// 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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