: 38px;
  }
  .yb-top__note {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--chalk-2);
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
  }
  .yb-top__note::before {
    content: "";
    width: 8px;
    height: 8px;
    background: var(--ref);
    transform: rotate(45deg);
  }
  .yb-top__meta {
    display: flex;
    align-items: center;
    gap: 20px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.06em;
  }
  .yb-top__meta a:hover { color: var(--ref); }

  /* --------------------------------------------------------------- header */
  .yb-head {
    position: sticky;
    top: 0;
    z-index: 60;
    background: var(--paper);
    border-bottom: 2px solid var(--ink);
  }
  .yb-head__bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    min-height: var(--head-h);
  }
  .yb-logo {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
  }
  .yb-logo__badge {
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 2px solid var(--ink);
    background: var(--turf-900);
    color: var(--ref);
    font-family: var(--font-mono);
    font-size: 0.94rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    box-shadow: inset 0 0 0 3px var(--paper);
  }
  .yb-logo__txt {
    display: grid;
    gap: 1px;
  }
  .yb-logo__txt strong {
    font-size: 1.16rem;
    letter-spacing: 0.1em;
    line-height: 1.2;
  }
  .yb-logo__txt em {
    font-family: var(--font-mono);
    font-size: 0.64rem;
    letter-spacing: 0.26em;
    text-transform: uppercase;
    color: var(--turf-700);
  }

  .yb-burger {
    display: none;
    padding: 9px 12px;
    border: 2px solid var(--ink);
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.16em;
  }

  .yb-nav {
    display: flex;
    align-items: center;
    gap: 26px;
  }
  .yb-nav__list {
    display: flex;
    align-items: center;
    gap: 22px;
  }
  .yb-nav__list a {
    display: grid;
    gap: 0;
    padding: 6px 0;
    font-size: 0.86rem;
    font-weight: 700;
    border-bottom: 2px solid transparent;
    transition: border-color 0.16s ease, color 0.16s ease;
  }
  .yb-nav__list a:hover { color: var(--turf-700); border-color: var(--ref); }
  .yb-nav__list a[aria-current="page"] { border-color: var(--flag); }
  .yb-nav__no {
    font-family: var(--font-mono);
    font-size: 0.58rem;
    font-weight: 400;
    letter-spacing: 0.16em;
    color: var(--turf-600);
  }
  .yb-nav__cta {
    display: flex;
    align-items: center;
    gap: 8px;
  }

  /* --------------------------------------------------------------- ticker */
  .yb-ticker {
    background: var(--turf-900);
    color: var(--chalk);
    border-block: 1px solid rgba(238, 243, 228, 0.18);
    overflow: hidden;
  }
  .yb-ticker__track {
    display: flex;
    gap: 46px;
    width: max-content;
    padding: 9px 0;
    animation: yb-slide 42s linear infinite;
  }
  .yb-ticker__item {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    white-space: nowrap;
  }
  .yb-ticker__item::before {
    content: "•";
    color: var(--ref);
  }
  @keyframes yb-slide {
    from { transform: translateX(0); }
    to { transform: translateX(-50%); }
  }

  /* -------------------------------------------------------------- sections */
  .yb-main { display: block; }

  .yb-sec {
    padding-block: 76px;
    border-bottom: 1px solid var(--hair);
  }
  .yb-sec--tight { padding-block: 48px; }
  .yb-sec--turf {
    background: var(--turf-900);
    color: var(--chalk);
    border-bottom: 0;
  }
  .yb-sec--turf p { color: var(--chalk-2); }
  .yb-sec--turf h2,
  .yb-sec--turf h3,
  .yb-sec--turf strong { color: var(--chalk); }
  .yb-sec--turf .yb-eyebrow { color: var(--ref); }
  .yb-sec--turf .yb-eyebrow::before { background: var(--ref); }
  .yb-sec--paper2 { background: var(--paper-2); }
  .yb-sec--flush { padding-block: 0; }

