body, html {
    height: 100%;
    margin: 0;
    font-family: 'Arial', sans-serif;
    background-color: #000000 !important;
    color: #ffffff;
}

.navbar {
    background-color: #333;
    padding: 10px 20px;
    text-align: center;
}

.challenge-container {
    width: 100%; 
    max-width: 1200px; 
    margin: 0 auto; 
    padding: 0 20px; 
}

.challenge {
    background-color: #252526;
    margin-bottom: 20px;
    padding: 20px;
    border-radius: 20px;
    margin-top: 30px;
    color: #ffffff;
}

.challenge-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.difficulty {
    background-color: #0f9d58;
    padding: 2px 8px;
    border-radius: 4px;
    color: #fff;
    font-weight: bold;
}

.date-range {
    background-color: #555;
    padding: 2px 8px;
    border-radius: 4px;
    color: #fff;
}

.challenge-description {
    background-color: #333;
    padding: 10px;
    overflow-x: auto;
    color: #ffffff;
}

.challenge-footer {
    display: flex;
    justify-content: space-around;
    margin-top: 20px;
}

button {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    color: white;
    background-color: #0f9d58;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #0c7c43;
}

.intro-section {
    background-color: #333; 
    color: #fff; 
    padding: 20px;
    border-radius: 10px; 
    margin-bottom: 30px; 
}

.intro-section h1 {
    font-size: 2.5rem; 
    font-weight: bold; 
    margin-bottom: 20px; 
}

@media (max-width: 992px) {
    .intro-section .row > div {
        margin-bottom: 15px;
    }
}

.filter-container {
    margin: 20px 0;
    text-align: center;
}

#difficulty-filter, #date-filter, #apply-filter {
    margin: 0 10px;
}


button {
    background-color: #0f9d58;
    
}


button.btn.btn-success {
    all: unset;
    padding: 10px 20px;
    border-radius: 4px;
    color: #ffffff;
    background-color: #0f9d58;
}

#difficulty-filter {
    color: white;
    background-color: black;
    border: 1px solid #ccc; 
}

#apply-filter {
    background-color: #28a745; 
    border-color: #28a745; 
}


#apply-filter:not(:last-child) {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}

#apply-filter:hover {
    background-color: #218838; 
    border-color: #1e7e34;
}