.page {
    max-width: 1400px;
    padding-left: clamp(1.2rem, 4vw, 2.5rem);
    padding-right: clamp(1.2rem, 4vw, 2.5rem);
}

.books-board {
    display: flex;
    gap: 14px;
    margin-top: 2rem;
    padding-bottom: 3rem;
    align-items: flex-start;
}

.books-column {
    flex: 0 0 auto;
    width: 176px;
    min-width: 160px;
}

.books-column-header {
    padding: 12px 14px;
    border-radius: 12px 12px 0 0;
    font-size: 0.82rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.92);
    display: flex;
    align-items: center;
    justify-content: space-between;
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-bottom: none;
}

.books-column-header .col-count {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.45);
    font-weight: 500;
}

.books-column-body {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-top: none;
    border-radius: 0 0 12px 12px;
    padding: 10px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.book-item {
    padding: 14px 12px;
    border-radius: 8px;
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.88);
    line-height: 1.5;
    font-weight: 600;
    transition: box-shadow 0.25s ease;
    cursor: default;
    overflow: hidden;
    word-wrap: break-word;
    word-break: break-word;
}

.book-item:hover {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.col-novel .books-column-header { background: rgba(220, 38, 38, 0.12); }
.col-novel .book-item { background: rgba(220, 38, 38, 0.08); }
.col-novel .book-item:hover { background: rgba(220, 38, 38, 0.16); }

.col-efficiency .books-column-header { background: rgba(16, 185, 129, 0.08); }
.col-efficiency .book-item { background: rgba(16, 185, 129, 0.06); }
.col-efficiency .book-item:hover { background: rgba(16, 185, 129, 0.12); }

.col-science .books-column-header { background: rgba(245, 158, 11, 0.08); }
.col-science .book-item { background: rgba(245, 158, 11, 0.06); }
.col-science .book-item:hover { background: rgba(245, 158, 11, 0.12); }

.col-stem .books-column-header { background: rgba(59, 130, 246, 0.08); }
.col-stem .book-item { background: rgba(59, 130, 246, 0.06); }
.col-stem .book-item:hover { background: rgba(59, 130, 246, 0.12); }

.col-code .books-column-header { background: rgba(148, 163, 184, 0.08); }
.col-code .book-item { background: rgba(148, 163, 184, 0.06); }
.col-code .book-item:hover { background: rgba(148, 163, 184, 0.12); }

.col-social .books-column-header { background: rgba(249, 115, 22, 0.08); }
.col-social .book-item { background: rgba(249, 115, 22, 0.06); }
.col-social .book-item:hover { background: rgba(249, 115, 22, 0.12); }

.col-bio .books-column-header { background: rgba(168, 85, 247, 0.08); }
.col-bio .book-item { background: rgba(168, 85, 247, 0.06); }
.col-bio .book-item:hover { background: rgba(168, 85, 247, 0.12); }

@media (max-width: 1200px) {
    .books-board {
        flex-wrap: nowrap;
        overflow-x: auto;
        padding-bottom: 2rem;
    }

    .books-column {
        width: 170px;
        min-width: 155px;
    }
}

@media (max-width: 900px) {
    .books-board {
        gap: 10px;
    }

    .books-column {
        width: 150px;
        min-width: 140px;
    }

    .books-column-header {
        font-size: 0.78rem;
        padding: 10px 12px;
    }

    .book-item {
        font-size: 0.82rem;
        padding: 11px 9px;
    }
}

@media (max-width: 600px) {
    .page {
        max-width: 100%;
    }

    .books-board {
        gap: 8px;
        margin-top: 1.5rem;
    }

    .books-column {
        width: 135px;
        min-width: 125px;
    }

    .book-item {
        font-size: 0.78rem;
        padding: 9px 8px;
    }
}