html {
    font-size: 14px;
}

@media (min-width: 768px) {
    html {
        font-size: 16px;
    }
}

.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
    box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
}

html {
    position: relative;
    min-height: 100%;
}

body {
    margin-bottom: 60px;
}

:root {
    --bg-color: #f6f8fa;
    --text-color: #1a1a1a;
    --nav-bg: linear-gradient(90deg, #ffffff, #f1f3f6);
    --nav-text: #1a1a1a;
    --link-hover: #0d6efd;
    --card-bg: #ffffff;
    --toggle-bg: #ffffff;
    --toggle-border: #1a1a1a;
}

body.dark-theme {
    --bg-color: #1e1e1e;
    --text-color: #e0e0e0;
    --nav-bg: #2b2b2b;
    --nav-text: #e0e0e0;
    --link-hover: #66b3ff;
    --card-bg: #2b2b2b;
    --toggle-bg: #333333;
    --toggle-border: #e0e0e0;
}

body {
    background: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s, background 0.3s;
}

.custom-navbar {
    background: var(--nav-bg);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: background 0.3s, box-shadow 0.3s;
}

    .custom-navbar .navbar-brand {
        font-weight: 700;
        letter-spacing: 0.5px;
    }

    .custom-navbar .nav-link {
        color: var(--nav-text);
        font-weight: 500;
        transition: color 0.3s;
    }

        .custom-navbar .nav-link:hover {
            color: var(--link-hover);
        }

.footer {
    background: var(--nav-bg);
    color: var(--nav-text);
    transition: background 0.3s, color 0.3s;
}

#theme-toggle {
    background-color: var(--toggle-bg);
    border: 1px solid var(--toggle-border);
    color: var(--nav-text);
    padding: 4px 12px;
    font-size: 0.9rem;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

    #theme-toggle:hover {
        background-color: var(--link-hover);
        color: #fff;
        border-color: var(--link-hover);
    }

.card, .content-box {
    background: var(--card-bg);
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    padding: 1rem;
    transition: background 0.3s, box-shadow 0.3s;
}