☑️ Checkbox

<label class="checkbox-custom">
  <input type="checkbox" checked>
  <span class="checkbox-custom-mark"></span>
  <span class="checkbox-custom-label">I agree to terms</span>
</label>

.checkbox-custom {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  user-select: none;
}
.checkbox-custom input {
  display: none;
}
.checkbox-custom-mark {
  width: 22px;
  height: 22px;
  border: 2px solid #d0d0d0;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  flex-shrink: 0;
}
.checkbox-custom input:checked + .checkbox-custom-mark {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-color: transparent;
}
.checkbox-custom input:checked + .checkbox-custom-mark::after {
  content: '✓';
  color: white;
  font-size: 14px;
  font-weight: bold;
}
.checkbox-custom-label {
  font-size: 0.95rem;
  color: #1a1a2e;
}

<label class="checkbox-toggle">
  <input type="checkbox" checked>
  <span class="checkbox-toggle-slider"></span>
  <span class="checkbox-toggle-label">Enable notifications</span>
</label>

.checkbox-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  user-select: none;
}
.checkbox-toggle input {
  display: none;
}
.checkbox-toggle-slider {
  width: 44px;
  height: 24px;
  background: #d0d0d0;
  border-radius: 12px;
  position: relative;
  transition: all 0.3s ease;
  flex-shrink: 0;
}
.checkbox-toggle-slider::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  background: white;
  border-radius: 50%;
  transition: all 0.3s ease;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}
.checkbox-toggle input:checked + .checkbox-toggle-slider {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}
.checkbox-toggle input:checked + .checkbox-toggle-slider::after {
  left: 22px;
}
.checkbox-toggle-label {
  font-size: 0.95rem;
  color: #1a1a2e;
}

<label class="checkbox-desc">
  <input type="checkbox" checked>
  <span class="checkbox-desc-mark"></span>
  <div class="checkbox-desc-content">
    <div class="checkbox-desc-title">Subscribe to newsletter</div>
    <div class="checkbox-desc-text">Get weekly updates and offers</div>
  </div>
</label>

.checkbox-desc {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  cursor: pointer;
  user-select: none;
  padding: 1rem;
  border: 2px solid #e0e0e0;
  border-radius: 10px;
  transition: all 0.3s ease;
  width: 280px;
}
.checkbox-desc:hover {
  border-color: #667eea;
}
.checkbox-desc input {
  display: none;
}
.checkbox-desc-mark {
  width: 22px;
  height: 22px;
  border: 2px solid #d0d0d0;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  flex-shrink: 0;
  margin-top: 2px;
}
.checkbox-desc input:checked + .checkbox-desc-mark {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-color: transparent;
}
.checkbox-desc input:checked + .checkbox-desc-mark::after {
  content: '✓';
  color: white;
  font-size: 14px;
  font-weight: bold;
}
.checkbox-desc-content {
  flex: 1;
}
.checkbox-desc-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: #1a1a2e;
  margin-bottom: 0.25rem;
}
.checkbox-desc-text {
  font-size: 0.8rem;
  color: #666;
}