:root {
    --bg-color: #ffffff;
    --text-color: #333333;
    --accent-color: #0066ff;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Back Button */
.back-btn {
    position: fixed;
    bottom: 30px;
    left: 30px;
    background: var(--accent-color);
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    z-index: 9999;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    border: 2px solid var(--accent-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.back-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 102, 255, 0.4);
    background: linear-gradient(135deg, var(--accent-color), #0052cc);
}

.back-btn::before {
    content: '←';
    font-size: 1.2rem;
}

/* Theme Palette */
.theme-palette {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;
}

.palette-toggle {
    width: 60px;
    height: 60px;
    background: rgba(0, 102, 255, 0.2);
    border: 2px solid var(--accent-color);
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.palette-toggle:hover {
    background: rgba(0, 102, 255, 0.4);
    transform: scale(1.1);
}

.palette-dots {
    display: none;
    position: absolute;
    bottom: 70px;
    right: 0;
    background: white;
    border-radius: 15px;
    padding: 1rem;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    gap: 0.8rem;
    flex-direction: column;
    animation: slideUp 0.3s ease;
}

.palette-dots.active {
    display: flex;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.dot {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 3px solid transparent;
}

.dot:hover {
    transform: scale(1.15);
    border-color: #333;
}

/* Header */
header {
    background-color: var(--bg-color);
    border-bottom: 2px solid var(--accent-color);
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s ease;
}

.header-content {
    display: flex;
    align-items: center;
    gap: 3rem;
    flex: 1;
}

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

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

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

nav a:hover {
    color: var(--accent-color);
}

/* Hero Section */
.hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 3rem;
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    min-height: 60vh;
}

.hero-text h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.hero-text p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.cta-button {
    display: inline-block;
    padding: 0.8rem 2rem;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    text-decoration: none;
}

.cta-button:hover {
    opacity: 0.8;
    transform: translateY(-2px);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-placeholder {
    width: 200px;
    height: 200px;
    background: linear-gradient(135deg, var(--accent-color) 0%, rgba(0, 102, 255, 0.1) 100%);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
}

/* Features Section */
.features {
    padding: 4rem 2rem;
    background-color: rgba(0, 0, 0, 0.02);
    text-align: center;
}

.features h2 {
    font-size: 2rem;
    margin-bottom: 3rem;
    color: var(--text-color);
}

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

.feature-card {
    padding: 2rem;
    background-color: var(--bg-color);
    border-radius: 10px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 102, 255, 0.2);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-color);
    opacity: 0.8;
}

/* Footer */
footer {
    background-color: var(--bg-color);
    border-top: 2px solid var(--accent-color);
    text-align: center;
    padding: 3rem 2rem;
    color: var(--text-color);
}

.footer-content {
    margin-bottom: 2rem;
}

.footer-content h3 {
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.footer-content p {
    margin-bottom: 0.5rem;
}

.footer-content a {
    color: var(--accent-color);
    text-decoration: none;
}

.footer-content a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        flex-direction: column;
        padding: 2rem 1rem;
    }

    .hero-text h1 {
        font-size: 2rem;
    }

    nav {
        gap: 1rem;
    }

    .header-content {
        gap: 1.5rem;
    }

    .back-btn {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
}