@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&display=swap");

:root {
  color-scheme: dark;
  --sb-bg: #141821;
  --sb-surface: #1a2230;
  --sb-surface-2: #222c3a;
  --sb-border: rgba(148, 163, 184, 0.24);
  --sb-text: #e6edf6;
  --sb-muted: #a2b1c4;
  --sb-accent: #38bdf8;
  --sb-accent-2: #0ea5e9;
  --sb-success: #22c55e;
  --sb-danger: #ef4444;
  --sb-radius: 16px;
  --sb-shadow: 0 16px 40px rgba(2, 6, 23, 0.45);
}

[data-theme="light"] {
  color-scheme: light;
  --sb-bg: #f8fafc;
  --sb-surface: #ffffff;
  --sb-surface-2: #f1f5f9;
  --sb-border: rgba(15, 23, 42, 0.12);
  --sb-text: #0f172a;
  --sb-muted: #475569;
  --sb-accent: #2563eb;
  --sb-accent-2: #1d4ed8;
  --sb-success: #16a34a;
  --sb-danger: #dc2626;
  --sb-shadow: 0 12px 32px rgba(15, 23, 42, 0.12);
}

* {
  box-sizing: border-box;
}

body.app-body {
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  color: var(--sb-text);
  background:
    radial-gradient(1200px circle at 10% 0%, rgba(56, 189, 248, 0.12), transparent 45%),
    radial-gradient(900px circle at 90% 20%, rgba(14, 165, 233, 0.1), transparent 42%),
    linear-gradient(180deg, var(--sb-bg), #10151d 100%);
  min-height: 100vh;
}

[data-theme="light"] body.app-body {
  background:
    radial-gradient(1200px circle at 10% 0%, rgba(37, 99, 235, 0.14), transparent 45%),
    radial-gradient(900px circle at 90% 20%, rgba(56, 189, 248, 0.18), transparent 42%),
    linear-gradient(180deg, var(--sb-bg), #e2e8f0 100%);
}

.nav-glass {
  background-color: rgba(9, 12, 18, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--sb-border);
}

[data-theme="light"] .nav-glass {
  background-color: rgba(248, 250, 252, 0.9);
}

.navbar-brand {
  font-weight: 700;
  letter-spacing: 0.4px;
}

.navbar-text {
  color: var(--sb-muted);
}

.app-content {
  padding: 2.5rem 0 4rem;
  animation: rise 450ms ease;
}

.app-container {
  max-width: 1100px;
}

.content-stack {
  gap: 1.75rem;
}

.theme-fab-wrapper {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  left: auto;
  top: auto;
  z-index: 1030;
  margin: 0;
}

.theme-fab {
  border-radius: 999px;
  padding: 0.65rem 1.15rem;
  box-shadow: 0 14px 30px rgba(2, 6, 23, 0.35);
}

.page-title {
  font-size: clamp(2rem, 1.2vw + 1.7rem, 2.8rem);
  margin: 0 0 0.5rem;
  text-align: center;
  font-weight: 700;
}

.page-subtitle {
  color: var(--sb-muted);
  margin: 0 0 1.5rem;
  text-align: center;
}

.section-title {
  margin: 1.5rem 0 0.75rem;
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--sb-text);
}

.card {
  background-color: var(--sb-surface);
  border: 1px solid var(--sb-border);
  border-radius: var(--sb-radius);
  box-shadow: var(--sb-shadow);
}

.card-body {
  padding: 1.75rem;
}

.auth-card {
  max-width: 520px;
}

form label {
  color: var(--sb-muted);
  font-size: 0.95rem;
}

.form-control {
  background-color: var(--sb-surface-2);
  border: 1px solid var(--sb-border);
  color: var(--sb-text);
  border-radius: 12px;
  padding: 0.65rem 0.85rem;
}

.form-control:focus {
  background-color: var(--sb-surface-2);
  color: var(--sb-text);
  border-color: rgba(56, 189, 248, 0.6);
  box-shadow: 0 0 0 0.2rem rgba(56, 189, 248, 0.2);
}

.form-select {
  background-color: var(--sb-surface-2);
  border: 1px solid var(--sb-border);
  color: var(--sb-text);
  border-radius: 12px;
  padding: 0.65rem 2.25rem 0.65rem 0.85rem;
}

.form-select:focus {
  background-color: var(--sb-surface-2);
  color: var(--sb-text);
  border-color: rgba(56, 189, 248, 0.6);
  box-shadow: 0 0 0 0.2rem rgba(56, 189, 248, 0.2);
}

.table {
  --bs-table-bg: transparent;
  --bs-table-striped-bg: rgba(56, 189, 248, 0.08);
  --bs-table-hover-bg: rgba(56, 189, 248, 0.12);
  --bs-table-color: var(--sb-text);
  --bs-table-border-color: var(--sb-border);
  color: var(--sb-text);
  border-color: var(--sb-border);
}

.table thead th {
  background-color: var(--sb-surface-2);
  color: var(--sb-muted);
  border-bottom: 1px solid var(--sb-border);
}

