/* CSS Variables - Professional Dark Space Theme */
:root {
    --primary-color: #4A90E2;
    --secondary-color: #FFD700;
    --accent-color: #00D4FF;
    --dark-blue: #0B1426;
    --darker-blue: #050A14;
    --light-blue: #1E3A8A;
    --gold: #FFD700;
    --white: #FFFFFF;
    --black: #000000;
    --light-gray: #2A2F3E;
    --medium-gray: #3A4151;
    --dark-gray: #1A1F2E;
    --text-color: #E8EAF6;
    --text-muted: #B0BEC5;
    --background-color: #0B1426;
    --card-bg: #1A1F2E;
    --card-hover: #2A2F3E;
    --border-color: #3A4151;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    --hover-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
    --gradient-primary: linear-gradient(135deg, #4A90E2 0%, #1E3A8A 50%, #0B1426 100%);
    --gradient-secondary: linear-gradient(135deg, #FFD700 0%, #FFA000 100%);
    --gradient-space: linear-gradient(135deg, #0B1426 0%, #1A1F2E 50%, #2A2F3E 100%);
    --section-bg: #1A1F2E;
    --accent-bg: #2A2F3E;
    --hero-overlay: rgba(11, 20, 38, 0.8);
    --star-color: rgba(255, 215, 0, 0.6);
}

/* Import Professional Fonts */
@import url('https://fonts.googleapis.com/css2?family=Merriweather:wght@300;400;700;900&family=Open+Sans:wght@300;400;500;600;700&family=Roboto+Slab:wght@300;400;500;600;700&display=swap');

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Open Sans', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--background-color);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-weight: 400;
    scroll-behavior: smooth;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Merriweather', serif;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

h1 {
    font-size: 3.8rem;
    font-weight: 900;
    color: var(--white);
    line-height: 1.1;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

h2 {
    font-size: 2.8rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--white);
}

h3 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--white);
}

h4 {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--white);
}

p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: var(--text-color);
    line-height: 1.7;
    font-family: 'Open Sans', sans-serif;
    font-weight: 400;
}

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

/* Navigation */
.navbar {
    background: rgba(26, 31, 46, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: var(--shadow);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo a {
    color: var(--primary-color);
    text-decoration: none;
    font-family: 'Merriweather', serif;
    font-size: 1.6rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    font-family: 'Open Sans', sans-serif;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: all 0.2s ease;
}

.nav-link:hover {
    color: var(--primary-color);
    background: var(--accent-bg);
}

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    background: none;
    border: none;
    padding: 0;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--primary-color);
    margin: 3px 0;
    transition: 0.3s;
}

/* Main Content */
.main-content {
    margin-top: 80px;
    min-height: calc(100vh - 80px - 200px);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, rgba(11, 20, 38, 0.9) 0%, rgba(26, 31, 46, 0.8) 100%), url('../ERAU.jpg');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: var(--white);
    padding: 12rem 0 10rem;
    text-align: center;
    position: relative;
    overflow: hidden;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(11, 20, 38, 0.7) 0%, rgba(26, 31, 46, 0.8) 100%);
    z-index: 1;
}

/* Animated Stars Background */
.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(2px 2px at 20px 30px, var(--star-color), transparent),
        radial-gradient(2px 2px at 40px 70px, var(--star-color), transparent),
        radial-gradient(1px 1px at 90px 40px, var(--star-color), transparent),
        radial-gradient(1px 1px at 130px 80px, var(--star-color), transparent),
        radial-gradient(2px 2px at 160px 30px, var(--star-color), transparent);
    background-repeat: repeat;
    background-size: 200px 100px;
    animation: twinkle 4s ease-in-out infinite;
    opacity: 0.6;
}

@keyframes twinkle {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

.hero-content {
    position: relative;
    z-index: 2;
    width: 100%;
}

.hero-header {
    display: flex;
    align-items: center;
    justify-content: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    gap: 4rem;
}

.hero-logo {
    flex-shrink: 0;
}

.erau-logo {
    width: 200px;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    background: var(--white);
    padding: 1rem;
}

