/* Components */

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 72px;
  background: rgba(var(--surface-rgb), 0.7);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 3rem;
  transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] .navbar {
  background: rgba(15, 18, 20, 0.8);
}

.navbar.scrolled {
  box-shadow: 0 8px 32px rgba(0,0,0,0.06);
  background: rgba(var(--surface-rgb), 0.85);
  height: 64px;
}

.navbar-brand {
  font-family: "Manrope", sans-serif;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.navbar-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  font-weight: 500;
  color: var(--on-surface);
  transition: color 0.2s ease;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
}

.navbar-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

/* Sidebar */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 240px;
  height: 100vh;
  background-color: var(--surface-container-low);
  padding: 64px 0 2rem 0; /* offset for navbar */
  display: flex;
  flex-direction: column;
  z-index: 900;
}

.sidebar-header {
  padding: 1.5rem;
}

.sidebar-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--outline);
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 0 1rem;
  flex: 1;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
  border-radius: 0.75rem;
  color: var(--on-surface);
  font-weight: 500;
  transition: all 0.2s ease;
}

.sidebar-item:hover {
  background-color: var(--surface-container-high);
}

.sidebar-item.active {
  background: var(--signature-gradient);
  color: #fff;
}

.sidebar-item.active-tutor {
  background: var(--secondary);
  color: #fff;
}

.sidebar-footer {
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  border-top: 1px solid var(--surface-container-high); /* Only allowed borders */
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 9999px;
  font-weight: 700;
  font-family: 'Lexend', sans-serif;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  border: none;
  text-decoration: none;
  letter-spacing: 0.02em;
}

.btn:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.btn:active {
  transform: translateY(0) scale(0.98);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-primary {
  background: var(--signature-gradient);
  color: #fff;
}

.btn-secondary {
  background-color: var(--secondary-container);
  color: var(--on-secondary-container);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  box-shadow: inset 0 0 0 2px var(--primary);
}

.btn-ghost {
  background: transparent;
  color: var(--on-surface);
}

.btn-ghost:hover {
  background-color: var(--surface-container-high);
  box-shadow: none;
}

.btn-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--on-surface);
  transition: background 0.2s ease;
}

.btn-icon:hover {
  background-color: var(--surface-container-high);
}

/* Cards */
.card {
  background-color: var(--surface-container-lowest);
  border-radius: 1.5rem;
  padding: 1.75rem;
  transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.05);
  box-shadow: var(--shadow-sm);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: rgba(255, 255, 255, 0.1);
}

.card-accent-left {
  border-left: 4px solid var(--primary);
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

.card-accent-error { border-left-color: var(--error); }
.card-accent-secondary { border-left-color: var(--secondary); }
.card-accent-tertiary { border-left-color: var(--tertiary); }

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  box-shadow: inset 0 0 0 1px rgba(0,0,0,0.05);
}

.badge-pending { background-color: var(--status-pending-bg); color: var(--status-pending-text); }
.badge-submitted { background-color: var(--status-submitted-bg); color: var(--status-submitted-text); }
.badge-ai { background-color: var(--status-ai-bg); color: var(--status-ai-text); }
.badge-graded { background-color: var(--status-graded-bg); color: var(--status-graded-text); }
.badge-urgent { background-color: var(--status-urgent-bg); color: var(--status-urgent-text); }

/* Pill (general) */
.pill {
  display: inline-block;
  padding: 0.25rem 1rem;
  border-radius: 9999px;
  font-size: 0.875rem;
  font-weight: 600;
}

/* Avatars */
.avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  background-color: var(--tertiary);
  background-size: cover;
  background-position: center;
  flex-shrink: 0;
}

.avatar-lg { width: 64px; height: 64px; font-size: 1.5rem; }
.avatar-sm { width: 32px; height: 32px; font-size: 0.75rem; }

/* Forms & Inputs */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  position: relative;
}

