/* ─── PROBLEM SECTION (público frio) ─── */
.problem-section {
    padding: 80px 24px;
    background: var(--champagne);
    position: relative;
}

.problem-section::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 2px;
    background: var(--gold);
}

.problem-intro {
    text-align: center;
    margin-bottom: 48px;
}

.problem-intro .section-label {
    margin-bottom: 12px;
}

.problem-intro .section-title {
    margin-bottom: 16px;
}

.problem-intro p {
    font-size: 0.95rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.7;
}

.problem-cards {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
    max-width: 840px;
    margin: 0 auto;
}

@media (min-width: 768px) {
    .problem-cards {
        grid-template-columns: 1fr 1fr 1fr;
    }
}

.problem-card {
    background: var(--warm-white);
    border-radius: 12px;
    padding: 32px 28px;
    border: 1px solid var(--border);
    transition: box-shadow 0.3s;
}

.problem-card:hover {
    box-shadow: 0 4px 24px rgba(27, 54, 93, 0.08);
}

.problem-card-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(197, 153, 58, 0.12);
    color: var(--gold-dark);
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    font-size: 0.85rem;
    margin-bottom: 16px;
}

.problem-card h4 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--petrol);
    margin-bottom: 10px;
    line-height: 1.3;
}

.problem-card p {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.7;
}

.problem-transition {
    text-align: center;
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--border);
}

.problem-transition p {
    font-size: 1rem;
    font-weight: 600;
    color: var(--petrol);
    max-width: 560px;
    margin: 0 auto;
    line-height: 1.6;
}

.problem-transition .proof-number {
    font-size: 1.1em;
}