body {
    background-image: url(./fond.jpg);
    background-size: cover;
    color: #f1f1f1;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin:0;
    overflow: hidden;
}
h1 {
    font-size: 26px;
    margin: 0;
}
ul {
    padding-left: 0;
    margin: 10px 0;
    margin-left: 20px;

}

header {
    display: flex;
    justify-content: space-between;
    box-sizing: border-box;
    padding: 10px 30px;
    background-color: rgba(24, 24, 24, 0.4);
}
header span {
    margin: 0 10px;
    font-size: 26px;
}
#left-header {
    display: flex;
    align-items: center;
}
#left-header img {
    position: absolute;
    z-index: 5;
    width: 50px;
    /* cursor: pointer; */
    background-color: cornflowerblue;
    border: 10px solid cornflowerblue;
    border-radius: 50%;
}
#left-header h1 {
    margin-left: 80px;
}

#right-header {
    display: flex;
    align-items: center;
    justify-content: right;
}
#right-header img {
    position: absolute;
    z-index: 5;
    width: 50px;
    background-color: cornflowerblue;
    border: 10px solid cornflowerblue;
    border-radius: 50%;
}
#right-header h1 {
    margin-right: 80px;
}
#menu {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 4;
    padding: 30px;
    padding-top: 50px;
    box-sizing: border-box;
    max-width: 85vw;
    background-color: rgb(41, 41, 41);
    font-size: 20px;
    border-radius: 20px;
    border-top-left-radius: 0;
    transition: 200ms;
}
#menu li {
    padding: 5px 0;
    cursor: pointer;
}
#menu li:hover {
    text-decoration: underline;
}

#flashcard-container {
    width: 100vw;
    height: 100vh;
}
#flashcard {
    position: absolute;
    left: 50%;
    top: 30%;
    width: 80%;
    z-index: 2;
    transform: translate(-50%);
    transform-style: preserve-3d;

    background-color: rgba(41, 41, 41, 0.8);
    border-radius: 20px;
    font-size: 24px;
    padding: 50px 0;
    box-sizing: border-box;
    text-align: center;
    user-select: none;
    transition: opacity 750ms, transform 200ms;
}

#flashcard.is-flipped {
    transform: rotateX(180deg) translate(-50%);
}
#answer {
    transform: rotateX(180deg);
}

#flashcard a {
    display: block;
    margin: auto;
    width: 30%;
}
#flashcard img {
    max-width: 300px;
    max-height: 200px;
}

.side-indicators {
    display: flex;
    justify-content: space-between;
    box-sizing: border-box;
    padding: 20px 0;
    
}
#false {
    padding:10px;
    margin:10px;
    width: 35px;
    font-size: 15px;
    text-align: center;
    border-radius: 20px;
    border: 5px solid red;
    color: red;
}
#correct {
    padding:10px;
    margin:10px;
    width: 35px;
    font-size: 15px;
    text-align: center;
    border-radius: 20px;
    border: 5px solid green;
    color: green;
}
#progress-div {
    display: block;
    text-align: center;
    color: black;
}
#progress-bar {
    display: block;
    margin: auto;
    height: 5px;
    width: calc(100vw - (35px + 10px + 10px)*2 - 100px);
    background-color: #f1f1f1;
    box-sizing: border-box;
    border: 0px solid rgb(41, 41, 41);
}
footer {
    position: absolute;
    bottom: 0;
    z-index: 0;
    text-align: center;
    width: 100%;
    padding-top:20px;
    background-color: rgba(24, 24, 24, 0.4);
}

#overlay {
    position: absolute;
    top:0;
    width: 100vw;
    height: 100vh;
    z-index: 3;
    background-color: rgba(0, 0, 0, 0.7);
}