/**
 * Spaced Repetition System - Apple/Manus Style Design
 * Clean, minimal, modern design with smooth animations
 */

/* ====== CSS VARIABLES ====== */
:root {
  /* Colors - Light Theme */
  --srs-bg-page: #ffffff;
  --srs-bg-card: #ffffff;
  --srs-bg-muted: #f4f4f5;
  --srs-bg-accent: #7c3aed;

  /* Text */
  --srs-text-primary: #18181b;
  --srs-text-secondary: #71717a;
  --srs-text-muted: #a1a1aa;
  --srs-text-accent: #ffffff;

  /* Accent Colors */
  --srs-accent: #7c3aed;
  --srs-accent-light: #8b5cf6;
  --srs-destructive: #ef4444;

  /* Borders & Shadows */
  --srs-border: #e4e4e7;
  --srs-border-hover: #d4d4d8;
  --srs-border-focus: rgba(124, 58, 237, 0.5);

  --srs-shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --srs-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --srs-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --srs-shadow-focus: 0 0 0 3px rgba(124, 58, 237, 0.2);

  /* Spacing */
  --srs-radius-sm: 0.5rem;
  --srs-radius-md: 0.75rem;
  --srs-radius-lg: 1rem;
  --srs-radius-xl: 1.5rem;

  /* Rating Colors */
  --srs-rating-1: #ef4444;
  --srs-rating-2: #f97316;
  --srs-rating-3: #eab308;
  --srs-rating-4: #22c55e;
  --srs-rating-5: #10b981;
}

/* ====== BASE RESET ====== */
.srs-learning-container *,
.srs-learning-container *::before,
.srs-learning-container *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

.srs-learning-container {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color: var(--srs-text-primary);
  line-height: 1.5;
  max-width: 1280px;
  margin: 0 auto;
  padding: 1rem;
}

@media (min-width: 640px) {
  .srs-learning-container {
    padding: 1.5rem;
  }
}

@media (min-width: 1024px) {
  .srs-learning-container {
    padding: 2rem;
  }
}

/* ====== ANIMATIONS ====== */
@keyframes srs-fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes srs-slideInUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes srs-slideInDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes srs-scaleIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes srs-spin {
  to { transform: rotate(360deg); }
}

@keyframes srs-flip {
  0% { transform: rotateY(0deg); }
  100% { transform: rotateY(180deg); }
}

.srs-animate-fadeIn { animation: srs-fadeIn 0.3s ease-out; }
.srs-animate-slideInUp { animation: srs-slideInUp 0.3s ease-out; }
.srs-animate-slideInDown { animation: srs-slideInDown 0.3s ease-out; }
.srs-animate-scaleIn { animation: srs-scaleIn 0.3s ease-out; }

/* ====== APPLE-STYLE CARD ====== */
.srs-card-apple {
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-xl);
  padding: 1.5rem;
  box-shadow: var(--srs-shadow-sm);
  transition: all 0.2s ease;
}

.srs-card-apple:hover {
  box-shadow: var(--srs-shadow-md);
}

/* ====== APPLE-STYLE BUTTONS ====== */
.srs-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--srs-radius-md);
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
  line-height: 1.5;
}

.srs-btn:focus-visible {
  outline: none;
  box-shadow: var(--srs-shadow-focus);
}

.srs-btn-primary {
  background: var(--srs-accent);
  color: var(--srs-text-accent);
}

.srs-btn-primary:hover {
  opacity: 0.9;
}

.srs-btn-primary:active {
  transform: scale(0.98);
}

.srs-btn-secondary {
  background: var(--srs-bg-muted);
  color: var(--srs-text-primary);
}

.srs-btn-secondary:hover {
  background: #e4e4e7;
}

.srs-btn-secondary:active {
  transform: scale(0.98);
}

.srs-btn-ghost {
  background: transparent;
  color: var(--srs-text-primary);
}

.srs-btn-ghost:hover {
  background: var(--srs-bg-muted);
}

.srs-btn-destructive {
  background: var(--srs-destructive);
  color: var(--srs-text-accent);
}

