/* === MODERN CSS VARIABLES === */
:root {
    /* Light theme colors */
    --bg-primary: #fafffe;
    --bg-secondary: #f0fdf4;
    --bg-tertiary: #dcfce7;
    --bg-accent: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
    --bg-card: #ffffff;
    --bg-glass: rgba(255, 255, 255, 0.1);
    
    /* Text colors */
    --text-primary: #0f172a;
    --text-secondary: #374151;
    --text-muted: #6b7280;
    --text-inverse: #ffffff;
    
    /* Brand colors - Green tech theme */
    --brand-primary: #22c55e;
    --brand-secondary: #16a34a;
    --brand-accent: #10b981;
    --brand-success: #059669;
    --brand-warning: #f59e0b;
    --brand-error: #ef4444;
    
    /* Interactive colors */
    --hover-primary: #16a34a;
    --hover-secondary: #059669;
    --active-primary: #15803d;
    
    /* Borders and shadows */
    --border-light: #d1fae5;
    --border-medium: #a7f3d0;
    --shadow-sm: 0 1px 2px 0 rgb(34 197 94 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(34 197 94 / 0.1), 0 2px 4px -2px rgb(34 197 94 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(34 197 94 / 0.1), 0 4px 6px -4px rgb(34 197 94 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(34 197 94 / 0.1), 0 8px 10px -6px rgb(34 197 94 / 0.1);
    --shadow-glow: 0 0 20px rgba(34, 197, 94, 0.3);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--brand-primary) 0%, var(--brand-secondary) 100%);
    --gradient-accent: linear-gradient(135deg, var(--brand-accent) 0%, var(--brand-primary) 100%);
    --gradient-text: linear-gradient(135deg, var(--brand-primary) 0%, var(--brand-secondary) 100%);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
}

/* Dark theme */
[data-theme="dark"] {
    --bg-primary: #0a0f0a;
    --bg-secondary: #0f1b0f;
    --bg-tertiary: #1a2e1a;
    --bg-card: #0f1b0f;
    --bg-glass: rgba(15, 27, 15, 0.8);
    
    --text-primary: #f0fdf4;
    --text-secondary: #bbf7d0;
    --text-muted: #86efac;
    --text-inverse: #0a0f0a;
    
    --border-light: #1a2e1a;
    --border-medium: #22543d;
    
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.3), 0 8px 10px -6px rgb(0 0 0 / 0.3);
}

/* === GLOBAL STYLES === */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: all var(--transition-normal);
}

/* === SECTION STYLES === */
#about { background: var(--bg-primary); }
#skills { background: var(--bg-secondary); }
#certification { background: var(--bg-primary); }
#projects { background: var(--bg-secondary); }
#publications { background: var(--bg-primary); }
#contact { background: var(--bg-secondary); }

/* === UTILITY CLASSES === */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.glass-effect {
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.gradient-text {
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-full);
    font-family: inherit;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left var(--transition-slow);
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--text-inverse);
    box-shadow: var(--shadow-md);
}

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

.btn-outline {
    background: transparent;
    color: var(--brand-primary);
    border: 2px solid var(--brand-primary);
}

.btn-outline:hover {
    background: var(--brand-primary);
    color: var(--text-inverse);
}

.section {
    padding: var(--spacing-3xl) 0;
    position: relative;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
}

.card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

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

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

.card:hover::before {
    transform: scaleX(1);
}

/* === HEADER === */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
    transition: all var(--transition-normal);
    perspective: 1000px; /* Menambahkan perspektif untuk efek 3D */
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--brand-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    perspective: 1000px;
    position: left;
    z-index: 1;
}

.logo::before,


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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: color var(--transition-normal);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-normal);
}

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

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

.header-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.toggle-btn {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: var(--radius-md);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
}

.toggle-btn:hover {
    background: var(--brand-primary);
    color: var(--text-inverse);
    transform: scale(1.1);
}

.mobile-menu-toggle {
    display: none;
}

.hamburger {
    display: none;
    cursor: pointer;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 1px auto;
    transition: all 0.3s ease-in-out;
    background-color: var(--text-primary); /* Ubah warna sesuai tema */
}

