:root {
  --max: 60rem;

  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 2rem;

  --bg: #ffffff;
  --surface: #ffffff;
  --surface-soft: #f6f6f6;
  --text: #111111;
  --muted: #555555;
  --link: #174ea6;
  --border: #e5e5e5;
  --focus: #b45309;

  --shadow: 0 1px 8px rgba(0, 0, 0, 0.08);
}

body.dark-theme {
  --bg: #111827;
  --surface: #1f2937;
  --surface-soft: #273449;
  --text: #f9fafb;
  --muted: #d1d5db;
  --link: #93c5fd;
  --border: #4b5563;
  --focus: #fbbf24;

  --shadow: 0 1px 12px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
}

h1 { font-size: 2rem; margin: 0; }
h2 { font-size: 1.5rem; margin: 0; }
h3 { font-size: 1.25rem; margin: 0; }

a { color: var(--link); }
a:hover { text-decoration: none; }
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: var(--space-2);
  top: var(--space-2);
  transform: translateY(-150%);
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  padding: 0.5rem 0.75rem;
  z-index: 10;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header,
.site-footer {
  border-bottom: 1px solid var(--border);
  padding: var(--space-2) 0;
  background: var(--surface);
}

.site-footer {
  border-top: 1px solid var(--border);
  border-bottom: none;
}

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--space-2);
}

.stack > * + * {
  margin-top: var(--space-2);
}

.muted { color: var(--muted); }

.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
}

.btn {
  display: inline-block;
  padding: 0.6rem 1rem;
  border: 1px solid var(--border);
  background: var(--surface-soft);
  color: var(--text);
  border-radius: 0.5rem;
  cursor: pointer;
}

.card {
  padding: var(--space-3);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.nav-list {
  list-style: none;
  padding: 0;
  margin: var(--space-1) 0 0;
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.nav-list a {
  color: var(--link);
}

.nav-list a[aria-current="page"] {
  color: var(--text);
  font-weight: 700;
}

.theme-toggle {
  display: inline-block;
  padding: 0.45rem 0.75rem;
  border: 1px solid var(--border);
  background: var(--surface-soft);
  color: var(--text);
  border-radius: 0.5rem;
  font: inherit;
  cursor: pointer;
}

.theme-toggle:hover,
.btn:hover {
  border-color: var(--link);
}

.profile-img {
  max-width: 100%;
  height: auto;
  border-radius: 0.75rem;
  border: 1px solid var(--border);
}

.embed {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  overflow: hidden;
}

.embed iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}


input, select, textarea {
  width: 100%;
  padding: 0.6rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--surface);
  color: var(--text);
  font: inherit;
}


input[type="radio"],
input[type="checkbox"] {
  width: auto;
  padding: 0;
}


.choice {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}


fieldset {
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: var(--space-2);
}
legend {
  padding: 0 0.25rem;
}

@media (max-width: 600px) {
  .header-top {
    align-items: flex-start;
    flex-direction: column;
  }
}