:root {
  color-scheme: light;
  --state-bg: #eef6ff;
  --state-surface: rgba(248, 251, 255, 0.9);
  --state-surface-strong: #ffffff;
  --state-text: #0b1f3a;
  --state-muted: #5b7090;
  --state-border: rgba(75, 128, 196, 0.28);
  --state-primary: #1762cc;
  --state-primary-strong: #0d4faf;
  --state-on-primary: #ffffff;
  --state-focus: #4c8df6;
  --state-shadow: 0 24px 70px rgba(25, 70, 125, 0.16);
  --skeleton-base: rgba(92, 125, 169, 0.13);
  --skeleton-highlight: rgba(255, 255, 255, 0.68);
}

[data-theme="dark"] {
  color-scheme: dark;
  --state-bg: #071a34;
  --state-surface: rgba(10, 34, 65, 0.91);
  --state-surface-strong: #0c294f;
  --state-text: #f3f7ff;
  --state-muted: #a8bad4;
  --state-border: rgba(119, 171, 238, 0.27);
  --state-primary: #6fa8ff;
  --state-primary-strong: #8db9ff;
  --state-on-primary: #061a35;
  --state-focus: #8ab7ff;
  --state-shadow: 0 28px 80px rgba(0, 4, 16, 0.42);
  --skeleton-base: rgba(159, 188, 226, 0.12);
  --skeleton-highlight: rgba(197, 220, 250, 0.22);
}

.error-root {
  --dot-grid-base: rgba(20, 87, 183, 0.19);
  --dot-grid-active: #0718a0;
}

.error-root[data-theme="dark"] {
  --dot-grid-base: rgba(111, 168, 255, 0.2);
  --dot-grid-active: #79aaff;
}

.error-page,
.error-page * {
  box-sizing: border-box;
}

.error-page {
  min-height: 100%;
  margin: 0;
  color: var(--state-text);
  background: var(--state-bg);
  font-family: "Inter", system-ui, sans-serif;
  transition:
    color 180ms ease,
    background-color 180ms ease;
}

.error-page button,
.error-page a {
  font: inherit;
}

.dot-grid-background {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.state-topbar {
  position: relative;
  z-index: 2;
  width: min(1120px, calc(100% - 40px));
  min-height: 76px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.state-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--state-text);
  text-decoration: none;
  font-weight: 800;
}

.state-brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  color: #fff;
  background: linear-gradient(145deg, #2978e6, #0c4ead);
  box-shadow: 0 10px 26px rgba(21, 91, 190, 0.25);
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.9rem;
}

.state-icon-button {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid var(--state-border);
  border-radius: 14px;
  color: var(--state-text);
  background: var(--state-surface);
  cursor: pointer;
  backdrop-filter: blur(14px);
}

.state-icon-button svg {
  width: 19px;
  height: 19px;
}

.error-main {
  position: relative;
  z-index: 1;
  min-height: calc(100vh - 76px);
  padding: 48px 20px 84px;
  display: grid;
  place-items: center;
}

.error-card {
  width: min(620px, 100%);
  padding: clamp(32px, 5vw, 54px);
  text-align: center;
  border: 1px solid var(--state-border);
  border-radius: 30px;
  background: var(--state-surface);
  box-shadow: var(--state-shadow);
  backdrop-filter: blur(22px);
}

.error-visual {
  position: relative;
  width: 118px;
  height: 118px;
  margin: 0 auto 18px;
  display: grid;
  place-items: center;
}

.error-icon-shell {
  position: relative;
  z-index: 2;
  width: 70px;
  height: 70px;
  display: grid;
  place-items: center;
  border: 1px solid var(--state-border);
  border-radius: 24px;
  color: var(--state-primary);
  background: var(--state-surface-strong);
  box-shadow: 0 15px 38px rgba(25, 91, 180, 0.16);
}

.error-icon-shell svg {
  width: 31px;
  height: 31px;
}

.error-orbit {
  position: absolute;
  border: 1px solid color-mix(in srgb, var(--state-primary) 28%, transparent);
  border-radius: 50%;
}

.error-orbit-one {
  width: 96px;
  height: 96px;
}
.error-orbit-two {
  width: 118px;
  height: 118px;
  opacity: 0.5;
}

