.rational-prompt {
    font-size: 1.2rem;
    font-weight: 600;
    color: #444;
    text-align: center;
    margin: 0.5rem 0 0.8rem;
}

.rational-display {
    display: flex;
    align-items: center;
    justify-content: center;
    width: fit-content;
    margin: 0.6rem auto 1rem;
    padding: 0.7rem 1.2rem;
    font-size: 2.6rem;
    font-weight: 700;
    color: #1e293b;
    background: #f1f5f9;
    border: 3px solid #cbd5e1;
    border-radius: 16px;
}

.rational-expression {
    gap: 0.6rem;
}

.rational-operator,
.rational-equals {
    font-size: 0.75em;
    font-weight: 800;
    color: #475569;
}

.rational-fraction {
    display: flex;
    flex-direction: column;
    align-items: center;
    line-height: 1.05;
}

.rational-num {
    padding: 0 0.35rem;
}

.rational-line {
    width: 100%;
    height: 3px;
    margin: 0.1rem 0;
    background: #1e293b;
    border-radius: 2px;
}

.rational-den {
    padding: 0 0.35rem;
}

.rational-mixed {
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.rational-whole {
    font-size: 1em;
}

.rational-options {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin: 0.8rem 0;
}

.rational-option {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 5rem;
    min-height: 4.2rem;
    padding: 0.6rem 1rem;
    font-size: 1.7rem;
    font-weight: 700;
    color: #1e293b;
    background: #ffffff;
    border: 2px solid #cbd5e1;
    border-radius: 14px;
    cursor: pointer;
    transition: transform 0.1s ease, border-color 0.1s ease;
}

.rational-option:hover {
    transform: scale(1.05);
    border-color: #94a3b8;
}

.rational-hint {
    text-align: left;
}

.rational-hint p {
    margin: 0.35rem 0;
}

.rational-compare {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin: 0.8rem 0;
}

.rational-compare-box {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 6rem;
    min-height: 4.6rem;
    padding: 0.6rem 1.2rem;
    font-size: 2rem;
    font-weight: 700;
    color: #1e293b;
    background: #ffffff;
    border: 2px solid #cbd5e1;
    border-radius: 14px;
}

.rational-ops {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.6rem;
}

.rational-op-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 3.2rem;
    min-height: 3.2rem;
    padding: 0.4rem 0.8rem;
    font-size: 1.8rem;
    font-weight: 800;
    color: #1e293b;
    background: #ffffff;
    border: 2px solid #cbd5e1;
    border-radius: 12px;
    cursor: pointer;
    transition: transform 0.1s ease, border-color 0.1s ease;
}

.rational-op-btn:hover {
    transform: scale(1.05);
    border-color: #94a3b8;
}