:root { color-scheme: light; --ink: #172c2b; --muted: #465d59; --paper: #f5f3eb; --accent: #174f43; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: system-ui, sans-serif; line-height: 1.6; }
.shell { width: min(1120px, calc(100% - 48px)); margin-inline: auto; }
.header { display: flex; justify-content: space-between; gap: 16px; align-items: center; padding-block: 28px; border-bottom: 1px solid #b9c3ba; }
.brand { font-weight: 750; }
.tag { font-size: .8rem; border: 1px solid #63756e; border-radius: 30px; padding: 5px 12px; }
.intro { max-width: 820px; padding-block: 64px 44px; }
.eyebrow, .number { color: var(--accent); font-weight: 700; font-size: .8rem; letter-spacing: .08em; }
h1 { font-size: clamp(2.4rem, 6vw, 4.8rem); line-height: 1.08; letter-spacing: -.045em; margin: 16px 0 24px; }
.lead { font-size: 1.15rem; max-width: 620px; color: var(--muted); }
h2 { font-size: 1.25rem; line-height: 1.3; margin-block: 12px; }
p { margin-block: 12px; }
.test-panel { background: #e2eade; border: 1px solid #aabca8; border-radius: 16px; padding: 32px; display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.controls { align-self: center; }
button { background: var(--accent); color: white; font: inherit; font-weight: 650; padding: 14px 22px; border: 2px solid var(--accent); border-radius: 8px; cursor: pointer; min-height: 48px; }
button:hover { background: #103a32; }
:focus-visible { outline: 3px solid #075ac8; outline-offset: 5px; }
#result { min-height: 3.2em; color: #284d3c; }
.checks { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; padding-block: 48px; }
.checks article { border-top: 2px solid #9aaa9d; padding-top: 20px; }
.checks p, .footer { color: var(--muted); }
.footer { display: flex; justify-content: space-between; gap: 20px; padding-block: 20px; border-top: 1px solid #b9c3ba; font-size: .85rem; }
.skip-link { position: absolute; top: 8px; left: 16px; transform: translateY(-200%); background: white; color: var(--ink); padding: 12px; z-index: 2; }
.skip-link:focus { transform: none; }
@media (max-width: 680px) {
  .shell { width: calc(100% - 32px); }
  .header, .footer { flex-direction: column; align-items: flex-start; gap: 8px; }
  .intro { padding-block: 36px 24px; }
  .test-panel { grid-template-columns: 1fr; padding: 22px; gap: 12px; }
  .checks { grid-template-columns: 1fr; gap: 20px; padding-block: 32px; }
  button { width: 100%; }
}