.srs-btn-destructive:hover {
  opacity: 0.9;
}

.srs-btn-lg {
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
}

.srs-btn-sm {
  padding: 0.375rem 0.75rem;
  font-size: 0.75rem;
}

.srs-btn-icon {
  padding: 0.5rem;
  width: 2.5rem;
  height: 2.5rem;
}

/* ====== HEADER ====== */
.srs-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  border-bottom: 1px solid var(--srs-border);
  margin-bottom: 1.5rem;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.srs-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--srs-text-primary);
}

.srs-header-actions {
  display: flex;
  gap: 0.5rem;
}

/* ====== NAVIGATION TABS ====== */
.srs-tabs-nav {
  display: flex;
  gap: 0.25rem;
  padding: 0.25rem;
  background: var(--srs-bg-muted);
  border-radius: var(--srs-radius-lg);
  margin-bottom: 1.5rem;
}

.srs-tab-btn {
  flex: 1;
  padding: 0.625rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-text-secondary);
  background: transparent;
  border: none;
  border-radius: var(--srs-radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-tab-btn:hover {
  color: var(--srs-text-primary);
}

.srs-tab-btn.active {
  background: var(--srs-bg-card);
  color: var(--srs-text-primary);
  box-shadow: var(--srs-shadow-sm);
}

/* ====== STATS GRID ====== */
.srs-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 1.5rem;
}

@media (min-width: 768px) {
  .srs-stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.srs-stat-card {
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-lg);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  transition: all 0.2s ease;
}

.srs-stat-card:hover {
  box-shadow: var(--srs-shadow-md);
  border-color: var(--srs-border-hover);
}

.srs-stat-label {
  font-size: 0.75rem;
  color: var(--srs-text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.srs-stat-value {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--srs-text-primary);
  line-height: 1;
}

.srs-stat-value.overdue {
  color: var(--srs-destructive);
}

.srs-stat-value.accent {
  color: var(--srs-accent);
}

/* ====== QUICK ADD SECTION ====== */
.srs-section {
  margin-bottom: 1.5rem;
}

.srs-section-title {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--srs-text-secondary);
  margin-bottom: 0.75rem;
}

.srs-quick-add-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.75rem;
}

@media (max-width: 640px) {
  .srs-quick-add-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.srs-quick-add-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem 0.5rem;
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-lg);
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-quick-add-btn:hover {
  border-color: var(--srs-accent);
  box-shadow: var(--srs-shadow-md);
}

.srs-quick-add-btn:active {
  transform: scale(0.98);
}

.srs-quick-add-icon {
  font-size: 1.5rem;
}

.srs-quick-add-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--srs-text-secondary);
}

/* ====== ACTION BUTTONS ====== */
.srs-action-buttons {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.srs-action-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1rem;
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-lg);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-text-primary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-action-btn:hover {
  box-shadow: var(--srs-shadow-md);
  border-color: var(--srs-border-hover);
}

.srs-action-btn:active {
  transform: scale(0.98);
}

.srs-action-btn.primary {
  background: var(--srs-accent);
  border-color: var(--srs-accent);
  color: var(--srs-text-accent);
}

.srs-action-btn.primary:hover {
  opacity: 0.9;
}

/* ====== REVIEW CARD ====== */
.srs-review-container {
  max-width: 600px;
  margin: 0 auto;
  padding: 1rem 0;
}

.srs-progress-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem;
  background: rgba(124, 58, 237, 0.1);
  border-radius: var(--srs-radius-lg);
  margin-bottom: 1rem;
}

.srs-progress-text {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-accent);
}

.srs-flashcard {
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-xl);
  padding: 2rem;
  text-align: center;
  box-shadow: var(--srs-shadow-md);
  min-height: 300px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  perspective: 1000px;
  animation: srs-scaleIn 0.3s ease-out;
}

.srs-flashcard-inner {
  transition: transform 0.6s;
  transform-style: preserve-3d;
}

