:root {
  --primary: #1a56db;
  --primary-dark: #1347b8;
  --bg: #f0f4f8;
  --card: #ffffff;
  --text: #1e293b;
  --muted: #64748b;
  --border: #e2e8f0;
  --danger: #dc2626;
  --success: #16a34a;
  --radius: 12px;
  --shadow: 0 4px 20px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei',
    sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

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

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

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

.btn-secondary {
  background: #e2e8f0;
  color: var(--text);
}

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

.btn-sm {
  padding: 6px 12px;
  font-size: 13px;
}

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

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.form-group label .required {
  color: var(--danger);
  margin-left: 2px;
}

.form-control {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 16px;
  background: #fff;
  transition: border-color 0.2s, box-shadow 0.2s;
  -webkit-appearance: none;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.15);
}

.toast {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(-80px);
  background: var(--text);
  color: #fff;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 14px;
  z-index: 9999;
  opacity: 0;
  transition: transform 0.3s, opacity 0.3s;
  pointer-events: none;
  max-width: 90%;
  text-align: center;
}

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

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

.toast.success {
  background: var(--success);
}

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 16px;
}

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

.modal {
  background: var(--card);
  border-radius: var(--radius);
  width: 100%;
  max-width: 520px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow);
}

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

.modal-header h3 {
  font-size: 18px;
}

.modal-close {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--muted);
  line-height: 1;
}

.modal-body {
  padding: 20px;
}

.modal-footer {
  padding: 16px 20px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 10px;
  justify-content: flex-end;
}