/* CSS Custom Properties - Color Constants */
:root {
    --primary-blue: #02a6e9;
    --secondary-blue: #2a3d8f;
    --darker-blue: #0288c5;
    --dark-purple: #1b113d;
    --text-gray: #666;
    --text-black: black;
    --text-white: white;
    --card-bg: rgba(255, 255, 255, 0.95);
    --card-border: rgba(255, 255, 255, 0.2);
    --button-border: rgba(2, 166, 233, 0.3);
    --gradient-primary: linear-gradient(135deg, var(--primary-blue), var(--secondary-blue));
    --shadow-blue: rgba(2, 166, 233, 0.25);
    --shadow-blue-hover: rgba(2, 166, 233, 0.4);
    --shadow-dark: rgba(0, 0, 0, 0.3);
    --shadow-purple: rgba(42, 61, 143, 0.10);
}

/* Expertise Section Styles */
.expertise-section {
    background: var(--gradient-primary);
    padding-top: 120px;
}

.expertise-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

.expertise-container h2 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-white);
}

.expertise-container p {
    text-align: center;
    font-size: 1.2rem;
    margin-bottom: 3rem;
    color: rgba(255, 255, 255, 0.9);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.expertise-card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 40px 30px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    height: 100%;
    display: flex;
    flex-direction: column;
    backdrop-filter: blur(10px);
    border: 1px solid var(--card-border);
}

.expertise-card.active {
    box-shadow: 0 30px 60px var(--shadow-blue), 0 2px 16px var(--shadow-purple);
}

.expertise-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 30px 60px var(--shadow-dark);
}

.expertise-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 25px;
    color: var(--text-black);
    line-height: 1.3;
}

.card-icons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
}

.card-icons img {
    display: inline-block;
    width: 45px;
    height: 45px;
    transition: all 0.3s ease;
    margin-bottom: 25px;
}

.expertise-list {
    list-style: none;
    text-align: left;
    flex-grow: 1;
    padding: 0;
    margin: 0;
}

.expertise-list li {
    padding: 8px 0;
    color: var(--text-gray);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    line-height: 1.4;
    transition: transform 0.25s cubic-bezier(0.4,0,0.2,1);
    cursor: default;
}

.expertise-list li a {
    color: inherit;
    text-decoration: none;
    display: flex;
    align-items: center;
    width: 100%;
    transition: color 0.3s ease;
}

.expertise-list li a:hover {
    color: var(--primary-blue);
}

.expertise-list li:hover {
    transform: translateX(12px);
}

.expertise-list li i {
    color: var(--primary-blue);
    margin-right: 12px;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.card-footer {
    margin-top: auto;
    padding-top: 20px;
}

.card-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: transparent;
    color: var(--text-black);
    text-decoration: none;
    padding: 12px 20px;
    border-radius: 25px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    border: 2px solid var(--button-border);
    box-sizing: border-box;
    overflow: hidden;
}

.card-btn:hover {
    background: var(--gradient-primary);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--shadow-blue-hover);
    color: var(--text-white);
    text-decoration: none;
    border: 2px solid var(--button-border);
    background-clip: padding-box;
}

.expertise-card:hover .card-btn {
    background: var(--gradient-primary);
    color: var(--text-white);
    border: 2px solid var(--button-border);
    box-shadow: 0 6px 20px var(--shadow-blue-hover);
    background-clip: padding-box;
}

.expertise-card.active {
    box-shadow: 0 30px 60px var(--shadow-blue), 0 2px 16px var(--shadow-purple);
    transform: translateY(-5px);
}

.expertise-card.active .card-btn {
    background: var(--gradient-primary);
    color: var(--text-white);
    border: 2px solid var(--button-border);
    box-shadow: 0 6px 20px var(--shadow-blue-hover);
    background-clip: padding-box;
}

.card-btn i {
    font-size: 0.8rem;
}

/* Responsive styles */
@media (max-width: 768px) {
    .expertise-container h2 {
        font-size: 2rem;
    }
    
    .expertise-container p {
        font-size: 1rem;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .expertise-card {
        padding: 30px 20px;
    }
    
    .expertise-card h3 {
        font-size: 1.3rem;
    }
    
    .card-icons {
        gap: 20px;
    }
    
    .card-icons img {
        width: 35px;
        height: 35px;
    }
}

@media (max-width: 480px) {
    .expertise-section {
        margin-top: 50px;
    }
    
    .expertise-container {
        padding: 0 15px;
    }
    
    .expertise-container h2 {
        font-size: 1.8rem;
    }
    
    .expertise-card {
        padding: 25px 15px;
    }
    
    .card-btn {
        padding: 10px 15px;
        font-size: 0.8rem;
    }
}