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

:root {
  --bg-primary: #1a1a2e;
  --bg-secondary: #16213e;
  --bg-card: #0f3460;
  --bg-input: #1a1a3e;
  --text-primary: #e0e0e0;
  --text-secondary: #a0a0b0;
  --text-muted: #6a6a7a;
  --accent: #00d2ff;
  --accent-hover: #00b8e6;
  --success: #00c853;
  --warning: #ffab00;
  --danger: #ff5252;
  --border: #2a2a4e;
  --radius: 8px;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  background: var(--bg-primary);
  color: var(--text-primary);
  -webkit-tap-highlight-color: transparent;
  overflow-x: hidden;
}

/* ========== App Shell ========== */
#app {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ========== Header ========== */
.header {
  background: var(--bg-secondary);
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
}

.header h1 {
  font-size: 18px;
  font-weight: 600;
  flex: 1;
}

.header .btn-back {
  background: none;
  border: none;
  color: var(--accent);
  font-size: 22px;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius);
}

.header .btn-back:active {
  background: var(--bg-card);
}

/* ========== Pages ========== */
.page {
  display: none;
  flex-direction: column;
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  padding-bottom: 80px;
}

.page.active {
  display: flex;
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border: none;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
  -webkit-user-select: none;
  user-select: none;
}

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

.btn-primary {
  background: var(--accent);
  color: #000;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-success {
  background: var(--success);
  color: #000;
}

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

.btn-block {
  width: 100%;
}

.btn-sm {
  padding: 8px 14px;
  font-size: 13px;
}

/* ========== Session List ========== */
.session-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  border: 1px solid var(--border);
  transition: border-color 0.15s;
}

.session-card:active {
  border-color: var(--accent);
}

.session-card .session-info {
  flex: 1;
}

.session-card .session-name {
  font-size: 15px;
  font-weight: 500;
  margin-bottom: 4px;
}

.session-card .session-meta {
  font-size: 12px;
  color: var(--text-secondary);
}

.session-card .session-count {
  background: var(--accent);
  color: #000;
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 12px;
}

.session-actions {
  display: flex;
  gap: 6px;
  align-items: center;
}

/* ========== Scanner ========== */
#scanner-container {
  width: 100%;
  aspect-ratio: 1;
  max-height: 350px;
  border-radius: var(--radius);
  overflow: hidden;
  background: #000;
  margin-bottom: 16px;
}

#scanner-container video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.scan-result {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
  border: 1px solid var(--accent);
  animation: fadeIn 0.3s ease;
}

.scan-result .field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.scan-result .field {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.scan-result .field-label {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.scan-result .field-value {
  font-size: 14px;
  font-weight: 500;
  color: var(--accent);
  word-break: break-all;
}

.scan-result .field-value.full-width {
  grid-column: 1 / -1;
}

/* ========== Form ========== */
.form-group {
  margin-bottom: 14px;
}

.form-group label {
  display: block;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 5px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 10px 12px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 15px;
  outline: none;
  transition: border-color 0.15s;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--accent);
}

.form-group textarea {
  resize: vertical;
  min-height: 60px;
}

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

/* ========== Record Table ========== */
.records-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.records-header h2 {
  font-size: 16px;
}

.record-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 12px 14px;
  margin-bottom: 8px;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
}

.record-card .record-index {
  font-size: 12px;
  color: var(--text-muted);
  min-width: 24px;
}

.record-card .record-body {
  flex: 1;
  min-width: 0;
}

.record-card .record-title {
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.record-card .record-subtitle {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 2px;
}

.record-card .record-actions {
  display: flex;
  gap: 4px;
}

.record-card .btn-icon {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 16px;
  padding: 4px;
  cursor: pointer;
  border-radius: 4px;
}

.record-card .btn-icon:active {
  background: var(--bg-primary);
}

.record-card .btn-icon.danger:active {
  color: var(--danger);
}

/* ========== Modal ========== */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 200;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.modal-overlay.active {
  display: flex;
}

.modal {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: 20px;
  width: 100%;
  max-width: 400px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal h3 {
  margin-bottom: 16px;
  font-size: 17px;
}

.modal .modal-actions {
  display: flex;
  gap: 10px;
  margin-top: 18px;
}

.modal .modal-actions .btn {
  flex: 1;
}

/* ========== Empty State ========== */
.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-muted);
}

.empty-state .empty-icon {
  font-size: 48px;
  margin-bottom: 12px;
}

.empty-state p {
  font-size: 14px;
}

/* ========== Toast ========== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: var(--success);
  color: #000;
  padding: 10px 24px;
  border-radius: 24px;
  font-size: 14px;
  font-weight: 500;
  z-index: 300;
  opacity: 0;
  transition: all 0.3s ease;
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

.toast.error {
  background: var(--danger);
  color: #fff;
}

/* ========== Animations ========== */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ========== FAB (扫码悬浮按钮) ========== */
.fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--accent);
  color: #000;
  border: none;
  font-size: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
  cursor: pointer;
  z-index: 50;
  transition: transform 0.15s;
}

.fab:active {
  transform: scale(0.92);
}

/* ========== Responsive ========== */
@media (min-width: 481px) {
  #app {
    border-left: 1px solid var(--border);
    border-right: 1px solid var(--border);
  }
}