.clearfix{*zoom:1}.clearfix:before,.clearfix:after{display:table;content:""}.clearfix:after{clear:both}.vertical-shadow{border:1px solid #ccc;border-bottom:1px solid #aaa;box-shadow:0 1px 3px #ccc}a.big-button:link,a.big-button:visited{text-decoration:none;color:inherit;display:inline-block}a.big-button:focus>div,a.big-button:hover>div,a.big-button:active>div{box-shadow:0 0 4px 0 #aaa}@-webkit-keyframes move-center-to-ur{85%{-webkit-transform:translate(510px,-202px);-ms-transform:translate(510px,-202px);transform:translate(510px,-202px)}100%{-webkit-transform:translate(510px,-202px);-ms-transform:translate(510px,-202px);transform:translate(510px,-202px)}}@-webkit-keyframes shrink-right-and-fade{85%{opacity:15 / 100;filter:alpha(opacity=15);-webkit-transform:scale(0.1);-ms-transform:scale(0.1);transform:scale(0.1)}100%{opacity:0 / 100;filter:alpha(opacity=0);-webkit-transform:scale(0.1);-ms-transform:scale(0.1);transform:scale(0.1)}}@-webkit-keyframes fly-in-leaf{0%{-webkit-transform:scale(8);-ms-transform:scale(8);transform:scale(8);opacity:0 / 100;filter:alpha(opacity=0)}66%{-webkit-transform:scale(1);-ms-transform:scale(1);transform:scale(1);opacity:17 / 100;filter:alpha(opacity=17)}100%{-webkit-transform:scale(1);-ms-transform:scale(1);transform:scale(1);opacity:100 / 100;filter:alpha(opacity=100)}}@-webkit-keyframes progress-bar{0%{width:0;opacity:60 / 100;filter:alpha(opacity=60)}}@-webkit-keyframes progress-bar-proficient{0%{opacity:0 / 100;filter:alpha(opacity=0)}66%{opacity:0 / 100;filter:alpha(opacity=0)}}.stack .card-container.into-pocket,.stack .card-container.into-pocket .card-container-inner{-webkit-animation-duration:.55s;-webkit-animation-timing-function:linear;-webkit-animation-fill-mode:forwards;-moz-animation-duration:.55s;-moz-animation-timing-function:linear;-moz-animation-fill-mode:forwards;-ms-animation-duration:.55s;-ms-animation-timing-function:linear;-ms-animation-fill-mode:forwards}.half-circle-arc 0{-webkit-transform:rotate(0deg) translateX(70px) rotate(0deg) translateX(-70px);-moz-transform:rotate(0deg) translateX(70px) rotate(0deg) translateX(-70px);-ms-transform:rotate(0deg) translateX(70px) rotate(0deg) translateX(-70px)}.half-circle-arc 100%{-webkit-transform:rotate(-180deg) translateX(70px) rotate(180deg) translateX(-70px);-moz-transform:rotate(-180deg) translateX(70px) rotate(180deg) translateX(-70px);-ms-transform:rotate(-180deg) translateX(70px) rotate(180deg) translateX(-70px)}@-webkit-keyframes card-up-down{0%{-webkit-transform:rotate(0deg) translateX(70px) rotate(0deg) translateX(-70px);-moz-transform:rotate(0deg) translateX(70px) rotate(0deg) translateX(-70px);-ms-transform:rotate(0deg) translateX(70px) rotate(0deg) translateX(-70px)}100%{-webkit-transform:rotate(-180deg) translateX(70px) rotate(180deg) translateX(-70px);-moz-transform:rotate(-180deg) translateX(70px) rotate(180deg) translateX(-70px);-ms-transform:rotate(-180deg) translateX(70px) rotate(180deg) translateX(-70px)}}.stack .card-container.into-pocket{-webkit-animation-name:card-up-down;-moz-animation-name:card-up-down;-ms-animation-name:card-up-down}@-webkit-keyframes card-left-right-0{100%{-webkit-transform:translate(-515px,45px);-ms-transform:translate(-515px,45px);transform:translate(-515px,45px)}}@-webkit-keyframes card-left-right-1{100%{-webkit-transform:translate(-487px,28px);-ms-transform:translate(-487px,28px);transform:translate(-487px,28px)}}@-webkit-keyframes card-left-right-2{100%{-webkit-transform:translate(-459px,-6px);-ms-transform:translate(-459px,-6px);transform:translate(-459px,-6px)}}@-webkit-keyframes card-left-right-3{100%{-webkit-transform:translate(-431px,-24px);-ms-transform:translate(-431px,-24px);transform:translate(-431px,-24px)}}@-webkit-keyframes