/* Universal selector */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Open Sans', sans-serif;
}

:root {
    --primary: #3498db;
    --secondary: #2c3e50;
    --accent: #e74c3c;
    --light: #ecf0f1;
    --dark: #34495e;
    --gradient: linear-gradient(135deg, #3498db, #2980b9);
}

/* Element selectors */
body {
    background-color: var(--light);
    color: var(--dark);
    line-height: 1.6;
    font-size: 16px;
}

header {
    background: var(--gradient);
    color: white;
    padding: 2rem 0;
    text-align: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Montserrat', sans-serif;
    margin-bottom: 1rem;
    color: var(--secondary);
}

h1 {
    font-size: 2.5rem;
    color: white;
}

h2 {
    font-size: 2rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary);
    margin-top: 2rem;
}

h3 {
    font-size: 1.5rem;
    color: var(--primary);
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--accent);
}

p {
    margin-bottom: 1rem;
}

hr {
    border: none;
    height: 1px;
    background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0));
    margin: 2rem 0;
}

ul, ol {
    margin: 1rem 0 1rem 2rem;
}

/* List style properties */
ul li {
    list-style-type: square;
    margin-bottom: 0.5rem;
}

ol li {
    margin-bottom: 0.5rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

table caption {
    font-weight: bold;
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--primary);
}

table th {
    background-color: var(--primary);
    color: white;
    padding: 0.75rem;
    text-align: left;
}

table td {
    border: 1px solid #ddd;
    padding: 0.75rem;
}

table tr:nth-child(even) {
    background-color: #f2f2f2;
}

/* Class selectors */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1rem;
}

.section {
    margin: 2rem 0;
    padding: 2rem;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

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

.nav-menu {
    display: flex;
    justify-content: center;
    list-style-type: none;
    margin: 0;
    padding: 0;
}

.nav-menu li {
    margin: 0;
}

.nav-menu a {
    display: block;
    padding: 1rem 1.5rem;
    color: white;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: background-color 0.3s ease;
}

/* Pseudo-class selector */
.nav-menu a:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
}

.nav-menu a.active {
    background-color: var(--primary);
}

.footer {
    background-color: var(--secondary);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

/* ID selector */
#current-date {
    background-color: var(--light);
    color: var(--dark);
    padding: 0.5rem;
    border-radius: 4px;
    display: inline-block;
    font-family: 'Montserrat', sans-serif;
    font-size: 0.9rem;
    margin-top: 1rem;
}

#profile {
    text-align: center;
    padding: 2rem 0;
}

#contact-form {
    max-width: 700px;
    margin: 0 auto;
}

/* Descendant selector */
#contact-form label {
    display: block;
    margin-top: 1rem;
    font-weight: bold;
}

#contact-form input,
#contact-form textarea,
#contact-form select {
    width: 100%;
    padding: 0.75rem;
    margin-top: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

#contact-form .radio-group {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 0.5rem;
}

#contact-form .radio-option {
    display: flex;
    align-items: center;
}

#contact-form .radio-option input {
    width: auto;
    margin-right: 0.5rem;
}

#contact-form button {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    font-size: 1rem;
    border-radius: 4px;
    cursor: pointer;
    margin-top: 1.5rem;
    transition: background-color 0.3s ease;
}

#contact-form button:hover {
    background-color: #2980b9;
}

/* Media elements */
.media-container {
    margin: 2rem 0;
}

.media-container img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
}

.media-container audio,
.media-container video {
    width: 100%;
    border-radius: 8px;
    margin: 1rem 0;
}

/* Special text formatting */
.highlight {
    background-color: #ffffa5;
    padding: 2px 5px;
    border-radius: 3px;
}

/* Responsive styles */
@media (max-width: 768px) {
    .nav-menu {
        flex-direction: column;
    }
    
    .section {
        padding: 1rem;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    #contact-form .radio-group {
        flex-direction: column;
        gap: 0.5rem;
    }
}