.problem-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-3xl) var(--spacing-xl);
    position: relative;
    background: linear-gradient(180deg, 
        rgba(255, 255, 255, 0.95) 0%,
        #ffffff 20%
    );
}

[data-theme="dark"] .problem-section {
    background: linear-gradient(180deg, 
        rgba(30, 41, 59, 0.95) 0%,
        var(--color-bg-secondary) 20%
    );
}

.problem-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
    position: relative;
    z-index: 1;
}

.problem-label {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(0, 212, 255, 0.1) 100%);
    border: 1px solid rgba(102, 126, 234, 0.2);
    border-radius: var(--border-radius-full);
    color: var(--color-accent-primary);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--spacing-md);
    transition: all 0.3s ease;
}

.problem-label:hover {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.15) 0%, rgba(0, 212, 255, 0.15) 100%);
    border-color: rgba(102, 126, 234, 0.3);
    transform: translateY(-2px);
}

.problem-title {
    font-size: clamp(2rem, 5vw, 2.5rem);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.2;
}

.problem-title-accent {
    font-size: clamp(2rem, 5vw, 2.5rem);
    font-weight: 700;
    background: linear-gradient(135deg, var(--color-accent-primary) 0%, var(--color-accent-tertiary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-lg);
}

.problem-intro {
    font-size: clamp(1rem, 2.5vw, 1.2rem);
    line-height: 1.7;
    color: var(--color-text-secondary);
    max-width: 800px;
    margin: 0 auto var(--spacing-3xl);
    position: relative;
    z-index: 1;
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-3xl);
    position: relative;
    z-index: 1;
}

.problem-item {
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-lg);
    background: var(--color-bg-card);
    border: var(--hairline);
    transition: transform 0.25s cubic-bezier(0.22, 1, 0.36, 1),
                border-color 0.25s ease,
                box-shadow 0.25s ease;
    position: relative;
    overflow: hidden;
}

.problem-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: var(--grid-bg);
    background-size: 28px 28px;
    opacity: 0.18;
    border-radius: var(--border-radius-lg);
    pointer-events: none;
    z-index: 0;
}

.problem-item::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 14px;
    height: 14px;
    border-top: 2px solid var(--color-accent-tertiary);
    border-left: 2px solid var(--color-accent-tertiary);
    border-radius: 2px 0 0 0;
    opacity: 0.7;
    pointer-events: none;
    z-index: 2;
}

.problem-item:hover {
    transform: translateY(-3px);
    border-color: var(--color-accent-primary);
    box-shadow: 0 8px 18px rgba(0, 0, 0, 0.12), 0 0 0 1px rgba(102, 126, 234, 0.2);
}

.problem-item > * {
    position: relative;
    z-index: 1;
}

.problem-item-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    display: inline-block;
    transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1);
}

.problem-item:hover .problem-item-icon {
    transform: scale(1.06);
}

.problem-item-title {
    font-size: clamp(1.1rem, 2vw, 1.3rem);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

.problem-item-description {
    font-size: clamp(0.9rem, 1.5vw, 1rem);
    line-height: 1.6;
    color: var(--color-text-secondary);
}

@media (max-width: 1024px) {
    .problem-section {
        padding: var(--spacing-2xl) var(--spacing-lg);
    }
    
    .problem-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: var(--spacing-md);
    }
}

@media (max-width: 768px) {
    .problem-section {
        padding: var(--spacing-xl) var(--spacing-md);
    }
    
    .problem-header {
        margin-bottom: var(--spacing-2xl);
    }
    
    .problem-intro {
        margin-bottom: var(--spacing-2xl);
    }
    
    .problem-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
        margin-top: var(--spacing-2xl);
    }
    
    .problem-item {
        padding: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .problem-section {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .problem-item {
        padding: var(--spacing-md);
    }
}