/* ============================================
   PORTFOLIO NDOUWE SALVADOR - STYLES
   Design: Modern Dark Theme with Blue Accents
   ============================================ */

/* CSS Variables */
:root {
    /* Colors - Dark Theme */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --bg-card: #161620;
    --bg-hover: #20202e;
    
    /* Accent Colors - Blue/Energy */
    --accent-primary: #00d4ff;
    --accent-secondary: #0099cc;
    --accent-glow: rgba(0, 212, 255, 0.3);
    --accent-gradient: linear-gradient(135deg, #00d4ff 0%, #0099cc 100%);
    
    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #6b6b7b;
    
    /* Additional Colors */
    --success: #00c853;
    --warning: #ffb300;
    --error: #ff1744;
    
    /* Typography */
    --font-primary: 'Poppins', sans-serif;
    
    /* Spacing */
    --section-padding: 100px;
    --container-max: 1200px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 30px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 5px 25px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px var(--accent-glow);
}

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

/* Container */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 20px;
}

/* Section Base */
.section {
    padding: var(--section-padding) 0;
    position: relative;
}

/* Section Header */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 8px 20px;
    background: var(--bg-tertiary);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: var(--radius-xl);
    color: var(--accent-primary);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 20px;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: 15px;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition-normal);
    cursor: pointer;
    border: none;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--accent-gradient);
    color: var(--bg-primary);
    box-shadow: 0 4px 15px rgba(0, 212, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0, 212, 255, 0.5);
}

.btn-primary i {
    transition: var(--transition-normal);
}

.btn-primary:hover i {
    transform: translateX(4px);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--bg-tertiary);
}

.btn-secondary:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    background: rgba(0, 212, 255, 0.05);
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* WhatsApp Button */
.btn-whatsapp {
    background: linear-gradient(135deg, #25d366 0%, #128c7e 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(37, 211, 102, 0.3);
}

.btn-whatsapp:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(37, 211, 102, 0.5);
}

.btn-whatsapp i {
    font-size: 1.2rem;
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 15px 0;
    transition: var(--transition-normal);
    background: transparent;
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-sm);
    padding: 10px 0;
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    font-size: 1.8rem;
}

.logo-text .highlight {
    color: var(--accent-primary);
}

.nav-menu {
    display: flex;
    gap: 35px;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
    padding: 5px 0;
}

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

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

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

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.bar {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition-normal);
    border-radius: 2px;
}

.hamburger.active .bar:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.hamburger.active .bar:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 100px 20px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 0;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 8s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: var(--accent-primary);
    top: -150px;
    right: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: #7c3aed;
    bottom: -100px;
    left: -100px;
    animation-delay: -2s;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: #00c853;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: -4s;
    opacity: 0.2;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    50% {
        transform: translate(30px, -30px) scale(1.1);
    }
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--accent-primary);
    border-radius: 50%;
    opacity: 0.5;
    animation: particle-float 15s infinite;
}

@keyframes particle-float {
    0%, 100% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.5;
    }
    90% {
        opacity: 0.5;
    }
    100% {
        transform: translateY(-100vh) rotate(720deg);
        opacity: 0;
    }
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 900px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: var(--radius-xl);
    color: var(--accent-primary);
    font-size: 0.9rem;
    margin-bottom: 30px;
    animation: fadeInUp 0.8s ease;
}

.hero-badge i {
    color: var(--success);
}

.hero-title {
    margin-bottom: 20px;
}

.greeting {
    display: block;
    font-size: 1.5rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 10px;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.name {
    display: block;
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 800;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 50%, var(--accent-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-subtitle {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    color: var(--text-secondary);
    margin-bottom: 25px;
    min-height: 40px;
    animation: fadeInUp 0.8s ease 0.6s both;
}

.typing-text {
    color: var(--accent-primary);
    font-weight: 600;
}

.cursor {
    color: var(--accent-primary);
    animation: blink 1s infinite;
}

@keyframes blink {
    0%, 50% {
        opacity: 1;
    }
    51%, 100% {
        opacity: 0;
    }
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.8;
    animation: fadeInUp 0.8s ease 0.8s both;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-bottom: 60px;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 1s both;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 1.2s both;
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--accent-primary);
    line-height: 1;
}

