:root {
    --primary-color: #1a237e;
    --secondary-color: #3f51b5;
    --accent-color: #ff6b35;
    --ai-color: #00e676;
    --light-color: #ecf0f1;
    --dark-color: #1a237e;
    --text-color: #333;
    --text-light: #7f8c8d;
    --gradient-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #f8f9fa;
}

header {
    background: var(--gradient-bg);
    color: white;
    padding: 3rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)" /></svg>');
    opacity: 0.3;
}

.header-content {
    position: relative;
    z-index: 2;
}

nav {
    background-color: rgba(26, 35, 126, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 20px rgba(0,0,0,0.1);
}

nav ul {
    display: flex;
    justify-content: center;
    list-style: none;
    max-width: 1200px;
    margin: 0 auto;
    flex-wrap: wrap;
}

nav ul li {
    margin: 0 1rem;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 1px;
    padding: 0.5rem 1rem;
    border-radius: 20px;
}

nav ul li a:hover {
    background-color: var(--ai-color);
    color: var(--dark-color);
    transform: translateY(-2px);
}

section {
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

h1, h2, h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

h1 {
    font-size: 3rem;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

h2 {
    font-size: 2.2rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--ai-color);
    margin-bottom: 2rem;
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 60px;
    height: 3px;
    background-color: var(--accent-color);
}

h3 {
    font-size: 1.5rem;
    color: var(--secondary-color);
}

.subtitle {
    font-size: 1.4rem;
    margin-top: 0.5rem;
    opacity: 0.9;
    font-weight: 300;
}

.ai-badge {
    display: inline-block;
    background: var(--ai-color);
    color: var(--dark-color);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin: 0.2rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.btn {
    display: inline-block;
    background: linear-gradient(45deg, var(--secondary-color), var(--ai-color));
    color: white;
    padding: 1rem 2rem;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

.profile-img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid white;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    margin-bottom: 1.5rem;
}

/* Project Cards */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.project-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s;
    border-left: 5px solid var(--ai-color);
    position: relative;
    overflow: hidden;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--ai-color), var(--secondary-color));
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.project-icon {
    font-size: 2.5rem;
    color: var(--ai-color);
    margin-bottom: 1rem;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.tech-tag {
    background: linear-gradient(45deg, var(--secondary-color), var(--primary-color));
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Skills Enhancement */
.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.skill-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.skill-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-bg);
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.skill-card h3 {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.skill-card h3 i {
    margin-right: 0.8rem;
    color: var(--ai-color);
    font-size: 1.8rem;
}

.skill-list {
    list-style: none;
}

.skill-list li {
    margin-bottom: 0.8rem;
    display: flex;
    align-items: center;
    padding: 0.5rem 0;
}

.skill-list li:before {
    content: "•";
    color: var(--ai-color);
    font-weight: bold;
    margin-right: 0.8rem;
    font-size: 1.2rem;
}

/* Progress bars enhancement */
.progress-container {
    width: 100%;
    background-color: #e8eaf6;
    border-radius: 10px;
    margin-bottom: 1rem;
    overflow: hidden;
}

.progress-bar {
    height: 12px;
    border-radius: 10px;
    background: linear-gradient(90deg, var(--ai-color), var(--secondary-color));
    transition: width 2s ease-in-out;
    position: relative;
}

.progress-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.progress-text {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.3rem;
    font-weight: 600;
}

/* Experience Timeline */
.experience-item {
    margin-bottom: 3rem;
    position: relative;
    padding-left: 2.5rem;
    border-left: 3px solid var(--ai-color);
    padding-bottom: 1.5rem;
    background: white;
    border-radius: 0 15px 15px 0;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.experience-item:before {
    content: "";
    position: absolute;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: linear-gradient(45deg, var(--ai-color), var(--secondary-color));
    left: -11.5px;
    top: 20px;
    box-shadow: 0 0 0 4px white, 0 0 0 8px var(--ai-color);
}

.experience-date {
    color: var(--ai-color);
    font-style: italic;
    margin-bottom: 1rem;
    font-weight: 600;
    font-size: 1.1rem;
}

/* Certifications Section */
.cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.cert-card {
    background: white;
    border-radius: 10px;
    padding: 1.5rem;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
    border: 2px solid transparent;
}

.cert-card:hover {
    transform: scale(1.05);
    border-color: var(--ai-color);
}

.cert-icon {
    font-size: 2rem;
    color: var(--ai-color);
    margin-bottom: 1rem;
}

/* Contact Form Enhancement */
.contact-form {
    background: white;
    padding: 3rem;
    border-radius: 20px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    margin: 0 auto;
    border-top: 5px solid var(--ai-color);
}