  .yb-sechead {
    display: grid;
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: start;
    gap: 26px;
    padding-bottom: 26px;
    margin-bottom: 34px;
    border-bottom: 1px dashed var(--hair-strong);
  }
  .yb-sechead__no {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    letter-spacing: 0.14em;
    color: var(--turf-700);
    padding-top: 8px;
  }
  .yb-sechead__no::after {
    content: "";
    display: block;
    width: 34px;
    height: 2px;
    margin-top: 8px;
    background: var(--flag);
  }
  .yb-sechead__body {
    display: grid;
    gap: 10px;
    max-width: 760px;
  }
  .yb-sechead__body h2 { font-size: var(--step-3); }
  .yb-sechead__body p { font-size: 0.95rem; }
  .yb-sechead--wide .yb-sechead__body { max-width: none; }
  .yb-sec--turf .yb-sechead { border-color: var(--hair-chalk); }
  .yb-sec--turf .yb-sechead__no { color: var(--chalk-3); }

  /* -------------------------------------------------------------- hero shell */
  .yb-hero {
    position: relative;
    background: var(--turf-950);
    color: var(--chalk);
    overflow: hidden;
  }
  .yb-hero__inner {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 48px;
    align-items: center;
    padding-block: 78px 86px;
  }
  .yb-hero__copy { display: grid; gap: 22px; justify-items: start; }
  .yb-hero__copy h1 { color: var(--chalk); }
  .yb-hero__copy p { color: var(--chalk-2); }
  .yb-kicker {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
  }
  .yb-lead {
    max-width: 56ch;
    font-size: 1rem;
    line-height: 1.9;
  }
  .yb-acts {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
  }
  .yb-hero__facts {
    display: flex;
    flex-wrap: wrap;
    gap: 28px;
    padding-top: 20px;
    margin-top: 4px;
    border-top: 1px solid var(--hair-chalk);
    width: 100%;
  }
  .yb-hero__facts li {
    display: grid;
    gap: 2px;
  }
  .yb-hero__facts strong {
    color: var(--ref);
    font-family: var(--font-mono);
    font-size: 1.5rem;
    letter-spacing: 0.02em;
  }
  .yb-hero__facts span {
    font-size: 0.76rem;
    letter-spacing: 0.1em;
    color: var(--chalk-3);
  }
  .yb-hero__art {
    position: relative;
    min-height: 360px;
  }

  /* -------------------------------------------------------------- page head */
  .yb-pagehead {
    position: relative;
    background: var(--paper-2);
    padding-block: 44px 40px;
    border-bottom: 2px solid var(--ink);
    overflow: hidden;
  }
  .yb-pagehead::after {
    content: "";
    position: absolute;
    right: -60px;
    top: -60px;
    width: 260px;
    height: 260px;
    border: 2px dashed var(--hair-strong);
    border-radius: 50%;
    pointer-events: none;
  }
  .yb-crumb {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--turf-700);
    margin-bottom: 14px;
  }
  .yb-crumb a:hover { color: var(--flag); }
  .yb-crumb li + li::before { content: "/"; margin-right: 8px; color: var(--hair-strong); }
  .yb-pagehead__body {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 14px;
    max-width: 820px;
  }
  .yb-pagehead__tag {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--flag);
  }
  .yb-pagehead h1 { font-size: var(--step-4); }
  .yb-pagehead p { font-size: 0.96rem; }

  .yb-split {
    display: grid;
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    gap: 46px;
    align-items: start;
  }
  .yb-split--wide { grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.75fr); }
  .yb-split--rev { grid-template-columns: minmax(0, 0.75fr) minmax(0, 1.25fr); }

  .yb-rail {
    display: flex;
    align-items: center;
    gap: 14px;
    font-family: var(--font-mono);
    font-size: 0.68rem;
    letter-spacing: 0.24em;
    text-transform: uppercase;
    color: var(--turf-700);
  }
  .yb-rail::before {
    content: "";
    width: 44px;
    height: 1px;
    background: currentColor;
  }

