.page-header {
    background: #ffffff;
    padding: 18px 16px;
    display: flex;
    align-items: center;
    gap: 13px;
    border-bottom: 1px solid #eceef5;
}

.back-button {
    width: 42px;
    height: 42px;
    border-radius: 13px;
    background: #f0f1ff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    color: #5555c9;
}

.page-title {
    flex: 1;
}

.page-title h1 {
    font-size: 19px;
    margin-bottom: 4px;
}

.page-title p {
    color: #85899b;
    font-size: 12px;
}

.header-book {
    width: 42px;
    height: 42px;
    border-radius: 13px;
    background: #f0f1ff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 21px;
}


/* Content */

.subjects-content {
    padding: 20px 16px;
}


/* Intro */

.subject-intro {
    display: flex;
    align-items: center;
    gap: 13px;
    background: #ffffff;
    padding: 16px;
    border-radius: 18px;
    margin-bottom: 20px;
    border: 1px solid #eceef5;
}

.subject-intro > span {
    width: 46px;
    height: 46px;
    border-radius: 14px;
    background: #eeeeff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 23px;
}

.subject-intro h2 {
    font-size: 16px;
    margin-bottom: 4px;
}

.subject-intro p {
    font-size: 12px;
    color: #85899b;
}


/* Subject Grid */

.subject-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 13px;
}


/* Subject Card */

.subject-card {
    background: #ffffff;
    border-radius: 21px;
    padding: 17px;
    border: 1px solid #eceef5;
    min-height: 155px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: transform .15s ease;
}

.subject-card:active {
    transform: scale(.97);
}


.subject-icon {
    width: 52px;
    height: 52px;
    border-radius: 16px;
    background: #f0f1ff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
}


.subject-info h3 {
    font-size: 15px;
    margin-bottom: 7px;
}


.subject-info span {
    font-size: 11px;
    color: #5b5bd6;
}


/* Empty */

.subject-empty {
    grid-column: 1 / -1;
    background: #ffffff;
    border-radius: 20px;
    padding: 45px 20px;
    text-align: center;
    border: 1px solid #eceef5;
}

.subject-empty div {
    font-size: 42px;
    margin-bottom: 12px;
}

.subject-empty h3 {
    font-size: 16px;
    margin-bottom: 6px;
}

.subject-empty p {
    color: #85899b;
    font-size: 12px;
}