card-left-right-4{100%{-webkit-transform:translate(-403px,-41px);-ms-transform:translate(-403px,-41px);transform:translate(-403px,-41px)}}@-webkit-keyframes card-left-right-5{100%{-webkit-transform:translate(-375px,-65px);-ms-transform:translate(-375px,-65px);transform:translate(-375px,-65px)}}@-webkit-keyframes card-left-right-6{100%{-webkit-transform:translate(-347px,-80px);-ms-transform:translate(-347px,-80px);transform:translate(-347px,-80px)}}@-webkit-keyframes card-left-right-7{100%{-webkit-transform:translate(-319px,-108px);-ms-transform:translate(-319px,-108px);transform:translate(-319px,-108px)}}.stack .card-container.into-pocket-0 .card-container-inner{-webkit-animation-name:card-left-right-0;-moz-animation-name:card-left-right-0}.stack .card-container.into-pocket-1 .card-container-inner{-webkit-animation-name:card-left-right-1;-moz-animation-name:card-left-right-1}.stack .card-container.into-pocket-2 .card-container-inner{-webkit-animation-name:card-left-right-2;-moz-animation-name:card-left-right-2}.stack .card-container.into-pocket-3 .card-container-inner{-webkit-animation-name:card-left-right-3;-moz-animation-name:card-left-right-3}.stack .card-container.into-pocket-4 .card-container-inner{-webkit-animation-name:card-left-right-4;-moz-animation-name:card-left-right-4}.stack .card-container.into-pocket-5 .card-container-inner{-webkit-animation-name:card-left-right-5;-moz-animation-name:card-left-right-5}.stack .card-container.into-pocket-6 .card-container-inner{-webkit-animation-name:card-left-right-6;-moz-animation-name:card-left-right-6}.stack .card-container.into-pocket-7 .card-container-inner{-webkit-animation-name:card-left-right-7;-moz-animation-name:card-left-right-7}@-webkit-keyframes rocketBounce{0%,20%,53%,80%,to{-webkit-animation-timing-function:cubic-bezier(0.215,0.61,0.355,1);-webkit-transform:translate(-50%,0);animation-timing-function:cubic-bezier(0.215,0.61,0.355,1);transform:translate(-50%,0)}40%,43%{-webkit-animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);-webkit-transform:translate(-50%,-30px);animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);transform:translate(-50%,-30px)}70%{-webkit-animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);-webkit-transform:translate(-50%,-15px);animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);transform:translate(-50%,-15px)}90%{-webkit-transform:translate(-50%,-4px);transform:translate(-50%,-4px)}}@keyframes rocketBounce{0%,20%,53%,80%,to{-webkit-animation-timing-function:cubic-bezier(0.215,0.61,0.355,1);-webkit-transform:translate(-50%,0);animation-timing-function:cubic-bezier(0.215,0.61,0.355,1);transform:translate(-50%,0)}40%,43%{-webkit-animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);-webkit-transform:translate(-50%,-30px);animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);transform:translate(-50%,-30px)}70%{-webkit-animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);-webkit-transform:translate(-50%,-15px);animation-timing-function:cubic-bezier(0.755,0.05,0.855,0.06);transform:translate(-50%,-15px)}90%{-webkit-transform:translate(-50%,-4px);transform:translate(-50%,-4px)}}.rocketBounce{-webkit-animation-name:rocketBounce;animation-name:rocketBounce}@media screen and (max-width:450px){.exercises-header{-webkit-transition:all 400ms ease-in-out;-webkit-transition:all .4s ease-in-out;transition:all .4s ease-in-out;width:100%;z-index:1011;background-color:white}}.exercises-header.exercises-header-fixed{position:fixed;top:-64px}#exercise-title{position:relative}#exercise-title #goback{display:none}@media screen and (max-width:1023px){#exercise-title #goback{position:absolute;display:block;left:15px;top:50%;-webkit-transform:translate(0,-50%);-ms-transform:translate(0,-50%);transform:translate(0,-50%);cursor:pointer;color:#4a90e2;font-size:30px}}@media screen and (max-width:1023px){#exercise-title{width:100%}#exercise-title .h3.section-headline{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;margin-bottom:auto}}#problem-history-block #problem-history-wrapper{position:relative;background-color:#2f435b;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;width:100%;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;height:64px;padding:15px;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between}@media screen and (max-width:450px){#problem-history-block #problem-history-wrapper{padding:15px 0 15px 10px}#problem-history-block #problem-history-wrapper.exam-or-custom-exam{padding:15px 10px 15px 10px}}#problem-history-block #problem-history.exercise{position:relative;height:40px;border-radius:61px;box-shadow:inset 0 1px 3px 0 rgba(0,0,0,0.5);background-color:#f6f6f6}#problem-history-block #problem-history.exercise>.problem-history-icon:first-child{position:absolute;left:-38px;top:1px;opacity:0}#problem-history-block #problem-history.exercise>.problem-history-icon:first-child.active{opacity:1}@media screen and (max-width:450px){#problem-history-block #problem-history.exercise>.problem-history-icon:first-child{top:5px;left:-32px}}#problem-history-block #problem-history-scroller{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;border-radius:61px;box-shadow:inset 0 1px 3px 0 rgba(0,0,0,0.5);background-color:#f6f6f6;padding:0 10px}#problem-history-block #problem-history-scroller .fa{font-size:24px;color:gray;margin:0 4px;cursor:pointer;-webkit-transition:all .5s ease-in-out;transition:all .5s ease-in-out}#problem-history-block #problem-history-scroller #problem-history.exam{position:relative;overflow:hidden;width:266px;height:37px;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}@media screen and (max-width:450px){#problem-history-block #problem-history-scroller #problem-history.exam{width:224px}}@media screen and (min-width:421px) and (max-width:465px){#problem-history-block #problem-history-scroller #problem-history.exam{width:224px}}#problem-history-block #problem-history-scroller #problem-history.exam.exam-or-custom-exam{width:380px}@media screen and (max-width:1023px){#problem-history-block #problem-history-scroller #problem-history.exam.exam-or-custom-exam{width:190px}}#problem-history-block #problem-history-scroller #problem-history.exam .no-transition{-webkit-transition:none!important;transition:none!important}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container{-webkit-flex-wrap:nowrap;-ms-flex-wrap:nowrap;flex-wrap:nowrap;padding:0;border-radius:0;background-color:transparent;-webkit-transition:all .5s ease-in-out;transition:all .5s ease-in-out}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .relative{position:relative}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .pointer{cursor:pointer}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .postponed-image{position:absolute;left:0;top:0;width:30px;height:30px;-webkit-transition:opacity .5s;transition:opacity .5s}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .postponed-image:hover{opacity:0}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon{-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;margin:4px;border-radius:15px;-webkit-transform:scale(0.5);-ms-transform:scale(0.5);transform:scale(0.5)}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon.done{background-color:#4a90e2}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon.done.current{-webkit-transform:scale(1);-ms-transform:scale(1);transform:scale(1);text-align:center;color:white;font-weight:100;line-height:2}@media screen and (max-width:450px){#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon.done.current{line-height:1.7}}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon.blank{background-color:#d2d2d2}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon.exam-or-custom-exam{-webkit-transform:scale(1);-ms-transform:scale(1);transform:scale(1);text-align:center;color:white;font-weight:100;line-height:2}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon.exam-or-custom-exam.done{background-color:#c5d8f1}#problem-history-block #problem-history-scroller #problem-history.exam #problem-history-container .problem-history-icon.exam-or-custom-exam.done.current{line-height:2;background-color:#4a90e2}#problem-history-block .problem-history-icon{width:30px;height:30px;position:relative;margin:4px;-webkit-transition:all .7s ease-in-out;transition:all .7s ease-in-out}#problem-history-block .problem-history-icon.active{-webkit-transform:translate(38px);-ms-transform:translate(38px);transform:translate(38px)}@media screen and (max-width:450px){#problem-history-block .problem-history-icon{width:24px;height:24px}#problem-history-block .problem-history-icon.active{-webkit-transform:translate(32px);-ms-transform:translate(32px);transform:translate(32px)}}@media screen and (min-width:421px) and (max-width:465px){#problem-history-block .problem-history-icon{width:24px;height:24px}#problem-history-block .problem-history-icon.active{-webkit-transform:translate(32px);-ms-transform:translate(32px);transform:translate(32px)}}#problem-history-block .problem-history-icon.exam-or-custom-exam{width:30px;height:30px}#problem-history-block .problem-history-icon.exam-or-custom-exam.active{-webkit-transform:translate(38px);-ms-transform:translate(38px);transform:translate(38px)}#problem-history-block .h3.section-headline .taller{font-size:27px}#problem-history-block .h3.section-headline .thick{font-weight:400}#problem-history-block .h3.section-headline.exercise{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}#problem-history-block .h3.section-headline.exercise p{color:white;font-size:14px;font-weight:100;letter-spacing:1.3px}@media screen and (max-width:529px){#problem-history-block .h3.section-headline.exercise p{color:#636363;font-weight:200;letter-spacing:normal}}#problem-history-block .h3.section-headline.exercise .problem-history-icon{width:21px;height:21px}@media screen and (max-width:529px){#problem-history-block .h3.section-headline.exercise{z-index:5;position:absolute;right:10px;bottom:-40px;background:white;padding:8px;margin:0;box-shadow:0 2px 4px 0 rgba(0,0,0,0.5);-webkit-transition:all .25s ease-in-out;transition:all .25s ease-in-out;-webkit-transform:translateY(50%);-ms-transform:translateY(50%);transform:translateY(50%);opacity:0;pointer-events:none}#problem-history-block .h3.section-headline.exercise:before{content:'';width:0;height:0;border-left:12px solid transparent;border-right:12px solid transparent;border-bottom:15px solid white;position:absolute;top:-15px;right:19px}}@media screen and (max-width:450px) and (min-width:401px){#problem-history-block .h3.section-headline.exercise{right:4px}#problem-history-block .h3.section-headline.exercise:before{right:4px}}@media screen and (max-width:340px){#problem-history-block .h3.section-headline.exercise{right:4px}#problem-history-block .h3.section-headline.exercise:before{right:4px}}#problem-history-block .h3.section-headline.exam p{color:white;font-weight:100;font-size:16px;padding-bottom:10px}@media screen and (max-width:383px){#problem-history-block .h3.section-headline.exam p{padding-bottom:0}}@media screen and (min-width:421px) and (max-width:465px){#problem-history-block .h3.section-headline.exam p{padding-bottom:0}}#problem-history-block .info{background:white;height:15px;width:14px;margin-right:20px}#problem-history-block .info i{font-size:24px;color:#778391;-webkit-transform:translate(-3px,-5px);-ms-transform:translate(-3px,-5px);transform:translate(-3px,-5px)}@media screen and (min-width:530px){#problem-history-block .info{display:none}}@media