:root {
    --primary-color: #4a90e2;
    --secondary-color: #50e3c2;
    --dark-slate-blue: #3a4a6e;
    --light-gray: #f7f9fb;
    --white: #ffffff;
    --font-family: 'Poppins', sans-serif;
    --border-radius: 12px;
    --accent-color: #ff6b6b;
    --success-color: #51cf66;
    --warning-color: #ffd43b;
    --dark-bg: #1a1a2e;
    --dark-card: #16213e;
    --dark-text: #eaeaea;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    color: var(--dark-slate-blue);
    padding-top: 70px;
    background-color: var(--light-gray);
    letter-spacing: 0.5px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark-mode {
    background-color: var(--dark-bg);
    color: var(--dark-text);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    color: var(--dark-slate-blue);
}

body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode h4,
body.dark-mode h5,
body.dark-mode h6 {
    color: var(--white);
}

section {
    padding: 80px 0;
    overflow: hidden;
}

.section-title {
    text-align: center;
    padding-bottom: 40px;
}

.section-title h2 {
    font-size: 36px;
    font-weight: 800;
    text-transform: uppercase;
    margin-bottom: 20px;
    padding-bottom: 20px;
    position: relative;
    letter-spacing: 1px;
}

.section-title h2::after {
    content: '';
    position: absolute;
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    bottom: 0;
    left: calc(50% - 30px);
    border-radius: 2px;
}

/* Navbar */
.navbar {
    transition: all 0.4s ease;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    background-color: var(--white);
    padding: 1rem 0;
}

body.dark-mode .navbar {
    background-color: var(--dark-card);
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.navbar-shrink {
    padding: 0.5rem 0;
    box-shadow: 0 6px 15px rgba(0,0,0,0.1);
}

.navbar-brand {
    font-weight: 800;
    font-size: 1.8rem;
    color: var(--dark-slate-blue);
    letter-spacing: -1px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-link {
    font-weight: 600;
    color: var(--dark-slate-blue);
    transition: color 0.3s, transform 0.3s;
    padding: 0.5rem 1rem !important;
    position: relative;
}

body.dark-mode .nav-link {
    color: var(--dark-text);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 1rem;
    right: 1rem;
    height: 2px;
    background-color: var(--primary-color);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

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

.nav-link:hover::after, .nav-link.active::after {
    transform: scaleX(1);
}

/* Dark Mode Toggle */
.dark-mode-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--dark-slate-blue);
    transition: transform 0.3s ease;
    padding: 0.5rem 1rem;
}

body.dark-mode .dark-mode-toggle {
    color: var(--dark-text);
}

.dark-mode-toggle:hover {
    transform: rotate(20deg);
}

/* Hero Section */
#hero {
    background: linear-gradient(135deg, var(--dark-slate-blue) 0%, var(--primary-color) 100%);
    color: var(--white);
    position: relative;
    overflow: hidden;
}

#hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 600"><defs><pattern id="grid" width="40" height="40" patternUnits="userSpaceOnUse"><path d="M 40 0 L 0 0 0 40" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="1"/></pattern></defs><rect width="1200" height="600" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

#hero .container {
    position: relative;
    z-index: 1;
}

#hero h1 {
    font-size: 4.5rem;
    font-weight: 800;
    letter-spacing: -2px;
    color: var(--white);
    animation: fadeInDown 1s ease-out;
}

#hero p {
    font-size: 1.5rem;
    font-weight: 300;
    animation: fadeInUp 1s ease-out 0.2s both;
}

.btn-primary {
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border: none;
    padding: 15px 35px;
    font-weight: 600;
    border-radius: 50px;
    transition: transform 0.3s, box-shadow 0.3s;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--white);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    color: var(--white);
}

.btn-secondary {
    background: var(--secondary-color);
    border: none;
    padding: 12px 30px;
    font-weight: 600;
    border-radius: 50px;
    transition: transform 0.3s, box-shadow 0.3s;
    color: var(--white);
}

.btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(80, 227, 194, 0.3);
    color: var(--white);
}

/* Cards */
.card {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: 0 8px 25px rgba(0,0,0,0.08);
    transition: transform 0.4s, box-shadow 0.4s;
    overflow: hidden;
    background-color: var(--white);
}

body.dark-mode .card {
    background-color: var(--dark-card);
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(74, 144, 226, 0.2);
}

body.dark-mode .card:hover {
    box-shadow: 0 15px 40px rgba(74, 144, 226, 0.4);
}

.card-title {
    font-weight: 700;
    color: var(--dark-slate-blue);
}

body.dark-mode .card-title {
    color: var(--white);
}

/* Skills & Tools Icons */
.skill-icon, .tool-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    transition: transform 0.3s ease;
}

