:root {
  --accent: #3E6AE1;
  --accent-hover: #3457bb;
  --ink: #171A20;
  --body: #393C41;
  --pewter: #5C5E62;
  --fog: #8E8E8E;
  --cloud: #EEEEEE;
  --silver: #D0D1D2;
  --ash: #F4F4F4;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: #fff; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--ink); text-decoration: none; }
.app { min-height: 100vh; display: flex; flex-direction: column; background: #fff; }

/* header */
.header { position: sticky; top: 0; z-index: 30; background: rgba(255,255,255,0.85); backdrop-filter: blur(6px); }
.header__bar { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 14px 24px; max-width: 1383px; margin: 0 auto; }
.brand { display: flex; align-items: center; gap: 12px; min-width: 0; }
.brand img { height: 20px; width: auto; display: block; }
.brand__word { font-size: 14px; font-weight: 500; letter-spacing: 0.22em; text-transform: uppercase; white-space: nowrap; }
.nav { display: none; align-items: center; gap: 4px; font-size: 14px; font-weight: 500; }
.nav--mobile { display: flex; flex-direction: column; background: #fff; padding: 8px 16px 20px; font-size: 14px; font-weight: 500; }
.navbtn { color: var(--ink); border-radius: 4px; padding: 8px 16px; transition: color 0.33s, background-color 0.33s; }
.nav--mobile .navbtn { padding: 14px 8px; }
.navbtn:hover { background: rgba(23,26,32,0.06); }

/* hamburger */
.hamburger { cursor: pointer; display: inline-flex; }
.hamburger input { display: none; }
.hamburger svg { height: 2em; transition: transform 600ms cubic-bezier(0.4, 0, 0.2, 1); }
.hamburger .line {
  fill: none; stroke: var(--ink); stroke-linecap: round; stroke-linejoin: round; stroke-width: 3;
  transition: stroke-dasharray 600ms cubic-bezier(0.4, 0, 0.2, 1), stroke-dashoffset 600ms cubic-bezier(0.4, 0, 0.2, 1);
}
.hamburger .line-top-bottom { stroke-dasharray: 12 63; }
.hamburger input:checked + svg { transform: rotate(-45deg); }
.hamburger input:checked + svg .line-top-bottom { stroke-dasharray: 20 300; stroke-dashoffset: -32.42; }

/* buttons */
.btn { display: flex; align-items: center; justify-content: center; width: 200px; min-height: 40px; font-size: 14px; font-weight: 500; border-radius: 4px; }
.btn--primary { background: var(--accent); color: #fff; transition: background-color 0.33s, color 0.33s; }
.btn--primary:hover { background: var(--accent-hover); color: #fff; }
.btn--secondary { background: rgba(255,255,255,0.92); color: var(--body); border: 1px solid var(--silver); transition: background-color 0.33s, color 0.33s; }
.btn--secondary:hover { background: #fff; color: var(--ink); }

/* hero */
.hero { max-width: 1383px; margin: 0 auto; padding: 72px 24px 64px; display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr)); gap: 40px; align-items: start; }
.hero__col { min-width: 0; }
.hero h1 { margin: 0 0 12px; font-size: clamp(28px, 4.4vw, 40px); font-weight: 500; line-height: 1.2; max-width: 20ch; }
.hero p { margin: 0 0 28px; font-size: 14px; font-weight: 400; line-height: 20px; color: var(--body); max-width: 56ch; }
.hero__actions { display: flex; flex-wrap: wrap; gap: 16px; }
.facts { min-width: 0; display: flex; flex-direction: column; }
.fact { display: flex; align-items: baseline; justify-content: space-between; gap: 20px; padding: 14px 0; border-top: 1px solid var(--cloud); }
.fact:last-child { border-bottom: 1px solid var(--cloud); }
.fact__key { font-size: 14px; font-weight: 400; line-height: 20px; color: var(--pewter); }
.fact__val { font-size: 14px; font-weight: 500; line-height: 20px; text-align: right; word-break: break-all; }