screen and (max-width:450px) and (min-width:401px){#problem-history-block .info{margin-right:0}}@media screen and (max-width:340px){#problem-history-block .info{margin-right:10px}}#problem-history-block .info:hover+h3.section-headline{-webkit-transform:translateY(0);-ms-transform:translateY(0);transform:translateY(0);opacity:1}@media screen and (max-width:450px){.content-pane-exercise .toggle-nav-btn{display:none}h3 .skill-progress{display:none}#exercise-title{width:100%;text-align:center}.content-pane-exercise>div{padding:0!important}.topic-exercise-title{font-size:16px;color:#3d3d3d;font-weight:600;max-width:250px;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}#recommend_action-row{display:none}footer{display:none}}@media screen and (min-width:450px) and (max-width:1023px){footer{display:none}}@media screen and (min-width:450px){.topic-exercise-title{font-size:20px}}.exercise-color.inactive{opacity:.3}.rocket-pic-container{text-align:center}img.rocket-pic{z-index:1;width:100%;max-width:80px}.arrow_box{border-radius:1em;position:relative;background:#88b7d5;padding:10px}.arrow_box:after{right:100%;top:50%;border:solid transparent;content:' ';height:0;width:0;position:absolute;pointer-events:none}.arrow_box:after{border-color:rgba(136,183,213,0);border-right-color:#88b7d5;border-width:10px;margin-top:-10px}.level-box{padding:5px;border-radius:5px}.card-header h6{color:#618c84}.card-header h6 .end-of-stack-title{color:white;text-shadow:lightblue 0 0 20px}.card-content{margin:20px}.skill-status-container{margin:20px}.skill-status-container .problem-history-icon{width:37px;height:37px}.card-type-endofreview .exercise-instruction{top:100px}.card-type-endofreview .card-content{height:350px}.stack{min-height:100px;margin-bottom:10px}.current-card-container{position:relative}.card-type-endofstack .current-card-container-inner{background-color:#e9efdd;position:relative;overflow:hidden;height:70vh}.card-type-endofreview .current-card-container-inner{background-color:#e9efdd}.card-type-endofexam .current-card-container-inner{background-color:#e9efdd;position:relative;min-height:70vh}.current-card.notransition .current-card-container,.current-card.notransition .current-card-container-inner,.current-card.shrinkRight .leaves .leaf.earned .full-leaf{-webkit-transition:none;transition:none;-webkit-animation:none;animation:none}.current-card.shrinkRight .current-card-container{-webkit-animation:move-center-to-ur .18s ease-in-out 0s 1 forwards normal;animation:move-center-to-ur .18s ease-in-out 0s 1 forwards normal}.current-card.shrinkRight .current-card-container-inner{-webkit-animation:shrink-right-and-fade .18s ease-in-out 0s 1 forwards normal;animation:shrink-right-and-fade .18s ease-in-out 0s 1 forwards normal}.current-card.shrinkLeft .current-card-container{-webkit-transform:translate(-510px,-202px);-ms-transform:translate(-510px,-202px);transform:translate(-510px,-202px)}.current-card.shrinkLeft .current-card-container-inner{-webkit-transform:scale(0.1);-ms-transform:scale(0.1);transform:scale(0.1);opacity:0 / 100;filter:alpha(opacity=0)}.current-card.shrinkRight #extras,.card-type-endofstack #extras,.card-type-happypicture #extras,.card-type-endofreview #extras,.card-type-endofexam #extras{visibility:hidden}.card-type-endofstack .stack .card{width:25px;height:40px;border:1px solid #bbb;margin:0 auto;-webkit-transition:all .18s ease-in-out;transition:all .18s ease-in-out;box-shadow:0 0 3px #ccc}.stack .card-container{position:relative;margin-bottom:-20px;-webkit-transform:rotate(-20deg);-ms-transform:rotate(-20deg);transform:rotate(-20deg);z-index:1}.lte8 .stack .card-container{filter:progid:DXImageTransform.Microsoft.Matrix(M11=0.9396926207859084,M12=0.3420201433256687,M21=-0.3420201433256687,M22=0.9396926207859084,sizingMethod='auto expand');zoom:1}.stack .card .card-face{position:absolute;width:25px;height:40px}.stack .card-face.card-front{background:#f7f7f7}.stack .card-face.card-back{color:white;text-align:center;background-color:#aaa}.stack .card-face.card-back{box-shadow:inset 0 0 0 2px #fff,inset 0 0 0 4px #cfcfcf;background-color:#ccc}.stack .card-container:last-child .card-face.card-back,.stack .card-container.end-of-stack-card .card-face.card-back{background-color:#e9efdd;box-shadow:inset 0 0 0 2px white,inset 0 0 0 4px #e9efdd}.exercises-stack,.exercises-card{float:left;width:7%;box-sizing:border-box}.exercises-card{width:100%}.exercises-card.current-card{position:initial}.current-card{position:relative;margin-bottom:20px}.current-card #answer_area .info-box{overflow:visible}.current-card .info-box:before{content:' ';display:block;border-right:7px solid transparent;border-bottom:8px solid #ccc;width:0;height:15px;position:absolute;right:-1px;top:-16px}.current-card .exercise_message{display:none}.leaves-container{margin:8px 0 0 15px;overflow:visible;position:absolute;right:10px;display:none}.card-type-problem .leaves-container{display:block}.qtip.ui-tooltip.leaf-tooltip{max-width:200px!important}.current-card .leaves .leaf{background:transparent url(/images/power-mode/card-leaf-empty-large.png) no-repeat 50% 0;background-size:40px 40px;float:left;color:transparent;width:40px;height:40px;margin-right:35px}.lte8 .current-card .leaves .leaf{background:transparent url(/images/power-mode/card-leaf-empty-small.png) no-repeat 50% 0}.stack .leaves .leaf{width:5px;height:5px;margin:2px 0 0 2px;float:left;background:#83a600;color:transparent;border:1px solid #a7b36b;position:relative;line-height:25px;text-align:center;-webkit-border-top-right-radius:50px;-webkit-border-bottom-right-radius:15px;-webkit-border-bottom-left-radius:50px;-webkit-border-top-left-radius:10px;-moz-border-radius-topright:50px;-moz-border-radius-bottomright:15px;-moz-border-radius-bottomleft:50px;-moz-border-radius-topleft:10px;border-top-right-radius:50px;border-bottom-right-radius:15px;border-bottom-left-radius:50px;border-top-left-radius:10px;background-clip:padding-box;box-sizing:border-box;box-shadow:inset 0 0 9px 1px rgba(0,0,0,0.25)}.leaves .leaf.unavailable{background-color:transparent}.leaves .leaf.earned .full-leaf{background:url(/images/power-mode/card-leaf-full-large.png) no-repeat;background-size:40px 40px;opacity:0;-moz-opacity:0;-webkit-transform:scale(8);-ms-transform:scale(8);transform:scale(8);-webkit-transition:all .18s ease-in-out;transition:all .18s ease-in-out;width:40px;height:40px;margin:0 auto}.lte8 .leaves .leaf.earned .full-leaf{background:url(/images/power-mode/card-leaf-full-small.png) no-repeat 50% 0}.leaves .leaf.earned .full-leaf.animated{-webkit-animation:fly-in-leaf .3s ease-out 0s 1 none normal;animation:fly-in-leaf .3s ease-out 0s 1 none normal;-webkit-transform:scale(1);-ms-transform:scale(1);transform:scale(1);opacity:1;-moz-opacity:1}.stack .leaves .leaf.earned{background:#83a600;border-color:#5a7300;color:transparent;box-shadow:none}.stack .leaves .leaf.unavailable{opacity:50 / 100;filter:alpha(opacity=50)}.stack .leaves .full-leaf{display:none}.card-type-endofstack .current-card-contents,.card-type-endofreview .current-card-contents,.card-type-endofexam .current-card-contents{padding:20px}.current-card #problemarea{margin-top:45px}#footer{-webkit-transform:translateZ(0)}.calculating-end-of-stack{padding:50px;height:70px;text-align:center}.calculating-end-of-stack .card-pocket{width:530px;margin-left:auto;margin-right:auto;position:relative;z-index:2}.calculating-end-of-stack .card-pocket .slit-overlay{background:transparent;height:0;position:relative;top:-17px}.calculating-end-of-stack .calc-text-spin{position:relative;line-height:40vh;top:-15px}.calculating-end-of-stack .calc-text-spin