.error-code {
  margin: 0 0 6px;
  color: var(--state-primary);
  font:
    700 clamp(1rem, 2vw, 1.12rem)/1 "Space Grotesk",
    sans-serif;
  letter-spacing: 0.18em;
}

.error-card h1 {
  margin: 0;
  font:
    700 clamp(2rem, 6vw, 3.2rem)/1.08 "Space Grotesk",
    sans-serif;
  letter-spacing: -0.04em;
  outline: none;
}

.error-message {
  max-width: 470px;
  margin: 16px auto 0;
  color: var(--state-muted);
  font-size: 1rem;
  line-height: 1.65;
}

.error-actions {
  margin-top: 30px;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
}

.error-action {
  min-height: 46px;
  padding: 0 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border: 1px solid var(--state-border);
  border-radius: 15px;
  color: var(--state-text);
  background: var(--state-surface-strong);
  font-weight: 700;
  cursor: pointer;
  transition:
    transform 180ms ease,
    border-color 180ms ease,
    background-color 180ms ease;
}

.error-action svg {
  width: 18px;
  height: 18px;
}

.error-action-primary {
  border-color: transparent;
  color: var(--state-on-primary);
  background: var(--state-primary);
}

.error-action:hover {
  transform: translateY(-2px);
  border-color: var(--state-primary);
}
.error-action-primary:hover {
  background: var(--state-primary-strong);
}

.error-action:focus-visible,
.state-icon-button:focus-visible,
.state-brand:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--state-focus) 68%, transparent);
  outline-offset: 3px;
}

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

body[data-page-state="loading"] {
  overflow: hidden;
}

.page-skeleton {
  position: fixed;
  inset: 0;
  z-index: 1000;
  padding: clamp(14px, 2.8vw, 36px);
  overflow: hidden;
  pointer-events: none;
  color: var(--state-text);
  background: color-mix(in srgb, var(--state-bg) 70%, transparent);
  backdrop-filter: blur(7px);
  opacity: 1;
  visibility: visible;
  transition:
    opacity 180ms ease,
    visibility 180ms ease;
}

body[data-page-state="ready"] .page-skeleton,
body[data-page-state="failed"] .page-skeleton {
  opacity: 0;
  visibility: hidden;
}

.skeleton-surface {
  border: 1px solid var(--state-border);
  background: color-mix(in srgb, var(--state-surface) 84%, transparent);
  box-shadow: 0 18px 54px rgba(19, 67, 125, 0.08);
  backdrop-filter: blur(15px);
}

.skeleton-block {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid color-mix(in srgb, var(--state-border) 52%, transparent);
  border-radius: 12px;
  background: var(--skeleton-base);
}

.skeleton-block::after {
  content: "";
  position: absolute;
  inset: 0;
  transform: translateX(-105%);
  background: linear-gradient(
    90deg,
    transparent,
    var(--skeleton-highlight),
    transparent
  );
  animation: skeleton-shimmer 1.45s ease-in-out infinite;
}

@keyframes skeleton-shimmer {
  to {
    transform: translateX(105%);
  }
}

.skeleton-logo {
  width: 42px;
  height: 42px;
  border-radius: 14px;
}
.skeleton-brand-line {
  width: clamp(140px, 17vw, 220px);
  height: 18px;
}
.skeleton-nav-line {
  width: 210px;
  height: 42px;
  margin-left: auto;
}
.skeleton-nav-wide {
  width: min(40vw, 440px);
  height: 42px;
  margin-left: auto;
}
.skeleton-icon-line {
  width: 116px;
  height: 42px;
}
.skeleton-kicker {
  width: 108px;
  height: 12px;
  border-radius: 8px;
}
.skeleton-title {
  width: min(78%, 320px);
  height: 42px;
}
.skeleton-copy {
  width: min(92%, 390px);
  height: 14px;
}
.skeleton-control,
.skeleton-button {
  width: 100%;
  height: 54px;
}
.skeleton-button {
  margin-top: 4px;
}
.skeleton-card-title {
  width: 42%;
  height: 18px;
}
.skeleton-pill-row {
  width: 72%;
  height: 24px;
  margin-top: auto;
}
.skeleton-wide-row {
  width: 100%;
  height: 72px;
}