.stat-suffix {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
}

.stat-label {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 5px;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    color: var(--text-muted);
    font-size: 0.8rem;
    animation: bounce 2s infinite;
    z-index: 2;
}

.mouse {
    width: 25px;
    height: 40px;
    border: 2px solid var(--text-muted);
    border-radius: 15px;
    position: relative;
}

.wheel {
    width: 4px;
    height: 8px;
    background: var(--accent-primary);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll-wheel 2s infinite;
}

@keyframes scroll-wheel {
    0% {
        opacity: 1;
        top: 8px;
    }
    100% {
        opacity: 0;
        top: 20px;
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

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

/* ============================================
   ABOUT SECTION
   ============================================ */
.about {
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 60px;
    align-items: center;
}

.about-image {
    position: relative;
}

.image-frame {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.image-placeholder {
    width: 100%;
    aspect-ratio: 1;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 8rem;
    color: var(--accent-primary);
    border-radius: var(--radius-lg);
    position: relative;
    overflow: hidden;
}

.image-placeholder::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--accent-gradient);
    opacity: 0.1;
}

.experience-badge {
    position: absolute;
    bottom: -20px;
    right: -20px;
    background: var(--accent-gradient);
    padding: 20px 25px;
    border-radius: var(--radius-md);
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.exp-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--bg-primary);
    line-height: 1;
}

.exp-text {
    font-size: 0.8rem;
    color: var(--bg-primary);
    font-weight: 600;
}

.about-text h3 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin: 30px 0;
}

.highlight-item {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 20px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
}

.highlight-item:hover {
    border-color: var(--accent-primary);
    transform: translateY(-5px);
}

.highlight-item i {
    font-size: 1.5rem;
    color: var(--accent-primary);
}

.highlight-item h4 {
    font-size: 1rem;
    color: var(--text-primary);
}

.highlight-item p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0;
}

/* ============================================
   SKILLS SECTION
   ============================================ */
.skills {
    background: var(--bg-primary);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.skill-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 35px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
}

.skill-card:hover {
    border-color: var(--accent-primary);
    transform: translateY(-5px);
    box-shadow: var(--shadow-glow);
}

.skill-icon {
    width: 60px;
    height: 60px;
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--bg-primary);
    margin-bottom: 20px;
}

.skill-card h3 {
    font-size: 1.3rem;
    margin-bottom: 25px;
    color: var(--text-primary);
}

.skill-items {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.skill-item {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 10px;
    align-items: center;
}

.skill-name {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.skill-bar {
    grid-column: 1 / -1;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 4px;
    width: 0;
    transition: width 1.5s ease;
}

.skill-percent {
    color: var(--accent-primary);
    font-weight: 600;
    font-size: 0.85rem;
}

/* ============================================
   PROJECTS SECTION
   ============================================ */
.projects {
    background: var(--bg-secondary);
}

.projects-filter {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 25px;
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
}

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

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.project-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-primary);
}

.project-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16/10;
}

.project-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    transition: var(--transition-normal);
}

.hf-theme {
    background: linear-gradient(135deg, #1a1a3e 0%, #2d1b69 100%);
    color: #a78bfa;
}

.solar-theme {
    background: linear-gradient(135deg, #1a2e1a 0%, #2d5a27 100%);
    color: #86efac;
}

.simulation-theme {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #60a5fa;
}

.embedded-theme {
    background: linear-gradient(135deg, #2e1a1a 0%, #5a2727 100%);
    color: #fca5a5;
}

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

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition-normal);
}

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

.project-link {
    width: 50px;
    height: 50px;
    background: var(--accent-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--bg-primary);
    font-size: 1.2rem;
    transform: scale(0);
    transition: var(--transition-normal);
}

.project-card:hover .project-link {
    transform: scale(1);
}

.project-content {
    padding: 25px;
}

.project-tags {
    display: flex;
    gap: 8px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.tag {
    padding: 5px 12px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: var(--radius-sm);
    color: var(--accent-primary);
    font-size: 0.75rem;
    font-weight: 500;
}