.form-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--on-surface);
}

.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.input-field {
  width: 100%;
  padding: 1.1rem 1rem 1.1rem 3rem;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 500;
  background-color: var(--surface-container-low);
  border: 1px solid transparent;
  border-bottom: 2px solid transparent;
  border-radius: 0.75rem 0.75rem 0 0;
  color: var(--on-surface);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.input-field.pl-4 {
  padding-left: 1rem;
}

.input-field:focus {
  outline: none;
  border-bottom-color: var(--primary);
  background-color: var(--surface-container);
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.02) inset, 0 4px 12px rgba(0, 102, 132, 0.08);
  transform: translateY(-1px);
}

.input-icon {
  position: absolute;
  left: 1rem;
  color: var(--outline);
  pointer-events: none;
}

.input-toggle {
  position: absolute;
  right: 1rem;
  background: none;
  border: none;
  color: var(--outline);
  cursor: pointer;
  padding: 0.25rem;
}

select.input-field {
  appearance: none;
  cursor: pointer;
}

textarea.input-field {
  min-height: 120px;
  resize: vertical;
  padding: 1rem;
  border-radius: 0.75rem;
  border: none;
  border-bottom: 2px solid transparent;
}

.form-error {
  color: var(--error);
  font-size: 0.75rem;
  margin-top: 0.25rem;
  display: none;
}

.form-group.has-error .input-field {
  border-bottom-color: var(--error);
}

.form-group.has-error .form-error {
  display: block;
}

/* Custom Checkbox */
.checkbox-label {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  cursor: pointer;
  font-size: 0.875rem;
}
.checkbox-input {
  width: 1.25rem;
  height: 1.25rem;
  accent-color: var(--primary);
  margin-top: 0.125rem;
}

/* Subject Chips (Grid) */
.subject-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.subject-chip {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 1.5rem 1rem;
  background-color: var(--surface-container-highest);
  border-radius: 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
  text-align: center;
}

.subject-chip:hover {
  background-color: var(--surface-container-low);
  transform: translateY(-2px);
}

.subject-chip.selected {
  background: var(--signature-gradient);
  color: #fff;
}

/* Progress Bars */
.progress-bar-container {
  width: 100%;
  height: 8px;
  background-color: var(--surface-container-high);
  border-radius: 9999px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--signature-gradient);
  border-radius: 9999px;
  transition: width 1s ease-out;
}

/* Circular Gauge */
.circular-gauge {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.gauge-svg {
  transform: rotate(-90deg);
}

.gauge-track {
  fill: none;
  stroke: var(--tertiary);
  opacity: 0.2;
}

.gauge-progress {
  fill: none;
  stroke-linecap: round;
  transition: stroke-dashoffset 1.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Tables */
.table-container {
  width: 100%;
  overflow-x: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
}

.data-table th {
  text-align: left;
  padding: 1rem;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--outline);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.data-table td {
  padding: 1rem;
  vertical-align: middle;
}

.data-table tbody tr {
  transition: background-color 0.2s ease;
  cursor: pointer;
}

.data-table tbody tr:nth-child(even) {
  background-color: var(--surface-container-low);
}

.data-table tbody tr:hover, .data-table tbody tr.active {
  background-color: var(--surface-container);
}

.data-table tbody tr.accent-row {
  border-left: 4px solid var(--primary);
}

/* File Upload Zone */
.file-upload-zone {
  border: 2px dashed var(--outline-variant);
  border-radius: 1.5rem;
  padding: 3rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.file-upload-zone:hover, .file-upload-zone.dragover {
  background-color: var(--surface-container-low);
  border-color: var(--primary);
}

/* Icon Container */
.icon-container {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 1rem;
}

.icon-container.primary { background-color: var(--primary-fixed); color: var(--on-primary-fixed); }
.icon-container.secondary { background-color: var(--secondary-container); color: var(--on-secondary-container); }
.icon-container.error { background-color: var(--error-container); color: var(--error); }

/* Overline Text */
.overline {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--outline);
  margin-bottom: 0.5rem;
  display: block;
}