/* ============================================================
   川师学业通 — main.css
   全局样式 / 主题变量 / 布局 / 共享组件 / 响应式 / 打印
   ============================================================ */

/* ---- CSS Custom Properties: Light Theme (default) ---- */
:root {
  --color-bg:              #f1f5f9;
  --color-surface:         #ffffff;
  --color-surface-hover:   #f8fafc;
  --color-text:            #1e293b;
  --color-text-secondary:  #475569;
  --color-text-muted:      #94a3b8;
  --color-border:          #e2e8f0;
  --color-border-light:    #f1f5f9;

  --color-primary:         #2563eb;
  --color-primary-light:   #3b82f6;
  --color-primary-dark:    #1d4ed8;
  --color-primary-bg:      #eff6ff;
  --color-primary-border:  #bfdbfe;

  --color-success:         #10b981;
  --color-success-bg:      #ecfdf5;
  --color-success-border:  #a7f3d0;

  --color-warning:         #f59e0b;
  --color-warning-bg:      #fffbeb;
  --color-warning-border:  #fde68a;

  --color-danger:          #ef4444;
  --color-danger-bg:       #fef2f2;
  --color-danger-border:   #fecaca;

  --color-info:            #6366f1;
  --color-info-bg:         #eef2ff;

  --color-accent-emerald:  #059669;
  --color-accent-teal:     #0d9488;
  --color-accent-blue:     #2563eb;
  --color-accent-indigo:   #4f46e5;
  --color-accent-violet:   #7c3aed;
  --color-accent-purple:   #a855f7;

  --color-accent-emerald-bg: #ecfdf5;
  --color-accent-teal-bg:    #f0fdfa;
  --color-accent-blue-bg:    #eff6ff;
  --color-accent-indigo-bg:  #eef2ff;
  --color-accent-violet-bg:  #f5f3ff;
  --color-accent-purple-bg:  #faf5ff;

  --color-card-shadow:    0 1px 3px 0 rgba(0,0,0,0.08), 0 1px 2px -1px rgba(0,0,0,0.06);
  --color-card-shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.08);
  --color-modal-bg:       rgba(0,0,0,0.45);

  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  14px;
  --transition: 0.2s ease;

  --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui,
               -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Cascadia Code", "Fira Code", "JetBrains Mono", Consolas, monospace;

  --color-chart-bar-from:  #6366f1;
  --color-chart-bar-to:    #818cf8;
  --color-chart-text:      #475569;

  --header-height: 64px;
  --tabs-height:   48px;
}

/* ---- Dark Theme ---- */
[data-theme="dark"] {
  --color-bg:              #0f172a;
  --color-surface:         #1e293b;
  --color-surface-hover:   #334155;
  --color-text:            #e2e8f0;
  --color-text-secondary:  #94a3b8;
  --color-text-muted:      #64748b;
  --color-border:          #334155;
  --color-border-light:    #1e293b;

  --color-primary:         #60a5fa;
  --color-primary-light:   #93bbfd;
  --color-primary-dark:    #3b82f6;
  --color-primary-bg:      #1e3a5f;
  --color-primary-border:  #1e40af;

  --color-success:         #34d399;
  --color-success-bg:      #064e3b;
  --color-success-border:  #065f46;

  --color-warning:         #fbbf24;
  --color-warning-bg:      #451a03;
  --color-warning-border:  #78350f;

  --color-danger:          #f87171;
  --color-danger-bg:       #450a0a;
  --color-danger-border:   #7f1d1d;

  --color-info:            #818cf8;
  --color-info-bg:         #1e1b4b;

  --color-accent-emerald-bg: #064e3b;
  --color-accent-teal-bg:    #0f4c47;
  --color-accent-blue-bg:    #1e3a5f;
  --color-accent-indigo-bg:  #1e1b4b;
  --color-accent-violet-bg:  #2e1065;
  --color-accent-purple-bg:  #3b0764;

  --color-card-shadow:    0 1px 3px 0 rgba(0,0,0,0.3), 0 1px 2px -1px rgba(0,0,0,0.2);
  --color-card-shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4), 0 2px 4px -2px rgba(0,0,0,0.3);
  --color-modal-bg:       rgba(0,0,0,0.7);

  --color-chart-bar-from:  #6366f1;
  --color-chart-bar-to:    #a5b4fc;
  --color-chart-text:      #cbd5e1;
}

/* ---- CSS Reset ---- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition), color var(--transition);
}

img, svg { display: block; max-width: 100%; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
ul, ol { list-style: none; }
input, select, textarea, button { font-family: inherit; font-size: inherit; }

/* ---- Utility ---- */
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

/* ---- App Header ---- */
.app-header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0 20px;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--color-card-shadow);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background-color var(--transition);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-logo { font-size: 32px; line-height: 1; }