span{display:none}.calculating-end-of-stack .throbber{position:relative;top:-5px}.skill-status-container.container,.end-of-stack-info.container{width:100%}.skill-status-container.container .rocket-pic-with-smoke,.end-of-stack-info.container .rocket-pic-with-smoke{-webkit-transition:all .5s cubic-bezier(0.02,0.01,0.47,1);transition:all .5s cubic-bezier(0.02,0.01,0.47,1)}.skill-status-container.container .start-level,.end-of-stack-info.container .start-level{-webkit-transition:all 2.5s cubic-bezier(0.02,0.01,0.47,1) .5s;transition:all 2.5s cubic-bezier(0.02,0.01,0.47,1) .5s;left:50%;-webkit-transform:translate(-50%);-ms-transform:translate(-50%);transform:translate(-50%)}.skill-status-container.container .current-level,.end-of-stack-info.container .current-level{-webkit-transition:all 2.5s cubic-bezier(0.02,0.01,0.47,1) .5s;transition:all 2.5s cubic-bezier(0.02,0.01,0.47,1) .5s;left:50%;-webkit-transform:translate(-50%);-ms-transform:translate(-50%);transform:translate(-50%)}.skill-status-container.container .next-level,.end-of-stack-info.container .next-level{-webkit-transition:all 2.5s cubic-bezier(0.02,0.01,0.47,1) .5s;transition:all 2.5s cubic-bezier(0.02,0.01,0.47,1) .5s;left:50%;-webkit-transform:translate(-50%);-ms-transform:translate(-50%);transform:translate(-50%)}.end-of-stack-info .title h1{float:left}.end-of-stack-info .stack-controls .simple-button{padding:8px 0;display:inline-block;font-size:150%;text-align:center;width:48%;box-sizing:border-box}.end-of-stack-info .stack-controls .simple-button.one-third{padding:8px 0;display:inline-block;font-size:150%;text-align:center;width:32%;box-sizing:border-box}.end-of-stack-info .stack-controls .right{margin:0 0 0 2%}.end-of-stack-info .stack-controls .center{margin:0 2% 0 2%}.end-of-stack-info .stack-controls .left{margin:0 2% 0 0}.end-of-stack-info .stack-stats{float:right;margin-top:-8px}.end-of-stack-info .stack-stats p{display:inline-block;text-align:center;font-size:150%;margin:0;margin-left:40px}.end-of-stack-info .stack-stats img{height:38px;vertical-align:-11px}.end-of-stack-info .stack-stats .times{display:inline-block;margin:0 7px}.end-of-stack-info .progress-graph{background:white;padding:20px;border:1px solid #ccc;margin-bottom:22px}.end-of-stack-info .progress-graph.current-topic{display:none}.current-topic .skill-bar-title{margin:0 0 0 25px}.proficient-tick{vertical-align:-1px}.current-topic .skill-bar{height:5px}.current-stack .skill-bar .fill.green{-webkit-animation:progress-bar 1s;animation:progress-bar 1s}.current-stack .skill-bar .fill.blue.just-earned{-webkit-animation:progress-bar-proficient 1.5s;animation:progress-bar-proficient 1.5s}.current-topic .skill-bar .fill{-webkit-animation:none;-moz-animation:none}.dashboard-drawer .skill-bar .fill.gray,.current-topic .skill-bar .fill.gray{visibility:hidden}.current-topic .skill-bar .fill.blue,.current-topic .skill-bar .fill.orange{top:-10px!important}.three-col{float:left;width:32%;box-sizing:border-box}.three-col.col-one,.three-col.col-two{margin-right:2%}#show-topic-details{position:relative;top:-2px;margin-left:10px}.read-only .stack{visibility:hidden}.read-only .leaves-container{display:none}.exercises-content{padding-left:0;padding-right:0}.exercises-body{min-height:380px;-webkit-transition:all 250ms ease-in-out;-webkit-transition:all .25s ease-in-out;transition:all .25s ease-in-out}.exercises-header .section-headline .row{margin:auto;margin-bottom:10px}.exercises-header .topic-exercise-badge{width:7%}.exercises-header .topic-exercise-image{width:40px;height:40px}.exercises-header .row .topic-exercise-image{width:30px;height:30px;vertical-align:middle;display:inline-block}@media screen and (max-width:450px){.exercises-header .row .topic-exercise-image{width:20px;height:20px;background-size:cover;margin:-3px 5px 