/* 
 * Main Stylesheet for Hazem Chaabi's Professional Website
 * Author: Manus AI
 * Version: 1.0
 */

/* ===== VARIABLES ===== */
:root {
    /* Colors */
    --primary-color: #1a3a63;
    --secondary-color: #2a9d8f;
    --accent-color: #e9c46a;
    --bg-color: #f8f9fa;
    --bg-alt-color: #e9ecef;
    --text-color: #333333;
    --text-light: #6c757d;
    --white: #ffffff;
    --black: #000000;
    --success: #28a745;
    --danger: #dc3545;
    --warning: #ffc107;
    --info: #17a2b8;
    
    /* Typography */
    --heading-font: 'Montserrat', sans-serif;
    --body-font: 'Open Sans', sans-serif;
    --code-font: 'Fira Code', monospace;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;
    
    /* Border Radius */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 1rem;
    --border-radius-full: 50%;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Container */
    --container-width: 1200px;
    --container-padding: 1rem;
}


/* ===== RESET & BASE STYLES ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    scroll-padding-top: 5rem;
}

body {
    font-family: var(--body-font);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color var(--transition-normal), color var(--transition-normal);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--heading-font);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
    transition: color var(--transition-normal);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

h4 {
    font-size: 1.25rem;
}

p {
    margin-bottom: var(--spacing-md);
}

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

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

ul, ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button, .btn {
    cursor: pointer;
    font-family: var(--body-font);
    font-size: 1rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
    border: none;
    outline: none;
    display: inline-block;
    text-align: center;
}

input, textarea, select {
    font-family: var(--body-font);
    font-size: 1rem;
    padding: 0.75rem 1rem;
    border: 1px solid var(--text-light);
    border-radius: var(--border-radius-md);
    background-color: var(--white);
    color: var(--text-color);
    transition: all var(--transition-fast);
    width: 100%;
    outline: none;
}

input:focus, textarea:focus, select:focus {
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 2px rgba(42, 157, 143, 0.2);
}

/* ===== UTILITY CLASSES ===== */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

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

.btn-primary:hover {
    background-color: var(--primary-color);
    filter: brightness(1.1);
    color: var(--white);
}

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

.btn-secondary:hover {
    background-color: var(--secondary-color);
    filter: brightness(1.1);
    color: var(--white);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.tag {
    display: inline-block;
    background-color: rgba(42, 157, 143, 0.1);
    color: var(--secondary-color);
    padding: 0.25rem 0.75rem;
    border-radius: var(--border-radius-full);
    font-size: 0.75rem;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

.section {
    padding: var(--spacing-xxl) 0;
}

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

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xxl);
}

.underline {
    height: 4px;
    width: 70px;
    background-color: var(--secondary-color);
    margin: 0 auto;
}

/* ===== HEADER & NAVIGATION ===== */
#header {
    position: relative;
}

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-family: var(--heading-font);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-menu li {
    margin-left: var(--spacing-md);
}

.nav-link {
    color: var(--text-color);
    font-weight: 500;
    padding: 0.5rem;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--secondary-color);
    transition: width var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    height: 3px;
    width: 100%;
    background-color: var(--primary-color);
    transition: all var(--transition-normal);
}

.theme-toggle {
    margin-left: var(--spacing-md);
    font-size: 1.2rem;
    cursor: pointer;
    color: var(--text-color);
}

/* ===== HERO SECTION ===== */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background-color: var(--bg-color);
    overflow: hidden;
}

#particles-js {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.hero-text {
    flex: 1;
    padding-right: var(--spacing-xl);
}

.hero-text h1 {
    font-size: 3.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.hero-text h2 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-color);
}

.hero-text h2 span {
    color: var(--secondary-color);
}

.typing-container {
    margin-bottom: var(--spacing-xl);
    height: 2rem;
}

.static-text {
    font-size: 1.25rem;
    color: var(--text-color);
}

.dynamic-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.profile-img-placeholder {
    width: 300px;
    height: 300px;
    border-radius: var(--border-radius-full);
    background-color: var(--bg-alt-color);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 8rem;
    color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