  /* ---------------------------------------------------------------- footer */
  .yb-foot {
    background: var(--turf-950);
    color: var(--chalk-2);
    padding-top: 58px;
  }
  .yb-foot a { color: var(--chalk-2); }
  .yb-foot a:hover { color: var(--ref); }
  .yb-foot__grid {
    display: grid;
    grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, 0.7fr));
    gap: 40px;
    padding-bottom: 42px;
  }
  .yb-foot__brand {
    display: grid;
    gap: 16px;
    max-width: 380px;
  }
  .yb-foot__brand .yb-logo__badge { box-shadow: inset 0 0 0 3px var(--turf-950); }
  .yb-foot__brand .yb-logo__txt strong { color: var(--chalk); }
  .yb-foot__brand .yb-logo__txt em { color: var(--chalk-3); }
  .yb-foot__brand p { color: var(--chalk-3); font-size: 0.86rem; }
  .yb-foot__mark {
    display: flex;
    gap: 26px;
    padding-top: 4px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.1em;
    color: var(--chalk-3);
  }
  .yb-foot__col { display: grid; gap: 14px; align-content: start; }
  .yb-foot__col h3 {
    color: var(--chalk);
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--hair-chalk);
  }
  .yb-foot__col ul { display: grid; gap: 9px; font-size: 0.86rem; }
  .yb-foot__legal {
    display: grid;
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    gap: 34px;
    padding-block: 28px;
    border-top: 1px dashed var(--hair-chalk);
  }
  .yb-foot__legal h4 {
    color: var(--ref);
    font-family: var(--font-mono);
    font-size: 0.74rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin-bottom: 8px;
  }
  .yb-foot__legal p { color: var(--chalk-3); font-size: 0.8rem; }
  .yb-foot__legal ul {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px 22px;
    font-size: 0.78rem;
    color: var(--chalk-3);
  }
  .yb-foot__legal li {
    position: relative;
    padding-left: 14px;
  }
  .yb-foot__legal li::before {
    content: "×";
    position: absolute;
    left: 0;
    color: var(--flag);
    font-family: var(--font-mono);
  }
  .yb-foot__base {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding-block: 18px;
    border-top: 1px solid var(--hair-chalk);
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.04em;
    color: var(--chalk-3);
  }
  .yb-foot__base p { color: var(--chalk-3); }

  .yb-totop {
    position: fixed;
    right: 18px;
    bottom: 18px;
    z-index: 70;
    width: 46px;
    height: 46px;
    display: grid;
    place-items: center;
    border: 2px solid var(--ink);
    background: var(--ref);
    color: var(--ink);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.08em;
    opacity: 0;
    pointer-events: none;
    transform: translateY(8px);
    transition: opacity 0.2s ease, transform 0.2s ease;
  }
  .yb-totop.is-on { opacity: 1; pointer-events: auto; transform: none; }
  .yb-totop:hover { background: var(--ink); color: var(--ref); }

  /* ------------------------------------------------------------ responsive */
  @media (max-width: 1080px) {
    .yb-nav { gap: 16px; }
    .yb-nav__list { gap: 16px; }
    .yb-nav__list a { font-size: 0.8rem; }
    .yb-hero__inner { gap: 32px; }
    .yb-sechead { grid-template-columns: 72px minmax(0, 1fr); gap: 18px; }
    .yb-foot__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  }

  @media (max-width: 900px) {
    .yb-top__meta li:last-child { display: none; }
    .yb-burger { display: inline-flex; }
    .yb-nav {
      position: absolute;
      left: 0;
      right: 0;
      top: 100%;
      display: none;
      flex-direction: column;
      align-items: stretch;
      gap: 18px;
      padding: 22px var(--gutter) 26px;
      background: var(--paper);
      border-bottom: 2px solid var(--ink);
      box-shadow: 0 18px 30px rgba(16, 26, 16, 0.14);
    }
    .yb-nav.is-open { display: flex; }
    .yb-nav__list { flex-direction: column; align-items: stretch; gap: 0; }
    .yb-nav__list li + li { border-top: 1px solid var(--hair); }
    .yb-nav__list a { padding: 11px 0; font-size: 0.94rem; }
    .yb-nav__cta { padding-top: 4px; }
    .yb-hero__inner { grid-template-columns: 1fr; padding-block: 54px 62px; }
    .yb-hero__art { min-height: 300px; order: -1; }
    .yb-split,
    .yb-split--wide,
    .yb-split--rev { grid-template-columns: 1fr; gap: 32px; }
    .yb-foot__legal { grid-template-columns: 1fr; }
  }

  @media (max-width: 620px) {
    :root { --gutter: 16px; }
    .yb-top__note { display: none; }
    .yb-top__in { justify-content: center; }
    .yb-sec { padding-block: 54px; }
    .yb-sechead { grid-template-columns: 1fr; gap: 8px; margin-bottom: 26px; }
    .yb-sechead__no::after { display: none; }
    .yb-hero__facts { gap: 18px; }
    .yb-logo__txt em { letter-spacing: 0.16em; }
    .yb-foot__legal ul { grid-template-columns: 1fr; }
    .yb-foot__base { font-size: 0.66rem; }
    .yb-pagehead { padding-block: 32px 30px; }
  }
}