0}}.exercises-header .row .topic-exercise-image{background-position:center;background-repeat:no-repeat}.exercises-header .row .topic-exercise-image.level-0{background-image:url(/images/node-not-started-26.png)}.exercises-header .row .topic-exercise-image.level-1{background-image:url(/images/node-level-1-26.png)}.exercises-header .row .topic-exercise-image.level-2{background-image:url(/images/node-level-2-26.png)}.exercises-header .row .topic-exercise-image.level-3{background-image:url(/images/node-level-3-26.png)}.exercises-header .row .topic-exercise-image.level-4{background-image:url(/images/node-complete-26.png)}.exercises-header .row .topic-exercise-image.level-0.is-formative{background-image:url(/images/formative-assessment-26-not-started.png)}.exercises-header .row .topic-exercise-image.level-1.is-formative{background-image:url(/images/formative-assessment-26-level-1.png)}.exercises-header .row .topic-exercise-image.level-2.is-formative{background-image:url(/images/formative-assessment-26-level-2.png)}.exercises-header .row .topic-exercise-image.level-3.is-formative{background-image:url(/images/formative-assessment-26-level-3.png)}.exercises-header .row .topic-exercise-image.level-4.is-formative{background-image:url(/images/formative-assessment-26-complete.png)}.exercises-header .row .topic-exercise-title{vertical-align:middle;display:inline-block}.exercises-header .topic-exercise-image.inline{display:inline-block;margin:-50% 0}.exercises-header .practice-exercise-topic-context{-webkit-transition:opacity .1s ease-in-out;transition:opacity .1s ease-in-out;opacity:30 / 100;filter:alpha(opacity=30);-webkit-backface-visibility:hidden}.exercises-header .practice-exercise-topic-context.solid-hover:hover{opacity:100 / 100;filter:alpha(opacity=100)}.exercises-header .practice-exercise-topic-context .topic-exercise-badge{width:20px;height:20px;margin-right:2px}.exercises-header #problem-history{float:right;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.exercises-header #problem-history-container{float:right;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;border-radius:20px;filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#41A5D6',endColorstr='#4069C1',GradientType=1);background:#4a90e2;height:100%}.card-type-happypicture{text-align:center}.card-type-happypicture h4,.card-type-happypicture .img-container{margin:22px 0}.card-type-happypicture .happy-picture{margin-left:auto;margin-right:auto}.hover-disclosure{background:#f7f7f7;padding:0 10px;border-radius:50px;background-clip:padding-box;border:1px solid #ddd;color:#777;cursor:default;display:inline-block}.hover-disclosure:hover,.hover-discolsure.hover{background:#777;color:#fff;text-decoration:none}.review-explain{font-size:12px;position:relative;top:-3px}.card-content.practice-mode{height:50vh;position:relative}.card-content.practice-mode .skill-bar-title a{color:white;text-shadow:lightblue 0 0 20px}.card-content.practice-mode .skill-bar-title a:hover{color:#c7e5f7;text-shadow:#c7e5f7 0 0 10px}.card-content .rocket-pic-with-smoke,.card-content .rocket-pic-without-smoke{z-index:100;position:absolute;width:80px;height:auto}.card-content .level-planet-container{margin:auto;position:absolute}.card-content .level-planet{text-align:center;text-shadow:lightblue 0 0 20px;color:white;background-size:cover;height:0;padding:0;padding-bottom:100%}.card-content .level-planet-0{background-image:url(/images/end-of-stack-start-planet.svg)}.card-content .level-planet-1{background-image:url(/images/end-of-stack-level1-planet.svg)}.card-content .level-planet-2{background-image:url(/images/end-of-stack-level2-planet.svg)}.card-content .level-planet-3{background-image:url(/images/end-of-stack-level3-planet.svg)}.card-content .level-planet-4{background-image:url(/images/end-of-stack-proficient-planet.svg)}