:root {
    --primary-green: #4A6B3D;
    /* Тёмно-зелёный - спина ужа */
    --secondary-green: #8BA888;
    /* Светло-зелёный - брюшко */
    --accent-yellow: #FFD700;
    /* Жёлтые пятна на голове */
    --dark-gray: #333333;
    /* Тёмные узоры */
    --light-gray: #E0E0E0;
    /* Светлые участки */
    --bg-light: #ffffff;
    --text-light: #2d2d2d;
    --bg-dark: #1E1E1E;
    --text-dark: #f5f5f5;
    --header-light: var(--primary-green);
    --header-dark: #2C3E26;
}

body {
    margin: 0;
    font-family: 'Roboto', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-light);
    transition: background-color 0.3s, color 0.3s;
    line-height: 1.6;
}

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

header {
    position: relative;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: var(--header-light);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s;
    position: sticky;
    top: 0;
    z-index: 1000;
}

body.dark .navbar {
    background: var(--header-dark);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.logo-container {
    background-color: var(--light-gray);
    border-radius: 46px;
    padding: 12px;
    line-height: 0;
}

.logo {
    height: 50px;
    transition: transform 0.3s;
}

.logo:hover {
    transform: scale(1.05);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 1.5rem;
    margin: 0;
    padding: 0;
}

.nav-links li a {
    text-decoration: none;
    color: var(--light-gray);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    transition: all 0.3s;
    position: relative;
}

.nav-links li a:hover {
    background-color: rgba(255, 215, 0, 0.2);
    color: white;
}

.nav-links li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--accent-yellow);
    transition: all 0.3s;
}

.nav-links li a:hover::after {
    width: 70%;
    left: 15%;
}

.burger,
#themeToggle {
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: var(--light-gray);
    transition: transform 0.3s;
}

.burger {
    display: none;
}

#themeToggle {
    display: block;
}

.burger:hover,
#themeToggle:hover {
    transform: scale(1.1);
    color: var(--accent-yellow);
}

.theme-switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 30px;
    margin-left: 15px;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--secondary-green);
    transition: .4s;
    border-radius: 34px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.slider:before {
    position: absolute;
    content: "";
    height: 22px;
    width: 22px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

input:checked+.slider {
    background-color: var(--accent-yellow);
}

input:checked+.slider:before {
    transform: translateX(30px);
}

.slider:after {
    content: "☀";
    color: var(--dark-gray);
    position: absolute;
    left: 9px;
    top: 3.6px;
    font-size: 14px;
}

input:checked+.slider:after {
    content: "☾";
    left: auto;
    right: 10px;
    color: var(--dark-gray);
}

@media (max-width: 768px) {
    .logo-container {
        padding: 9px;
        border-radius: 30px;
    }

    .logo {
        width: 100%;
        height: auto;
        max-width: 150px;
    }

    .navbar {
        padding: 1rem;
    }

    .theme-switch {
        width: 50px;
        height: 25px;
    }

    .slider:before {
        height: 17px;
        width: 17px;
    }

    input:checked+.slider:before {
        transform: translateX(25px);
    }

    .slider:after {
        font-size: 12px;
        top: 3.5px;
        left: 7.5px;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 91px;
        right: 0;
        background: var(--header-light);
        padding: 1rem 2rem;
        box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    }

    body.dark .nav-links {
        background: var(--header-dark);
    }

    .nav-links.active {
        display: flex;
        width: 50%;
    }

    .nav-links li a {
        padding: 1rem;
        border-radius: 0;
    }

    .nav-links li:not(:last-child) a {
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }

    .nav-controls {
        display: flex;
        flex-direction: row;
        align-items: center;
    }

    .burger {
        display: block;
    }
}

/* Cекция с градиентом, напоминающим кожу ужа */
#hero {
    background: linear-gradient(135deg, var(--primary-green) 0%, var(--secondary-green) 100%);
    color: white;
    padding: 5rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

#hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 10px;
    background: repeating-linear-gradient(45deg,
            var(--accent-yellow),
            var(--accent-yellow) 10px,
            var(--primary-green) 10px,
            var(--primary-green) 20px);
}

#hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
}

#hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto;
}

.section {
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.section h2 {
    font-size: 2.2rem;
    margin-bottom: 2rem;
    color: var(--primary-green);
    position: relative;
    display: inline-block;
}

body.dark .section h2 {
    color: var(--secondary-green);
}

.section h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--accent-yellow);
}

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

.card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s;
    border-top: 4px solid var(--accent-yellow);
}

body.dark .card {
    background: #252525;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.card h3 {
    color: var(--primary-green);
    margin-top: 0;
}

body.dark .card h3 {
    color: var(--secondary-green);
}

form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin: 0 auto;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

body.dark form {
    background: #252525;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

label {
    font-weight: 500;
    color: var(--primary-green);
}

body.dark label {
    color: var(--secondary-green);
}

input,
textarea {
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid #ddd;
    font-size: 1rem;
    width: 100%;
    box-sizing: border-box;
    transition: all 0.3s;
}

input:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-green);
    box-shadow: 0 0 0 2px rgba(74, 107, 61, 0.2);
}

body.dark input,
body.dark textarea {
    background: #333;
    border-color: #444;
    color: white;
}

button[type="submit"] {
    background: var(--primary-green);
    color: white;
    padding: 1rem;
    border: none;
    border-radius: 8px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
    text-transform: uppercase;
    letter-spacing: 1px;
}

button[type="submit"]:hover {
    background: #3A5A30;
    transform: translateY(-2px);
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
}

footer {
    text-align: center;
    padding: 3rem 2rem;
    background: var(--primary-green);
    color: white;
    margin-top: 3rem;
}

body.dark footer {
    background: var(--header-dark);
}

/* Анимация для логотипа ужа */
@keyframes slither {
    0% {
        transform: translateX(0) scaleY(1);
    }

    25% {
        transform: translateX(5px) scaleY(0.95);
    }

    50% {
        transform: translateX(0) scaleY(1);
    }

    75% {
        transform: translateX(-5px) scaleY(0.95);
    }

    100% {
        transform: translateX(0) scaleY(1);
    }
}

.logo:hover {
    animation: slither 1s infinite;
}