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

:root {
    --primary-color: #4a6a8a;
    --secondary-color: #d4a017;
    --text-light: #333;
    --text-dark: #e0e0e0;
    --bg-light: #f4f4f9;
    --bg-dark: #1a1a2e;
    --card-light: #fff;
    --card-dark: #2c3e50;
    --border-light: #e0e0e0;
    --border-dark: #2a2a3c;
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    font-size: 18px;
    color: var(--text-light);
    background-color: var(--bg-light);
    transition: background-color 0.3s, color 0.3s;
}

body.dark-mode {
    background-color: var(--bg-dark);
    color: var(--text-dark);
}

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

header {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #2c3e50, #4a6a8a);
    color: #fff;
    border-bottom: 5px solid var(--secondary-color);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.mode-toggle {
    background: var(--secondary-color);
    border: none;
    padding: 10px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 1rem;
    color: #fff;
    transition: background 0.3s;
}

.dark-mode .mode-toggle {
    background: #1a1a2e;
}

.dark-mode .mode-toggle:hover {
    background: #020239;
}

.mode-toggle:hover {
    background: #b58814;
}

.nav-bar {
    background-color: var(--card-light);
    border: 1px solid var(--border-light);
    padding: 15px;
    margin: 20px 0;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    position: relative;
}

.dark-mode .nav-bar {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.nav-button {
    background: var(--primary-color);
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

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

.hamburger {
    display: none;
    background: var(--primary-color);
    color: #fff;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    text-align: center;
    width: 100%;
    max-width: 300px;
}

.nav-menu {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    width: 100%;
}

.nav-menu.active {
    display: flex;
}

.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    font-size: 1.5rem;
    transition: background-color 0.3s ease, transform 0.3s ease;
    z-index: 1000;
}

.back-to-top:hover {
    background: #b58814;
    transform: scale(1.1);
}

section {
    padding: 40px 20px;
    margin-bottom: 30px;
    border-left: 4px solid var(--secondary-color);
    background: var(--card-light);
    border-radius: 0 10px 10px 0;
    transition: background 0.3s;
}

.dark-mode section {
    background: var(--card-dark);
}

h2 {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 15px;
}

.dark-mode h2 {
    color: var(--secondary-color);
}

h3 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-top: 20px;
    margin-bottom: 10px;
}

.dark-mode h3 {
    color: #a0b4d4;
}

p,
li {
    margin-bottom: 10px;
}

ul {
    list-style-type: disc;
    padding-left: 20px;
}

@media (max-width: 768px) {
    body {
        font-size: 16px;
    }

    .container {
        padding: 10px;
    }

    section {
        padding: 30px 10px;
        margin-bottom: 50px;
    }

    header h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.8rem;
    }

    h3 {
        font-size: 1.3rem;
    }

    .hamburger {
        display: block;
    }

    .nav-menu {
        display: none;
        flex-direction: column;
        align-items: center;
        background-color: var(--card-light);
        border: 1px solid var(--border-light);
        border-radius: 8px;
        padding: 10px;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        z-index: 1000;
        box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    }

    .dark-mode .nav-menu {
        background-color: var(--card-dark);
        border-color: var(--border-dark);
        box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-button {
        width: 80%;
        max-width: 300px;
        text-align: center;
    }

    .back-to-top {
        display: block;
    }
}