.header-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.3;
}

.header-subtitle {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  line-height: 1.3;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* ---- Icon Button ---- */
.btn-icon {
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--color-text-secondary);
  transition: background-color var(--transition), color var(--transition);
}

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

/* ---- Tabs Navigation ---- */
.main-tabs {
  display: flex;
  background-color: var(--color-surface);
  border-bottom: 2px solid var(--color-border);
  position: sticky;
  top: var(--header-height);
  z-index: 99;
  height: var(--tabs-height);
  padding: 0 16px;
  gap: 4px;
  transition: background-color var(--transition);
}

.tab-btn {
  flex: 0 0 auto;
  padding: 10px 22px;
  border: none;
  background: transparent;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  transition: color var(--transition), border-color var(--transition);
  white-space: nowrap;
}

.tab-btn:hover { color: var(--color-text); }
.tab-btn.tab-active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: 600;
}

/* ---- Semester Selector in Tab Bar ---- */
.semester-selector {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
  padding: 0 10px 0 0;
  border-right: 1px solid var(--color-border);
  margin-right: 6px;
}

.semester-select {
  padding: 4px 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  color: var(--color-text);
  font-size: 0.8rem;
  max-width: 210px;
  cursor: pointer;
  transition: border-color var(--transition);
}

.semester-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px var(--color-primary-bg);
}

.current-semester-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  white-space: nowrap;
  padding: 3px 8px;
  background-color: var(--color-primary-bg);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-primary-border);
}

/* ---- Profile Placeholder ---- */
.profile-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 20px;
  text-align: center;
}

.profile-icon-large {
  font-size: 5rem;
  margin-bottom: 20px;
  opacity: 0.6;
}

.profile-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.profile-desc {
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

/* ---- Panel ---- */
.panel {
  flex: 1;
  padding: 20px;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  animation: fadeIn 0.25s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---- Card ---- */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  box-shadow: var(--color-card-shadow);
  transition: background-color var(--transition), box-shadow var(--transition);
}

.card:hover {
  box-shadow: var(--color-card-shadow-md);
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 18px;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 0.9rem;
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
  transition: all var(--transition);
  line-height: 1.4;
}

.btn:active { transform: scale(0.97); }

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

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

.btn-outline {
  background-color: transparent;
  color: var(--color-text-secondary);
  border-color: var(--color-border);
}

.btn-outline:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-text);
  border-color: var(--color-text-muted);
}

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

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

.btn-sm {
  padding: 5px 12px;
  font-size: 0.82rem;
}

.btn-xs {
  padding: 3px 8px;
  font-size: 0.75rem;
}

/* ---- Badge ---- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  padding: 2px 10px;
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 500;
  white-space: nowrap;
  line-height: 1.6;
}

.badge-emerald { background: var(--color-accent-emerald-bg); color: var(--color-accent-emerald); }
.badge-teal    { background: var(--color-accent-teal-bg);    color: var(--color-accent-teal); }
.badge-blue    { background: var(--color-accent-blue-bg);    color: var(--color-accent-blue); }
.badge-indigo  { background: var(--color-accent-indigo-bg);  color: var(--color-accent-indigo); }
.badge-violet  { background: var(--color-accent-violet-bg);  color: var(--color-accent-violet); }
.badge-purple  { background: var(--color-accent-purple-bg);  color: var(--color-accent-purple); }
.badge-success { background: var(--color-success-bg); color: var(--color-success); }
.badge-warning { background: var(--color-warning-bg); color: var(--color-warning); }
.badge-danger  { background: var(--color-danger-bg);  color: var(--color-danger); }

/* ---- Stat Card ---- */
.stat-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  box-shadow: var(--color-card-shadow);
  transition: background-color var(--transition), box-shadow var(--transition);
}

.stat-card:hover {
  box-shadow: var(--color-card-shadow-md);
}

/* ---- Modal ---- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background-color: var(--color-modal-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 20px;
  animation: fadeIn 0.15s ease;
}

.modal-content {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 520px;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: var(--color-card-shadow-md);
  transition: background-color var(--transition);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--color-border);
}

.modal-header h3 {
  font-size: 1.1rem;
  font-weight: 600;
}

.modal-body {
  padding: 20px;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-top: 1px solid var(--color-border);
  gap: 10px;
}

.modal-footer-right {
  display: flex;
  gap: 8px;
  margin-left: auto;
}

/* ---- Form ---- */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.required { color: var(--color-danger); }

.form-group input,
.form-group select {
  padding: 8px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  color: var(--color-text);
  font-size: 0.9rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-bg);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 12px;
  margin-top: 14px;
}

.form-row.two-col {
  grid-template-columns: 1fr 1fr;
}

.form-error {
  margin-top: 12px;
  padding: 10px 14px;
  background-color: var(--color-danger-bg);
  color: var(--color-danger);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
}

