:root {
    --bg-primary: #f9f9f9;
    --bg-secondary: #fff;
    --bg-tertiary: #f2f2f2;
    --text-primary: #333;
    --text-secondary: #666;
    --text-tertiary: #777;
    --shadow-color: rgba(0, 0, 0, 0.08);
    --shadow-hover: rgba(0, 0, 0, 0.1);
    --button-bg: #1a1a1a;
    --button-text: white;
    --button-hover: #333;
}

[data-theme="dark"] {
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --bg-tertiary: #252525;
    --text-primary: #f5f5f5;
    --text-secondary: #b3b3b3;
    --text-tertiary: #909090;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --shadow-hover: rgba(0, 0, 0, 0.3);
    --button-bg: #2d2d2d;
    --button-text: #f5f5f5;
    --button-hover: #404040;
}

/* Base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        sans-serif;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

/* Common components */
header {
    padding: 30px 0;
    text-align: center;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 28px;
    font-weight: bold;
    display: flex;
    align-items: center;
}

/* Theme toggle */
.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--bg-secondary);
    box-shadow: 0 2px 8px var(--shadow-color);
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow-color);
}

/* Typography */
.headline {
    font-size: 3.5rem;
    font-weight: 700;
    margin: 40px 0 20px;
    text-align: center;
}

.subheadline {
    font-size: 1.4rem;
    font-weight: 400;
    max-width: 700px;
    margin: 0 auto 60px;
    color: var(--text-secondary);
    text-align: center;
}

/* Footer */
footer {
    padding: 40px 0;
    text-align: center;
    color: var(--text-tertiary);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.footer-link {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-link:hover {
    color: var(--text-primary);
}

/* Animations */
.fade-in {
    opacity: 0;
    animation: fadeIn 1s forwards;
}

.slide-up {
    opacity: 0;
    transform: translateY(30px);
    animation: slideUp 0.8s forwards;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

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

/* Responsive */
@media (max-width: 768px) {
    .headline {
        font-size: 2.5rem;
    }
    .subheadline {
        font-size: 1.2rem;
    }
    .footer-links {
        flex-direction: column;
        gap: 15px;
    }
}