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

:root {
    --primary-blue: #1e88e5;
    --dark-blue: #0d47a1;
    --light-blue: #42a5f5;
    --text-dark: #1a1a1a;
    --text-light: #ffffff;
    --text-gray: #666666;
    --light-bg: #f5f7fa;
    --white: #ffffff;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: var(--white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== NAVIGATION ===== */
.navbar {
    background: var(--white);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-blue);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    position: relative;
    transition: var(--transition);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: width 0.3s ease;
}

.nav-links a:hover {
    color: var(--primary-blue);
}

.nav-links a:hover::after {
    width: 100%;
}

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(10px, 10px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }

    .nav-links {
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--white);
        gap: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }

    .nav-links.active {
        max-height: 300px;
    }

    .nav-links li {
        padding: 1rem 20px;
        border-bottom: 1px solid var(--light-bg);
    }
}

/* ===== PROFILE SECTION ===== */
.profile-section {
    background: linear-gradient(135deg, #2196F3 0%, #1976D2 100%);
    min-height: 100vh;
    padding: 60px 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.profile-container {
    width: 100%;
    max-width: 900px;
}

.profile-card {
    background: var(--white);
    border-radius: 16px;
    padding: 3rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
    position: relative;
}

.profile-header {
    text-align: center;
    margin-bottom: 2rem;
}

.avatar-circle {
    width: 120px;
    height: 120px;
    background: linear-gradient(135deg, #2196F3, #1976D2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--white);
    margin: 0 auto 1.5rem;
    box-shadow: 0 10px 30px rgba(33, 150, 243, 0.3);
    position: relative;
    overflow: hidden;
    transition: var(--transition);
}

.avatar-circle:hover {
    box-shadow: 0 15px 40px rgba(33, 150, 243, 0.5);
    transform: scale(1.05);
}

.photo-placeholder {
    font-size: 3rem;
    color: rgba(255, 255, 255, 0.6);
}

.profile-name {
    font-size: 2.5rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.profile-title {
    font-size: 1.2rem;
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.profile-institution {
    font-size: 0.95rem;
    color: var(--text-gray);
    margin-bottom: 2rem;
}

.profile-section-divider {
    height: 1px;
    background: #e0e0e0;
    margin: 2rem 0;
}

.profile-highlights {
    margin-bottom: 2rem;
}

.profile-highlights h3 {
    font-size: 0.95rem;
    color: var(--text-gray);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 1rem;
    font-weight: 600;
}

.highlights-content {
    background: #f5f5f5;
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid var(--primary-blue);
}

.highlights-content p {
    color: var(--text-gray);
    font-size: 0.95rem;
    line-height: 1.6;
}

.profile-technologies {
    margin-bottom: 0;
}

.profile-technologies h3 {
    font-size: 0.95rem;
    color: var(--text-gray);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 1.2rem;
    font-weight: 600;
}

.tech-badges {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.tech-badge {
    background: #f0f0f0;
    color: var(--text-dark);
    padding: 0.75rem 1.2rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
    cursor: pointer;
}

.tech-badge i {
    color: var(--primary-blue);
}

.tech-badge:hover {
    background: var(--light-blue);
    color: var(--white);
}

.tech-badge:hover i {
    color: var(--white);
}

.profile-tagline {
    text-align: center;
    margin-top: 4rem;
    color: var(--white);
}

.profile-tagline h2 {
    font-size: 2rem;
    font-weight: 700;
    line-height: 1.3;
}

/* ===== ABOUT SECTION ===== */
.about {
    padding: 80px 20px;
    background: var(--light-bg);
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
    color: var(--text-dark);
    font-weight: 700;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text {
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--text-gray);
    margin-bottom: 2rem;
    text-align: center;
}

/* ===== CONTACT SECTION ===== */
.contact {
    padding: 80px 20px;
    background: var(--white);
}

.contact .section-title {
    color: var(--text-dark);
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.contact-intro {
    font-size: 1.1rem;
    margin-bottom: 3rem;
    color: var(--text-gray);
    text-align: center;
}

.contact-methods {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    max-width: 800px;
    margin: 0 auto;
}

.contact-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.75rem 1.2rem;
    border-radius: 20px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    font-size: 0.9rem;
    cursor: pointer;
    background: #f0f0f0;
    color: var(--text-dark);
    border: none;
}

.contact-btn i {
    font-size: 1.2rem;
    color: var(--primary-blue);
}

.contact-btn:hover {
    background: var(--light-blue);
    color: var(--white);
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.contact-btn:hover i {
    color: var(--white);
}

.btn-email {
}

.btn-linkedin {
}

.btn-github {
}

/* ===== FOOTER ===== */
.footer {
    background: var(--text-dark);
    color: var(--white);
    text-align: center;
    padding: 2rem 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .profile-card {
        padding: 2rem;
    }

    .profile-name {
        font-size: 1.8rem;
    }

    .avatar-circle {
        width: 100px;
        height: 100px;
        font-size: 2.5rem;
    }

    .profile-tagline h2 {
        font-size: 1.5rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .tech-badges {
        justify-content: center;
    }

    .contact-methods {
        flex-direction: column;
        align-items: center;
    }

    .contact-btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .profile-section {
        padding: 40px 20px;
    }

    .profile-card {
        padding: 1.5rem;
    }

    .profile-name {
        font-size: 1.5rem;
    }

    .profile-tagline h2 {
        font-size: 1.2rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .nav-links {
        gap: 0;
    }
}