* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.card-detail-container {
    max-width: 900px;
    margin: 0 auto;
}

.back-link {
    display: inline-block;
    color: white;
    text-decoration: none;
    margin-bottom: 20px;
    font-size: 1.1em;
    font-weight: 500;
    padding: 10px 20px;
    background: rgba(255,255,255,0.2);
    border-radius: 8px;
    transition: background 0.3s;
}

.back-link:hover {
    background: rgba(255,255,255,0.3);
}

.card-detail {
    background: white;
    border-radius: 15px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.card-header {
    display: flex;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 3px solid #f0f0f0;
}

.card-icon {
    font-size: 3em;
    margin-right: 20px;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 15px;
}

.card-detail h1 {
    color: #333;
    font-size: 2.5em;
    font-weight: bold;
}

.card-content {
    line-height: 1.8;
}

.intro {
    font-size: 1.2em;
    color: #666;
    margin-bottom: 30px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid #667eea;
}

h2 {
    color: #667eea;
    margin: 30px 0 15px 0;
    font-size: 1.8em;
    font-weight: bold;
}

h3 {
    color: #667eea;
    margin: 25px 0 15px 0;
    font-size: 1.4em;
}

p {
    margin-bottom: 15px;
    font-size: 1.1em;
}

ul {
    margin-left: 25px;
    margin-bottom: 20px;
}

li {
    margin-bottom: 10px;
    font-size: 1.1em;
}

.tip-box {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 20px;
    margin: 25px 0;
    border-radius: 8px;
    font-size: 1.1em;
}

.summary-box {
    background: #e7f3ff;
    border-left: 4px solid #2196F3;
    padding: 20px;
    margin: 25px 0;
    border-radius: 8px;
    font-size: 1.1em;
}

.links-section {
    margin-top: 40px;
    padding-top: 30px;
    border-top: 2px solid #f0f0f0;
}

.links-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin-top: 15px;
}

.link-btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
}

.web-link {
    background: #48bb78;
    color: white;
}

.web-link:hover {
    background: #38a169;
    transform: translateY(-2px);
}

.app-link {
    background: #667eea;
    color: white;
}

.app-link:hover {
    background: #764ba2;
    transform: translateY(-2px);
}

@media (max-width: 768px) {
    .card-detail {
        padding: 25px;
    }

    .card-detail h1 {
        font-size: 2em;
    }

    .card-header {
        flex-direction: column;
        text-align: center;
    }

    .card-icon {
        margin-right: 0;
        margin-bottom: 15px;
    }
}