/* ===========================
   CSS Variables for Easy Customization
   =========================== */
:root {
    /* Color Palette - Customize these to change the entire theme */
    --primary-color: #4A90E2;
    --primary-dark: #357ABD;
    --secondary-color: #6C757D;
    --accent-color: #5C9FD6;
    --background-light: #F8F9FA;
    --background-white: #FFFFFF;
    --text-dark: #2C3E50;
    --text-medium: #5A6C7D;
    --text-light: #7F8C8D;
    --border-color: #E1E8ED;
    --shadow-light: rgba(0, 0, 0, 0.08);
    --shadow-medium: rgba(0, 0, 0, 0.12);
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

body {
    font-family: var(--font-primary);
    color: var(--text-dark);
    line-height: var(--line-height-base);
    background-color: var(--background-white);
}

/* ===========================
   Typography
   =========================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: 3rem;
}

h2 {
    font-size: 2.5rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-medium);
}

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

/* ===========================
   Container & Layout
   =========================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

/* ===========================
   Navigation Bar
   =========================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--background-white);
    box-shadow: 0 2px 10px var(--shadow-light);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-link {
    color: var(--text-medium);
    font-weight: 500;
    transition: color var(--transition-fast);
}

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

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

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    margin: 3px 0;
    transition: all var(--transition-fast);
    border-radius: 2px;
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background: linear-gradient(135deg, var(--background-light) 0%, #E8F4F8 100%);
    margin-top: 60px;
    position: relative;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: var(--spacing-sm);
    animation: fadeInUp 0.8s ease;
}

.highlight {
    color: var(--primary-color);
    position: relative;
}

.hero-subtitle {
    font-size: 1.8rem;
    color: var(--text-medium);
    margin-bottom: var(--spacing-md);
    font-weight: 500;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-description {
    font-size: 1.2rem;
    color: var(--text-medium);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.6s backwards;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-base);
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px var(--shadow-medium);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* ===========================
   Section Titles
   =========================== */
.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-dark);
    position: relative;
    padding-bottom: var(--spacing-sm);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--primary-color);
    border-radius: 2px;
}

/* ===========================
   About Section
   =========================== */
.about {
    background: var(--background-white);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    color: var(--text-medium);
}

/* ===========================
   Skills Section
   =========================== */
.skills {
    background: var(--background-light);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: var(--spacing-sm);
    max-width: 900px;
    margin: 0 auto;
}

.skill-badge {
    background: var(--background-white);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
    font-weight: 600;
    color: var(--text-dark);
    box-shadow: 0 4px 12px var(--shadow-light);
    transition: all var(--transition-base);
    cursor: default;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    min-height: 50px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.skill-badge .skill-icon {
    width: 28px;
    height: 28px;
    object-fit: contain;
    flex-shrink: 0;
}

.skill-badge:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px var(--shadow-medium);
    background: var(--primary-color);
    color: white;
}

/* ===========================
   Projects Section
   =========================== */
.projects {
    background: var(--background-white);
}

/* Company Section Styling */
.company-section {
    margin-bottom: var(--spacing-xl);
    background: var(--background-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
}

.company-header {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.company-name {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-dark);
    line-height: 1.3;
}

.company-role {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.company-role::before {
    content: "";
    width: 8px;
    height: 8px;
    background: var(--primary-color);
    border-radius: 50%;
}

.company-period {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-light);
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.company-period::before {
    content: "📅";
    font-size: 1rem;
}

/* Project Card Styling */
.project-card {
    background: var(--background-white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    transition: all var(--transition-base);
    box-shadow: 0 2px 8px var(--shadow-light);
}

.project-card:last-child {
    margin-bottom: 0;
}

.project-card:hover {
    transform: translateX(8px);
    box-shadow: 0 8px 24px var(--shadow-medium);
    border-color: var(--primary-color);
}

.project-content {
    display: flex;
    flex-direction: column;
}

.project-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.project-name::before {
    content: "▸";
    color: var(--primary-color);
    font-size: 1.5rem;
}

.project-summary {
    color: var(--text-medium);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
    font-size: 1rem;
    text-align: justify;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tag {
    background: var(--background-light);
    color: var(--primary-color);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

.project-link {
    color: var(--primary-color);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    transition: all var(--transition-fast);
    align-self: flex-start;
}

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

/* ===========================
   Achievements Section
   =========================== */
.achievements {
    background: var(--background-light);
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.achievement-card {
    background: var(--background-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: 0 4px 12px var(--shadow-light);
    transition: all var(--transition-base);
}

.achievement-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 30px var(--shadow-medium);
}

.achievement-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.achievement-title {
    color: var(--text-dark);
    margin-bottom: var(--spacing-xs);
    font-size: 1.3rem;
}

.achievement-org {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.achievement-description {
    color: var(--text-medium);
    line-height: 1.7;
}

/* ===========================
   Contact Section
   =========================== */
.contact {
    background: var(--background-white);
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-description {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-medium);
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.contact-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--background-light);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    border: 2px solid transparent;
}

.contact-item:hover {
    background: var(--primary-color);
    color: white;
    transform: translateX(8px);
    border-color: var(--primary-color);
}

.contact-icon {
    font-size: 1.5rem;
}

.contact-text {
    font-weight: 600;
}

/* ===========================
   Footer
   =========================== */
.footer {
    background: var(--text-dark);
    color: var(--background-light);
    text-align: center;
    padding: var(--spacing-md) 0;
}

.footer p {
    margin-bottom: var(--spacing-xs);
    color: var(--background-light);
}

.footer-note {
    font-size: 0.9rem;
    opacity: 0.8;
}

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

/* ===========================
   Responsive Design - Tablet
   =========================== */
@media (max-width: 768px) {
    /* Typography adjustments */
    h1 {
        font-size: 2.5rem;
    }
    
    h2 {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.4rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    /* Navigation */
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 60px;
        flex-direction: column;
        background-color: var(--background-white);
        width: 100%;
        text-align: center;
        transition: left var(--transition-base);
        box-shadow: 0 10px 27px var(--shadow-medium);
        padding: var(--spacing-md) 0;
        gap: 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-menu li {
        padding: var(--spacing-sm) 0;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .mobile-menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }
    
    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .mobile-menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    /* Sections */
    section {
        padding: var(--spacing-lg) 0;
    }
    
    /* Grids */
    .projects-grid,
    .achievements-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
        gap: var(--spacing-xs);
    }
    
    /* Buttons */
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 280px;
    }
}

/* ===========================
   Responsive Design - Mobile
   =========================== */
@media (max-width: 480px) {
    :root {
        --font-size-base: 14px;
        --spacing-md: 1.5rem;
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .project-card,
    .achievement-card {
        padding: var(--spacing-sm);
    }
}

/* ===========================
   Print Styles
   =========================== */
@media print {
    .navbar,
    .mobile-menu-toggle,
    .hero-buttons {
        display: none;
    }
    
    section {
        page-break-inside: avoid;
    }
}