Bootstrap 基础CSS - 按钮（Buttons）
默认按钮建议只在<a>和<button>标签上应用.btn。
Buttonclass=""DescriptionDefaultbtnStandard gray button with gradientPrimarybtn btn-primaryProvides extra visual weight and identifies the primary action in a set of buttonsInfobtn btn-infoUsed as an alternative to the default stylesSuccessbtn btn-successIndicates a successful or positive actionWarningbtn btn-warningIndicates caution should be taken with this actionDangerbtn btn-dangerIndicates a dangerous or potentially negative actionInversebtn btn-inverseAlternate dark gray button, not tied to a semantic action or useLinkbtn btn-linkDeemphasize a button by making it look like a link while maintaining button behavior
按钮大小可以通过以下类来控制按钮大小。

<button type="button" class="btn btn-large btn-primary disabled" disabled="disabled">Primary button</button><button type="button" class="btn btn-large" disabled>Button</button>