.form-group {
    margin-bottom: 2rem;
}

label {
    display: block;
    margin-bottom: 0.8rem;
    font-weight: 600;
    color: var(--primary-color);
}

input, textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid #e8eaf6;
    border-radius: 10px;
    font-family: inherit;
    transition: border-color 0.3s;
}

input:focus, textarea:focus {
    outline: none;
    border-color: var(--ai-color);
}

textarea {
    min-height: 150px;
    resize: vertical;
}

footer {
    background: var(--gradient-bg);
    color: white;
    text-align: center;
    padding: 3rem 0;
    margin-top: 4rem;
}

.social-links {
    margin-top: 2rem;
}

.social-links a {
    display: inline-block;
    margin: 0 1rem;
    color: white;
    font-size: 2rem;
    transition: all 0.3s;
    padding: 0.5rem;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
}

.social-links a:hover {
    color: var(--ai-color);
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.2);
}

/* Responsive styles */
@media (max-width: 768px) {
    nav ul {
        flex-direction: column;
        align-items: center;
    }
    
    nav ul li {
        margin: 0.5rem 0;
    }
    
    header {
        padding: 2rem 0;
    }
    
    h1 {
        font-size: 2.5rem;
        margin-bottom: 0.5rem;
    }
    
    .subtitle {
        font-size: 1.2rem;
        margin-bottom: 1rem;
        padding: 0 1rem;
        text-align: center;
    }
    
    .profile-img {
        width: 150px;
        height: 150px;
        margin-bottom: 1rem;
    }
    
    .ai-badge {
        font-size: 0.7rem;
        padding: 0.25rem 0.6rem;
        margin: 0.15rem;
    }
    
    .btn {
        padding: 0.8rem 1.5rem;
        font-size: 0.9rem;
        margin: 0.5rem 0.5rem;
        display: block;
        text-align: center;
        width: calc(100% - 2rem);
        max-width: 250px;
    }
    
    .projects-grid, .skills-container {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .project-card, .skill-card {
        margin: 0 0.5rem;
        padding: 1.5rem;
    }
    
    section {
        padding: 2rem 1rem;
    }
    
    .container {
        padding: 0 1rem;
    }
    
    h2 {
        font-size: 1.8rem;
        text-align: center;
        margin-bottom: 1.5rem;
    }
    
    h3 {
        font-size: 1.3rem;
    }
    
    /* About section mobile fix */
    #about .container > div {
        display: block !important;
        text-align: center;
    }
    
    #about .container > div > div:first-child {
        margin-bottom: 2rem;
    }
    
    /* Experience timeline mobile improvements */
    .experience-item {
        padding: 1.5rem;
        margin-bottom: 2rem;
        padding-left: 1.5rem;
        border-left: 3px solid var(--ai-color);
    }
    
    .experience-item:before {
        left: -7px;
        width: 14px;
        height: 14px;
        top: 15px;
    }
    
    .experience-date {
        font-size: 1rem;
        margin-bottom: 0.8rem;
    }
    
    /* Contact form mobile improvements */
    .contact-form {
        padding: 2rem 1.5rem;
        margin: 0 1rem;
    }
    
    /* Footer mobile improvements */
    footer {
        padding: 2rem 1rem;
    }
    
    .social-links a {
        font-size: 1.5rem;
        margin: 0 0.5rem;
    }
    
    /* AI Strategy section mobile */
    #ai-strategy {
        padding: 2rem 1rem !important;
    }
    
    #ai-strategy .container > div {
        grid-template-columns: 1fr !important;
        gap: 2rem !important;
    }
    
    /* Education cards mobile */
    .education-card {
        margin: 0 0.5rem 1.5rem 0.5rem !important;
    }
    
    /* Certification grid mobile */
    .cert-grid {
        grid-template-columns: 1fr !important;
        gap: 1rem;
    }
    
    .cert-card {
        margin: 0 1rem;
    }
    
    /* Mobile menu button */
    .mobile-menu-btn {
        display: block !important;
        position: absolute;
        top: 1rem;
        right: 1rem;
        background: none;
        border: none;
        color: white;
        font-size: 1.5rem;
        cursor: pointer;
        padding: 0.5rem;
        z-index: 101;
    }
    
    nav {
        position: relative;
    }
    
    nav ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(26, 35, 126, 0.98);
        backdrop-filter: blur(10px);
        padding: 1rem 0;
        box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    }
    
    nav ul.active {
        display: flex;
    }
    
    nav ul li a {
        padding: 0.8rem 2rem;
        display: block;
        text-align: center;
        border-radius: 0;
    }
}

/* Animation for cards on scroll */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}