/* ===== ABOUT SECTION ===== */
.about-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-xxl);
}

.about-image {
    flex: 1;
    display: flex;
    justify-content: center;
}

.about-image .profile-img-placeholder {
    width: 250px;
    height: 250px;
    font-size: 6rem;
}

.about-text {
    flex: 2;
}

.about-details {
    margin-top: var(--spacing-lg);
}

.detail-item {
    display: flex;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.detail-item i {
    width: 30px;
    color: var(--secondary-color);
    margin-right: var(--spacing-md);
}

/* ===== RESEARCH SECTION ===== */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.research-card {
    background-color: var(--white);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    text-align: center;
}

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

.research-icon {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-md);
}

.research-card h3 {
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
}

/* ===== PUBLICATIONS SECTION ===== */
.publications-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.publication-card {
    background-color: var(--white);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

.publication-header {
    padding: var(--spacing-lg);
    background-color: var(--primary-color);
    color: var(--white);
}

.publication-header h3 {
    color: var(--white);
    margin-bottom: var(--spacing-md);
}

.publication-tags {
    display: flex;
    flex-wrap: wrap;
}

.publication-body {
    padding: var(--spacing-lg);
}

.publication-authors {
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.publication-affiliation {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.publication-links {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

/* ===== PROJECTS SECTION ===== */
.projects-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.project-card {
    display: flex;
    background-color: var(--white);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

.project-image {
    width: 150px;
    min-width: 150px;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--primary-color);
    color: var(--white);
    font-size: 3rem;
}

.project-info {
    padding: var(--spacing-lg);
    flex: 1;
}

.project-date {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-md);
}

.project-tags {
    margin-top: var(--spacing-md);
}

/* ===== EXPERIENCE & EDUCATION SECTION ===== */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    width: 2px;
    background-color: var(--secondary-color);
    top: 0;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
}

.timeline-item {
    padding: var(--spacing-lg) 0;
    position: relative;
    width: 100%;
    display: flex;
    justify-content: center;
}

.timeline-dot {
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: var(--secondary-color);
    border-radius: 50%;
    top: 25px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
}

.timeline-date {
    width: 45%;
    padding-right: var(--spacing-xl);
    text-align: right;
}

.timeline-content {
    width: 45%;
    padding-left: var(--spacing-xl);
}

.timeline-content h3 {
    margin-bottom: var(--spacing-xs);
}

.timeline-content h4 {
    color: var(--secondary-color);
    margin-bottom: var(--spacing-md);
    font-weight: 500;
}

/* ===== SKILLS SECTION ===== */
.skills-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xxl);
}

.skills-category h3 {
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.skill-item {
    background-color: var(--white);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.skill-info h4 {
    margin-bottom: var(--spacing-md);
}

.skill-progress {
    height: 8px;
    background-color: var(--bg-alt-color);
    border-radius: var(--border-radius-full);
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background-color: var(--secondary-color);
    border-radius: var(--border-radius-full);
    width: 0;
    transition: width 1.5s ease;
}

.certifications h3,
.languages h3 {
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.cert-grid,
.lang-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.cert-item {
    display: flex;
    align-items: center;
    background-color: var(--white);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.cert-icon {
    font-size: 2rem;
    color: var(--accent-color);
    margin-right: var(--spacing-lg);
}

.cert-info h4 {
    margin-bottom: var(--spacing-xs);
}

.cert-info p {
    color: var(--text-light);
    margin-bottom: 0;
}

.lang-item {
    background-color: var(--white);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.lang-info h4 {
    margin-bottom: var(--spacing-xs);
}

.lang-info p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.lang-level {
    display: flex;
    gap: 5px;
}