.project-content h3 {
    font-size: 1.2rem;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.project-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: 15px;
}

.project-tech {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-bottom: 15px;
}

.project-tech span {
    display: flex;
    align-items: center;
    gap: 5px;
    color: var(--text-muted);
    font-size: 0.8rem;
}

.project-tech i {
    color: var(--accent-primary);
}

.project-results {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 15px;
    background: rgba(0, 200, 83, 0.1);
    border-radius: var(--radius-sm);
    color: var(--success);
    font-size: 0.85rem;
    font-weight: 500;
}

/* ============================================
   SERVICES SECTION
   ============================================ */
.services {
    background: var(--bg-primary);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.service-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 35px 25px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
    text-align: center;
}

.service-card:hover {
    border-color: var(--accent-primary);
    transform: translateY(-10px);
    box-shadow: var(--shadow-glow);
}

.service-icon {
    width: 70px;
    height: 70px;
    background: var(--accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: var(--bg-primary);
    margin: 0 auto 20px;
    transition: var(--transition-normal);
}

.service-card:hover .service-icon {
    transform: scale(1.1) rotate(5deg);
}

.service-card h3 {
    font-size: 1.2rem;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.service-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: 20px;
}

.service-features {
    text-align: left;
}

.service-features li {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
    color: var(--text-muted);
    font-size: 0.85rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.service-features li:last-child {
    border-bottom: none;
}

.service-features i {
    color: var(--success);
    font-size: 0.8rem;
}

/* ============================================
   RESEARCH SECTION
   ============================================ */
.research {
    background: var(--bg-secondary);
}

.research-content {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.research-main {
    width: 100%;
}

.research-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.research-card.featured {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
}

.research-image {
    position: relative;
    overflow: hidden;
}

.research-placeholder {
    width: 100%;
    height: 100%;
    min-height: 300px;
    background: linear-gradient(135deg, #1a0a2e 0%, #2d1b4e 50%, #1a1a3e 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6rem;
    color: var(--accent-primary);
}

.research-info {
    padding: 40px;
}

.research-badge {
    display: inline-block;
    padding: 8px 16px;
    background: var(--accent-primary);
    border-radius: var(--radius-sm);
    color: var(--bg-primary);
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.research-info h3 {
    font-size: 1.8rem;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.research-info p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 25px;
}

.research-stats {
    display: flex;
    gap: 40px;
}

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

.r-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--accent-primary);
    line-height: 1;
}

.r-label {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.research-grid .research-card {
    padding: 30px;
    text-align: center;
}

.research-icon {
    width: 60px;
    height: 60px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--accent-primary);
    margin: 0 auto 20px;
}

.research-grid h4 {
    font-size: 1.1rem;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.research-grid p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: 15px;
}

.research-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--accent-primary);
    font-weight: 500;
    font-size: 0.9rem;
}

.research-link:hover {
    gap: 12px;
}

/* ============================================
   CONTACT SECTION
   ============================================ */
.contact {
    background: var(--bg-primary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.contact-card {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 25px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
}

.contact-card:hover {
    border-color: var(--accent-primary);
    transform: translateX(10px);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: var(--bg-primary);
    flex-shrink: 0;
}

.contact-details h4 {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 5px;
}

.contact-details a,
.contact-details span {
    color: var(--text-primary);
    font-weight: 500;
}

.contact-details a:hover {
    color: var(--accent-primary);
}

.social-links {
    padding: 25px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.social-links h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.social-icons {
    display: flex;
    gap: 12px;
}

.social-icon {
    width: 45px;
    height: 45px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--text-secondary);
    transition: var(--transition-normal);
}

.social-icon:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: translateY(-3px);
}

/* Contact Form */
.contact-form-wrapper {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 40px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group {
    position: relative;
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.9rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 45px 14px 15px;
    background: var(--bg-tertiary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: var(--font-primary);
    font-size: 0.95rem;
    transition: var(--transition-normal);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

.form-group i {
    position: absolute;
    right: 15px;
    bottom: 16px;
    color: var(--text-muted);
    font-size: 1rem;
}

