body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background-color: #0d1117;
    color: #c9d1d9;
    /* Usamos flexbox para centrar todo el contenido vertical y horizontalmente */
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    line-height: 1.6;
    padding: 20px;
    box-sizing: border-box;
}

/* Nuevos estilos para el logo, basados en los ejemplos anteriores */
.logo-container {
    text-align: center;
    margin-bottom: 20px;
}

.logo-container img {
    width: 150px;
    height: auto;
}

.container {
    background-color: #161b22;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.6);
    width: 90%;
    max-width: 800px;
    text-align: center;
    /* Eliminamos el margin: 0 auto; ya que el body con flexbox lo centra */
}

.header {
    margin-bottom: 30px;
}

/* Eliminamos la regla .logo ya que la imagen está en .logo-container */
/*
.logo {
    width: 150px;
    height: auto;
    margin-bottom: 20px;
}
*/

h1 {
    color: #58a6ff;
    border-bottom: 2px solid #30363d;
    padding-bottom: 15px;
    margin-bottom: 10px;
}

p {
    color: #8b949e;
}

.challenges-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 30px;
}

.challenge-link {
    display: flex;
    align-items: center;
    background-color: #21262d;
    padding: 20px;
    border-radius: 8px;
    text-decoration: none;
    color: #c9d1d9;
    transition: background-color 0.3s ease, transform 0.3s ease;
    border: 1px solid #30363d;
}

.challenge-link:hover {
    background-color: #2d333b;
    transform: translateY(-3px);
}

.challenge-icon {
    font-size: 2rem;
    margin-right: 20px;
    color: #58a6ff;
}

.challenge-title {
    font-size: 1.2em;
    font-weight: bold;
}

.challenge-container {
    text-align: center;
    padding: 20px;
}

.solution-area {
    margin-top: 25px;
}

#flagInput {
    padding: 10px;
    border-radius: 5px;
    border: 1px solid #30363d;
    background-color: #010409;
    color: #e6edf3;
    width: calc(100% - 24px);
    max-width: 400px;
    margin-right: 10px;
    margin-bottom: 10px;
}

button {
    background-color: #238636;
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #2ea043;
}

#feedbackMessage {
    margin-top: 15px;
    font-weight: bold;
}