/* --- Theme 4: Modern Slate --- */
.premium-content-wrapper {
    font-family: 'Pretendard', 'Noto Sans KR', 'Apple SD Gothic Neo', sans-serif;
    background: #f8f9fa;
    color: #212529;
    line-height: 1.8;
    word-break: keep-all;
    padding: 40px;
    border-radius: 12px;
    margin: 20px 0;
    border: 1px solid #dee2e6;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.05);
}

.premium-title {
    font-size: 2.6em;
    font-weight: 800;
    color: #007bff;
    text-align: center;
    margin-bottom: 40px;
}

.premium-content-wrapper h2 {
    font-size: 2.1em;
    font-weight: 700;
    color: #343a40;
    text-align: center;
    padding-bottom: 20px;
    margin: 40px 0 30px 0;
    border-bottom: 1px solid #e9ecef;
}

.premium-content-wrapper h3 {
    font-size: 1.7em;
    font-weight: 600;
    color: #007bff;
    margin: 35px 0 20px 0;
    padding-bottom: 10px;
    border-bottom: 2px solid #007bff;
    display: inline-block;
}

.premium-content-wrapper p {
    font-size: 1.05em;
    margin-bottom: 1.5em;
    text-align: justify;
    color: #495057;
}

.premium-content-wrapper strong {
    color: #0056b3;
    font-weight: 600;
}

.premium-content-wrapper u {
    text-decoration: none;
    font-weight: 500;
    box-shadow: inset 0 -3px 0 rgba(0, 123, 255, 0.2);
    transition: box-shadow 0.3s ease;
}
.premium-content-wrapper u:hover {
    box-shadow: inset 0 -20px 0 rgba(0, 123, 255, 0.2);
}

.info-highlight {
    background: #e7f3ff;
    border-left: 4px solid #007bff;
    border-radius: 8px;
    padding: 25px;
    margin: 30px 0;
}

.info-highlight p {
    color: #004085;
    margin: 0;
    font-size: 1.05em;
}

.premium-purchase-section {
    text-align: center;
    margin: 50px 0;
    padding: 40px;
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.07);
    border: 1px solid #dee2e6;
    transition: all 0.3s ease;
}

.purchase-content {
    max-width: 600px;
    margin: 0 auto;
}

.premium-purchase-section h3 {
    color: #212529 !important;
    font-size: 1.8em !important;
    font-weight: 700 !important;
    margin-bottom: 15px !important;
    border: none !important;
    padding: 0 !important;
    text-shadow: none !important;
}

.premium-purchase-button {
    display: inline-block !important;
    padding: 17px 48px !important;
    font-size: 1.2em !important;
    font-weight: 700 !important;
    color: #fff !important;
    background-color: #007bff !important;
    border: none !important;
    border-radius: 8px !important;
    text-decoration: none !important;
    transition: all 0.3s ease !important;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.2) !important;
    transform: translateY(0) !important;
    cursor: pointer !important;
}

.premium-purchase-button:hover {
    transform: translateY(-3px) !important;
    background-color: #0056b3 !important;
    box-shadow: 0 7px 20px rgba(0, 123, 255, 0.3) !important;
    text-decoration: none !important;
}