@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;600;700&family=Roboto:wght@300;400;500;700&display=swap');

:root {
    --bg-dark: #070d19;
    /* Deep Navy Background */
    --bg-card: #0f172a;
    /* Dark Slate Card Background */
    --bg-gradient: linear-gradient(135deg, #070d19 0%, #0f172a 100%);
    --cyan-glow: #00f0ff;
    /* Neon Tech Cyan */
    --cyan-dim: rgba(0, 240, 255, 0.1);
    --purple-glow: #b055ff;
    /* Tech Purple */
    --text-main: #f8fafc;
    --text-muted: #cbd5e1;
    --text-darker: #94a3b8;
    --border-subtle: rgba(255, 255, 255, 0.05);
    --border-cyan: rgba(0, 240, 255, 0.3);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Roboto', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.7;
    overflow-x: hidden;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    color: var(--text-main);
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

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

section {
    padding: 6rem 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 4rem;
    position: relative;
    letter-spacing: 1px;
}

.section-title::after {
    content: '';
    position: absolute;
    width: 60px;
    height: 3px;
    background: var(--cyan-glow);
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    box-shadow: 0 0 10px var(--cyan-glow);
}

.highlight {
    color: var(--cyan-glow);
}

.highlight-purple {
    color: var(--purple-glow);
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(7, 13, 25, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-subtle);
    padding: 1.2rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo i {
    color: var(--cyan-glow);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links li a {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-weight: 500;
    position: relative;
}

.nav-links li a:hover {
    color: var(--cyan-glow);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: linear-gradient(to right, rgba(7, 13, 25, 0.9) 0%, rgba(7, 13, 25, 0.6) 100%),
        url('assets/ai_academic_bg.png') no-repeat center center/cover;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 150px;
    background: linear-gradient(to top, var(--bg-dark), transparent);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 900px;
    padding: 2rem;
}

.profile-container {
    width: 160px;
    height: 160px;
    margin: 0 auto 2rem;
    border-radius: 50%;
    padding: 4px;
    background: linear-gradient(135deg, var(--cyan-glow), var(--purple-glow));
    box-shadow: 0 0 30px rgba(0, 240, 255, 0.3);
}

.profile-container img {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--bg-dark);
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 0.5rem;
    letter-spacing: 1px;
}

.hero h2 {
    font-size: 1.4rem;
    color: var(--text-muted);
    font-weight: 400;
    font-family: var(--font-body);
    margin-bottom: 1.5rem;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.hero p {
    font-size: 1.1rem;
    color: var(--text-darker);
    max-width: 700px;
    margin: 0 auto 2.5rem;
}

.btn-container {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
}

.btn {
    padding: 1rem 2.5rem;
    border-radius: 30px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-size: 0.9rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.btn-primary {
    background: transparent;
    color: var(--cyan-glow);
    border: 1px solid var(--cyan-glow);
    box-shadow: 0 0 15px var(--cyan-dim);
}

.btn-primary:hover {
    background: var(--cyan-glow);
    color: var(--bg-dark);
    box-shadow: 0 0 25px rgba(0, 240, 255, 0.5);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-main);
    border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
    border-color: var(--purple-glow);
    color: var(--purple-glow);
}

/* About Section */
#about .about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.stat-box {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    transition: var(--transition);
}

.stat-box:hover {
    border-color: var(--cyan-glow);
    transform: translateY(-5px);
    box-shadow: 0 10px 20px var(--cyan-dim);
}

.stat-number {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    color: var(--cyan-glow);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-darker);
}

/* Experience Timeline */
#experience {
    background: var(--bg-gradient);
}

.timeline {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-subtle);
}

.exp-item {
    position: relative;
    padding-left: 60px;
    margin-bottom: 3rem;
}

.exp-marker {
    position: absolute;
    left: 11px;
    top: 5px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--bg-dark);
    border: 4px solid var(--cyan-glow);
    box-shadow: 0 0 10px var(--cyan-glow);
    z-index: 2;
}

.exp-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    padding: 2.5rem;
    border-radius: 12px;
    transition: var(--transition);
}

.exp-card:hover {
    border-color: var(--purple-glow);
    box-shadow: 0 10px 30px rgba(176, 85, 255, 0.1);
}

.exp-date {
    display: inline-block;
    color: var(--cyan-glow);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 1rem;
    background: var(--cyan-dim);
    padding: 0.4rem 1rem;
    border-radius: 20px;
}

