:root { --bg: #fff; --text: #1a1a2e; --accent: #0f4c81; --btn-bg: #0056b3; --btn-text: #fff; --border: #b0b0b0; --focus: #0f4c81; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #121212; --text: #e0e0e0; --accent: #6cb2eb; --btn-bg: #1e90ff; --btn-text: #000; --border: #555; --focus: #6cb2eb; }
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: system-ui, -apple-system, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; padding: 1rem; max-width: 800px; margin: auto; min-height: 100vh; display: flex; flex-direction: column; }
header, main, footer { margin-bottom: 2rem; }
h1 { font-size: 2rem; margin-bottom: 0.5rem; }
header p { font-size: 1.1rem; opacity: 0.85; }
.btn-primary { display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.75rem 1.5rem; font-size: 1rem; font-weight: bold; background: var(--btn-bg); color: var(--btn-text); border: none; border-radius: 8px; cursor: pointer; transition: background 0.2s; }
.btn-primary:hover { opacity: 0.9; }
.btn-primary:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-secondary { display:inline-flex;align-items:center;gap:0.5rem;padding:0.5rem 1rem;font-size:0.85rem;font-weight:600;background:transparent;color:var(--accent);border:2px solid var(--accent);border-radius:6px;cursor:pointer;text-decoration:none;transition:opacity 0.2s; }
.btn-secondary:hover { opacity: 0.8; }
.btn-secondary:focus-visible { outline:3px solid var(--focus);outline-offset:2px; }
.info-section, .pro-section { margin-top: 2rem; padding: 1rem; border: 1px solid var(--border); border-radius: 8px; }
.info-section h2, .pro-section h2 { font-size: 1.3rem; margin-bottom: 0.5rem; }
.info-section ol { margin-left: 1.5rem; margin-bottom: 0.5rem; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }
.skip-link { position: absolute; top: -100%; left: 0; background: var(--btn-bg); color: var(--btn-text); padding: 0.5rem 1rem; z-index: 100; text-decoration: none; font-weight: bold; }
.skip-link:focus { top: 0; outline: 3px solid var(--focus); outline-offset: 2px; }
footer { margin-top: auto; font-size: 0.9rem; opacity: 0.8; border-top: 1px solid var(--border); padding-top: 1rem; }
a { color: var(--accent); }
@media (max-width: 600px) { body { padding: 0.75rem; } h1 { font-size: 1.5rem; } .btn-primary { width: 100%; justify-content: center; } }