:root {
  --color-primary: #22d3ee;
  --color-primary-hover: #0ea5e9;
  --color-surface-top: rgba(10, 15, 29, 0.92);
  --color-surface: #111c33;
  --color-surface-muted: #182448;
  --color-page: #0d1223;
  --color-text-primary: #f8fafc;
  --color-text-secondary: #cbd5f5;
  --color-text: var(--color-text-primary);
  --color-text-muted: var(--color-text-secondary);
  --color-border: rgba(148, 163, 184, 0.3);
  --color-focus: #facc15;
  --color-danger: #f87171;
  --color-ghost: rgba(34, 211, 238, 0.12);
  --shadow-soft: 0 20px 45px rgba(15, 23, 42, 0.55);
  --shadow-hover: 0 18px 36px rgba(14, 165, 233, 0.35);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition-base: 0.3s ease;
  --container-gutter: clamp(1.25rem, 5vw, 3rem);
  --container-max-width: 1180px;
}

body.theme-dark {
  font-family: var(--font-sans);
  color: var(--color-text-primary);
  background: radial-gradient(circle at top right, rgba(34, 211, 238, 0.1), transparent 55%),
    radial-gradient(circle at 20% 20%, rgba(14, 165, 233, 0.08), transparent 60%),
    var(--color-page);
  min-height: 100vh;
}

body.theme-dark a {
  color: var(--color-primary);
}

.container {
  width: 100%;
  max-width: calc(var(--container-max-width) + var(--container-gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--container-gutter);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base),
    border var(--transition-base);
  cursor: pointer;
  text-decoration: none;
  font-family: inherit;
}

.btn:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

.btn--primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
  color: #06131f;
  box-shadow: var(--shadow-soft);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.btn--ghost {
  background: rgba(34, 211, 238, 0.12);
  border-color: rgba(34, 211, 238, 0.45);
  color: var(--color-text-primary);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  background: rgba(34, 211, 238, 0.18);
}

.input {
  width: 100%;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(148, 163, 184, 0.32);
  background: rgba(15, 23, 42, 0.65);
  color: var(--color-text-primary);
  font-family: inherit;
  transition: border-color var(--transition-base), box-shadow var(--transition-base), background var(--transition-base);
}

.input::placeholder {
  color: rgba(203, 213, 225, 0.7);
}

.input:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px rgba(34, 211, 238, 0.18);
}

.input.is-invalid,
.input[aria-invalid='true'] {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 4px rgba(248, 113, 113, 0.2);
}

.card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  border: 1px solid rgba(148, 163, 184, 0.22);
  padding: 1.75rem;
  box-shadow: 0 14px 32px rgba(2, 6, 23, 0.45);
  transition: transform var(--transition-base), border var(--transition-base);
}

.card:hover,
.card:focus-within {
  transform: translateY(-4px);
  border-color: rgba(34, 211, 238, 0.5);
}

.card__title {
  font-size: 1.35rem;
  margin: 0 0 1rem;
}

.section-title {
  font-size: clamp(2rem, 3vw, 2.75rem);
  margin: 0 0 1.5rem;
  line-height: 1.2;
}

.help-text {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-top: 0.35rem;
}

.error-text {
  font-size: 0.875rem;
  color: var(--color-danger);
  margin-top: 0.5rem;
}

.form-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-label {
  font-weight: 600;
  color: var(--color-text-secondary);
  letter-spacing: 0.01em;
}

.form-field--sm {
  max-width: 220px;
}

.form-field--xs {
  max-width: 160px;
}

.form-actions {
  margin-top: 2rem;
  display: flex;
  gap: 1rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--color-surface-top);
  border-bottom: 1px solid rgba(148, 163, 184, 0.18);
  backdrop-filter: blur(14px);
}

.nav {
  display: flex;
  align-items: center;
  gap: 2rem;
  padding: 1rem 0;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: clamp(0.6rem, 1.4vw, 0.9rem);
  color: var(--color-text-primary);
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.brand__logo {
  width: clamp(44px, 4vw, 48px);
  height: clamp(44px, 4vw, 48px);
  flex-shrink: 0;
  display: block;
}

.brand__name {
  font-size: 1.1rem;
  letter-spacing: 0.01em;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-left: auto;
}

.nav__links a {
  color: var(--color-text-secondary);
  font-weight: 500;
  text-decoration: none;
}

.nav__links a:hover,
.nav__links a:focus-visible {
  color: var(--color-text-primary);
}

.nav__login {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav__login--error {
  flex-wrap: wrap;
  justify-content: center;
}

.nav__login .input {
  min-width: 200px;
  background: rgba(17, 25, 40, 0.75);
}

.nav__login-message {
  flex-basis: 100%;
  text-align: center;
}

.nav__login--error .nav__login-message {
  flex-basis: 100%;
  text-align: center;
  margin: 0;
}

.nav__login-message:empty {
  display: none;
}

.nav__actions {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
}

.nav__login .error-text {
  margin: 0;
}

@media (max-width: 1080px) {
  .nav__links {
    order: 2;
    width: 100%;
    justify-content: center;
  }

  .nav__login {
    order: 3;
    width: 100%;
    flex-wrap: wrap;
    justify-content: center;
  }

  .nav__login .input {
    flex: 1 1 240px;
    min-width: unset;
  }

  .nav__actions {
    order: 4;
    width: 100%;
    justify-content: center;
    flex-wrap: wrap;
  }
}

.page-section {
  padding-block: clamp(3rem, 6vw, 4.5rem);
}

.card-stack {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}