/* ═══════════════════════════════════════════════════════
   TEACHER PORTAL — common.css
   Shared base styles: reset, variables, buttons, tables,
   forms, modals, toast, utilities.
   ═══════════════════════════════════════════════════════ */

/* ── RESET & ROOT ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --accent:         #4f46e5;
  --accent-dark:    #3730a3;
  --accent-light:   #6366f1;
  --accent-soft:    #eef2ff;
  --green:          #10b981;
  --amber:          #f59e0b;
  --sky:            #0ea5e9;
  --red:            #ef4444;
  --red-soft:       #fef2f2;

  --sidebar-bg:     #0f172a;
  --sidebar-border: rgba(255,255,255,0.06);
  --sidebar-text:   #94a3b8;
  --sidebar-active: #fff;
  --sidebar-w:      260px;

  --topnav-h:       64px;
  --topnav-bg:      #ffffff;
  --topnav-border:  #f1f5f9;

  --bg-page:        #f8fafc;
  --bg-card:        #ffffff;
  --border:         #e2e8f0;
  --border-light:   #f1f5f9;

  --text-main:      #0f172a;
  --text-sub:       #475569;
  --text-muted:     #94a3b8;

  --radius-sm:      6px;
  --radius-md:      12px;
  --radius-lg:      18px;
  --radius-xl:      24px;

  --shadow-sm:      0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:      0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg:      0 12px 40px rgba(0,0,0,0.12);
}

html, body {
  height: 100%;
  font-family: 'DM Sans', sans-serif;
  background: var(--bg-page);
  color: var(--text-main);
  font-size: 15px;
  line-height: 1.5;
}

/* ── AUTH GUARD ── */
.auth-guard {
  position: fixed;
  inset: 0;
  background: #0f172a;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  z-index: 9999;
  color: #94a3b8;
  font-size: 0.9rem;
}

.auth-guard-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(79,70,229,0.2);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.auth-guard.hidden { display: none; }

/* ── APP SHELL ── */
.app-shell {
  display: flex;
  min-height: 100vh;
  opacity: 0;
  transition: opacity 0.35s;
}

.app-shell.visible { opacity: 1; }

/* ── MAIN CONTENT ── */
.main-content {
  flex: 1;
  padding: 32px 36px;
  overflow-y: auto;
}

/* Sections */
.section        { display: none; animation: fadeUp 0.3s ease; }
.section.active { display: block; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

.section-header { margin-bottom: 28px; }

.section-title {
  font-family: 'Sora', sans-serif;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 4px;
}

.section-sub {
  font-size: 0.9rem;
  color: var(--text-sub);
}

/* ── FORM CARD ── */
.form-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  max-width: 720px;
}

.form-card-compact { max-width: 100%; }

.form-card-title {
  font-family: 'Sora', sans-serif;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 22px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.field-group { margin-bottom: 18px; }

.field-label {
  display: block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-main);
  margin-bottom: 7px;
}

.field-input {
  width: 100%;
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.9rem;
  color: var(--text-main);
  background: #fff;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.field-input::placeholder { color: #cbd5e1; }

.field-input:focus {
  border-color: var(--accent-light);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.1);
}

.field-input[readonly] { background: #f8fafc; color: var(--text-sub); cursor: not-allowed; }

.field-textarea { resize: vertical; min-height: 80px; }

.error-msg {
  font-size: 0.78rem;
  color: var(--red);
  margin-top: 5px;
  min-height: 16px;
  display: block;
}

.success-msg {
  font-size: 0.82rem;
  color: var(--green);
  margin-bottom: 12px;
  font-weight: 500;
}

.success-msg.hidden { display: none; }

/* ── FILE DROP ZONE ── */
.file-drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius-md);
  padding: 32px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
  position: relative;
  background: #fafafa;
}

.file-drop-zone:hover,
.file-drop-zone.dragover {
  border-color: var(--accent-light);
  background: var(--accent-soft);
}

.file-drop-inner { pointer-events: none; }

.file-drop-text {
  font-size: 0.875rem;
  color: var(--text-sub);
  margin-top: 10px;
}

.file-drop-link {
  color: var(--accent);
  font-weight: 600;
  cursor: pointer;
  pointer-events: all;
}

.file-drop-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.file-input-hidden {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}

.file-selected {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 600;
  margin-top: 8px;
  min-height: 18px;
}

/* ── UPLOAD PROGRESS ── */
.upload-progress-wrap {
  margin-top: 14px;
}

.upload-progress-wrap.hidden { display: none; }

.upload-progress-track {
  height: 6px;
  background: var(--border);
  border-radius: 10px;
  overflow: hidden;
}

.upload-progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent) 0%, var(--accent-light) 100%);
  border-radius: 10px;
  width: 0%;
  transition: width 0.3s;
}

.upload-progress-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 5px;
  display: block;
}

/* ── FORM ACTIONS ── */
.form-actions {
  display: flex;
  gap: 12px;
  margin-top: 8px;
}