.table tbody tr {
  border-color: var(--sb-border);
}

.table-hover tbody tr:hover {
  color: var(--sb-text);
}

.profile-tabs {
  align-items: center;
  border-bottom: 1px solid rgba(56, 189, 248, 0.25);
  display: flex;
  gap: 1rem;
  margin: 0;
  padding: 0.6rem 1.25rem 0;
  width: 100%;
}

.profile-tabs-header {
  background: transparent;
  padding: 0;
}

.profile-tabs .profile-tab {
  background: transparent;
  border: 0;
  color: var(--sb-muted);
  font-weight: 600;
  letter-spacing: 0.2px;
  padding: 0.35rem 0 0.65rem;
  position: relative;
  transition: color 0.15s ease;
}

.profile-tabs .profile-tab:hover {
  color: var(--sb-text);
}

.profile-tabs .profile-tab.active {
  color: var(--sb-text);
}

[data-theme="light"] .profile-tabs {
  border-bottom-color: rgba(37, 99, 235, 0.25);
}

.profile-tabs .profile-tab.active::after {
  background: linear-gradient(90deg, var(--sb-accent), var(--sb-accent-2));
  border-radius: 999px;
  bottom: -1px;
  content: "";
  height: 2px;
  left: 0;
  position: absolute;
  right: 0;
}

.profile-tabs .nav-item.show .nav-link,
.profile-tabs .nav-link.active {
  background-color: transparent !important;
}

.btn {
  border-radius: 12px;
  font-weight: 600;
  padding: 0.6rem 1rem;
  transition: transform 150ms ease, box-shadow 150ms ease, background-color 150ms ease, border-color 150ms ease;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 18px rgba(2, 6, 23, 0.35);
}

.btn-primary {
  background: linear-gradient(135deg, var(--sb-accent), var(--sb-accent-2));
  border: none;
  color: #0b1220;
}

.btn-primary:hover {
  color: #0b1220;
}

.btn-success {
  background: linear-gradient(135deg, #34d399, var(--sb-success));
  border: none;
}

.btn-danger {
  background: linear-gradient(135deg, #f87171, var(--sb-danger));
  border: none;
}

.btn-outline-light {
  color: var(--sb-text);
  border-color: var(--sb-border);
}

.btn-outline-light:hover {
  background-color: var(--sb-surface-2);
  border-color: rgba(56, 189, 248, 0.4);
}

.btn-light {
  background-color: #e2e8f0;
  color: #0f172a;
  border: none;
}

[data-theme="light"] .btn-light {
  background-color: var(--sb-surface-2);
  color: var(--sb-text);
  border: 1px solid var(--sb-border);
}

.link-light {
  color: var(--sb-accent);
}

.link-light:hover {
  color: #7dd3fc;
}

.accordion {
  display: grid;
  gap: 1rem;
}

.accordion-item {
  background-color: var(--sb-surface);
  border: 1px solid var(--sb-border);
  border-radius: var(--sb-radius);
  overflow: hidden;
}

.accordion-item.question-ignored {
  border: 2px solid var(--bs-warning);
}

.accordion-button {
  background-color: var(--sb-surface-2);
  color: var(--sb-text);
  font-weight: 600;
  padding: 1rem 1.25rem;
}

.accordion-button:not(.collapsed) {
  color: var(--sb-text);
  background-color: var(--sb-surface-2);
  box-shadow: none;
}

.accordion-button::after {
  filter: brightness(0) invert(1);
}

[data-theme="light"] .accordion-button::after {
  filter: none;
}

.accordion-body {
  padding: 1.25rem;
  color: var(--sb-text);
}

.blockquote {
  margin: 0;
  padding-left: 1rem;
  border-left: 2px solid rgba(56, 189, 248, 0.5);
  color: var(--sb-text);
}

.blockquote-footer {
  color: var(--sb-muted);
}

.question-actions {
  align-items: center;
  flex-wrap: wrap;
}

.question-grid__legend {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.5rem;
  color: var(--sb-muted);
  font-size: 0.95rem;
}

.question-grid__legend-item {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.question-grid__count {
  font-weight: 600;
}

.question-grid__legend-summary {
  margin-left: auto;
  font-weight: 600;
}

.question-grid__controls {
  margin-top: 1rem;
  display: grid;
  gap: 0.75rem;
}

.question-grid__controls-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.question-grid__controls-group {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.question-grid__toggle {
  margin: 0;
}

.question-grid__control-label {
  margin: 0;
  font-size: 0.85rem;
  color: var(--sb-muted);
}

.question-grid__speed-select {
  min-width: 130px;
}

.question-grid__progress {
  font-weight: 600;
}

.question-grid__timestamp {
  font-size: 0.9rem;
}

.question-grid {
  --cell-size: 14px;
  display: grid;
  grid-template-columns: repeat(auto-fill, var(--cell-size));
  gap: 6px;
  margin-top: 1rem;
  justify-content: start;
}