.lang-level span {
    width: 20px;
    height: 10px;
    background-color: var(--bg-alt-color);
    border-radius: var(--border-radius-sm);
}

.lang-level span.filled {
    background-color: var(--secondary-color);
}

/* ===== CONTACT SECTION ===== */
.contact-content {
    display: flex;
    gap: var(--spacing-xxl);
}

.contact-info {
    flex: 1;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: var(--spacing-lg);
}

.contact-icon {
    font-size: 1.5rem;
    color: var(--secondary-color);
    margin-right: var(--spacing-lg);
    width: 30px;
    text-align: center;
}

.contact-text h3 {
    margin-bottom: var(--spacing-xs);
}

.contact-text p {
    margin-bottom: 0;
}

.contact-form {
    flex: 1;
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
}

/* ===== FOOTER ===== */
.footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: var(--spacing-xxl) 0 var(--spacing-md);
    position: relative;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xxl);
}

.footer-logo h3 {
    color: var(--white);
    margin-bottom: var(--spacing-xs);
}

.footer-logo p {
    color: rgba(255, 255, 255, 0.7);
}

.footer-links h3,
.footer-social h3 {
    color: var(--white);
    margin-bottom: var(--spacing-md);
}

.footer-links ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-fast);
}

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

.social-icons {
    display: flex;
    gap: var(--spacing-md);
}

.social-icons a {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius-full);
    color: var(--white);
    transition: all var(--transition-fast);
}

.social-icons a:hover {
    background-color: var(--secondary-color);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.back-to-top {
    position: absolute;
    right: 30px;
    bottom: 30px;
    width: 40px;
    height: 40px;
    background-color: var(--secondary-color);
    color: var(--white);
    border-radius: var(--border-radius-full);
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all var(--transition-fast);
    opacity: 0;
    visibility: hidden;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

/* ===== RESPONSIVE STYLES ===== */
@media (max-width: 992px) {
    html {
        font-size: 15px;
    }
    
    .hero-content {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-text {
        padding-right: 0;
        margin-bottom: var(--spacing-xl);
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .about-content {
        flex-direction: column;
        text-align: center;
    }
    
    .about-image {
        margin-bottom: var(--spacing-xl);
    }
    
    .detail-item {
        justify-content: center;
    }
    
    .timeline::before {
        left: 40px;
    }
    
    .timeline-item {
        flex-direction: column;
        align-items: flex-start;
        padding-left: 80px;
    }
    
    .timeline-dot {
        left: 40px;
    }
    
    .timeline-date,
    .timeline-content {
        width: 100%;
        text-align: left;
        padding: 0;
    }
    
    .timeline-date {
        margin-bottom: var(--spacing-sm);
    }
    
    .contact-content {
        flex-direction: column;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-links ul {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--spacing-md);
    }
    
    .social-icons {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .navbar .container {
        height: 60px;
    }
    
    .nav-menu {
        position: fixed;
        top: 60px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 60px);
        background-color: var(--white);
        flex-direction: column;
        align-items: center;
        padding: var(--spacing-xl) 0;
        transition: left var(--transition-normal);
        box-shadow: var(--shadow-md);
        overflow-y: auto;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-menu li {
        margin: 0 0 var(--spacing-md);
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: translateY(9px) rotate(45deg);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: translateY(-9px) rotate(-45deg);
    }
    
    .project-card {
        flex-direction: column;
    }
    
    .project-image {
        width: 100%;
        height: 150px;
    }
}

@media (max-width: 576px) {
    html {
        font-size: 14px;
    }
    
    .hero-text h1 {
        font-size: 2.5rem;
    }
    
    .hero-text h2 {
        font-size: 1.5rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .hero-buttons .btn {
        width: 100%;
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    .section-header {
        margin-bottom: var(--spacing-xl);
    }
    
    .skills-grid,
    .cert-grid,
    .lang-grid {
        grid-template-columns: 1fr;
    }
}

.profile-img {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.profile-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}