/* Design Tokens */
:root {
  --primary: #4255ff;
  --primary-hover: #423ed8;
  --navy: #2e3856;
  --dark-navy: #0a092d;
  --gold: #ffcd1f;
  --bg-color: #f6f7fb;
  --card-bg: #ffffff;
  --text-primary: #2e3856;
  --text-secondary: #586380;
  --border-color: #f6f7fb;
  --border-active: #d9dde8;
  --success: #23b26d;
  --error: #ff725b;

  --shadow-sm: 0 0.25rem 1rem 0 rgba(46, 56, 86, 0.08);
  --shadow-md: 0 0.5rem 1.5rem 0 rgba(46, 56, 86, 0.12);

  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;

  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

.text-error {
  color: var(--error);
}

.hidden {
  display: none !important;
}

.flex {
  display: flex;
}

.gap-2 {
  gap: 0.5rem;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.font-bold {
  font-weight: 700;
}

.text-center {
  text-align: center;
}

.cursor-pointer {
  cursor: pointer;
}

.block {
  display: block;
}

.text-secondary {
  color: var(--text-secondary);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  border-radius: 0.5rem;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 1rem;
}

.btn-primary {
  background-color: var(--primary);
  color: white;
}

.btn-primary:hover {
  background-color: var(--primary-hover);
}

.btn-secondary {
  background-color: transparent;
  border: 2px solid var(--border-active);
  color: var(--text-secondary);
}

.btn-secondary:hover {
  border-color: var(--text-primary);
  color: var(--text-primary);
}

/* Navbar */
.navbar {
  background: white;
  padding: 1rem 2rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 50;
}

.logo {
  font-size: 1.5rem;
  color: var(--primary);
  font-weight: 800;
  text-decoration: none;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

/* Dashboard */
.set-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.set-card {
  background: white;
  padding: 1.5rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  border: 1px solid transparent;
}

.set-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--border-active);
}

.set-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.set-meta {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Set View */
.set-header {
  margin-bottom: 2rem;
}

.mode-tabs {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
  border-bottom: 2px solid var(--border-active);
}

.mode-tab {
  padding: 0.75rem 0;
  color: var(--text-secondary);
  font-weight: 600;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
}

.mode-tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

/* Flashcard */
.flashcard-container {
  perspective: 1000px;
  max-width: 800px;
  margin: 0 auto;
  height: 400px;
}

.flashcard {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  cursor: pointer;
}

.flashcard.flipped {
  transform: rotateX(180deg);
}

.card-face {
  position: absolute;
  width: 100%;
  height: 100%;
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  font-size: 2rem;
  padding: 2rem;
  text-align: center;
  border: 1px solid var(--border-active);
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  overflow-y: auto;
}

.card-face p {
  margin: auto;
}

.card-face.back {
  transform: rotateX(180deg);
}

.controls {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 2rem;
  margin-bottom: 3rem;
}

.control-btn {
  background: white;
  border: 2px solid var(--border-active);
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.control-btn:hover {
  border-color: var(--text-primary);
  color: var(--text-primary);
}

/* Term List */
.terms-list-section {
  max-width: 800px;
  margin: 0 auto;
}

.term-item {
  background: white;
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  gap: 2rem;
  border-left: 4px solid var(--border-active);
  position: relative;
  align-items: flex-start;
}

.term-item:hover .term-actions {
  opacity: 1;
}

.term-actions {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  justify-content: flex-end;
  opacity: 0.5;
  transition: opacity 0.2s;
  min-width: 100px;
}

.btn-icon {
  background: transparent;
  border: none;
  font-size: 1.25rem;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 50%;
  transition: background 0.2s;
}

.btn-icon:hover {
  background: var(--bg-color);
  color: var(--primary);
}

.term-item.editing {
  background: #fbfbff;
  border-left-color: var(--primary);
  align-items: center;
}

.term-item-col {
  flex: 1;
}

.term-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--text-secondary);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

/* Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(46, 56, 86, 0.6);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}

.modal-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.modal {
  background: white;
  width: 90%;
  max-width: 800px;
  max-height: 90vh;
  border-radius: var(--radius-md);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.input-group {
  margin-bottom: 1rem;
}

.input-label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  font-size: 0.875rem;
}

.input-field {
  width: 100%;
  padding: 0.75rem;
  border: 2px solid var(--border-active);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  transition: border-color 0.2s;
}

.input-field:focus {
  border-color: var(--primary);
  outline: none;
}

.card-rows {
  margin-top: 1rem;
}

.card-row {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
  align-items: flex-start;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

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

.delete-row {
  padding: 0.75rem;
  color: var(--error);
  cursor: pointer;
  background: none;
  border: none;
}

/* Test Mode Styles */
.config-section {
  background: var(--bg-color);
  padding: 1.5rem;
  border-radius: var(--radius-sm);
}

.checkbox-group label {
  display: block;
  margin-bottom: 0.5rem;
  cursor: pointer;
}

.test-question {
  background: white;
  padding: 2rem;
  border-radius: var(--radius-md);
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
  border: 2px solid transparent;
}

.test-question.correct {
  border-color: var(--success);
}

.test-question.incorrect {
  border-color: var(--error);
}

.test-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 1.5rem;
}

.test-option {
  padding: 1rem;
  border: 2px solid var(--border-active);
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-align: center;
  transition: all 0.2s;
}

.test-option:hover {
  border-color: var(--primary);
  background: #f0f2ff;
}

.test-option.selected.correct {
  background: var(--success);
  color: white;
  border-color: var(--success);
}

.test-option.selected.incorrect {
  background: var(--error);
  color: white;
  border-color: var(--error);
}

.tf-options {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
}

.tf-btn {
  flex: 1;
  padding: 1rem;
  border: 2px solid var(--border-active);
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-align: center;
  font-weight: bold;
}

.tf-btn:hover {
  border-color: var(--primary);
}

.tf-btn.true {
  color: var(--success);
}

.tf-btn.false {
  color: var(--error);
}

.test-feedback {
  margin-top: 1rem;
  font-weight: bold;
}

.text-success {
  color: var(--success);
}

/* Multiline Support */
.term-def,
.flashcard-back,
.card-face,
.term-def p,
.flashcard-back p,
.card-face p {
  white-space: pre-wrap;
  word-wrap: break-word;
}

/* Individual Card Stats */
.card-stats {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px dashed var(--border-active);
  display: flex;
  gap: 1rem;
}

.stat-trend {
  letter-spacing: 2px;
}