.hero-text {
    text-align: left;
    flex: 1;
    max-width: 600px;
}

.hero-text h1 {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    color: var(--white);
}

.hero-subtitle {
    font-family: 'Open Sans', sans-serif;
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.hero-description {
    font-size: 1.3rem;
    color: var(--white);
    margin-bottom: 3rem;
    opacity: 0.95;
    line-height: 1.6;
    font-weight: 400;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2rem;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
    font-family: 'Open Sans', sans-serif;
}

.cta-button.primary {
    background: var(--gradient-primary);
    color: var(--white);
    box-shadow: var(--shadow);
}

.cta-button.primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--hover-shadow);
    background: linear-gradient(135deg, #5A9FE2 0%, #2E4A9A 50%, #1B2A46 100%);
}

.cta-button.secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--primary-color);
}

.cta-button.secondary:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.cta-button.third {
    background: var(--gradient-secondary);
    color: var(--white);
    box-shadow: var(--shadow);
}

.cta-button.third:hover {
    transform: translateY(-2px);
    box-shadow: var(--hover-shadow);
    background: linear-gradient(135deg, #FFE55C 0%,  #9b9858 50%, #ddbc04 100%);
}

/* Section Headers and Footers */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    color: var(--white);
    position: relative;
    display: inline-block;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient-secondary);
    border-radius: 2px;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto;
}

.section-footer {
    text-align: center;
    margin-top: 4rem;
}

/* Research Cards */
.research-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow);
}

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

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

.card-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.card-icon svg {
    color: var(--white);
}

.card-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
    transition: all 0.3s ease;
}

.card-link:hover {
    color: var(--accent-color);
    transform: translateX(5px);
}

/* Team Section */
.team-section {
    background: var(--section-bg);
}

.team-member {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

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

.team-member img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1.5rem;
    border: 4px solid var(--primary-color);
    box-shadow: var(--shadow);
}

.team-member h3 {
    color: var(--white);
    margin-bottom: 0.5rem;
}

.team-member .academic-subtitle {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 1rem;
}

/* Team Member Links */
.team-member-links {
    margin-top: 1rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.team-link {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: var(--accent-color);
    color: var(--primary-color);
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.team-link:hover {
    background: #FFB800;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

/* Publications Section */
.publications-section {
    background: var(--background-color);
}

.publication-item {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.publication-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--hover-shadow);
    background: var(--card-hover);
}

.publication-badge {
    display: inline-block;
    background: var(--gradient-secondary);
    color: var(--dark-blue);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.publication-badge.award {
    background: var(--gradient-primary);
    color: var(--white);
}

.publication-item h3 {
    color: var(--white);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.publication-item .authors {
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: 0.5rem;
}

.publication-item .journal {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.publication-item .year {
    color: var(--secondary-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

.publication-item .academic-text {
    color: var(--text-color);
    line-height: 1.6;
}

/* Academic Styling */
.academic-text {
    color: var(--text-color);
    line-height: 1.7;
}

.academic-title {
    color: var(--white);
    font-weight: 700;
}

.academic-subtitle {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

/* PI Profile Styles */
.pi-profile {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 3rem;
    margin-bottom: 3rem;
    box-shadow: var(--shadow);
}

.pi-content {
    display: flex;
    gap: 3rem;
    align-items: flex-start;
}

.pi-image {
    flex-shrink: 0;
}

.pi-image img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary-color);
    box-shadow: var(--shadow);
}

.pi-info {
    flex: 1;
}

.pi-info h3 {
    color: var(--white);
    margin-bottom: 0.5rem;
}

.pi-info .title {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.pi-info .biography {
    color: var(--text-color);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

/* PI Contact Buttons */
.pi-contact {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.pi-contact a {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: var(--gradient-primary);
    color: var(--white);
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.pi-contact a:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
    background: linear-gradient(135deg, #5A9FE2 0%, #2E4A9A 50%, #1B2A46 100%);
}