.srs-flashcard.flipped .srs-flashcard-inner {
  transform: rotateY(180deg);
}

.srs-card-type-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: var(--srs-accent);
  color: var(--srs-text-accent);
  font-size: 0.625rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  border-radius: 9999px;
  margin-bottom: 1rem;
}

.srs-card-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--srs-text-primary);
  margin-bottom: 0.5rem;
}

.srs-card-content {
  font-size: 1rem;
  color: var(--srs-text-secondary);
  margin-bottom: 1rem;
}

.srs-card-meta {
  font-size: 0.875rem;
  color: var(--srs-text-muted);
  font-style: italic;
}

.srs-show-answer-btn {
  width: 100%;
  padding: 1rem;
  margin-top: 1rem;
  background: var(--srs-accent);
  color: var(--srs-text-accent);
  border: none;
  border-radius: var(--srs-radius-lg);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-show-answer-btn:hover {
  opacity: 0.9;
}

.srs-show-answer-btn:active {
  transform: scale(0.98);
}

/* ====== RATING BUTTONS ====== */
.srs-rating-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  margin-top: 1rem;
}

@media (max-width: 480px) {
  .srs-rating-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.srs-rating-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
  padding: 0.75rem 0.5rem;
  background: var(--srs-bg-card);
  border: 2px solid var(--srs-border);
  border-radius: var(--srs-radius-lg);
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-rating-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--srs-shadow-md);
}

.srs-rating-btn:active {
  transform: scale(0.98);
}

.srs-rating-btn[data-rating="1"] { border-color: var(--srs-rating-1); }
.srs-rating-btn[data-rating="2"] { border-color: var(--srs-rating-2); }
.srs-rating-btn[data-rating="3"] { border-color: var(--srs-rating-3); }
.srs-rating-btn[data-rating="4"] { border-color: var(--srs-rating-4); }
.srs-rating-btn[data-rating="5"] { border-color: var(--srs-rating-5); }

.srs-rating-btn[data-rating="1"]:hover { background: var(--srs-rating-1); color: white; }
.srs-rating-btn[data-rating="2"]:hover { background: var(--srs-rating-2); color: white; }
.srs-rating-btn[data-rating="3"]:hover { background: var(--srs-rating-3); color: white; }
.srs-rating-btn[data-rating="4"]:hover { background: var(--srs-rating-4); color: white; }
.srs-rating-btn[data-rating="5"]:hover { background: var(--srs-rating-5); color: white; }

.srs-rating-value {
  font-size: 1.25rem;
  font-weight: 700;
}

.srs-rating-label {
  font-size: 0.625rem;
  font-weight: 500;
  color: var(--srs-text-secondary);
  text-transform: uppercase;
}

/* ====== LIBRARY / ITEMS LIST ====== */
.srs-library-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.srs-search-input {
  flex: 1;
  padding: 0.75rem 1rem;
  padding-left: 2.5rem;
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-lg);
  font-size: 0.875rem;
  color: var(--srs-text-primary);
  transition: all 0.2s ease;
}

.srs-search-input:focus {
  outline: none;
  border-color: var(--srs-accent);
  box-shadow: var(--srs-shadow-focus);
}

.srs-search-input::placeholder {
  color: var(--srs-text-muted);
}

.srs-filter-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.srs-filter-btn {
  padding: 0.5rem 1rem;
  background: var(--srs-bg-muted);
  border: none;
  border-radius: var(--srs-radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-filter-btn:hover {
  background: #e4e4e7;
}

.srs-filter-btn.active {
  background: var(--srs-accent);
  color: var(--srs-text-accent);
}

.srs-view-toggle {
  display: flex;
  gap: 0.25rem;
  padding: 0.25rem;
  background: var(--srs-bg-muted);
  border-radius: var(--srs-radius-md);
}

.srs-view-btn {
  padding: 0.5rem;
  background: transparent;
  border: none;
  border-radius: var(--srs-radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--srs-text-secondary);
}

