/* Hanzi Learning App Stylesheet */

:root {
  --bg-color: #ffffff;
  --surface-color: #f7f8fa;
  --border-color: #e5e7eb;
  --text-color: #1f2328;
  --muted-color: #57606a;
  --accent-color: #3b82d4;
  --danger-color: #d9383a;
  --font-family: -apple-system, "Segoe UI", system-ui, sans-serif;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  font-size: 15px;
}

.app-layout {
  max-width: 760px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-color);
}

.header-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-color);
}

.app-nav {
  display: flex;
  gap: 0.5rem;
}

.nav-btn {
  background: none;
  border: 1px solid transparent;
  padding: 0.4rem 0.8rem;
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: 4px;
  cursor: pointer;
  color: var(--muted-color);
  transition: all 0.2s ease;
}

.nav-btn:hover {
  background-color: var(--surface-color);
  color: var(--text-color);
}

.nav-btn.active {
  background-color: var(--surface-color);
  border-color: var(--border-color);
  color: var(--accent-color);
}

.app-content {
  flex: 1;
  padding: 1.5rem;
  background-color: var(--bg-color);
}

.view-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

h2 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-color);
}

h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-color);
  margin-bottom: 0.5rem;
}

p {
  color: var(--muted-color);
}

.card {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 1rem;
  margin-top: 0.5rem;
}

.btn {
  background-color: var(--accent-color);
  color: #ffffff;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s ease;
  display: inline-block;
}

.btn:hover {
  background-color: #2b6cb0;
}

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

.btn-danger:hover {
  background-color: #b82d30;
}
/* Profile forms */
.card label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.card input[type="text"] {
  display: block;
  width: 100%;
  max-width: 24rem;
  padding: 0.5rem;
  margin-bottom: 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 1rem;
}

.form-error {
  color: var(--danger-color);
  margin: 0 0 0.5rem;
}
/* Learn card */
.learn-card {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.learn-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.learn-character {
  font-size: 6rem;
  line-height: 1.1;
  color: var(--text-color);
}

.learn-still {
  width: 128px;
  height: 128px;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 4px;
}

.learn-details {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.learn-row {
  display: flex;
  gap: 0.75rem;
}

.learn-label {
  flex: 0 0 7rem;
  color: var(--muted-color);
  font-weight: 500;
}

.learn-value {
  flex: 1;
  overflow-wrap: anywhere;
}

.learn-card .btn {
  align-self: flex-start;
}





/* Fullscreen/State screen styles */
.fullscreen-state {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  gap: 1rem;
  background-color: var(--bg-color);
  text-align: center;
  padding: 2rem;
}

.error-state h2 {
  color: var(--danger-color);
}

/* Spinner */
.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--border-color);
  border-top-color: var(--accent-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

/* Writing practice */
.btn-secondary {
  background-color: var(--surface-color);
  color: var(--text-color);
  border: 1px solid var(--border-color);
}

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

.practice {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.practice-steps {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--muted-color);
}

.practice-step.active {
  color: var(--accent-color);
  font-weight: 600;
}

.practice-prompt {
  color: var(--text-color);
}

.practice-watch,
.practice-draw {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.practice-animation {
  width: min(100%, 320px);
  aspect-ratio: 1 / 1;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
}

.practice-surface-wrap {
  width: min(100%, 360px);
  aspect-ratio: 1 / 1;
}

.practice-surface {
  display: block;
  width: 100%;
  height: 100%;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  cursor: crosshair;
}

.practice-surface .stroke-guide {
  fill: #e3e6ea;
}

.practice-surface .stroke-guide-next {
  fill: #cfd6de;
}

.practice-surface .stroke-hint {
  fill: var(--accent-color);
  opacity: 0.55;
}

.practice-surface .ink {
  fill: none;
  stroke: var(--text-color);
  stroke-width: 28;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.practice-surface .ink-rejected {
  stroke: var(--danger-color);
  opacity: 0.8;
}

.practice-feedback {
  min-height: 1.6em;
  text-align: center;
}

.practice-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}

.practice-result {
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
  text-align: center;
}

.practice-result.passed {
  border-color: #2f9e44;
  color: #2f9e44;
}

.practice-result.failed {
  border-color: var(--danger-color);
  color: var(--danger-color);
}

/* Study home and active session styles */
.btn-large {
  padding: 0.75rem 1.5rem;
  font-size: 1.05rem;
  font-weight: 600;
}

.btn-small {
  padding: 0.25rem 0.5rem;
  font-size: 0.8rem;
}

.study-home {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.study-stats-grid,
.summary-stats-grid,
.progress-stats-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
  gap: 0.75rem;
  text-align: center;
  margin-bottom: 1rem;
}

.stat-box {
  display: flex;
  flex-direction: column;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem 0.5rem;
}

.stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-color);
}

.stat-label {
  font-size: 0.8rem;
  color: var(--muted-color);
  margin-top: 0.25rem;
}

.study-actions {
  display: flex;
  justify-content: center;
  margin-top: 0.5rem;
}

.study-unfamiliar-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.study-char-card {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem;
}

.study-char-badge {
  font-size: 2.2rem;
  line-height: 1;
  font-weight: 600;
  color: var(--text-color);
  flex: 0 0 3rem;
  text-align: center;
}

.study-char-info {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  min-width: 0;
}

.study-char-pinyin {
  font-weight: 600;
  color: var(--accent-color);
  font-size: 0.95rem;
}

