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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* Diamond Pattern Background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.1) 1px, transparent 1px),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.1) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    z-index: -1;
}

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

/* Header Styles */
.header {
    text-align: center;
    margin-bottom: 40px;
    position: relative;
}

.title-section {
    margin-bottom: 20px;
}

h1 {
    font-size: 2.5rem;
    color: #1565c0;
    margin-bottom: 10px;
    font-weight: 700;
}

.online-indicator {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.9);
    padding: 8px 16px;
    border-radius: 20px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.green-dot {
    width: 12px;
    height: 12px;
    background: #4caf50;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.description {
    margin: 20px 0;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.description p {
    font-size: 1.1rem;
    color: #424242;
    line-height: 1.6;
}

.header-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin: 30px 0;
}

.btn-primary {
    background: linear-gradient(135deg, #4caf50, #45a049);
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 25px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
    transition: all 0.3s ease;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(76, 175, 80, 0.4);
}

.btn-secondary {
    background: white;
    color: #1565c0;
    border: 2px solid #1565c0;
    padding: 15px 30px;
    border-radius: 25px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background: #1565c0;
    color: white;
    transform: translateY(-2px);
}

.asterisk-icon {
    position: absolute;
    top: 20px;
    right: 20px;
    color: #ffc107;
    font-size: 1.5rem;
    animation: rotate 3s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Section Styles */
section {
    margin-bottom: 40px;
}

h2 {
    font-size: 1.8rem;
    color: #1565c0;
    margin-bottom: 10px;
    text-align: center;
}

.instruction {
    text-align: center;
    color: #666;
    margin-bottom: 30px;
    font-size: 1.1rem;
}

/* Card Styles */
.selection-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.card {
    background: white;
    border-radius: 15px;
    padding: 30px 20px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    border: 3px solid transparent;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.card.selected {
    border-color: #4caf50;
    background: linear-gradient(135deg, #f8fff8, #e8f5e8);
}

/* Diamond Cards */
.diamond-card {
    min-height: 150px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.diamond-icon {
    font-size: 3rem;
    color: #2196f3;
    margin-bottom: 15px;
}

.diamond-card h3 {
    font-size: 1.3rem;
    color: #1565c0;
    font-weight: 600;
}

.recommended-tag {
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    background: #1565c0;
    color: white;
    padding: 5px 15px;
    border-radius: 15px;
    font-size: 0.9rem;
    font-weight: 600;
}

/* Class Cards */
.class-card {
    min-height: 200px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.class-icon {
    margin-bottom: 20px;
}

.hexagon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #2196f3, #1976d2);
    clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    margin: 0 auto;
}

.hexagon i {
    font-size: 2rem;
    color: white;
    z-index: 2;
}

.class-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
    z-index: 2;
}

.watermark {
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.7rem;
    color: #666;
    background: white;
    padding: 2px 6px;
    border-radius: 3px;
    white-space: nowrap;
}

.class-card h3 {
    font-size: 1.3rem;
    color: #1565c0;
    font-weight: 600;
}

/* Continue Button */
.btn-continue {
    background: linear-gradient(135deg, #2196f3, #1976d2);
    color: white;
    border: none;
    padding: 15px 40px;
    border-radius: 25px;
    font-size: 1.2rem;
    font-weight: 600;
    cursor: pointer;
    display: block;
    margin: 30px auto 0;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(33, 150, 243, 0.3);
}

.btn-continue:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(33, 150, 243, 0.4);
}

.btn-continue:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Steps Section */
.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 40px 0;
}

.step-card {
    background: white;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    display: flex;
    align-items: center;
    gap: 20px;
}

.step-number {
    background: linear-gradient(135deg, #4caf50, #45a049);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
    flex-shrink: 0;
}

.step-content h4 {
    color: #1565c0;
    margin-bottom: 5px;
    font-size: 1.1rem;
}