.srs-view-btn.active {
  background: var(--srs-bg-card);
  color: var(--srs-text-primary);
  box-shadow: var(--srs-shadow-sm);
}

/* Items Grid */
.srs-items-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}

.srs-items-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.srs-item-card {
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-lg);
  padding: 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
  animation: srs-slideInUp 0.3s ease-out;
}

.srs-item-card:hover {
  box-shadow: var(--srs-shadow-lg);
  border-color: var(--srs-border-hover);
}

.srs-item-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.srs-item-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.srs-item-info {
  flex: 1;
  min-width: 0;
}

.srs-item-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--srs-text-primary);
  margin-bottom: 0.25rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.srs-item-type {
  font-size: 0.75rem;
  color: var(--srs-text-muted);
}

.srs-item-content {
  font-size: 0.875rem;
  color: var(--srs-text-secondary);
  margin-top: 0.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.srs-item-tags {
  display: flex;
  gap: 0.25rem;
  flex-wrap: wrap;
  margin-top: 0.75rem;
}

.srs-tag {
  padding: 0.25rem 0.5rem;
  background: var(--srs-bg-muted);
  border-radius: 9999px;
  font-size: 0.75rem;
  color: var(--srs-text-secondary);
}

.srs-item-actions {
  display: flex;
  gap: 0.5rem;
  margin-left: auto;
}

.srs-delete-btn {
  padding: 0.5rem;
  background: transparent;
  border: none;
  border-radius: var(--srs-radius-md);
  cursor: pointer;
  color: var(--srs-text-muted);
  transition: all 0.2s ease;
}

.srs-delete-btn:hover {
  background: rgba(239, 68, 68, 0.1);
  color: var(--srs-destructive);
}

/* ====== ADD ITEM FORM ====== */
.srs-form-container {
  max-width: 600px;
  margin: 0 auto;
}

.srs-form-card {
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-xl);
  padding: 1.5rem;
  margin-bottom: 1rem;
}

.srs-form-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--srs-text-primary);
  margin-bottom: 1rem;
}

.srs-type-selector {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

@media (max-width: 480px) {
  .srs-type-selector {
    grid-template-columns: repeat(3, 1fr);
  }
}

.srs-type-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.375rem;
  padding: 0.75rem 0.5rem;
  background: var(--srs-bg-card);
  border: 2px solid var(--srs-border);
  border-radius: var(--srs-radius-lg);
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-type-btn:hover {
  border-color: var(--srs-accent);
}

.srs-type-btn.active {
  border-color: var(--srs-accent);
  background: rgba(124, 58, 237, 0.08);
}

.srs-type-icon {
  font-size: 1.5rem;
}

.srs-type-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--srs-text-secondary);
}

.srs-form-group {
  margin-bottom: 1rem;
}

.srs-form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-text-primary);
  margin-bottom: 0.5rem;
}

.srs-form-label .required {
  color: var(--srs-destructive);
}

.srs-form-input,
.srs-form-textarea,
.srs-form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-md);
  font-size: 0.875rem;
  color: var(--srs-text-primary);
  transition: all 0.2s ease;
  font-family: inherit;
}

.srs-form-input:focus,
.srs-form-textarea:focus,
.srs-form-select:focus {
  outline: none;
  border-color: var(--srs-accent);
  box-shadow: var(--srs-shadow-focus);
}

.srs-form-input::placeholder,
.srs-form-textarea::placeholder {
  color: var(--srs-text-muted);
}

.srs-form-textarea {
  min-height: 100px;
  resize: vertical;
}

.srs-submit-btn {
  width: 100%;
  padding: 0.875rem 1.5rem;
  background: var(--srs-accent);
  color: var(--srs-text-accent);
  border: none;
  border-radius: var(--srs-radius-lg);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-submit-btn:hover {
  opacity: 0.9;
}

.srs-submit-btn:active {
  transform: scale(0.98);
}

.srs-submit-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ====== ITEM DETAIL PAGE ====== */
.srs-detail-container {
  max-width: 1000px;
  margin: 0 auto;
}

