/* ===================================
   The Steel Lab Website - Main Stylesheet
   =================================== */

/* CSS Variables */
:root {
    --primary-color: #4682b4;
    --primary-dark: #2c5aa0;
    --primary-light: #6fa3d8;
    --bg-light: #f5f8fa;
    --text-dark: #333333;
    --text-medium: #666666;
    --text-light: #999999;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: 1rem;
}

.lead {
    font-size: 1.25rem;
    font-weight: 300;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

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

a:hover {
    color: var(--primary-dark);
}

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

.section {
    padding: 5rem 0;
}

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

/* Header and Navigation */
.header {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo .logo {
    height: 50px;
    width: auto;
}

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

.nav-menu a {
    color: var(--text-dark);
    font-weight: 600;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-dark);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    padding: 5rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    min-height: 70vh;
}

.hero-content {
    animation: fadeInUp 0.8s ease-out;
}

.hero-title {
    font-size: 3.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-medium);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero-image {
    animation: fadeIn 1s ease-out;
}

.hero-image img {
    width: 100%;
    height: auto;
    border-radius: 12px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 6px;
    font-weight: 600;
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

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

.btn-small {
    padding: 0.5rem 1.25rem;
    font-size: 0.9rem;
}

/* Research Themes */
.section-title {
    text-align: center;
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 3rem;
}

.themes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.theme-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
}

.theme-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
}

.theme-icon {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.theme-card h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

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

.publication-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
}

.publication-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.publication-year {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.publication-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.publication-authors {
    font-size: 0.9rem;
    color: var(--text-medium);
    margin-bottom: 0.5rem;
}

.publication-journal {
    font-size: 0.9rem;
    font-style: italic;
    color: var(--text-medium);
    margin-bottom: 1rem;
}

.publication-link {
    color: var(--primary-color);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.publication-link:hover {
    color: var(--primary-dark);
}

/* Lab Location */
.location-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.location-details {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.location-image img {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: var(--shadow-hover);
}

/* Page Header */
.page-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 4rem 0;
    text-align: center;
}

.page-title {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-subtitle {
    font-size: 1.25rem;
    font-weight: 300;
    opacity: 0.9;
}

/* Content Blocks */
.content-block {
    max-width: 900px;
    margin: 0 auto;
}

.content-block h2 {
    color: var(--primary-dark);
    margin-bottom: 1.5rem;
}

/* Projects */
.project-card {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 2rem;
    background: var(--white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.project-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-color);
    opacity: 0.3;
}

.project-content h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

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

.tag {
    background-color: var(--bg-light);
    color: var(--primary-dark);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

/* Methods Grid */
.methods-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.method-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
    box-shadow: var(--shadow);
}

.method-card h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

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

.featured-pub-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-top: 4px solid var(--primary-color);
}

.featured-pub-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.pub-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.pub-authors {
    color: var(--text-medium);
    margin-bottom: 0.5rem;
}

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

.pub-summary {
    color: var(--text-medium);
    margin-bottom: 1.5rem;
}

/* Publications Page */
.publications-controls {
    background: var(--white);
    border-bottom: 1px solid var(--border-color);
    padding: 2rem 0;
}

.controls-wrapper {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.search-input {
    width: 100%;
    padding: 0.875rem 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(70, 130, 180, 0.1);
}

.filter-buttons {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    justify-content: center;
}

.filter-btn {
    padding: 0.5rem 1.25rem;
    border: 2px solid var(--primary-color);
    background: var(--white);
    color: var(--primary-color);
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-color);
    color: var(--white);
}

.year-section {
    margin-bottom: 3rem;
}

.year-header {
    font-size: 2rem;
    color: var(--primary-dark);
    margin-bottom: 2rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--primary-color);
}

.pub-item {
    background: var(--white);
    padding: 2rem;
    margin-bottom: 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    position: relative;
    transition: var(--transition);
}

.pub-item:hover {
    box-shadow: var(--shadow-hover);
}

.pub-item.first-author {
    border-left: 4px solid var(--primary-color);
}

.pub-item.featured {
    background: linear-gradient(135deg, rgba(70, 130, 180, 0.05) 0%, rgba(44, 90, 160, 0.05) 100%);
}

.pub-marker {
    display: inline-block;
    background: var(--primary-color);
    color: var(--white);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.featured-badge {
    display: inline-block;
    background: linear-gradient(135deg, #FFD700 0%, #FFA500 100%);
    color: var(--white);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-left: 0.5rem;
    margin-bottom: 0.75rem;
}

.pub-title {
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.pub-links {
    margin-top: 1rem;
    display: flex;
    gap: 1rem;
}

