:root {
  --bg: #fafaf8;
  --surface: #ffffff;
  --ink: #16181d;
  --muted: #5d6370;
  --line: #e4e4e0;
  --accent: #1f6f4a;
  --accent-soft: #e6f2ec;
  --error: #b42318;
  --error-soft: #fdecea;
  --warning: #8a5a00;
  --warning-soft: #fdf3dc;
  --info: #35588f;
  --info-soft: #e8eef8;
  --code-bg: #16181d;
  --code-ink: #e8e9ec;
  --code-muted: #8a909c;
  --x-tag: #7cc4fa;
  --x-attr: #f5c46b;
  --x-val: #5fd39a;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111317;
    --surface: #181b20;
    --ink: #eceef2;
    --muted: #9aa0ac;
    --line: #2a2e35;
    --accent: #5fd39a;
    --accent-soft: #17291f;
    --error: #ff8a80;
    --error-soft: #3a1d1b;
    --warning: #f5c46b;
    --warning-soft: #33290f;
    --info: #9cbcf0;
    --info-soft: #1b2535;
    --code-bg: #0b0d10;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
main { max-width: 760px; margin: 0 auto; padding: 40px 16px 40px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 650; font-size: 18px; letter-spacing: -0.01em; color: var(--ink); text-decoration: none; }
.brand svg { width: 28px; height: 28px; }
.topbar { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.topbar nav { display: flex; gap: 16px; font-size: 14px; }
.topbar nav a { color: var(--muted); text-decoration: none; }
.topbar nav a:hover, .topbar nav a[aria-current] { color: var(--ink); }
h1 { margin: 40px 0 12px; font-size: clamp(28px, 5.5vw, 40px); line-height: 1.15; letter-spacing: -0.025em; }
h2 { margin: 48px 0 12px; font-size: 22px; letter-spacing: -0.015em; }
h3 { margin: 24px 0 4px; font-size: 17px; }
.lede { margin: 0; color: var(--muted); font-size: 18px; }
.muted { color: var(--muted); }
code, pre, .mono { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
code { font-size: 0.9em; }

/* Upload */
.drop {
  margin-top: 28px; padding: 28px 20px; text-align: center;
  border: 2px dashed var(--line); border-radius: 14px; background: var(--surface);
  transition: border-color .15s, background .15s;
}
.drop.dragging { border-color: var(--accent); background: var(--accent-soft); }
.drop p { margin: 0; }
.drop .hint { margin-top: 8px; color: var(--muted); font-size: 14px; }
.drop input[type=file] { position: absolute; width: 1px; height: 1px; opacity: 0; }
.button {
  display: inline-block; padding: 10px 18px; border-radius: 8px; border: 0; cursor: pointer;
  background: var(--accent); color: var(--bg); text-decoration: none; font: inherit; font-weight: 600;
}
.button:hover { opacity: 0.9; }
.button:focus-visible, .drop input:focus-visible + label { outline: 3px solid var(--accent); outline-offset: 2px; }
.button.secondary { background: transparent; color: var(--ink); border: 1px solid var(--line); font-weight: 500; padding: 7px 14px; font-size: 14px; }
.privacy { margin-top: 10px; font-size: 13px; color: var(--muted); text-align: center; }

/* Result */
#result:empty { display: none; }
#result { margin-top: 28px; }
.status {
  display: flex; gap: 14px; align-items: flex-start; padding: 18px 20px; border-radius: 14px;
  background: var(--surface); border: 1px solid var(--line);
}
.status .icon { flex: none; width: 36px; height: 36px; border-radius: 50%; display: grid; place-items: center; font-weight: 700; font-size: 18px; }
.status.valid .icon { background: var(--accent-soft); color: var(--accent); }
.status.invalid .icon { background: var(--error-soft); color: var(--error); }
.status.unsupported .icon, .status.busy .icon { background: var(--warning-soft); color: var(--warning); }
.status h2 { margin: 0; font-size: 20px; }
.status p { margin: 2px 0 0; color: var(--muted); font-size: 14px; overflow-wrap: anywhere; }
.loading { display: flex; gap: 12px; align-items: center; color: var(--muted); }
.spinner { width: 18px; height: 18px; border-radius: 50%; border: 2.5px solid var(--line); border-top-color: var(--accent); animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.check { margin-top: 16px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); overflow: hidden; }
.check header { display: flex; justify-content: space-between; gap: 12px; align-items: baseline; padding: 14px 18px; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.check header h3 { margin: 0; font-size: 16px; }
.check header .engine { color: var(--muted); font-size: 13px; }
.check .empty { padding: 14px 18px; color: var(--muted); font-size: 14px; margin: 0; }
.badge { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: 12px; font-weight: 600; white-space: nowrap; }
.badge.pass { background: var(--accent-soft); color: var(--accent); }
.badge.fail, .badge.error { background: var(--error-soft); color: var(--error); }
.badge.warning { background: var(--warning-soft); color: var(--warning); }
.badge.info { background: var(--info-soft); color: var(--info); }
.findings { list-style: none; margin: 0; padding: 0; }
.findings li { display: grid; grid-template-columns: 76px 1fr; gap: 4px 12px; padding: 12px 18px; border-top: 1px solid var(--line); }
.findings li:first-child { border-top: 0; }
.findings .rule { font-weight: 600; font-size: 13.5px; overflow-wrap: anywhere; }
.findings .msg { margin: 2px 0 0; overflow-wrap: anywhere; }
.findings .loc { margin: 4px 0 0; font-size: 12.5px; color: var(--muted); overflow-wrap: anywhere; }
.more { padding: 10px 18px; border-top: 1px solid var(--line); }
.actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 16px; }
.actions.flush { margin-top: 0; }
.spec { margin: 10px 2px 0; color: var(--muted); font-size: 14px; overflow-wrap: anywhere; }
.note { color: var(--muted); font-size: 14px; }

/* XML view */
.xml { margin: 0; max-height: 560px; overflow: auto; padding: 16px 18px; background: var(--code-bg); color: var(--code-ink); font-size: 12.5px; line-height: 1.55; white-space: pre; tab-size: 2; }
.xml-panel { margin-top: 16px; border-radius: 14px; overflow: hidden; border: 1px solid var(--line); background: var(--surface); }
.xml-panel header { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 12px 18px; flex-wrap: wrap; }
.xml-panel header h3 { margin: 0; font-size: 16px; }
.x-t { color: var(--x-tag); }
.x-a { color: var(--x-attr); }
.x-v { color: var(--x-val); }
.x-c, .x-p { color: var(--code-muted); }

/* Content */
.formats { display: grid; gap: 14px; margin-top: 16px; }
.formats article { padding: 16px 18px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); }
.formats h3 { margin: 0 0 4px; }
.formats p { margin: 6px 0 0; color: var(--muted); }
dl.faq dt { font-weight: 600; margin-top: 18px; }
dl.faq dd { margin: 4px 0 0; color: var(--muted); }
.cta { margin-top: 48px; padding: 22px; border-radius: 14px; background: var(--accent-soft); }
.cta p { margin: 0 0 12px; }
footer { margin-top: 56px; padding-top: 24px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
footer a { color: inherit; }

@media (max-width: 520px) {
  .findings li { grid-template-columns: 1fr; }
  .status { padding: 16px; }
}