.skeleton-auth {
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 24px;
}
.skeleton-auth-top,
.skeleton-tracker-top,
.skeleton-admin-top {
  width: min(1180px, 100%);
  min-height: 76px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 14px;
  border-radius: 22px;
}
.skeleton-auth-card {
  align-self: center;
  justify-self: center;
  width: min(500px, 100%);
  padding: clamp(28px, 5vw, 46px);
  display: grid;
  gap: 22px;
  border-radius: 28px;
}

.skeleton-tracker-shell,
.skeleton-admin-shell {
  width: min(1440px, 100%);
  height: 100%;
  margin: 0 auto;
  display: grid;
  align-content: start;
  gap: 24px;
}
.skeleton-tracker-heading,
.skeleton-admin-heading {
  display: grid;
  gap: 10px;
  padding: 8px 4px 0;
}
.skeleton-tracker-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}
.skeleton-course-card {
  min-height: 220px;
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  border-radius: 22px;
}
.skeleton-tracker-panel {
  min-height: 230px;
  padding: 24px;
  display: grid;
  gap: 18px;
  border-radius: 24px;
}

.skeleton-admin-actions {
  width: 220px;
  height: 42px;
  margin-left: auto;
}
.skeleton-admin-panel {
  min-height: 430px;
  padding: 20px;
  border-radius: 24px;
}
.skeleton-admin-tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 22px;
}
.skeleton-tab {
  width: 92px;
  height: 42px;
}
.skeleton-admin-filters {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) 180px 180px;
  gap: 14px;
  margin-bottom: 24px;
}
.skeleton-search,
.skeleton-filter {
  width: 100%;
  height: 48px;
}
.skeleton-admin-rows {
  display: grid;
  gap: 12px;
}
.skeleton-table-row {
  width: 100%;
  height: 62px;
}

.admin-list-skeleton {
  min-height: 350px;
  padding: 22px;
  display: grid;
  align-content: start;
  gap: 12px;
}

.skeleton-detail {
  padding: 4px 0;
  display: grid;
  gap: 16px;
}

.skeleton-detail-head {
  width: 62%;
  height: 28px;
}
.skeleton-detail-card {
  width: 100%;
  height: 150px;
  border-radius: 20px;
}
.skeleton-detail-card:last-child {
  height: 260px;
}

@media (max-width: 640px) {
  .state-topbar {
    width: min(100% - 28px, 1120px);
    min-height: 68px;
  }
  .state-brand {
    font-size: 0.92rem;
  }
  .state-brand-mark {
    width: 38px;
    height: 38px;
    border-radius: 12px;
  }
  .error-main {
    min-height: calc(100vh - 68px);
    padding: 28px 14px 54px;
  }
  .error-card {
    padding: 30px 20px;
    border-radius: 24px;
  }
  .error-actions {
    display: grid;
    grid-template-columns: 1fr;
  }
  .error-action {
    width: 100%;
  }
  .page-skeleton {
    padding: 12px;
  }
  .skeleton-auth-top,
  .skeleton-tracker-top,
  .skeleton-admin-top {
    min-height: 64px;
    padding: 11px 12px;
    border-radius: 18px;
  }
  .skeleton-nav-line,
  .skeleton-nav-wide,
  .skeleton-brand-line {
    display: none;
  }
  .skeleton-icon-line,
  .skeleton-admin-actions {
    width: 104px;
    margin-left: auto;
  }
  .skeleton-auth-card {
    padding: 26px 20px;
    border-radius: 22px;
  }
  .skeleton-tracker-grid {
    grid-template-columns: 1fr;
  }
  .skeleton-course-card:nth-child(n + 3) {
    display: none;
  }
  .skeleton-admin-filters {
    grid-template-columns: 1fr 1fr;
  }
  .skeleton-search {
    grid-column: 1 / -1;
  }
  .skeleton-admin-panel {
    padding: 14px;
  }
  .admin-list-skeleton {
    min-height: 390px;
    padding: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .error-page *,
  .error-page *::before,
  .error-page *::after {
    scroll-behavior: auto !important;
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 1ms !important;
  }
  .error-action:hover {
    transform: none;
  }
  .skeleton-block::after {
    animation: none;
    opacity: 0.24;
  }
}