.question-grid--hide-ignored .question-grid__cell--ignored {
  display: none;
}

.question-grid__cell,
.question-grid__swatch {
  border-radius: 4px;
  border: 1px solid var(--sb-border);
  background-color: var(--sb-surface-2);
}

.question-grid__cell {
  width: var(--cell-size);
  height: var(--cell-size);
}

.question-grid__cell--active {
  box-shadow: 0 0 0 2px #fff;
}

.question-grid__swatch {
  width: 12px;
  height: 12px;
}

.question-grid__cell--correct,
.question-grid__swatch--correct {
  background-color: var(--bs-success);
  border-color: var(--bs-success);
}

.question-grid__cell--incorrect,
.question-grid__swatch--incorrect {
  background-color: var(--bs-danger);
  border-color: var(--bs-danger);
}

.question-grid__cell--ignored,
.question-grid__swatch--ignored {
  background-color: var(--bs-warning);
  border-color: var(--bs-warning);
}

.question-grid__cell--even,
.question-grid__swatch--even {
  background-color: #6b7280;
  border-color: #6b7280;
}

.question-grid__cell--neutral,
.question-grid__swatch--neutral {
  background-color: var(--sb-surface-2);
  border-color: var(--sb-border);
}

@media (max-width: 768px) {
  .question-grid__controls-row {
    flex-direction: column;
    align-items: flex-start;
  }
}

.course-grid {
  margin-top: 1.5rem;
}

.course-card {
  display: block;
  text-decoration: none;
  color: var(--sb-text);
  background: var(--sb-surface);
  border: 1px solid var(--sb-border);
  border-radius: var(--sb-radius);
  box-shadow: var(--sb-shadow);
  padding: 1.4rem;
  height: 100%;
  transition: transform 160ms ease, border-color 160ms ease;
}

.course-card:hover {
  transform: translateY(-3px);
  border-color: rgba(56, 189, 248, 0.6);
  color: var(--sb-text);
}

.course-card__body {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.course-card__title {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0;
}

.course-card__meta {
  color: var(--sb-muted);
  margin: 0;
}

.upload-error-list {
  margin: 0;
  padding-left: 1.25rem;
}

.upload-drop-zone {
  border: 2px dashed var(--sb-border);
  border-radius: 12px;
  padding: 1.2rem 1rem;
  text-align: center;
  color: var(--sb-muted);
  background: rgba(15, 23, 42, 0.25);
  cursor: pointer;
  transition: border-color 140ms ease, background-color 140ms ease, color 140ms ease;
}

.upload-drop-zone:hover,
.upload-drop-zone:focus,
.upload-drop-zone.is-dragging {
  border-color: rgba(56, 189, 248, 0.6);
  background: rgba(56, 189, 248, 0.12);
  color: var(--sb-text);
}

.upload-source-panel {
  border: 1px solid var(--sb-border);
  border-radius: 12px;
  background-color: var(--sb-surface-2);
  padding: 0.9rem;
}

.upload-source-title {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 0.6rem;
}

.upload-source-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.upload-source-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  border: 1px solid var(--sb-border);
  border-radius: 10px;
  padding: 0.5rem 0.65rem;
  background-color: var(--sb-surface);
}

.upload-source-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.upload-source-mode {
  color: var(--sb-muted);
  font-size: 0.9rem;
  white-space: nowrap;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 768px) {
  .app-content {
    padding: 2rem 0 3rem;
  }

  .content-stack {
    gap: 1.25rem;
  }

  .card-body {
    padding: 1.4rem;
  }

  .upload-source-item {
    align-items: flex-start;
    flex-direction: column;
  }

  .upload-source-mode {
    white-space: normal;
  }
}

@media (prefers-reduced-motion: reduce) {
  .app-content {
    animation: none;
  }

  .btn {
    transition: none;
  }
}

.lecture-carousel {
  position: relative;
}

.lecture-header {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 1.5rem 0 0.75rem;
  min-height: 2.25rem;
}

.lecture-header__title {
  margin: 0;
}

.lecture-header__actions {
  margin: 0;
  position: absolute;
  top: 50%;
  right: 0;
  transform: translateY(-50%);
}

.lecture-delete-btn {
  white-space: nowrap;
}

.lecture-carousel__slide {
  padding: 0 3.25rem 1rem;
}

.lecture-carousel .carousel-control-prev,
.lecture-carousel .carousel-control-next {
  position: fixed;
  width: 3rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 1050;
}

.lecture-carousel .carousel-control-prev {
  left: clamp(0.25rem, 2vw, 1rem);
}

.lecture-carousel .carousel-control-next {
  right: clamp(0.25rem, 2vw, 1rem);
}

@media (max-width: 768px) {
  .lecture-header {
    flex-direction: column;
    gap: 0.55rem;
    min-height: 0;
  }

  .lecture-header__actions {
    position: static;
    transform: none;
  }

  .lecture-carousel__slide {
    padding: 0 2.5rem 1rem;
  }

  .lecture-carousel .carousel-control-prev,
  .lecture-carousel .carousel-control-next {
    width: 2.5rem;
  }
}