html, body {
    height: 100%;
    width: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden; /* Отключаем прокрутку */
}

body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: #f0f0f0;
    font-family: 'Arial', sans-serif;
    box-sizing: border-box;
}

.container {
    text-align: center;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    width: 90%;
    max-width: 400px;
    margin-bottom: 60px;
}

.book-image {
    width: 100px;
    height: 100px;
}

h1, p {
    font-weight: bold;
    margin: 20px 0;
}

.btn-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin-top: 20px;
}

.btn {
    flex: 1 1 100%;
    padding: 15px;
    margin: 5px 0;
    background-color: #40a9ff;
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    text-align: center;
    font-weight: bold;
}

.btn:hover {
    background-color: #1890ff;
}

#question {
    font-size: 20px;
    margin-bottom: 20px;
}

#score {
    font-size: 18px;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgb(0,0,0);
    background-color: rgba(0,0,0,0.4);
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: white;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 300px;
    text-align: center;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.modal-content h2 {
    font-weight: bold;
}

.modal-content p {
    font-weight: bold;
    margin: 20px 0;
}

.bottom-nav {
    position: fixed;
    bottom: 0;
    width: 100%;
    background: white;
    box-shadow: 0 -1px 10px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: space-around;
    padding: 10px 0;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex: 1;
    text-align: center;
    color: #5f6368;
}

.nav-item.active {
    color: #40a9ff;
}

.nav-item svg, .nav-item img.nav-icon {
    width: 24px;
    height: 24px;
    margin-bottom: 5px;
}

.nav-item span {
    font-size: 12px;
    font-weight: bold;
}

.balance-info {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 20px;
}

#balance {
    font-size: 36px;
    font-weight: bold;
    margin-right: 10px;
}

.money-icon {
    width: 38px;
    height: 38px;
}

.ref-intro {
    font-size: 24px;
    font-weight: bold;
}

.testing {
    display: none;
    justify-content: center;
}