body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f7f6;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}
main {
    background: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    width: 100%;
    max-width: 500px;
    margin: 1rem;
}
h1 {
    text-align: center;
    color: #000;
    margin-top: 0;
}
h1 .prefix { color: #aaa; }
p { color: #666; }
.form-group {
    margin-bottom: 1rem;
}
.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}
input[type="url"], input[type="text"], input[type="password"], input[type="date"] {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box; /* Importante */
}
.form-group-inline {
    display: flex;
    margin-bottom: 1rem;
}
.form-group-inline .prefix {
    padding: 0.75rem;
    background: #eee;
    border: 1px solid #ddd;
    border-right: 0;
    border-radius: 4px 0 0 4px;
    color: #666;
    white-space: nowrap;
}
.form-group-inline input {
    border-radius: 0 4px 4px 0;
    flex-grow: 1;
}
.form-group-inline button {
    border-radius: 0 4px 4px 0;
    border-left: 0;
}
button {
    width: 100%;
    padding: 0.85rem;
    border: none;
    border-radius: 4px;
    background-color: #007bff;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}
button:hover {
    background-color: #0056b3;
}
details {
    margin-bottom: 1rem;
    border: 1px solid #eee;
    border-radius: 4px;
}
details[open] { padding-bottom: 1rem; }
details summary {
    padding: 0.75rem;
    cursor: pointer;
    font-weight: 500;
    color: #007bff;
}
details > * {
    padding: 0 1rem;
}
.hidden { display: none; }
#result {
    margin-top: 1.5rem;
    border-top: 1px solid #eee;
    padding-top: 1.5rem;
}

/* Estilos de Analytics */
.stat-box {
    background: #fdfdfd;
    border: 1px solid #eee;
    border-radius: 8px;
    padding: 1rem;
    text-align: center;
}
.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #007bff;
}
.stat-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 1.5rem;
}
#pro-analytics table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}
#pro-analytics th, #pro-analytics td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: left;
    font-size: 0.9rem;
}
#pro-analytics th { background-color: #f4f4f4; }
#upgrade-button { background-color: #28a745; }
#upgrade-button:hover { background-color: #218838; }
ul { list-style: none; padding-left: 0; }