/* Base styles */
:root {
    --primary-color: #3498db;
    --secondary-color: #2980b9;
    --accent-color: #e74c3c;
    --text-color: #333;
    --light-gray: #f5f5f5;
    --medium-gray: #ddd;
    --dark-gray: #888;
    --white: #fff;
    --shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-gray);
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Header */
header {
    background-color: var(--white);
    box-shadow: var(--shadow);
    padding: 1rem 0;
    margin-bottom: 2rem;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    color: var(--primary-color);
    font-size: 1.8rem;
}

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

nav ul li {
    margin-left: 1.5rem;
}

nav ul li a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: var(--primary-color);
}

/* Main content */
main {
    min-height: calc(100vh - 180px);
    padding-bottom: 2rem;
}

section {
    margin-bottom: 2rem;
}

h2 {
    margin-bottom: 1rem;
    color: var(--text-color);
}

h3 {
    margin-bottom: 0.8rem;
    color: var(--text-color);
}

/* Hero section */
.hero {
    text-align: center;
    padding: 2rem 0;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    color: var(--dark-gray);
    max-width: 600px;
    margin: 0 auto;
}

/* Form styles */
.url-form {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    max-width: 800px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input[type="url"],
input[type="text"] {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid var(--medium-gray);
    border-radius: 4px;
    font-size: 1rem;
}

input[type="url"]:focus,
input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: var(--secondary-color);
}

.btn-secondary {
    background-color: var(--dark-gray);
}

.btn-secondary:hover {
    background-color: #777;
}

.btn-danger {
    background-color: var(--accent-color);
}

.btn-danger:hover {
    background-color: #c0392b;
}

.btn-small {
    padding: 0.4rem 0.8rem;
    font-size: 0.9rem;
}

/* Features section */
.features {
    padding: 2rem 0;
}

.features h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature {
    background-color: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    text-align: center;
}

.feature h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Result page */
.result {
    text-align: center;
}

.result h2 {
    margin-bottom: 2rem;
}

.result-card {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    max-width: 800px;
    margin: 0 auto 2rem;
}

.result-item {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--medium-gray);
}

.result-item:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.short-url-container {
    display: flex;
    margin-top: 0.5rem;
}

.short-url-container input {
    flex: 1;
    margin-right: 0.5rem;
    font-weight: 500;
}

.copy-btn {
    min-width: 80px;
}

.long-url {
    word-break: break-all;
    color: var(--dark-gray);
}

.qr-code {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.qr-code img {
    width: 200px;
    height: 200px;
    margin-bottom: 1rem;
}

.actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

/* URL list page */
.url-list {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.empty-state {
    text-align: center;
    padding: 3rem 0;
}

.empty-state p {
    margin-bottom: 1.5rem;
    color: var(--dark-gray);
}

.url-table-container {
    overflow-x: auto;
}

.url-table {
    width: 100%;
    border-collapse: collapse;
}

.url-table th,
.url-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--medium-gray);
}

.url-table th {
    background-color: var(--light-gray);
    font-weight: 600;
}

.url-table td.long-url {
    max-width: 300px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.url-table td.actions {
    display: flex;
    gap: 0.5rem;
}

/* Error page */
.error {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 50vh;
}

.error-container {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    text-align: center;
    max-width: 500px;
}

.error-container h2 {
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.error-container p {
    margin-bottom: 1.5rem;
}

/* Footer */
footer {
    background-color: var(--white);
    padding: 1.5rem 0;
    text-align: center;
    box-shadow: 0 -2px 5px rgba(0, 0, 0, 0.05);
    margin-top: 2rem;
}

footer p {
    color: var(--dark-gray);
    font-size: 0.9rem;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    header .container {
        flex-direction: column;
    }
    
    nav ul {
        margin-top: 1rem;
    }
    
    nav ul li {
        margin: 0 0.75rem;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .actions {
        flex-direction: column;
    }
    
    .actions .btn {
        width: 100%;
    }
}