/* === MOBILE MENU === */
.mobile-menu {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--bg-glass);
    backdrop-filter: blur(30px);
    border-bottom: 1px solid var(--border-light);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 999;
}

.mobile-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
}

.mobile-nav {
    display: flex;
    flex-direction: column;
    list-style: none;
    padding: var(--spacing-lg);
    gap: var(--spacing-md);
}

.mobile-nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

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

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

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: var(--gradient-accent);
    clip-path: polygon(30% 0%, 100% 0%, 100% 100%, 0% 100%);
    opacity: 0.08;
}

.hero::after {
    content: '';
    position: absolute;
    top: 20%;
    right: 10%;
    width: 200px;
    height: 200px;
    background: linear-gradient(45deg, var(--brand-primary), var(--brand-accent));
    border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
    opacity: 0.1;
    animation: morph 8s ease-in-out infinite;
}

@keyframes morph {
    0%, 100% {
        border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
        transform: rotate(0deg) scale(1);
    }
    25% {
        border-radius: 58% 42% 75% 25% / 76% 46% 54% 24%;
        transform: rotate(90deg) scale(1.1);
    }
    50% {
        border-radius: 50% 50% 33% 67% / 55% 27% 73% 45%;
        transform: rotate(180deg) scale(0.9);
    }
    75% {
        border-radius: 33% 67% 58% 42% / 63% 68% 32% 37%;
        transform: rotate(270deg) scale(1.2);
    }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 600px;
}

.hero-subtitle {
    color: var(--brand-primary);
    font-weight: 600;
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.hero-subtitle::before {
    content: '';
    width: 40px;
    height: 2px;
    background: var(--gradient-primary);
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2xl);
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.hero-stats {
    display: flex;
    gap: var(--spacing-2xl);
    margin-top: var(--spacing-2xl);
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--brand-primary);
    font-family: 'JetBrains Mono', monospace;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* === ABOUT SECTION === */
.about-content {
    display: grid;
    grid-template-columns: 1fr 3fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

.about-image-container {
    position: relative;
}

.about-image {
    width: 100%;
    max-width: 400px;
    border-radius: var(--radius-full); /* Membuat foto profil menjadi lingkaran sempurna */
    box-shadow: var(--shadow-xl);
    transition: transform var(--transition-normal);
    aspect-ratio: 1; /* Memastikan rasio 1:1 untuk lingkaran sempurna */
    object-fit: cover; /* Memastikan gambar terpotong dengan baik dalam lingkaran */
}

.about-image:hover {
    transform: scale(1.05);
    box-shadow: 0 0 30px rgba(139, 92, 246, 0.4), 0 0 60px rgba(34, 197, 94, 0.2);
}

.about-image-container::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 20px;
    right: 20px;
    bottom: 20px;
    border: 0 solid transparent;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    z-index: -1;
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: xor;
    -webkit-mask-composite: xor;
}

.about-text h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--brand-primary);
}

.about-text p {
    margin-bottom: var(--spacing-lg);
    color: var(--text-secondary);
}

/* === SKILLS SECTION === */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.skill-item {
    background: var(--bg-card);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.skill-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.skill-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.skill-name {
    font-weight: 600;
    font-size: 1.125rem;
}

.skill-percentage {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    color: var(--brand-primary);
}

.skill-progress {
    width: 100%;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    overflow: hidden;
    position: relative;
}

.skill-progress-bar {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width 1s ease-in-out 0.5s;
    position: relative;
}

.skill-progress-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* === CERTIFICATIONS SECTION === */
.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.certification-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    cursor: pointer;
    position: relative;
}

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

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

.certification-header {
    padding: var(--spacing-xl);
    border-bottom: 1px solid var(--border-light);
}

.certification-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.certification-institution {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-xs);
}

.certification-year {
    display: inline-block;
    background: var(--gradient-primary);
    color: var(--text-inverse);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
}

.certification-body {
    padding: var(--spacing-xl);
}

.certification-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* === PROJECTS SECTION === */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-2xl);
}

.project-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    position: relative;
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.project-image-container {
    position: relative;
    overflow: hidden;
    height: 250px;
}

.project-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.project-card:hover .project-image {
    transform: scale(1.1);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, transparent, rgba(0,0,0,0.7));
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: var(--spacing-lg);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-content {
    padding: var(--spacing-xl);
}