.exp-title {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.exp-company {
    color: var(--text-darker);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.exp-card ul {
    padding-left: 1rem;
    margin-bottom: 1.5rem;
}

.exp-card li {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 0.8rem;
    position: relative;
}

.exp-card li::before {
    content: "▹";
    position: absolute;
    left: -1rem;
    color: var(--cyan-glow);
}

.subject-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-subtle);
}

.s-tag {
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-muted);
    font-size: 0.85rem;
    padding: 0.4rem 1rem;
    border-radius: 4px;
    border: 1px solid var(--border-subtle);
}

/* Research & Publications */
#research {
    background: var(--bg-dark);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.pub-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    padding: 2.5rem;
    border-radius: 12px;
    transition: var(--transition);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.pub-card:hover {
    border-color: var(--cyan-glow);
    transform: translateY(-5px);
}

.pub-icon {
    font-size: 2rem;
    color: var(--purple-glow);
    margin-bottom: 1.5rem;
}

.pub-title {
    font-family: var(--font-body);
    font-size: 1.1rem;
    font-weight: 500;
    line-height: 1.5;
    margin-bottom: 1rem;
    color: var(--text-main);
    flex-grow: 1;
}

.pub-meta {
    color: var(--text-darker);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-subtle);
}

.pub-link {
    color: var(--cyan-glow);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.pub-link:hover {
    text-decoration: underline;
}

/* Education, Tech Skills & Certs */
#credentials {
    background: var(--bg-gradient);
}

.cred-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.cred-column h3 {
    font-size: 1.8rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 15px;
    color: var(--text-main);
}

.cred-column h3 i {
    color: var(--purple-glow);
}

.edu-box {
    background: rgba(255, 255, 255, 0.02);
    border-left: 3px solid var(--cyan-glow);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border-radius: 0 8px 8px 0;
}

.edu-box h4 {
    font-size: 1.2rem;
    margin-bottom: 0.3rem;
    color: var(--text-main);
}

.edu-box p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.edu-box .thesis {
    margin-top: 0.8rem;
    font-size: 0.9rem;
    color: var(--text-darker);
    font-style: italic;
}

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

.tech-group h4 {
    font-family: var(--font-body);
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-darker);
    margin-bottom: 1rem;
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.t-tag {
    background: var(--bg-card);
    border: 1px solid var(--border-cyan);
    color: var(--cyan-glow);
    padding: 0.5rem 1.2rem;
    border-radius: 20px;
    font-size: 0.85rem;
}

/* Footer / Contact */
.footer {
    background: var(--bg-dark);
    padding: 5rem 0 2rem;
    border-top: 1px solid var(--border-subtle);
    text-align: center;
}

.footer-contact {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 4rem;
    flex-wrap: wrap;
}

.f-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.f-item i {
    font-size: 1.8rem;
    color: var(--cyan-glow);
    margin-bottom: 1rem;
}

.f-item h4 {
    font-family: var(--font-body);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--text-darker);
    margin-bottom: 0.5rem;
}

.f-item p,
.f-item a {
    color: var(--text-muted);
}

.f-item a:hover {
    color: var(--cyan-glow);
}

.copyright {
    border-top: 1px solid var(--border-subtle);
    padding-top: 2rem;
    font-size: 0.9rem;
    color: var(--text-darker);
}

/* Responsive */
@media (max-width: 900px) {

    #about .about-grid,
    .cred-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    .nav-links {
        display: none;
    }

    .profile-container {
        width: 130px;
        height: 130px;
        margin-bottom: 1.5rem;
    }

    .hero h1 {
        font-size: 2.2rem;
    }

    .hero h2 {
        font-size: 1rem;
        letter-spacing: 1px;
    }

    .hero p {
        font-size: 0.95rem;
        margin-bottom: 2rem;
        padding: 0;
    }

    .btn-container {
        flex-direction: column;
        gap: 1rem;
        padding: 0;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .exp-item {
        padding-left: 40px;
    }

    .timeline::before {
        left: 10px;
    }

    .exp-marker {
        left: 1px;
    }

    .exp-card {
        padding: 1.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .footer-contact {
        flex-direction: column;
        gap: 2rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.8rem;
    }

    .hero h2 {
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .research-grid {
        grid-template-columns: 1fr;
    }

    .edu-box,
    .stat-box,
    .pub-card,
    .exp-card {
        padding: 1.25rem;
    }
}