:root {
    --white-color: #ffffff;
    --black-color: #343a40;
    --blue-color: #0d6efd;
    --gray-color: #6c757d;
    --light-gray: #f8f9fa;
}

:root[data-bs-theme="dark"] {
    --white-color: #343a40;
    --black-color: #ffffff;
    --gray-color: #adb5bd;
    --light-gray: #6c757d;
}

body {
    font-family: "Roboto", sans-serif;
}

.header {
    position: sticky; 
    top: 0; 
    z-index: 2;
    background-color: var(--light-gray);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}


.header__logo {
    max-width: 150px;
    transition: transform 0.3s ease;
}

.header__logo:hover {
    transform: scale(1.1);
}

.nav-link {
    color: var(--black-color); 
    font-weight: 500;
    padding: 10px 15px;
    transition: color 0.3s ease;
}

.nav-link:hover, .nav-link:focus {
    color: var(--blue-color); 
}


.container {
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
}

.about {
    font-size: 1.1rem;
    color: var(--gray-color); 
    margin-bottom: 1.5rem;
    font-weight: 400;
}

h2 {
    color: var(--black-color);
    font-size: 2.5rem;
    font-weight: 700;
    position: relative;
}


h2::after {
    content: "";
    display: block;
    width: 100px;
    height: 3px;
    background: linear-gradient(to right, #00C0FF, #4218B8);
    margin: 0.5rem;
}

.education {
    padding: 1.5rem;
    border-bottom: 1px solid #e0e0e0;
}

.education:last-child {
    border-bottom: none;
}

h3 {
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--black-color); 
    margin-bottom: 0.5rem;
}

.education__date,
.education__technologies {
    font-size: 1rem;
    color: #6c757d;
    margin-bottom: 0.5rem;
}

.education__img {
    width: 100%;
    max-width: 100px;
    margin-bottom: 1rem;
}

footer {
    background-color: var(--light-gray);
}

.footer__link {
    text-decoration: none;
    color: var(--black-color);
    font-weight: 500;
    font-size: 1rem;
}

.footer__link svg {
    margin-right: 8px;
    fill: var(--black-color);
}

.footer__link:hover {
    color: var(--blue-color);
}

.footer__link svg:hover {
    fill: var(--blue-color);
}

.certificate {
    height: 500px;
    width: auto;
    margin: 0 auto;
}

.carousel-indicators {
    margin-bottom: -30px;
}

.carousel-indicators button {
    background-color: var(--blue-color) !important;
}

.carousel-control-prev-icon,
.carousel-control-next-icon {
    background-color: var(--blue-color);
    border-radius: 5px;
}

@media (max-width: 992px) {
    .header__logo {
        max-width: 120px;
    }

    .nav-link {
        font-size: 0.9rem;
        padding: 8px 12px;
    }

    .container {
        padding: 30px;
    }

    h1 {
        font-size: 2.5rem;
    }

    .text {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 2rem;
    }

    h3 {
        font-size: 1.4rem;
    }

    .card-title {
        font-size: 1.1rem;
    }

    .card-text {
        font-size: 0.9rem;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 10px 0;
    }

    .header__logo {
        max-width: 100px;
    }

    .container {
        padding: 20px;
    }

    h1 {
        font-size: 2rem;
        text-align: center;
    }

    .text {
        font-size: 1.3rem;
        text-align: center;
    }

    h2 {
        font-size: 1.8rem;
    }

    h3 {
        font-size: 1.3rem;
    }

    .card-title {
        font-size: 1rem;
    }

    .card-text {
        font-size: 0.85rem;
    }

    .certificate {
        height: 300px;
    }
}

@media (max-width: 576px) {
    .header__logo {
        max-width: 80px;
    }

    .nav-link {
        font-size: 0.8rem;
        padding: 5px 10px;
    }

    h1 {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    h3 {
        font-size: 1.2rem;
    }

    .card img {
        height: 150px;
    }

    .card-title {
        font-size: 0.9rem;
    }

    .card-text {
        font-size: 0.8rem;
    }

    .btn-primary {
        margin-bottom: 8px;
    }

    .footer__link {
        font-size: 0.9rem;
    }

    .certificate {
        height: 200px;
    }
}