/* ── BUTTONS ── */
.btn-primary {
  padding: 11px 22px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, box-shadow 0.2s, transform 0.15s;
  letter-spacing: 0.01em;
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.btn-primary:hover {
  background: var(--accent-dark);
  box-shadow: 0 4px 14px rgba(79,70,229,0.3);
  transform: translateY(-1px);
}

.btn-primary:active  { transform: translateY(0); }
.btn-primary:disabled { opacity: 0.6; cursor: not-allowed; transform: none; }

.btn-primary.btn-sm { padding: 8px 16px; font-size: 0.825rem; }

.btn-ghost {
  padding: 11px 20px;
  background: #f1f5f9;
  color: var(--text-sub);
  border: none;
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.18s;
}

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

.btn-danger {
  padding: 11px 20px;
  background: var(--red);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.18s;
}

.btn-danger:hover { background: #dc2626; }

.btn-icon {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 5px 8px;
  border-radius: var(--radius-sm);
  transition: background 0.15s, color 0.15s;
}

.btn-icon:hover { background: #f1f5f9; color: var(--text-main); }

.btn-icon.delete:hover { background: var(--red-soft); color: var(--red); }

/* spinner */
.spinner {
  display: inline-block;
  width: 14px;
  height: 14px;
  border: 2px solid rgba(255,255,255,0.35);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  flex-shrink: 0;
}

/* ── TABLE TOOLBAR ── */
.table-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 16px;
}

.search-input {
  padding: 9px 14px 9px 36px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.875rem;
  color: var(--text-main);
  background: #fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2'%3E%3Ccircle cx='11' cy='11' r='8'/%3E%3Cline x1='21' y1='21' x2='16.65' y2='16.65'/%3E%3C/svg%3E") no-repeat 10px center;
  outline: none;
  min-width: 220px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input:focus {
  border-color: var(--accent-light);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.1);
}

.count-label {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* ── TABLE CARD ── */
.table-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  overflow: hidden;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  min-width: 540px;
}

.data-table thead {
  background: #f8fafc;
  border-bottom: 1px solid var(--border);
}

.data-table th {
  padding: 13px 18px;
  text-align: left;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  white-space: nowrap;
}

.data-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-main);
  vertical-align: middle;
}

.data-table tbody tr:last-child td { border-bottom: none; }

.data-table tbody tr:hover td { background: #fafafa; }

.table-empty {
  text-align: center;
  color: var(--text-muted);
  padding: 40px 18px !important;
  font-size: 0.875rem;
}

.empty-state-sm {
  text-align: center;
  color: var(--text-muted);
  padding: 20px 0;
  font-size: 0.85rem;
}

/* ── Row status pills ── */
.pill {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  white-space: nowrap;
}

.pill-green  { background: #dcfce7; color: #15803d; }
.pill-amber  { background: #fef9c3; color: #92400e; }
.pill-red    { background: var(--red-soft); color: var(--red); }
.pill-blue   { background: #dbeafe; color: #1d4ed8; }
.pill-purple { background: var(--accent-soft); color: var(--accent-dark); }
.pill-gray   { background: #f1f5f9; color: #64748b; }

/* ── MODAL ── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15,23,42,0.55);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.22s;
}

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

.modal-box {
  background: #fff;
  border-radius: var(--radius-xl);
  padding: 30px 30px 24px;
  width: 100%;
  max-width: 420px;
  box-shadow: var(--shadow-lg);
  transform: translateY(14px) scale(0.97);
  transition: transform 0.26s cubic-bezier(0.34,1.56,0.64,1), opacity 0.22s;
  opacity: 0;
}

.modal-overlay.open .modal-box { transform: none; opacity: 1; }

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.modal-title {
  font-family: 'Sora', sans-serif;
  font-size: 1.1rem;
  font-weight: 700;
}

.modal-close {
  width: 30px;
  height: 30px;
  border: none;
  background: #f1f5f9;
  border-radius: 50%;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
}

.modal-close:hover { background: var(--border); }

.modal-sub {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 22px;
}

.modal-body-text {
  font-size: 0.9rem;
  color: var(--text-sub);
  margin-bottom: 22px;
  line-height: 1.6;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

/* Wide modal */
.modal-box-wide { max-width: 680px; }

/* ── TOAST ── */
.toast {
  position: fixed;
  bottom: 28px;
  right: 28px;
  background: #0f172a;
  color: #fff;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 9000;
  transform: translateY(80px);
  opacity: 0;
  transition: transform 0.3s cubic-bezier(0.34,1.2,0.64,1), opacity 0.3s;
  max-width: 320px;
}

.toast.show { transform: translateY(0); opacity: 1; }
.toast.success { border-left: 4px solid var(--green); }
.toast.error   { border-left: 4px solid var(--red); }
.toast.info    { border-left: 4px solid var(--accent-light); }

/* ── SIDEBAR COLLAPSED STATE ── */
.sidebar-collapsed .sidebar   { transform: translateX(calc(-1 * var(--sidebar-w))); }
.sidebar-collapsed .main-wrap { margin-left: 0; }

/* ── UTILITIES ── */
.hidden { display: none !important; }