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

.form-group textarea + i {
    bottom: auto;
    top: 50px;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background: var(--bg-secondary);
    padding: 60px 0 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-brand {
    max-width: 300px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.8;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.footer-column h4 {
    color: var(--text-primary);
    font-size: 1rem;
    margin-bottom: 20px;
}

.footer-column ul li {
    margin-bottom: 12px;
}

.footer-column ul li a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: var(--transition-normal);
}

.footer-column ul li a:hover {
    color: var(--accent-primary);
    padding-left: 5px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.footer-legal {
    display: flex;
    gap: 20px;
}

.footer-legal a {
    color: var(--text-muted);
    font-size: 0.85rem;
}

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

/* ============================================
   WHATSAPP FLOAT BUTTON
   ============================================ */
.whatsapp-float {
    position: fixed;
    bottom: 100px;
    right: 30px;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #25d366 0%, #128c7e 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px) scale(0.8);
    transition: var(--transition-normal);
    z-index: 998;
    box-shadow: 0 4px 20px rgba(37, 211, 102, 0.4);
    text-decoration: none;
}

.whatsapp-float.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

.whatsapp-float:hover {
    transform: translateY(-5px) scale(1.1);
    box-shadow: 0 8px 30px rgba(37, 211, 102, 0.6);
}

.whatsapp-float::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: rgba(37, 211, 102, 0.3);
    animation: whatsapp-pulse 2s infinite;
    z-index: -1;
}

@keyframes whatsapp-pulse {
    0% {
        transform: scale(1);
        opacity: 1;
    }
    100% {
        transform: scale(1.5);
        opacity: 0;
    }
}

/* ============================================
   WHATSAPP CONTACT CARD
   ============================================ */
.whatsapp-card {
    border: 1px solid rgba(37, 211, 102, 0.3);
}

.whatsapp-card:hover {
    border-color: #25d366;
}

.whatsapp-icon {
    background: linear-gradient(135deg, #25d366 0%, #128c7e 100%);
}

/* ============================================
   FORM FOOTER
   ============================================ */
.form-footer {
    margin-top: 25px;
    text-align: center;
}

.response-guarantee {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    color: var(--success);
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 15px;
}

.response-guarantee i {
    font-size: 1rem;
}

/* ============================================
   BACK TO TOP BUTTON
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--accent-gradient);
    border: none;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: var(--bg-primary);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition-normal);
    z-index: 999;
    box-shadow: var(--shadow-md);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-glow);
}

/* ============================================
   TOAST NOTIFICATION
   ============================================ */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--success);
    color: white;
    padding: 15px 30px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
    z-index: 1001;
}

.toast.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* ============================================
   ANIMATIONS
   ============================================ */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.animated {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1024px) {
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .about-image {
        max-width: 400px;
        margin: 0 auto;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .research-card.featured {
        grid-template-columns: 1fr;
    }
    
    .research-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(10, 10, 15, 0.98);
        flex-direction: column;
        padding: 30px;
        gap: 20px;
        transform: translateX(-100%);
        transition: var(--transition-normal);
        backdrop-filter: blur(20px);
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero-stats {
        gap: 30px;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .about-highlights {
        grid-template-columns: 1fr;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .research-stats {
        flex-wrap: wrap;
        gap: 20px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-buttons .btn {
        width: 100%;
        justify-content: center;
    }
    
    .whatsapp-float {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
        bottom: 90px;
        right: 15px;
    }
    
    .back-to-top {
        right: 15px;
        bottom: 25px;
    }
    
    .experience-badge {
        position: relative;
        bottom: auto;
        right: auto;
        margin-top: 20px;
    }
    
    .projects-filter {
        flex-direction: column;
        align-items: center;
    }
    
    .filter-btn {
        width: 100%;
        max-width: 200px;
    }
    
    .contact-form-wrapper {
        padding: 25px;
    }
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
    .navbar,
    .scroll-indicator,
    .back-to-top,
    .whatsapp-float,
    .hero-background,
    .hero-particles {
        display: none !important;
    }
    
    .hero {
        min-height: auto;
        padding: 50px 20px;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .section {
        padding: 30px 0;
        page-break-inside: avoid;
    }
}