/* diagram sections */
.diagrams { padding: 0 0 40px; }
.diagram { position: relative; height: calc(100vh - 56px); min-height: 520px; overflow: hidden; border-top: 1px solid var(--silver); margin-top: 40px; }
.diagram__media { position: absolute; inset: 0; background: var(--ash); }
.diagram__media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.diagram__empty { position: absolute; inset: auto 0 24px; z-index: 3; display: flex; align-items: flex-end; justify-content: center; font-size: 14px; line-height: 20px; color: var(--pewter); text-align: center; padding: 0 24px; }
.diagram__veil { position: absolute; inset: 0; z-index: 1; background: rgba(255,255,255,0.62); backdrop-filter: blur(3px) saturate(0.85); pointer-events: none; }
.diagram__content { position: relative; z-index: 2; height: 100%; display: flex; flex-direction: column; align-items: center; justify-content: space-between; padding: 64px 24px 56px; pointer-events: none; }
.diagram__head { display: flex; flex-direction: column; align-items: center; gap: 8px; text-align: center; }
.eyebrow { font-size: 14px; font-weight: 500; line-height: 20px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--pewter); }
.diagram h2 { margin: 0; font-size: clamp(26px, 4.2vw, 40px); font-weight: 500; line-height: 1.2; }
.diagram__blurb { margin: 0; font-size: 14px; font-weight: 400; line-height: 20px; color: var(--body); max-width: 46ch; }
.diagram__note { font-size: 14px; font-weight: 500; line-height: 20px; color: var(--accent); }
.diagram__foot { display: flex; flex-direction: column; align-items: center; gap: 20px; pointer-events: auto; }
.diagram__host { font-size: 14px; font-weight: 400; line-height: 20px; color: var(--pewter); word-break: break-all; text-align: center; }

/* access */
.access { display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; gap: 12px; padding: 140px 24px; border-top: 1px solid var(--silver); }
.access__eyebrow { font-size: 14px; font-weight: 400; line-height: 20px; color: var(--accent); }
.access h2 { margin: 0; font-size: clamp(26px, 4.2vw, 40px); font-weight: 500; line-height: 1.2; max-width: 22ch; }
.access p { margin: 0; font-size: 14px; font-weight: 400; line-height: 20px; color: var(--body); max-width: 56ch; }

/* license */
.license { flex: 1; padding: 72px 24px 96px; }
.license__inner { max-width: 720px; margin: 0 auto; }
.license h1 { margin: 28px 0 8px; font-size: clamp(28px, 4.4vw, 40px); font-weight: 500; line-height: 1.2; }
.license h2 { margin: 0 0 10px; font-size: 17px; font-weight: 500; line-height: 20px; }
.license__meta { margin: 0 0 40px; font-size: 14px; line-height: 20px; color: var(--pewter); }
.license p { font-size: 14px; font-weight: 400; line-height: 20px; color: var(--body); }
.terms { display: flex; flex-direction: column; }
.term { display: flex; gap: 20px; padding: 18px 0; border-top: 1px solid var(--cloud); }
.term:last-child { border-bottom: 1px solid var(--cloud); }
.term__num { font-size: 14px; line-height: 20px; color: var(--fog); flex: 0 0 24px; }
.term p { margin: 0; }
.term strong { font-weight: 500; color: var(--ink); }
.tlink { color: var(--pewter); transition: color 0.33s; }
.tlink:hover { color: var(--ink); text-decoration: underline; }

/* footer */
.footer { background: var(--ash); padding: 56px 24px 40px; }
.footer__grid { max-width: 1383px; margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 220px), 1fr)); gap: 32px; }
.footer__col { display: flex; flex-direction: column; gap: 8px; min-width: 0; }
.footer__name { font-size: 17px; font-weight: 500; line-height: 20px; }
.footer__col span, .footer__col a { font-size: 14px; font-weight: 400; line-height: 20px; color: var(--pewter); word-break: break-word; }
.footer__col .footer__name { color: var(--ink); }
.footer__legal { max-width: 1383px; margin: 32px auto 0; padding-top: 20px; border-top: 1px solid var(--silver); font-size: 14px; line-height: 20px; color: var(--pewter); }

.only-mobile { display: flex; }
@media (min-width: 900px) {
  .only-mobile { display: none !important; }
  .nav { display: flex; }
}