:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --bg-color: #ffffff;
    --text-color: #1f2937;
    --card-bg: #f3f4f6;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --bg-color: #111827;
    --text-color: #f3f4f6;
    --card-bg: #1f2937;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
}

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

html {
    scroll-behavior: smooth;
}

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

header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

[data-theme="dark"] header {
    background: rgba(17, 24, 39, 0.95);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

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

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

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    transition: var(--transition);
}

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 6rem 5% 2rem;
}

.hero-content {
    animation: fadeInUp 1s ease;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.8;
}

.cta-button {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.3);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(99, 102, 241, 0.4);
}

.about {
    padding: 5rem 5%;
    max-width: 1200px;
    margin: 0 auto;
}

.about h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
}

.about-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 20px;
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
    box-shadow: var(--shadow);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.card h3 {
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.features {
    padding: 5rem 5%;
    background: var(--card-bg);
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-item {
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature-item:hover {
    transform: scale(1.02);
}

.feature-item h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.theme-toggle {
    margin-top: 1rem;
    padding: 0.5rem 1rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    transition: var(--transition);
}

.theme-toggle:hover {
    transform: scale(1.05);
}

.counter {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-top: 1rem;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-top: 1rem;
}

.contact-form input,
.contact-form textarea {
    padding: 0.75rem;
    border: 2px solid var(--card-bg);
    border-radius: 8px;
    background: var(--bg-color);
    color: var(--text-color);
    transition: var(--transition);
    font-family: inherit;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.contact-form button {
    padding: 0.75rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.contact-form button:hover {
    background: var(--secondary-color);
}

footer {
    text-align: center;
    padding: 2rem;
    background: var(--card-bg);
    color: var(--text-color);
}

.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    font-size: 1.5rem;
    box-shadow: var(--shadow);
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    transform: translateY(-5px);
    background: var(--secondary-color);
}

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

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--bg-color);
        flex-direction: column;
        align-items: center;
        justify-content: start;
        padding-top: 3rem;
        gap: 2rem;
        transition: var(--transition);
    }

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

    .hamburger {
        display: flex;
    }

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

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

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero h1 {
        font-size: 2.5rem;
    }
}