/* Theme variables */
:root {
  --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #e0f2fe 100%);
  --text-color: #1e293b;
  --header-bg: #fff;
  --nav-link: #334155;
  --nav-current-bg: #e0f2fe;
  --nav-current-color: #0893b3;
  --input-bg: #f1f5f9;
  --input-border: #cbd5e1;
  --focus-ring: #bae6fd;
  --button-fg: #fff;
  --button-grad: linear-gradient(90deg, #0893b3 60%, #38bdf8 100%);
  --button-grad-hover: linear-gradient(90deg, #38bdf8 0%, #0893b3 100%);
  --box-shadow: 0 4px 32px 0 rgba(16, 30, 54, 0.08);
  --critical-bg: #fff1f2; --critical-border: #ef4444; --critical-text: #b91c1c;
  --warning-bg: #fff7ed; --warning-border: #f59e42; --warning-text: #b45309;
  --success-bg: #f0fdf4; --success-border: #22c55e; --success-text: #166534;
  --info-bg: #e0f2fe; --info-border: #0893b3; --info-text: #075985;
  --pre-bg: #0f172a; --pre-text: #f1f5f9;
  --footer-text: #64748b;
}

[data-theme="dark"] {
  --bg-gradient: linear-gradient(135deg, #0b1220 0%, #0b1a2b 100%);
  --text-color: #e5eef8;
  --header-bg: #0b1220;
  --nav-link: #cbd5e1;
  --nav-current-bg: #0f2440;
  --nav-current-color: #7dd3fc;
  --input-bg: #0f172a;
  --input-border: #334155;
  --focus-ring: #155e75;
  --button-fg: #e6f8ff;
  --button-grad: linear-gradient(90deg, #036980 60%, #1d9acb 100%);
  --button-grad-hover: linear-gradient(90deg, #1d9acb 0%, #036980 100%);
  --box-shadow: 0 4px 32px 0 rgba(0, 0, 0, 0.35);
  --critical-bg: #3b0d0d; --critical-border: #ef4444; --critical-text: #fecaca;
  --warning-bg: #3b2a0d; --warning-border: #f59e42; --warning-text: #fde68a;
  --success-bg: #0f2d1a; --success-border: #22c55e; --success-text: #bbf7d0;
  --info-bg: #071a26; --info-border: #1ab6d7; --info-text: #cfefff;
  --pre-bg: #0b1220; --pre-text: #e5eef8;
  --footer-text: #93a3b8;
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg-gradient);
  color: var(--text-color);
  margin: 0;
  padding: 0;
  min-height: 100vh;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 2rem 2rem 1rem 2rem;
  background: var(--header-bg);
  box-shadow: 0 2px 8px 0 rgba(16, 30, 54, 0.04);
  border-radius: 0 0 1.5rem 1.5rem;
  margin-bottom: 2rem;
}

.logo img {
  max-width: 140px;
  height: auto;
  display: block;
}

nav {
  display: flex;
  gap: 1.5rem;
}

nav a {
  text-decoration: none;
  color: var(--nav-link);
  font-weight: 500;
  font-size: 1.1rem;
  padding: 0.5rem 1rem;
  border-radius: 0.5rem;
  transition: background 0.15s, color 0.15s;
}

nav a.current,
nav a:hover,
nav a:focus {
  background: var(--nav-current-bg);
  color: var(--nav-current-color);
  outline: none;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
  z-index: 1000;
  background: #fff;
  color: #0893b3;
  padding: 8px 16px;
  border-radius: 4px;
  font-weight: 600;
}
.user-is-tabbing .skip-link:focus {
  left: 8px !important;
  width: auto !important;
  height: auto !important;
}

main {
  max-width: 600px;
  margin: 2rem auto;
  background: var(--header-bg);
  border-radius: 1.25rem;
  box-shadow: var(--box-shadow);
  padding: 2.5rem 2rem 2rem 2rem;
}

h1, h2, h3 {
  font-family: inherit;
  font-weight: 700;
  color: var(--nav-current-color);
  margin-top: 0;
}

h1 {
  font-size: 2.2rem;
  margin-bottom: 1rem;
}

h2 {
  font-size: 1.4rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}

form > div {
  display: flex;
  align-items: center;
  gap: 1rem;
  width: 100%;
}

label {
  font-weight: 600;
  min-width: 110px;
  color: var(--nav-link);
}

input {
  flex: 1;
  min-width: 0;
  padding: 0.75rem 1rem;
  font-size: 1.1rem;
  border: 1.5px solid var(--input-border);
  border-radius: 0.75rem;
  background: var(--input-bg);
  color: var(--text-color);
  transition: border 0.15s, box-shadow 0.15s;
  outline: none;
}

input:focus {
  border-color: var(--nav-current-color);
  box-shadow: 0 0 0 2px var(--focus-ring);
}

button {
  padding: 0.75rem 1.5rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--button-fg);
  background: var(--button-grad);
  border: none;
  border-radius: 0.75rem;
  cursor: pointer;
  transition: background 0.15s, box-shadow 0.15s;
  box-shadow: 0 2px 8px 0 rgba(8, 147, 179, 0.08);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

button:hover,
button:focus {
  background: var(--button-grad-hover);
  outline: none;
}

.box {
  padding: 1.25rem 1rem;
  border-radius: 1rem;
  margin-bottom: 1.25rem;
  font-size: 1rem;
  box-shadow: 0 2px 8px 0 rgba(16, 30, 54, 0.04);
}

.critical {
  background: var(--critical-bg);
  border: 1.5px solid var(--critical-border);
  color: var(--critical-text);
}

.warning {
  background: var(--warning-bg);
  border: 1.5px solid var(--warning-border);
  color: var(--warning-text);
}

.success {
  background: var(--success-bg);
  border: 1.5px solid var(--success-border);
  color: var(--success-text);
}

.info {
  background: var(--info-bg);
  border: 1.5px solid var(--info-border);
  color: var(--info-text);
}

pre {
  background: var(--pre-bg);
  color: var(--pre-text);
  padding: 1rem;
  border-radius: 0.75rem;
  overflow-x: auto;
  font-size: 1rem;
  margin-bottom: 1.25rem;
}

footer {
  text-align: center;
  margin: 2.5rem 0 1rem 0;
  color: var(--footer-text);
  font-size: 1rem;
  letter-spacing: 0.01em;
}

hr.section-divider {
  border: none;
  height: 1px;
  background: linear-gradient(90deg, rgba(8,147,179,0), rgba(8,147,179,0.35), rgba(8,147,179,0));
  margin: 1.5rem 0 1rem 0;
}

/* Theme toggle */
.theme-toggle {
  background: transparent;
  color: var(--nav-link);
  border: 1.5px solid var(--input-border);
  padding: 0.5rem 0.75rem;
  border-radius: 0.75rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}
.theme-toggle:hover,
.theme-toggle:focus {
  background: var(--nav-current-bg);
  color: var(--nav-current-color);
}

@media (max-width: 700px) {
  main {
    max-width: 98vw;
    padding: 1.25rem 0.5rem;
  }
  header {
    flex-direction: column;
    align-items: flex-start;
    padding: 1.25rem 1rem 0.5rem 1rem;
    border-radius: 0 0 1rem 1rem;
  }
  nav {
    width: 100%;
    justify-content: flex-start;
    gap: 1rem;
    margin-top: 0.5rem;
  }
  .logo img {
    max-width: 110px;
  }
  form > div {
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
  }
  label {
    min-width: 0;
  }
}