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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --crypto-color: #f59e0b;
    --author-color: #8b5cf6;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 120px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 30px 20px;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    flex-wrap: wrap;
    gap: 20px;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: white;
    transition: opacity 0.3s ease;
}

.logo-link:hover {
    opacity: 0.9;
}

.logo-icon {
    width: 40px;
    height: 40px;
    flex-shrink: 0;
}

.logo {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    margin: 0;
    color: white;
}

.tagline {
    font-size: 1rem;
    opacity: 0.95;
    font-weight: 300;
    text-align: center;
    margin: 0;
}

/* Navigation */
.main-nav ul {
    list-style: none;
    display: flex;
    gap: 30px;
    margin: 0;
    padding: 0;
}

.main-nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: opacity 0.3s ease;
    position: relative;
}

.main-nav a:hover {
    opacity: 0.8;
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: white;
    transition: width 0.3s ease;
}

.main-nav a:hover::after {
    width: 100%;
}

/* Hero Section */
.hero {
    background-color: var(--bg-light);
    padding: 80px 20px;
    text-align: center;
}

.hero h2 {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: var(--text-dark);
    font-weight: 800;
    letter-spacing: -1px;
}

.hero-text {
    font-size: 1.25rem;
    color: var(--text-light);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.8;
}

/* Portfolio Section */
.portfolio {
    padding: 80px 20px;
}

.section-title {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 60px;
    font-weight: 800;
    letter-spacing: -1px;
    color: var(--text-dark);
    font-weight: 700;
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.portfolio-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.portfolio-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 15px;
    border-left: 4px solid var(--primary-color);
    padding-left: 15px;
}

.card-header.app {
    border-left-color: var(--success-color);
}

.card-header.crypto {
    border-left-color: var(--crypto-color);
}

.card-header.author {
    border-left-color: var(--author-color);
}

.card-header h3 {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 1.5rem;
    color: var(--text-dark);
    font-weight: 700;
    letter-spacing: -0.5px;
}

.badge {
    background-color: var(--bg-light);
    color: var(--text-light);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.portfolio-card p {
    color: var(--text-light);
    margin-bottom: 20px;
    flex-grow: 1;
    line-height: 1.7;
}

.card-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    transition: color 0.3s ease;
}

.card-link:hover {
    color: var(--secondary-color);
}

/* About Section */
.about {
    background-color: var(--bg-light);
    padding: 80px 20px;
}

.about-text {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-light);
    text-align: center;
}

/* Collaborations Section */
.collaborations {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 80px 20px;
}

.collaborations .section-title {
    color: white;
}

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

.collaborations-text {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 20px;
    opacity: 0.95;
}

.cta-button {
    display: inline-block;
    background-color: white;
    color: var(--primary-color);
    padding: 14px 40px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    margin-top: 20px;
    transition: transform 0.2s ease, box-shadow 0.3s ease;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

/* Contact Section */
.contact {
    padding: 80px 20px;
    background-color: var(--bg-white);
}

.contact-intro {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 50px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.contact-form {
    max-width: 700px;
    margin: 0 auto 40px;
}

.hidden {
    display: none;
}

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

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-dark);
    font-weight: 500;
    font-size: 0.95rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    background-color: var(--bg-white);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

.submit-btn {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 14px 40px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.3s ease;
    width: 100%;
    max-width: 200px;
    display: block;
    margin: 0 auto;
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(37, 99, 235, 0.3);
}

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

.contact-email {
    text-align: center;
    margin-top: 40px;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
}

.contact-email p {
    font-size: 1rem;
    color: var(--text-light);
}

.contact-email a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.contact-email a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Footer */
footer {
    background-color: var(--text-dark);
    color: white;
    padding: 40px 20px;
    text-align: center;
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: center;
}

.footer-copyright {
    opacity: 0.8;
    font-size: 0.9rem;
    margin: 0;
}

.footer-registration {
    opacity: 0.7;
    font-size: 0.85rem;
    margin: 0;
}

.footer-contact {
    opacity: 0.9;
}

.footer-contact p {
    margin: 0;
    font-size: 0.9rem;
}

.footer-contact a {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s ease;
}

.footer-contact a:hover {
    opacity: 0.7;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        padding: 20px;
    }

    .header-content {
        flex-direction: column;
        align-items: center;
        gap: 15px;
    }

    .logo-link {
        flex-direction: row;
    }

    .logo-icon {
        width: 35px;
        height: 35px;
    }

    .logo {
        font-size: 1.5rem;
        text-align: center;
    }

    .tagline {
        font-size: 0.9rem;
    }

    .main-nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .main-nav a {
        font-size: 0.9rem;
    }

    .hero h2 {
        font-size: 2rem;
    }

    .hero-text {
        font-size: 1.1rem;
    }

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

    .portfolio-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .hero,
    .portfolio,
    .about,
    .collaborations,
    .contact {
        padding: 50px 20px;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.75rem;
    }

    .tagline {
        font-size: 1rem;
    }

    .hero h2 {
        font-size: 1.75rem;
    }

    .section-title {
        font-size: 1.75rem;
        margin-bottom: 40px;
    }

    .card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
}