:root {
  --color-bg: #f9f9f9;
  --color-text: #111;
  --color-primary: #1a1a2e;
  --color-primary-hover: #2a2a4e;
  --color-accent: #c0392b;
  --color-border: #e0e0e0;
  --color-muted: #888;
  --color-white: #fff;
  --radius: 4px;
  --header-height: 3.5rem;
}

* { box-sizing: border-box; margin: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
}

/* Header */
.header {
  background: var(--color-primary);
  color: var(--color-white);
  padding: 0 2rem;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.header-brand {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-white);
  text-decoration: none;
}
.header-actions { display: flex; align-items: center; gap: 1rem; }
.btn-logout {
  background: none;
  border: 1px solid #555;
  color: #ccc;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius);
  font-size: 0.8rem;
  cursor: pointer;
  touch-action: manipulation;
  transition: border-color 0.15s, color 0.15s;
}
.btn-logout:hover { border-color: #aaa; color: var(--color-white); }
.btn-logout:focus-visible { outline: 2px solid var(--color-white); outline-offset: 2px; }

/* Login */
.login-wrap {
  max-width: 360px;
  margin: 8rem auto;
  padding: 2rem;
  background: var(--color-white);
  border-radius: 8px;
  border: 1px solid var(--color-border);
  text-align: center;
}
.login-wrap h1 { font-size: 1.5rem; margin-bottom: 1.5rem; }
.login-wrap input {
  width: 100%;
  padding: 0.65rem 0.75rem;
  font-size: 1rem;
  border: 1px solid #ccc;
  border-radius: var(--radius);
  margin-bottom: 1rem;
}
.login-wrap input:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 1px; }
.login-wrap button {
  width: 100%;
  padding: 0.65rem;
  font-size: 1rem;
  background: var(--color-primary);
  color: var(--color-white);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  touch-action: manipulation;
}
.login-wrap button:hover { background: var(--color-primary-hover); }
.login-wrap button:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; }
.login-error { color: var(--color-accent); font-size: 0.875rem; margin-bottom: 1rem; display: none; }

/* Index page */
.main { max-width: 720px; margin: 4rem auto; padding: 0 2rem; }
.main h1 { font-size: 1.75rem; font-weight: 700; margin: 0 0 2rem; }
.spec-list { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 0.75rem; }
.spec-item {
  border-radius: 6px;
  border: 1px solid var(--color-border);
  background: var(--color-white);
  transition: box-shadow 0.15s;
}
.spec-item:hover { box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08); }
.spec-link {
  display: block;
  padding: 1rem 1.25rem;
  color: var(--color-primary);
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
}
.spec-link:hover { color: var(--color-accent); }
.spec-link:focus-visible { outline: 2px solid var(--color-primary); outline-offset: -2px; border-radius: 4px; }
.empty { color: #666; font-style: italic; }

/* Breadcrumb */
.breadcrumb-bar { padding: 0.75rem 1.5rem; border-bottom: 1px solid var(--color-border); background: var(--color-white); }
.breadcrumb { display: flex; align-items: center; gap: 0.25rem; font-size: 0.875rem; }
.breadcrumb a { color: #555; text-decoration: none; }
.breadcrumb a:hover { color: var(--color-accent); }
.breadcrumb .sep { color: #bbb; }
.breadcrumb .current { color: var(--color-primary); font-weight: 500; }

/* Groups (sub-index) */
.groups { display: flex; flex-direction: column; gap: 2rem; }
.group h2 { font-size: 1.1rem; font-weight: 600; margin: 0 0 0.75rem; color: var(--color-primary); }
.spec-item--featured .spec-link { font-weight: 600; }
.group > .spec-list { margin-bottom: 0.75rem; }
.group details { margin-bottom: 0.75rem; }
.group details + details { margin-top: -0.25rem; }
.subgroup-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-muted);
  cursor: pointer;
  user-select: none;
  margin-bottom: 0.5rem;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.subgroup-label::-webkit-details-marker { display: none; }
.subgroup-label::before { content: '▶'; font-size: 0.6rem; transition: transform 0.15s; }
details[open] .subgroup-label::before { transform: rotate(90deg); }

/* Swagger viewer */
.swagger-wrap { background: var(--color-white); min-height: calc(100vh - var(--header-height)); }

@media (prefers-reduced-motion: reduce) {
  .btn-logout,
  .spec-item,
  .subgroup-label::before { transition: none; }
}