:root {
    --primary-color: #007bff;
    --background-color: #f4f7f6;
    --card-background: #ffffff;
    --text-color: #333;
    --light-gray: #e9ecef;
    --border-radius: 8px;
}
body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}
.container {
    width: 100%;
    max-width: 600px;
    background-color: var(--card-background);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    text-align: center;
}
header h1 { margin-bottom: 0.5rem; }
header p { color: #6c757d; margin-bottom: 2rem; }
#url-form { display: flex; gap: 10px; }
#url-input {
    flex-grow: 1;
    padding: 12px 15px;
    font-size: 1rem;
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    outline: none;
    transition: box-shadow 0.2s;
}
#url-input:focus {
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
    border-color: var(--primary-color);
}
button {
    padding: 12px 20px;
    font-size: 1rem;
    font-weight: 600;
    color: #fff;
    background-color: var(--primary-color);
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.2s;
}
button:hover { background-color: #0056b3; }
.hidden { display: none !important; }
#loader {
    margin: 2rem auto;
    border: 5px solid var(--light-gray);
    border-top: 5px solid var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
#results { margin-top: 2rem; text-align: left; }
.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background-color: var(--background-color);
    border-radius: var(--border-radius);
    margin-bottom: 10px;
}
.result-item span { font-weight: 600; }
.result-item a {
    text-decoration: none;
    padding: 8px 15px;
    font-size: 0.9rem;
    color: #fff;
    background-color: #28a745;
    border-radius: var(--border-radius);
    transition: background-color 0.2s;
}
.result-item a:hover { background-color: #218838; }