/*
 * External CSS File - Week 3
 * This file demonstrates the use of external CSS to style HTML documents.
 */

/* Reset some browser defaults */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Base styles */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f4f4f4;
    padding: 20px;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    overflow: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: 15px;
    color: #333;
    font-weight: 600;
}

h1 {
    font-size: 2.5rem;
    color: #2c3e50;
}

h2 {
    font-size: 2rem;
    color: #3498db;
}

h3 {
    font-size: 1.75rem;
    color: #2980b9;
}

p {
    margin-bottom: 20px;
}

a {
    color: #3498db;
    text-decoration: none;
}

a:hover {
    color: #2980b9;
    text-decoration: underline;
}

/* Header styles */
header {
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 30px 0;
    margin-bottom: 30px;
    text-align: center;
    border-radius: 5px;
}

header h1 {
    color: #ecf0f1;
    margin-bottom: 10px;
}

header p {
    color: #bdc3c7;
}

/* Navigation */
nav {
    background-color: #34495e;
    border-radius: 5px;
    margin-bottom: 30px;
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li {
    padding: 15px;
}

nav ul li a {
    color: #ecf0f1;
    text-decoration: none;
}

nav ul li a:hover {
    color: #3498db;
    text-decoration: none;
}

/* Main content */
.main-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

/* Card styles */
.card {
    background-color: white;
    border-radius: 5px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.feature-card {
    flex: 0 0 calc(33.333% - 20px);
    min-width: 300px;
    margin-right: 10px;
    margin-left: 10px;
}

.feature-card h3 {
    color: #3498db;
    border-bottom: 2px solid #3498db;
    padding-bottom: 10px;
    margin-bottom: 15px;
}

.feature-card .icon {
    background-color: #3498db;
    color: white;
    width: 50px;
    height: 50px;
    line-height: 50px;
    text-align: center;
    border-radius: 50%;
    margin-bottom: 15px;
    font-size: 20px;
}

/* Code block styling */
.code-block {
    background-color: #f9f9f9;
    border-left: 4px solid #3498db;
    padding: 15px;
    margin-bottom: 20px;
    font-family: monospace;
    overflow-x: auto;
}

/* Full-width section */
.full-width {
    background-color: white;
    padding: 30px;
    margin-bottom: 30px;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* Image styling */
.img-responsive {
    max-width: 100%;
    height: auto;
    display: block;
    margin-bottom: 20px;
}

/* Button styles */
.btn {
    display: inline-block;
    background-color: #3498db;
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    font-size: 16px;
    margin-right: 10px;
    margin-bottom: 10px;
}

.btn:hover {
    background-color: #2980b9;
    color: white;
    text-decoration: none;
}

.btn-secondary {
    background-color: #7f8c8d;
}

.btn-secondary:hover {
    background-color: #95a5a6;
}

/* Table styles */
table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

table, th, td {
    border: 1px solid #ddd;
}

th {
    background-color: #3498db;
    color: white;
    text-align: left;
    padding: 12px;
}

td {
    padding: 12px;
}

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

/* Form styles */
form {
    background-color: white;
    padding: 20px;
    border-radius: 5px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

input[type="text"],
input[type="email"],
input[type="password"],
textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

/* Footer styles */
footer {
    text-align: center;
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 20px 0;
    margin-top: 30px;
    border-radius: 5px;
}

footer p {
    margin-bottom: 0;
}