// nvue下hover-class无效 
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$u-button-before-top:50% !default; 
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$u-button-before-left:50% !default; 
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$u-button-before-width:100% !default; 
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$u-button-before-height:100% !default; 
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$u-button-before-transform:translate(-50%, -50%) !default; 
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$u-button-before-opacity:0 !default; 
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$u-button-before-background-color:#000 !default; 
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$u-button-before-border-color:#000 !default; 
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$u-button-active-before-opacity:.15 !default; 
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$u-button-icon-margin-left:4px !default; 
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$u-button-plain-u-button-info-color:$u-info; 
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$u-button-plain-u-button-success-color:$u-success; 
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$u-button-plain-u-button-error-color:$u-error; 
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$u-button-plain-u-button-warning-color:$u-error; 
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.u-button { 
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    width: 100%; 
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    &__text { 
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        white-space: nowrap; 
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        line-height: 1; 
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    } 
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    &:before { 
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        position: absolute; 
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        top:$u-button-before-top; 
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        left:$u-button-before-left; 
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        width:$u-button-before-width; 
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        height:$u-button-before-height; 
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        border: inherit; 
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        border-radius: inherit; 
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        transform:$u-button-before-transform; 
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        opacity:$u-button-before-opacity; 
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        content: " "; 
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        background-color:$u-button-before-background-color; 
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        border-color:$u-button-before-border-color; 
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    } 
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    &--active { 
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        &:before { 
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            opacity: .15 
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        } 
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    } 
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    &__icon+&__text:not(:empty), 
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    &__loading-text { 
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        margin-left:$u-button-icon-margin-left; 
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    } 
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    &--plain { 
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        &.u-button--primary { 
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            color: $u-primary; 
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        } 
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    } 
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    &--plain { 
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        &.u-button--info { 
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            color:$u-button-plain-u-button-info-color; 
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        } 
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    } 
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    &--plain { 
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        &.u-button--success { 
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            color:$u-button-plain-u-button-success-color; 
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        } 
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    } 
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    &--plain { 
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        &.u-button--error { 
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            color:$u-button-plain-u-button-error-color; 
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        } 
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    } 
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    &--plain { 
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        &.u-button--warning { 
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            color:$u-button-plain-u-button-warning-color; 
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        } 
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    } 
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} 
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