.step-content p {
    color: #666;
    line-height: 1.5;
}

/* Footer */
.footer {
    text-align: center;
    margin-top: 60px;
    padding: 20px;
}

.footer p {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Enhanced Responsive Design */
@media (max-width: 1200px) {
    .container {
        max-width: 100%;
        padding: 20px;
    }
    
    .selection-cards {
        grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    }
}

@media (max-width: 992px) {
    h1 {
        font-size: 2.2rem;
    }
    
    .selection-cards {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
        gap: 15px;
    }
    
    .steps {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    }
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    h1 {
        font-size: 1.8rem;
        line-height: 1.2;
    }
    
    .header-buttons {
        flex-direction: column;
        align-items: center;
        gap: 10px;
    }
    
    .btn-primary,
    .btn-secondary {
        width: 100%;
        max-width: 300px;
        padding: 12px 25px;
        font-size: 1rem;
    }
    
    .selection-cards {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .card {
        padding: 25px 20px;
        min-height: auto;
    }
    
    .steps {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .step-card {
        flex-direction: column;
        text-align: center;
        padding: 20px;
    }
    
    .step-number {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
    
    .asterisk-icon {
        position: static;
        margin-top: 15px;
        font-size: 1.2rem;
    }
    
    .online-indicator {
        padding: 6px 12px;
        font-size: 0.9rem;
    }
    
    .description p {
        font-size: 1rem;
        line-height: 1.5;
    }
}

@media (max-width: 576px) {
    .container {
        padding: 10px;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    h2 {
        font-size: 1.4rem;
    }
    
    .card {
        padding: 20px 15px;
        margin: 0 5px;
    }
    
    .diamond-icon {
        font-size: 2.5rem;
    }
    
    .hexagon {
        width: 60px;
        height: 60px;
    }
    
    .hexagon i {
        font-size: 1.5rem;
    }
    
    .class-image {
        width: 100%;
        height: 100%;
    }
    
    .btn-continue {
        padding: 12px 30px;
        font-size: 1.1rem;
        margin: 20px auto 0;
    }
    
    .step-card {
        padding: 15px;
        margin: 0 5px;
    }
    
    .footer {
        margin-top: 40px;
        padding: 15px;
    }
    
    .footer p {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.3rem;
    }
    
    .card {
        padding: 15px 10px;
    }
    
    .diamond-icon {
        font-size: 2rem;
    }
    
    .hexagon {
        width: 50px;
        height: 50px;
    }
    
    .hexagon i {
        font-size: 1.2rem;
    }
    
    .class-image {
        width: 100%;
        height: 100%;
    }
    
    .watermark {
        font-size: 0.6rem;
        bottom: -12px;
    }
    
    .btn-primary,
    .btn-secondary {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    
    .btn-continue {
        padding: 10px 25px;
        font-size: 1rem;
    }
}

/* Touch-friendly interactions */
@media (hover: none) and (pointer: coarse) {
    .card {
        min-height: 120px;
    }
    
    .btn-primary,
    .btn-secondary,
    .btn-continue {
        min-height: 44px;
        touch-action: manipulation;
    }
    
    .card:hover {
        transform: none;
    }
    
    .card:active {
        transform: scale(0.98);
        transition: transform 0.1s ease;
    }
}

/* Landscape mobile optimization */
@media (max-height: 500px) and (orientation: landscape) {
    .header {
        margin-bottom: 20px;
    }
    
    h1 {
        font-size: 1.5rem;
        margin-bottom: 5px;
    }
    
    .description {
        margin: 10px 0;
    }
    
    .description p {
        font-size: 0.9rem;
    }
    
    .header-buttons {
        margin: 15px 0;
    }
    
    section {
        margin-bottom: 20px;
    }
    
    .card {
        padding: 15px 10px;
        min-height: 100px;
    }
    
    .steps {
        margin: 20px 0;
    }
    
    .step-card {
        padding: 10px;
    }
}