/* =========================
   CSS Variables
   ========================= */
:root {
    --primary: #2c5282;
    --primary-dk: #1e3a5f;
    --accent: #3182ce;
    --gray: #4a5568;
    --light: #f7fafc;
    --white: #ffffff;
    --text-dark: #2d3748;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 15px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 30px rgba(0, 0, 0, 0.1);
    --transition: all 0.18s ease;
}

/* =========================
   Global Styles
   ========================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Roboto', system-ui, -apple-system, sans-serif;
    color: var(--text-dark);
    background-color: var(--light);
    line-height: 1.65;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Roboto Slab', Georgia, serif;
    font-weight: 500;
    color: var(--primary-dk);
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1rem;
}

.lead {
    font-size: 1.15rem;
    font-weight: 400;
    color: var(--gray);
}

/* =========================
   Navigation
   ========================= */
.navbar {
    background-color: var(--white);
    border-bottom: 1px solid #e2e8f0;
    box-shadow: var(--shadow-sm);
    padding: 0.75rem 0;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--primary) !important;
    transition: var(--transition);
}

.navbar-brand:hover {
    color: var(--accent) !important;
}

.nav-link {
    color: var(--gray) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent) !important;
}

/* =========================
   Hero Section
   ========================= */
.hero {
    position: relative;
    height: 45vh;
    min-height: 320px;
    background-image: url('./img/header.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    color: var(--white);
    display: flex;
    align-items: center;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(30, 58, 138, 0.58);
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 1100px;
    padding: 0 25px;
    margin-top: -70px;
    margin-left: 140px;
}

.hero h1 {
    font-size: 2.8rem;
    font-weight: 700;
    color: var(--white) !important;
    margin-bottom: 0.6rem;
    text-shadow: 0 3px 12px rgba(0, 0, 0, 0.65);
}

.hero p {
    font-size: 1.55rem;
    font-weight: 300;
    opacity: 0.95;
    margin-bottom: 0;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
}

.profile-photo-container {
    position: absolute;
    top: 50%;
    right: 15%;
    transform: translateY(-50%);
    z-index: 3;
}

.profile-photo {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    border: 5px solid rgba(255, 255, 255, 0.35);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
    object-fit: cover;
    transition: var(--transition);
}

.profile-photo:hover {
    border-color: rgba(255, 255, 255, 0.6);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.5);
}

/* =========================
   Main Content
   ========================= */
.main-content {
    padding: 3rem 0 2rem;
}

.section-title {
    position: relative;
    padding-bottom: 0.8rem;
    margin-bottom: 2rem;
    text-align: left;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background-color: var(--accent);
}

/* =========================
   Cards
   ========================= */
.card {
    border: none;
    border-radius: 8px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

/* =========================
   Research Highlights
   ========================= */
.research-icon i {
    color: var(--primary);
}

.research-icon:hover i {
    color: var(--accent);
    transition: var(--transition);
}

/* =========================
   Key Achievements
   ========================= */
.achievement-item {
    padding: 1rem;
}

.achievement-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
    font-family: 'Roboto Slab', Georgia, serif;
    line-height: 1;
}

.achievement-label {
    font-size: 0.95rem;
    color: var(--gray);
    margin-top: 0.5rem;
}

.awards-list {
    list-style: none;
    padding-left: 0;
}

.awards-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #e2e8f0;
}

.awards-list li:last-child {
    border-bottom: none;
}

/* =========================
   Featured Projects
   ========================= */
.project-badge {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.project-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

/* =========================
   Call to Action
   ========================= */
.social-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.social-links .btn {
    white-space: nowrap;
}

/* =========================
   Buttons
   ========================= */
.btn-primary {
    background-color: var(--primary);
    border-color: var(--primary);
}

.btn-primary:hover {
    background-color: var(--primary-dk);
    border-color: var(--primary-dk);
}

.btn-outline-primary {
    color: var(--primary);
    border-color: var(--primary);
}

.btn-outline-primary:hover {
    background-color: var(--primary);
    border-color: var(--primary);
    color: var(--white);
}

/* =========================
   Footer
   ========================= */
footer {
    background-color: var(--primary-dk);
    color: #e2e8f0;
    padding: 1.5rem 0;
    margin-top: 3rem;
}

footer p {
    margin-bottom: 0;
}

footer a {
    color: #a0d2ff;
    text-decoration: none;
    transition: var(--transition);
}

footer a:hover {
    color: var(--white);
    text-decoration: underline;
}

/* =========================
   Responsive Design
   ========================= */
@media (max-width: 991px) {
    .hero {
        height: 40vh;
        min-height: 280px;
    }

    .hero-content {
        margin-left: 0;
        margin-top: -40px;
        text-align: center;
    }

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

    .hero p {
        font-size: 1.4rem;
    }

    .profile-photo-container {
        position: static;
        transform: none;
        margin: 1.5rem auto 0;
        text-align: center;
    }

    .profile-photo {
        width: 140px;
        height: 140px;
    }

    .main-content {
        padding: 2rem 0 1.5rem;
    }

    .achievement-number {
        font-size: 2.5rem;
    }
}

@media (max-width: 576px) {
    .hero h1 {
        font-size: 1.9rem;
    }

    .hero p {
        font-size: 1.2rem;
    }

    .profile-photo {
        width: 120px;
        height: 120px;
    }

    .main-content {
        padding: 1.5rem 0 1rem;
    }

    footer {
        margin-top: 2rem;
    }

    .achievement-number {
        font-size: 2rem;
    }

    .social-links {
        flex-direction: column;
    }

    .social-links .btn {
        width: 100%;
    }
}

/* =========================
   Utility Classes
   ========================= */
.text-muted {
    color: var(--gray) !important;
}

.bg-light {
    background-color: var(--light) !important;
}