/* ---- Toast ---- */
#toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: var(--color-card-shadow-md);
  animation: toastIn 0.3s ease, toastOut 0.3s ease 2.7s forwards;
  max-width: 380px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toast-success { background: var(--color-success-bg); color: var(--color-success); border: 1px solid var(--color-success-border); }
.toast-error   { background: var(--color-danger-bg);  color: var(--color-danger);  border: 1px solid var(--color-danger-border); }
.toast-warning { background: var(--color-warning-bg); color: var(--color-warning); border: 1px solid var(--color-warning-border); }
.toast-info    { background: var(--color-info-bg);    color: var(--color-info);    border: 1px solid var(--color-info-bg); }

@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes toastOut {
  from { opacity: 1; transform: translateX(0); }
  to   { opacity: 0; transform: translateX(40px); }
}

/* ---- PWA Install Banner ---- */
.pwa-install-banner {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  z-index: 250;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-primary-border);
  border-radius: var(--radius-lg);
  padding: 14px 20px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.15), 0 2px 6px rgba(0,0,0,0.08);
  max-width: 520px;
  width: calc(100vw - 40px);
  opacity: 0;
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.25s ease;
}

.pwa-install-banner--visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.pwa-install-banner-text {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  white-space: nowrap;
}

.pwa-install-banner-actions {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
}

@media (max-width: 767px) {
  .pwa-install-banner {
    flex-direction: column;
    text-align: center;
    gap: 10px;
    padding: 12px 16px;
    bottom: 12px;
  }

  .pwa-install-banner-text {
    white-space: normal;
    font-size: 0.85rem;
  }
}

/* ---- Footer ---- */
.app-footer {
  text-align: center;
  padding: 20px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
  margin-top: auto;
  transition: background-color var(--transition);
}

.app-footer p { margin: 2px 0; }

/* ---- Bottom Navigation (Mobile) ---- */
.bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 150;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  height: 56px;
  padding-bottom: env(safe-area-inset-bottom, 0);
}

.bottom-nav-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  border: none;
  background: transparent;
  color: var(--color-text-muted);
  font-size: 0.68rem;
  cursor: pointer;
  padding: 4px 0;
  transition: color var(--transition);
}

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

.bottom-nav-active {
  color: var(--color-primary);
  font-weight: 600;
}

.bottom-nav-icon { font-size: 1.2rem; line-height: 1; }
.bottom-nav-label { line-height: 1; }

/* ---- Responsive ---- */
@media (max-width: 767px) {
  .header-title { font-size: 1.1rem; }
  .header-subtitle { font-size: 0.7rem; display: none; }
  .header-left { gap: 8px; }
  .header-logo { font-size: 26px; }
  .app-header { padding: 0 12px; }

  .panel { padding: 12px; padding-bottom: 72px; }
  .tab-btn { padding: 10px 14px; font-size: 0.88rem; }

  .form-row {
    grid-template-columns: 1fr 1fr;
  }

  .toast {
    max-width: calc(100vw - 48px);
    bottom: 72px;
  }

  .semester-selector {
    padding: 0 4px 0 0;
    border-right: none;
    margin-right: 0;
    gap: 4px;
  }

  .semester-select {
    max-width: 140px;
    font-size: 0.72rem;
    padding: 3px 4px;
  }

  .current-semester-label {
    font-size: 0.7rem;
    padding: 2px 4px;
  }

  #btn-confirm-semester {
    font-size: 0.72rem;
    padding: 4px 8px;
  }

  /* Bottom nav visible */
  .bottom-nav {
    display: flex;
  }

  /* Hide top tab buttons on mobile (keep semester selector visible) */
  .main-tabs .tab-btn {
    display: none;
  }

  .main-tabs {
    padding: 0 8px;
  }

  /* PWA install banner adjust */
  .pwa-install-banner {
    bottom: 72px;
  }

  /* Modal adjust for bottom nav */
  .modal-content {
    max-height: calc(85vh - 56px);
  }
}

@media (min-width: 768px) and (max-width: 1023px) {
  .panel { padding: 16px; }
}

@media (min-width: 1024px) {
  .panel { padding: 24px 20px; }
}

/* ---- Print ---- */
@media print {
  @page { margin: 15mm; size: A4; }

  body {
    background: #fff !important;
    color: #000 !important;
    font-size: 11pt;
  }

  .app-header,
  .main-tabs,
  .app-footer,
  #theme-toggle,
  #btn-print,
  #plan-reset-actions,
  .timetable-toolbar,
  #timetable-timeslots,
  #course-modal,
  #toast-container,
  .btn-icon,
  .btn,
  .plan-reset-actions {
    display: none !important;
  }

  .panel {
    max-width: 100%;
    padding: 0;
  }

  .panel.hidden { display: block !important; }

  .card, .stat-card {
    box-shadow: none !important;
    border: 1px solid #ccc !important;
    page-break-inside: avoid;
  }

  .timetable-grid {
    font-size: 9pt;
  }

  a { color: #000 !important; }
}