.study-char-def {
  font-size: 0.85rem;
  color: var(--muted-color);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.study-char-progress {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.25rem;
}

.progress-bar-bg {
  flex: 1;
  height: 6px;
  background-color: var(--border-color);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background-color: #2f9e44;
  border-radius: 3px;
  transition: width 0.3s ease;
}

.progress-text {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--muted-color);
  flex: 0 0 2rem;
  text-align: right;
}

.study-finished-card {
  text-align: center;
  padding: 2rem;
}

.study-due-alert {
  margin-top: 1rem;
}

/* Active Session */
.active-session {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.session-top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.session-badge {
  display: inline-block;
  padding: 0.25rem 0.6rem;
  border-radius: 4px;
  font-size: 0.85rem;
  font-weight: 600;
}

.session-badge.learn-badge {
  background-color: #e8f3ff;
  color: var(--accent-color);
  border: 1px solid #b3d7ff;
}

.session-badge.test-badge {
  background-color: #fff4e6;
  color: #d9730d;
  border: 1px solid #ffd8a8;
}

.test-practice-prompt {
  text-align: center;
  margin-bottom: 0.5rem;
}

.test-pinyin {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent-color);
}

.test-def {
  font-size: 0.95rem;
  color: var(--muted-color);
}

.session-practice-wrapper {
  width: 100%;
}

/* Session Result */
.session-result-view {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding: 1.5rem;
  text-align: center;
}

.session-result-header {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.result-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  font-weight: bold;
}

.session-result-header.passed .result-icon {
  background-color: #ebfbee;
  color: #2f9e44;
  border: 2px solid #2f9e44;
}

.session-result-header.failed .result-icon {
  background-color: #fff5f5;
  color: var(--danger-color);
  border: 2px solid var(--danger-color);
}

.session-result-header.passed h3 {
  color: #2f9e44;
}

.session-result-header.failed h3 {
  color: var(--danger-color);
}

.session-result-details {
  font-size: 1rem;
  color: var(--text-color);
}

.lapsed-character-preview {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
  padding: 0.75rem;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
}

.lapsed-char {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1;
}

.lapsed-info {
  text-align: left;
}

.lapsed-pinyin {
  font-weight: 600;
  color: var(--accent-color);
}

.lapsed-def {
  font-size: 0.85rem;
  color: var(--muted-color);
}

.session-result-actions {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

/* Session Summary */
.session-summary-card {
  text-align: center;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.summary-mastered-section {
  text-align: left;
}

.mastered-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.mastered-chip {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background-color: #ebfbee;
  border: 1px solid #b2f2bb;
  padding: 0.3rem 0.6rem;
  border-radius: 20px;
}

.chip-char {
  font-weight: 700;
  font-size: 1.1rem;
  color: #2b8a3e;
}

.chip-pinyin {
  font-size: 0.8rem;
  color: var(--muted-color);
}

.summary-actions {
  display: flex;
  justify-content: center;
  margin-top: 0.5rem;
}

/* Progress View */
.progress-view {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.text-familiar {
  color: #2f9e44;
}

.text-unfamiliar {
  color: #d9730d;
}

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

.progress-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--muted-color);
  align-items: center;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.legend-dot.familiar {
  background-color: #2f9e44;
}

.legend-dot.unfamiliar {
  background-color: #f59f00;
}

.legend-dot.not-introduced {
  background-color: #adb5bd;
}

.groups-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.group-card {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.group-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted-color);
}

.group-cells {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 0.35rem;
}

.progress-cell {
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  border: 1px solid transparent;
  font-size: 1.15rem;
  font-family: var(--font-family);
  font-weight: 500;
  cursor: pointer;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: transform 0.1s ease, border-color 0.1s ease;
  padding: 0;
}

.progress-cell:hover {
  transform: scale(1.1);
  z-index: 2;
}

.progress-cell.selected {
  outline: 2px solid var(--accent-color);
  outline-offset: 1px;
}

.progress-cell.familiar {
  background-color: #ebfbee;
  border-color: #b2f2bb;
  color: #2b8a3e;
  font-weight: 600;
}

.progress-cell.unfamiliar {
  background-color: #fff9db;
  border-color: #ffe066;
  color: #d9730d;
  font-weight: 600;
}

.progress-cell.not-introduced {
  background-color: var(--surface-color);
  border-color: var(--border-color);
  color: #868e96;
}

.progress-detail-panel {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  border: 2px solid var(--accent-color);
}

.progress-detail-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
}

.detail-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.25rem;
}

.status-badge {
  display: inline-block;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
}

.status-badge.familiar {
  background-color: #ebfbee;
  color: #2b8a3e;
  border: 1px solid #b2f2bb;
}

.status-badge.unfamiliar {
  background-color: #fff9db;
  color: #d9730d;
  border: 1px solid #ffe066;
}

.status-badge.not-introduced {
  background-color: #f1f3f5;
  color: #868e96;
  border: 1px solid #dee2e6;
}

.badge-rank {
  font-size: 0.8rem;
  color: var(--muted-color);
  align-self: center;
}

.progress-srs-stats {
  display: flex;
  gap: 1.5rem;
  font-size: 0.85rem;
  padding: 0.5rem 0.75rem;
  background-color: var(--bg-color);
  border-radius: 4px;
  border: 1px solid var(--border-color);
}