/* Standalone shell chrome for the engine's own HTML pages (index.html):
   page resets, header, footer. The ECOllaboration site provides its own chrome
   and never loads this file — see README "Embedding". */

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--surface); font-family: var(--font-body); }
button, input, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
img { display: block; max-width: 100%; }
a { color: inherit; }

.skip-link { position: fixed; z-index: 1000; left: 1rem; top: 1rem; padding: .8rem 1rem; background: white; transform: translateY(-200%); }
.skip-link:focus { transform: none; }

.site-header { height: var(--header-h); display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 2rem; padding: 0 clamp(1.25rem, 4vw, 4.5rem); background: rgba(255, 255, 255, .93); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 50; backdrop-filter: blur(18px); }
.site-brand-group { display: flex; align-items: center; gap: .9rem; min-width: 0; justify-self: start; }
.site-brand { display: inline-flex; align-items: center; gap: .75rem; text-decoration: none; justify-self: start; }
.site-brand > span:last-child { display: flex; flex-direction: column; line-height: 1.05; }
.site-brand strong { font-size: 1.05rem; letter-spacing: -.02em; }
.site-brand small { color: var(--muted); margin-top: .25rem; font-size: .75rem; }
.brand-ripple { position: relative; width: 40px; height: 28px; display: block; }
.brand-ripple i { position: absolute; left: 50%; top: 50%; border: 2px solid var(--eco-sky); border-radius: 50%; transform: translate(-50%, -50%); }
.brand-ripple i:nth-child(1) { width: 34px; height: 11px; }
.brand-ripple i:nth-child(2) { width: 24px; height: 8px; border-color: var(--eco-green); }
.brand-ripple i:nth-child(3) { width: 11px; height: 4px; border-color: var(--eco-yellow); background: var(--eco-yellow); }
.site-header nav { display: flex; gap: 1.8rem; font-size: .86rem; font-weight: 600; }
.site-header nav a { text-decoration: none; }
.site-header nav a:hover { color: var(--green-deep); }
.header-action { justify-self: end; text-decoration: none; color: var(--ink); background: var(--eco-yellow); border-radius: 999px; padding: .8rem 1.15rem; font-size: .82rem; font-weight: 700; }

footer { min-height: 230px; display: grid; grid-template-columns: 1fr 1.3fr 1fr; gap: 3rem; align-items: center; padding: 3rem clamp(1.25rem,6vw,7rem); color: white; background: var(--teal-deep); }
.footer-brand small { color: #c6d9d7; }
footer > p { color: #c6d9d7; font-size: .72rem; line-height: 1.6; }

footer > div { display: flex; flex-direction: column; align-items: flex-end; gap: .55rem; font-size: .74rem; }
footer > .acknowledgement { grid-column: 1 / -1; max-width: 70ch; margin: 0; padding-top: 1.5rem; border-top: 1px solid rgba(255,255,255,.18); }

@media (max-width: 1050px) {
  .site-header { grid-template-columns: 1fr auto auto; gap: 1.2rem; }
  .site-header nav { gap: 1.2rem; }
  }

@media (max-width: 760px) {
  .site-header { padding: 0 1rem; gap: .6rem; }
  .brand-ripple { display: none; }
  .site-brand strong { font-size: 1rem; }
  .header-action { padding: .6rem .8rem; font-size: .74rem; }
  footer > div { align-items: flex-start; }
  footer > div a { padding: .5rem 0; }
}

@media (max-width: 390px) {
  .site-brand small { font-size: .75rem; }
}

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

/* Phones: one row for the brand and the Join button, the three page links on
   a second row. The ECOllaboration bar above carries the only hamburger. */
@media (max-width: 760px) {
  .site-header { height: auto; min-height: 0; grid-template-columns: 1fr auto; row-gap: .1rem; padding: .55rem 1rem .5rem; }
  .site-header nav { grid-column: 1 / -1; grid-row: 2; gap: 1.25rem; font-size: .84rem; }
  .site-header nav a { display: inline-flex; align-items: center; min-height: 40px; }
  .header-action { justify-self: end; }
}