.srs-detail-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 1024px) {
  .srs-detail-grid {
    grid-template-columns: 2fr 1fr;
  }
}

.srs-detail-main {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.srs-detail-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.srs-detail-card {
  background: var(--srs-bg-card);
  border: 1px solid var(--srs-border);
  border-radius: var(--srs-radius-xl);
  padding: 1.5rem;
}

.srs-detail-card h2 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--srs-text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.srs-stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--srs-border);
}

.srs-stat-row:last-child {
  border-bottom: none;
}

.srs-stat-row-label {
  font-size: 0.875rem;
  color: var(--srs-text-muted);
}

.srs-stat-row-value {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--srs-text-primary);
}

.srs-next-review-card {
  background: rgba(124, 58, 237, 0.05);
  border: 2px solid rgba(124, 58, 237, 0.2);
}

.srs-next-review-date {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--srs-accent);
}

.srs-next-review-relative {
  font-size: 0.875rem;
  color: var(--srs-text-muted);
}

/* ====== REVIEW HISTORY ====== */
.srs-history-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.srs-history-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: var(--srs-bg-muted);
  border-radius: var(--srs-radius-lg);
}

.srs-history-date {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-text-primary);
}

.srs-history-grade {
  font-size: 0.75rem;
  color: var(--srs-text-muted);
}

.srs-history-interval {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-text-primary);
}

.srs-history-ease {
  font-size: 0.75rem;
  color: var(--srs-text-muted);
}

/* ====== MESSAGES ====== */
.srs-message {
  padding: 1rem;
  border-radius: var(--srs-radius-lg);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 1rem;
  animation: srs-slideInDown 0.3s ease-out;
}

.srs-message.success {
  background: #d1fae5;
  color: #065f46;
  border: 1px solid #6ee7b7;
}

.srs-message.error {
  background: #fee2e2;
  color: #991b1b;
  border: 1px solid #fca5a5;
}

.srs-message.info {
  background: #dbeafe;
  color: #1e40af;
  border: 1px solid #93c5fd;
}

/* ====== LOADING STATES ====== */
.srs-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem;
  gap: 1rem;
}

.srs-spinner {
  width: 2.5rem;
  height: 2.5rem;
  border: 3px solid var(--srs-border);
  border-top-color: var(--srs-accent);
  border-radius: 50%;
  animation: srs-spin 1s linear infinite;
}

.srs-loading-text {
  font-size: 0.875rem;
  color: var(--srs-text-muted);
}

/* ====== EMPTY STATES ====== */
.srs-empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem;
  text-align: center;
}

.srs-empty-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
}

.srs-empty-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--srs-text-primary);
  margin-bottom: 0.5rem;
}

.srs-empty-text {
  font-size: 0.875rem;
  color: var(--srs-text-muted);
  margin-bottom: 1.5rem;
}

/* ====== HIDDEN/SHOW UTILITIES ====== */
.srs-hidden {
  display: none !important;
}

.srs-visible {
  display: block !important;
}

/* Tab content visibility */
.srs-tab-content {
  display: none;
}

.srs-tab-content.active {
  display: block;
  animation: srs-fadeIn 0.3s ease-out;
}

/* Form visibility */
.srs-type-form {
  display: none;
}

.srs-type-form.active {
  display: block;
  animation: srs-slideInUp 0.3s ease-out;
}

/* ====== BACK BUTTON ====== */
.srs-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  background: transparent;
  border: none;
  border-radius: var(--srs-radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--srs-accent);
  cursor: pointer;
  transition: all 0.2s ease;
}

.srs-back-btn:hover {
  background: rgba(124, 58, 237, 0.08);
}

/* ====== ICON STYLES ====== */
.srs-icon {
  width: 1.25rem;
  height: 1.25rem;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
}

.srs-icon-lg {
  width: 1.5rem;
  height: 1.5rem;
}

.srs-icon-sm {
  width: 1rem;
  height: 1rem;
}