:root {
    --primary-color: #FF6B00;
    --text-color: #333333;
    --bg-color: #ffffff;
    --secondary-bg: #f5f5f5;
    --modal-bg: #ffffff;
    --border-color: #ddd;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --font-family: 'Rubik', sans-serif;
}

[data-theme="dark"] {
    --primary-color: #FF8533;
    --text-color: #ffffff;
    --bg-color: #121212;
    --secondary-bg: #1e1e1e;
    --modal-bg: #1e1e1e;
    --border-color: #2d2d2d;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    font-weight: 500;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    min-height: 100vh;
    display: flex;
    user-select: none;
    flex-direction: column;
}

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

.header {
    background-color: var(--bg-color);
    box-shadow: 0 2px 4px var(--shadow-color);
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

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

.main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 80px 0;
}

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

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    font-weight: 700;
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    color: var(--text-color);
    opacity: 0.9;
    font-weight: 500;
}

.download-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem 2.5rem;
    font-size: 1.2rem;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(255, 107, 0, 0.3);
    font-weight: 600;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 107, 0, 0.4);
}

.footer {
    background-color: var(--secondary-bg);
    padding: 1rem 0;
    margin-top: auto;
    transition: background-color 0.3s ease;
}

.footer-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.copyright {
    color: var(--text-color);
    opacity: 0.8;
    font-size: 0.9rem;
    font-weight: 500;
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    z-index: 2000;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal.show {
    opacity: 1;
}

.modal-content {
    position: relative;
    background-color: var(--modal-bg);
    margin: 10% auto;
    padding: 2.5rem;
    width: 90%;
    max-width: 500px;
    border-radius: 15px;
    box-shadow: 0 4px 6px var(--shadow-color);
    transform: translateY(-20px);
    transition: transform 0.3s ease;
}

.modal.show .modal-content {
    transform: translateY(0);
}

.modal h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
    font-weight: 600;
}

.close-modal {
    position: absolute;
    right: 1.5rem;
    top: 1.5rem;
    font-size: 1.8rem;
    cursor: pointer;
    color: var(--text-color);
    transition: all 0.3s ease;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.close-modal:hover {
    color: var(--primary-color);
    background-color: var(--secondary-bg);
}

.os-selection {
    display: flex;
    gap: 1rem;
    margin: 2rem 0;
    justify-content: center;
}

.os-switch {
    position: relative;
    cursor: pointer;
    flex: 1;
    max-width: 200px;
}

.os-switch input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
}

.os-switch-label {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    transition: all 0.3s ease;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-weight: 500;
}

.os-switch input:checked + .os-switch-label {
    border-color: var(--primary-color);
    background-color: var(--primary-color);
    color: white;
}

.os-switch:hover .os-switch-label {
    border-color: var(--primary-color);
}

.os-icon {
    width: 24px;
    height: 24px;
    margin-right: 0.5rem;
    filter: invert(0.2);
    transition: all 0.3s ease;
}

.os-switch input:checked + .os-switch-label .os-icon {
    filter: brightness(0) invert(1);
}

.os-description {
    text-align: center;
    margin-top: 2rem;
    padding: 1rem;
    border-radius: 10px;
    background-color: var(--secondary-bg);
}

.os-description h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
    font-weight: 600;
}

.os-description p {
    color: var(--text-color);
    margin-bottom: 1.5rem;
    opacity: 0.9;
    font-weight: 500;
}

.download-btn, .download-os-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem 2.5rem;
    font-size: 1.2rem;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(255, 107, 0, 0.3);
    font-weight: 600;
}

.download-btn:hover, .download-os-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 107, 0, 0.4);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-text {
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
}

.delay-1 {
    animation-delay: 0.2s;
}

.delay-2 {
    animation-delay: 0.4s;
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .nav {
        gap: 1rem;
    }
    
    .os-selection {
        flex-direction: column;
        align-items: center;
    }
    
    .os-switch {
        width: 100%;
        max-width: 300px;
    }
    
    .modal-content {
        padding: 1.5rem;
    }
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--bg-color);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: 0 2px 8px var(--shadow-color);
    padding: 8px;
}

.theme-toggle:hover {
    transform: scale(1.05);
    background-color: var(--primary-color);
}

.theme-toggle:hover .theme-toggle-icon {
    filter: brightness(0) invert(1);
}

.theme-toggle-icon {
    width: 100%;
    height: 100%;
    transition: all 0.3s ease;
}

[data-theme="light"] .theme-toggle-icon {
    filter: invert(0.2);
}

[data-theme="dark"] .theme-toggle-icon {
    filter: invert(0.9);
}

.sun-icon {
    display: none;
}

.moon-icon {
    display: block;
}

[data-theme="dark"] .sun-icon {
    display: block;
}

[data-theme="dark"] .moon-icon {
    display: none;
}

[data-theme="light"] .sun-icon {
    display: block;
}

[data-theme="light"] .moon-icon {
    display: none;
}