.project-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--brand-primary);
    text-decoration: none;
    font-weight: 500;
    transition: all var(--transition-normal);
}

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

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

.publication-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    border-left: 4px solid var(--brand-primary);
}

.publication-card:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-xl);
}

.publication-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    line-height: 1.4;
}

.publication-meta {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.publication-journal,
.publication-year {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.publication-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--brand-primary);
    text-decoration: none;
    font-weight: 500;
    transition: all var(--transition-normal);
}

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

/* === CONTACT SECTION === */
.contact-content {
    max-width: 600px;
    margin: 0 auto;
}

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

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

.form-label {
    font-weight: 500;
    color: var(--text-primary);
}

.form-input,
.form-textarea {
    padding: var(--spacing-md);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-family: inherit;
    transition: all var(--transition-normal);
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--brand-primary);
    box-shadow: 0 0 0 3px rgba(34, 197, 94, 0.1);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

.form-submit {
    background: var(--gradient-primary);
    color: var(--text-inverse);
    border: none;
    padding: var(--spacing-lg) var(--spacing-2xl);
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 1.125rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    display: inline-flex;       /* supaya teks + ikon bisa sejajar */
    align-items: center;        /* vertikal center */
    justify-content: center;    /* posisi rata tengah */
    gap: 1rem;     /* <== jarak antara teks dan ikon */

}

.form-submit:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.form-submit:active {
    transform: translateY(0);
}

/* === MODAL === */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    padding: var(--spacing-lg);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    max-width: 90vw;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-close {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 40px;
    height: 40px;
    border: none;
    border-radius: var(--radius-full);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-normal);
}

.modal-close:hover {
    background: var(--brand-error);
    color: var(--text-inverse);
    transform: rotate(90deg);
}

.cert-image {
    width: 100%;
    max-width: 500px;
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-lg);
}

/* === FOOTER === */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-light);
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

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

.social-link {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-full);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: all var(--transition-normal);
}

.social-link:hover {
    background: var(--brand-primary);
    color: var(--text-inverse);
    transform: translateY(-5px);
}

/* === RESPONSIVE DESIGN === */
@media (max-width: 1024px) {
    .nav {
        display: none;
    }

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

    .about-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
        text-align: center;
    }

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

    .projects-grid {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }

    .hero-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-lg);
        align-items: center;
    }

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

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

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

    .publication-meta {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .modal-content {
        margin: var(--spacing-md);
        padding: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .header-content {
        height: 70px;
    }

    .hero {
        padding-top: 70px;
    }

    .section {
        padding: var(--spacing-2xl) 0;
    }

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

    .project-image-container {
        height: 200px;
    }
}

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

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

.animate-fade-in-up { animation: fadeInUp 0.6s ease-out; }
.animate-fade-in-left { animation: fadeInLeft 0.6s ease-out; }
.animate-fade-in-right { animation: fadeInRight 0.6s ease-out; }

/* === SCROLL ANIMATIONS === */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* === LOADING ANIMATION === */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* === SUCCESS/ERROR MESSAGES === */
.message-box {
    position: fixed;
    top: 100px;
    right: var(--spacing-lg);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-xl);
    border-left: 4px solid var(--brand-success);
    z-index: 9998;
    transform: translateX(400px);
    opacity: 0;
    transition: all var(--transition-normal);
    max-width: 400px;
}

.message-box.show {
    transform: translateX(0);
    opacity: 1;
}

.message-box.error {
    border-left-color: var(--brand-error);
}

.message-box-title {
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.message-box.error .message-box-title {
    color: var(--brand-error);
}

.message-box:not(.error) .message-box-title {
    color: var(--brand-success);
}

.message-box-close {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color var(--transition-normal);
}

.message-box-close:hover {
    color: var(--text-primary);
}

.hamburger {
    display: none;
    cursor: pointer;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    transition: all 0.3s ease-in-out;
    background-color: var(--text-primary); /* Ubah warna sesuai tema */
}

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

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 80px;
        gap: 0;
        flex-direction: column;
        background-color: var(--bg-card);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: var(--spacing-lg) 0;
        box-shadow: var(--shadow-md);
    }

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

    .nav-menu li {
        margin: var(--spacing-md) 0;
    }
}