/* =============================================================================
   NOTES PANEL — Slide-out notes sidebar
   ============================================================================= */

/* Toggle Tab (fixed to right edge) */
.notes-tab {
  position: fixed;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 900;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-lg) 0 0 var(--radius-lg);
  padding: 14px 8px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  font-family: var(--font-body);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  box-shadow: -4px 0 20px rgba(59, 130, 246, 0.25);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  opacity: 0.9;
}
.notes-tab:hover {
  opacity: 1;
  padding-right: 12px;
  box-shadow: -4px 0 30px rgba(59, 130, 246, 0.4);
}
.notes-tab svg {
  transform: rotate(90deg);
}
.notes-tab.has-notes::after {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-success);
  position: absolute;
  top: 8px;
  left: 8px;
}

/* Panel Overlay */
.notes-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  backdrop-filter: blur(4px);
}
.notes-overlay.open {
  opacity: 1;
  visibility: visible;
}

/* Panel */
.notes-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: 420px;
  max-width: 90vw;
  height: 100vh;
  background: var(--color-surface);
  border-left: 1px solid var(--color-border);
  z-index: 1000;
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
  box-shadow: -20px 0 60px rgba(0, 0, 0, 0.3);
}
.notes-panel.open {
  transform: translateX(0);
}

/* Panel Header */
.notes-panel-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}
.notes-panel-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 10px;
}
.notes-panel-title svg {
  color: var(--color-primary);
}
.notes-close-btn {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-interactive);
}
.notes-close-btn:hover {
  color: var(--color-text);
  background: var(--color-card-hover);
  border-color: var(--color-text-faint);
}

/* Notes List / Course Selector */
.notes-course-select {
  padding: 12px 24px;
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}
.notes-course-select label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  display: block;
  margin-bottom: 8px;
}
.notes-course-dropdown {
  width: 100%;
  padding: 10px 14px;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: border-color var(--transition-interactive);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%2394A3B8' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
}
.notes-course-dropdown:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-subtle);
}

/* Notes Editor Area */
.notes-editor-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 16px 24px;
}
.notes-textarea {
  flex: 1;
  width: 100%;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.7;
  padding: 16px 18px;
  resize: none;
  transition: border-color var(--transition-interactive);
}
.notes-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-subtle);
}
.notes-textarea::placeholder {
  color: var(--color-text-faint);
}

/* Save Bar */
.notes-save-bar {
  padding: 16px 24px;
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}
.notes-save-status {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  display: flex;
  align-items: center;
  gap: 6px;
}
.notes-save-status.saved {
  color: var(--color-success);
}
.notes-save-status.saving {
  color: var(--color-warning);
}
.notes-save-status.error {
  color: var(--color-error);
}
.notes-save-btn {
  padding: 10px 20px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-interactive);
  display: flex;
  align-items: center;
  gap: 8px;
}
.notes-save-btn:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
}
.notes-save-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* Login prompt inside notes panel */
.notes-login-prompt {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 24px;
  gap: 16px;
}
.notes-login-prompt svg {
  color: var(--color-text-faint);
  margin-bottom: 8px;
}
.notes-login-prompt h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  font-weight: 700;
}
.notes-login-prompt p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 280px;
  line-height: 1.6;
}

/* Character count */
.notes-char-count {
  font-size: 11px;
  color: var(--color-text-faint);
  text-align: right;
  margin-top: 6px;
}

@media (max-width: 640px) {
  .notes-panel { width: 100vw; max-width: 100vw; }
  .notes-tab { padding: 10px 6px; font-size: 10px; }
}