:root {
    --primary-color: #2563eb;
    --secondary-color: #0f172a;
    --text-color: #334155;
    --text-light: #64748b;
    --background: #ffffff;
    --background-alt: #f8fafc;
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --border-radius: 10px;
    --border-radius-lg: 50px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background);
}

.container {
    width: 100%;
    max-width: max(1200px, 70%);
    margin: 0 auto;
    padding: 0 20px;
}

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

a {
    color: inherit;
    text-decoration: none;
}

ul {
    list-style: none;
}

button {
    cursor: pointer;
    border: none;
    background: transparent;
    font: inherit;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    color: var(--secondary-color);
    line-height: 1.2;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 3rem);
}

h2 {
    font-size: clamp(2rem, 4vw, 2.5rem);
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

.skip-link:focus {
    left: 16px;
    top: 16px;
    width: auto;
    height: auto;
    padding: 10px 14px;
    background: var(--secondary-color);
    color: #fff;
    border-radius: var(--border-radius);
    z-index: 2000;
}

.scroll-top-btn {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--primary-color);
    color: #fff;
    display: grid;
    place-items: center;
    font-size: 1.25rem;
    line-height: 1;
    box-shadow: var(--shadow-md);
    opacity: 0;
    transform: translateY(10px);
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: 1200;
}

.scroll-top-btn.is-visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.25rem 0;
}

.logo img {
    width: 10rem;
    height: auto;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 35px;
}

.nav-links a {
    font-weight: 500;
    color: var(--text-color);
}

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 5px;
}

.mobile-menu-btn span {
    display: block;
    width: 25px;
    height: 3px;
    background: var(--secondary-color);
    border-radius: 2px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1.25rem;
    border-radius: var(--border-radius-lg);
    font-weight: 600;
}

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

.btn-secondary {
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-white {
    background: #fff;
    color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 100px 0 60px;
    background: var(--background-alt);
    overflow: hidden;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero h1 {
    margin-bottom: 20px;
    font-size: clamp(3.5rem, 3.75vw, 5rem);
}

.hero h1 span {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-text {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 30px;
}

.hero-buttons {
    display: flex;
    gap: 0.9rem;
    flex-wrap: wrap;
}

.about-hero,
.contact-hero,
.apps-hero {
    padding: 140px 0 80px;
    background: var(--background-alt);
    text-align: center;
}

.legal-hero {
    padding: 140px 0 60px;
    background: var(--background-alt);
    text-align: center;
}

.about-hero p,
.contact-hero p,
.apps-hero p,
.legal-hero p {
    color: var(--text-light);
    max-width: max(640px, 60%);
    margin: 0 auto;
}

.section,
.section-projects {
    padding: 2.5rem 0;
}

.section-alt {
    background: var(--background-alt);
}

@media (max-width: 767px) {
    .container {
        padding: 0 16px;
    }

    .nav-links {
        position: fixed;
        top: 50px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 16px;
        gap: 10px;
        transform: translateY(-150%);
        opacity: 0;
        transition: var(--transition);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
    }

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

    .hero {
        min-height: auto;
        padding: 100px 0 50px;
    }

    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }

    .hero h1 {
        font-size: clamp(1.4rem, 7vw, 1.6rem);
    }

    .hero-image {
        display: none;
    }

    .about-hero,
    .contact-hero,
    .apps-hero,
    .legal-hero {
        padding: 6rem 0 3rem;
    }

    .scroll-top-btn {
        right: 14px;
        bottom: 14px;
        width: 40px;
        height: 40px;
    }
}