.pub-link {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    transition: var(--transition);
}

.pub-link:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.no-results {
    text-align: center;
    padding: 3rem;
    color: var(--text-medium);
}

/* People Page */
.pi-profile {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
    background: var(--white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.pi-image img {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.pi-details h3 {
    font-size: 2rem;
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

.pi-title {
    font-size: 1.25rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

.pi-affiliation {
    color: var(--text-medium);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.pi-contact {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.contact-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    font-weight: 600;
    transition: var(--transition);
}

.contact-link:hover {
    color: var(--primary-dark);
    transform: translateX(4px);
}

.pi-bio {
    max-width: 900px;
    margin: 0 auto;
    background: var(--white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.pi-bio h4 {
    color: var(--primary-dark);
    margin-bottom: 1.5rem;
}

.cv-download {
    margin-top: 2rem;
}

.team-placeholder {
    text-align: center;
    padding: 3rem;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

/* Join Page */
.join-card {
    max-width: 900px;
    margin: 0 auto;
    background: var(--white);
    padding: 3rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.join-icon {
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 1.5rem;
}

.join-card h2 {
    color: var(--primary-dark);
    text-align: center;
    margin-bottom: 1.5rem;
}

.requirements-box,
.opportunities-box {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 8px;
    margin: 2rem 0;
    border-left: 4px solid var(--primary-color);
}

.requirements-box h3,
.opportunities-box h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

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

.check-list li {
    padding-left: 2rem;
    position: relative;
    margin-bottom: 0.75rem;
}

.check-list li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
    font-size: 1.2rem;
}

.skills-list {
    list-style: none;
    padding-left: 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 0.75rem;
}

.skills-list li {
    padding-left: 2rem;
    position: relative;
}

.skills-list li:before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
    font-size: 1.5rem;
}

.how-to-apply {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.how-to-apply h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

.how-to-apply ol {
    margin-left: 1.5rem;
    margin-bottom: 2rem;
}

.how-to-apply ol li {
    margin-bottom: 0.5rem;
}

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

.benefit-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.benefit-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.benefit-icon {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.benefit-card h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

/* Contact Page */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.contact-info h2 {
    color: var(--primary-dark);
    margin-bottom: 2rem;
}

.contact-block {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.contact-block:last-child {
    border-bottom: none;
}

.contact-block h3 {
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

.contact-block h4 {
    color: var(--primary-color);
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
}

.contact-title {
    color: var(--text-medium);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.contact-link-large {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-color);
}

.social-links h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.social-icons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--primary-color);
    font-weight: 600;
    transition: var(--transition);
}

.social-link:hover {
    color: var(--primary-dark);
    transform: translateX(4px);
}

.contact-map {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.contact-map h2 {
    color: var(--primary-dark);
    margin-bottom: 2rem;
}

.map-container {
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 1.5rem;
}

.map-info h3 {
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

.quick-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.quick-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.quick-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.quick-icon {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.quick-card h3 {
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

/* Footer */
.footer {
    background-color: var(--text-dark);
    color: var(--white);
    padding: 3rem 0 1rem;
    margin-top: 5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: var(--white);
    margin-bottom: 1rem;
}

.footer-logo {
    height: 60px;
    width: auto;
    margin-bottom: 1rem;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--white);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* Utilities */
.text-center {
    text-align: center;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    opacity: 0;
    animation: fadeInUp 0.6s ease-out forwards;
}

.fade-in:nth-child(1) { animation-delay: 0.1s; }
.fade-in:nth-child(2) { animation-delay: 0.2s; }
.fade-in:nth-child(3) { animation-delay: 0.3s; }
.fade-in:nth-child(4) { animation-delay: 0.4s; }
.fade-in:nth-child(5) { animation-delay: 0.5s; }

/* Responsive Design */
@media (max-width: 968px) {
    .hero {
        grid-template-columns: 1fr;
        gap: 3rem;
        text-align: center;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-cta {
        justify-content: center;
    }

    .location-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

    .pi-profile {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .pi-contact {
        align-items: center;
    }
}

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

    .nav-menu.active {
        left: 0;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .mobile-menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }

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

    .section {
        padding: 3rem 0;
    }

    .container {
        padding: 0 1rem;
    }

    .project-card {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

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

@media (max-width: 480px) {
    .themes-grid,
    .publications-grid,
    .methods-grid,
    .featured-grid {
        grid-template-columns: 1fr;
    }

    .filter-buttons {
        gap: 0.5rem;
    }

    .filter-btn {
        padding: 0.4rem 1rem;
        font-size: 0.9rem;
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .hero-cta,
    .btn {
        display: none;
    }
}