/* Section Spacing */
.section-padding {
    padding: 8rem 0;
}

.section-margin {
    margin: 4rem 0;
}

/* Grid Layouts */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 3rem;
    margin-bottom: 2rem;
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    margin-bottom: 2rem;
}

/* Page Header Styles */
.page-header {
    background: var(--gradient-primary);
    color: var(--white);
    padding: 6rem 0 4rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(2px 2px at 20px 30px, var(--star-color), transparent),
        radial-gradient(2px 2px at 40px 70px, var(--star-color), transparent),
        radial-gradient(1px 1px at 90px 40px, var(--star-color), transparent);
    background-repeat: repeat;
    background-size: 200px 100px;
    opacity: 0.3;
}

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

.page-header h1 {
    color: var(--white);
    margin-bottom: 1.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

.page-header p {
    color: var(--text-muted);
    font-size: 1.2rem;
}

/* Page Content Styles */
.page-content {
    background: var(--background-color);
    padding: 4rem 0;
}

.page-content:nth-child(even) {
    background: var(--section-bg);
}

/* Publications Search Styles */
.publications-search {
    background: var(--card-bg);
    border-radius: 16px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    padding: 3rem;
    margin-bottom: 4rem;
}

.publications-search h2 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.search-controls {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 2rem;
    align-items: end;
}

.search-group {
    display: flex;
    flex-direction: column;
}

.search-group label {
    display: block;
    margin-bottom: 0.8rem;
    font-weight: 600;
    color: var(--primary-color);
    font-family: 'Open Sans', sans-serif;
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.search-group input,
.search-group select {
    background: var(--white);
    color: var(--text-color);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    font-family: 'Open Sans', sans-serif;
    font-size: 1rem;
    transition: all 0.2s ease;
    width: 100%;
}

.search-group input:focus,
.search-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 84, 154, 0.1);
}

.search-group input::placeholder {
    color: var(--dark-gray);
    opacity: 0.7;
}

.search-group select {
    min-width: 150px;
    cursor: pointer;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 2rem 0;
        border-top: 1px solid var(--border-color);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .container {
        padding: 0 1rem;
    }
    
    .main-content {
        margin-top: 70px;
    }
    
    h1 {
        font-size: 2.8rem;
    }
    
    h2 {
        font-size: 2.2rem;
    }
    
    .hero {
        padding: 8rem 0 6rem;
        background-attachment: scroll;
    }
    
    .hero-header {
        flex-direction: column;
        gap: 3rem;
        text-align: center;
        padding: 0 1rem;
    }
    
    .hero-text {
        text-align: center;
        max-width: 100%;
    }
    
    .erau-logo {
        width: 150px;
        padding: 0.8rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .research-card, .team-member, .publication-item {
        padding: 2rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .cta-button {
        width: 100%;
        max-width: 300px;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .team-grid {
        grid-template-columns: 1fr;
    }
    
    .search-controls {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .search-group select {
        min-width: 100%;
    }
    
    /* Responsive design for PI section */
    .pi-content {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
    }
    
    .pi-image img {
        width: 150px;
        height: 150px;
    }
    
    .pi-info h3 {
        font-size: 1.6rem;
    }
    
    .pi-contact {
        justify-content: center;
        flex-wrap: wrap;
    }
}

/* Footer */
footer {
    background: var(--darker-blue);
    color: var(--text-color);
    padding: 3rem 0 1rem;
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(1px 1px at 20px 30px, var(--star-color), transparent),
        radial-gradient(1px 1px at 40px 70px, var(--star-color), transparent);
    background-repeat: repeat;
    background-size: 100px 50px;
    opacity: 0.2;
}

.footer-content {
    position: relative;
    z-index: 2;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    color: var(--white);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.footer-section p {
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
    text-align: center;
    color: var(--text-muted);
}

/* Section Footer */
.section-footer {
    text-align: center;
    margin-top: 3rem;
}

.section-footer .cta-button {
    display: inline-block;
    margin: 0 auto;
}

/* Responsive Footer */
@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-section {
        margin-bottom: 2rem;
    }
    
    footer {
        padding: 3rem 0 2rem;
    }
}