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

/* Skill Progress Bars */
.skill-item {
    margin-bottom: 2rem;
}

.skill-name {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.skill-bar {
    height: 8px;
    background-color: #e0e0e0;
    border-radius: 10px;
    overflow: hidden;
}

body.dark-mode .skill-bar {
    background-color: rgba(255, 255, 255, 0.1);
}

.skill-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 10px;
    animation: fillProgress 1.5s ease-out forwards;
    opacity: 0;
}

@keyframes fillProgress {
    from {
        width: 0;
        opacity: 1;
    }
    to {
        opacity: 1;
    }
}

/* Experience Section */
#experience .card {
    border-left: 4px solid var(--primary-color);
}

.experience-date {
    color: var(--primary-color);
    font-weight: 600;
    background-color: rgba(74, 144, 226, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
}

body.dark-mode .experience-date {
    background-color: rgba(74, 144, 226, 0.2);
}

/* Stats Section */
.stat-card {
    text-align: center;
    padding: 2rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-weight: 600;
    color: var(--dark-slate-blue);
    margin-top: 0.5rem;
}

body.dark-mode .stat-label {
    color: var(--dark-text);
}

/* Contact Section */
#contact .bi {
    font-size: 2.5rem;
    color: var(--primary-color);
    transition: transform 0.3s;
}

#contact a:hover .bi {
    transform: scale(1.1);
    color: var(--secondary-color);
}

#contact a {
    text-decoration: none;
    color: var(--dark-slate-blue);
    transition: color 0.3s;
}

body.dark-mode #contact a {
    color: var(--dark-text);
}

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

/* Testimonials Section */
.testimonial-card {
    border-left: 4px solid var(--secondary-color);
    padding: 2rem;
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: 0 8px 25px rgba(0,0,0,0.08);
    transition: transform 0.4s, box-shadow 0.4s;
}

body.dark-mode .testimonial-card {
    background-color: var(--dark-card);
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
}

.testimonial-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(80, 227, 194, 0.2);
}

.testimonial-stars {
    color: var(--warning-color);
    font-size: 1.2rem;
    margin-bottom: 1rem;
}

.testimonial-text {
    font-style: italic;
    margin-bottom: 1rem;
    color: var(--dark-slate-blue);
}

body.dark-mode .testimonial-text {
    color: var(--dark-text);
}

.testimonial-author {
    font-weight: 600;
    color: var(--primary-color);
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 4rem 2rem;
    border-radius: var(--border-radius);
    text-align: center;
}

.cta-section h3 {
    color: var(--white);
    font-size: 2rem;
    margin-bottom: 1rem;
}

.cta-section p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

/* Newsletter Form */
.newsletter-form {
    display: flex;
    gap: 0.5rem;
    max-width: 500px;
    margin: 0 auto;
}

.newsletter-form input {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 50px;
    font-family: var(--font-family);
}

.newsletter-form button {
    padding: 12px 30px;
    background-color: var(--white);
    color: var(--primary-color);
    border: none;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s;
}

.newsletter-form button:hover {
    transform: scale(1.05);
}

/* Footer */
.footer {
    padding: 30px 0;
    background-color: var(--dark-slate-blue);
    color: var(--light-gray);
}

body.dark-mode .footer {
    background-color: #0f0f1e;
}

.footer a {
    color: var(--light-gray);
    text-decoration: none;
    transition: color 0.3s;
}

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

/* Animations */
.slide-up {
    opacity: 0;
    transform: translateY(60px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

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

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

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

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
}

.float-animation {
    animation: float 3s ease-in-out infinite;
}

/* Portfolio Filter */
.portfolio-filter {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--primary-color);
    background-color: transparent;
    color: var(--primary-color);
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

body.dark-mode .filter-btn {
    border-color: var(--secondary-color);
    color: var(--secondary-color);
}

body.dark-mode .filter-btn:hover,
body.dark-mode .filter-btn.active {
    background-color: var(--secondary-color);
    color: var(--dark-bg);
}

/* Responsive */
@media (max-width: 768px) {
    #hero h1 {
        font-size: 2.5rem;
    }

    #hero p {
        font-size: 1.1rem;
    }

    .section-title h2 {
        font-size: 28px;
    }

    .newsletter-form {
        flex-direction: column;
    }

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

/* Scroll to top button */
.scroll-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    transition: all 0.3s ease;
    z-index: 999;
}

.scroll-to-top.show {
    display: flex;
}

.scroll-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(74, 144, 226, 0.4);
}

/* Loading animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(74, 144, 226, 0.3);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

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