:root {
    --primary-color: #4158D0;
    --secondary-color: #C850C0;
    --accent-color: #FFCC70;
    --text-dark: #2c3e50;
    --text-light: #ffffff;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.2);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

/* Header Styles */
.header {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    color: var(--text-dark);
    padding: 1.2rem 0;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 3px solid var(--primary-color);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
}

.header h1 {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.whatsapp-btn {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
    color: white;
    padding: 0.9rem 1.8rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    box-shadow: 0 4px 15px rgba(37, 211, 102, 0.4);
    position: relative;
    overflow: hidden;
}

.whatsapp-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.whatsapp-btn:hover::before {
    width: 300px;
    height: 300px;
}

.whatsapp-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 25px rgba(37, 211, 102, 0.5);
}

.whatsapp-btn:active {
    transform: translateY(-1px);
}

.whatsapp-btn svg {
    width: 26px;
    height: 26px;
    position: relative;
    z-index: 1;
}

.whatsapp-btn span {
    position: relative;
    z-index: 1;
}

/* Main Content */
.main-content {
    flex: 1;
    width: 100%;
    overflow-y: auto;
    overflow-x: hidden;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, #4158D0 0%, #5B4FB8 30%, #7B5FA0 60%, #9B6B8E 100%);
    min-height: 600px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: 4rem;
    padding: 4rem 3rem;
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 20s ease-in-out infinite;
}

.hero-section::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 15s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    50% {
        transform: translate(30px, -30px) scale(1.1);
    }
}

.hero-content {
    max-width: 600px;
    color: white;
    z-index: 2;
    animation: slideInLeft 0.8s ease-out;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.hero-content h2 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.3);
}

.hero-content p {
    font-size: 1.15rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    line-height: 1.6;
}

/* Course Selector */
.course-selector {
    background: rgba(255, 255, 255, 0.98);
    border-radius: 20px;
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    animation: slideUp 0.8s ease-out 0.2s both;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.course-selector h3 {
    color: var(--text-dark);
    font-size: 1.5rem;
    margin-bottom: 1.8rem;
    font-weight: 700;
}

.course-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    background: #f5f5f5;
    padding: 0.4rem;
    border-radius: 12px;
}

.course-tab {
    flex: 1;
    background: transparent;
    border: none;
    padding: 1rem 1.5rem;
    font-size: 1rem;
    cursor: pointer;
    color: #666;
    border-radius: 10px;
    transition: var(--transition);
    font-weight: 600;
}

.course-tab.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: var(--shadow-sm);
}

.course-tab:hover:not(.active) {
    background: rgba(65, 88, 208, 0.1);
    color: var(--primary-color);
}

.search-box {
    display: flex;
    gap: 0.8rem;
    position: relative;
}

.search-input {
    flex: 1;
    padding: 1.1rem 1.3rem;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
    background: white;
}

.search-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(65, 88, 208, 0.1);
}

.search-input::placeholder {
    color: #999;
}

.search-btn {
    padding: 1.1rem 2.5rem;
    background: linear-gradient(135deg, #e0e0e0, #d0d0d0);
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
    color: #555;
}

.search-btn:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.search-btn:active {
    transform: translateY(0);
}

/* Hero Image Section */
.hero-image {
    position: relative;
    z-index: 2;
    display: flex;
    justify-content: center;
    align-items: center;
    animation: slideInRight 0.8s ease-out 0.3s both;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.student-image {
    width: 350px;
    height: 450px;
    object-fit: cover;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    border: 5px solid rgba(255, 255, 255, 0.2);
}

/* Price Badge */
.price-badge {
    position: absolute;
    right: -80px;
    top: 50%;
    transform: translateY(-50%);
    background: linear-gradient(135deg, rgba(65, 88, 208, 0.95), rgba(123, 95, 160, 0.95));
    backdrop-filter: blur(20px);
    border: 4px solid #FFD700;
    border-radius: 25px;
    padding: 2rem 1.8rem;
    text-align: center;
    color: white;
    min-width: 320px;
    box-shadow: 0 15px 50px rgba(0, 0, 0, 0.4);
    animation: pulse-badge 3s ease-in-out infinite;
}

@keyframes pulse-badge {
    0%, 100% {
        transform: translateY(-50%) scale(1);
        box-shadow: 0 15px 50px rgba(0, 0, 0, 0.4);
    }
    50% {
        transform: translateY(-50%) scale(1.02);
        box-shadow: 0 20px 60px rgba(255, 215, 0, 0.3);
    }
}

.price-badge h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.price-badge .price-label {
    font-size: 0.85rem;
    margin-bottom: 0.5rem;
    opacity: 0.9;
}

.price-badge .price {
    font-size: 4.5rem;
    font-weight: 900;
    color: #FFD700;
    line-height: 1;
    margin: 0.8rem 0;
    text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: flex-start;
    justify-content: center;
}

.price-badge .price-small {
    font-size: 2.2rem;
    margin-right: 0.2rem;
}

.price-badge .period {
    font-size: 1.4rem;
    font-weight: 700;
    align-self: flex-end;
    margin-bottom: 0.8rem;
}

.price-badge .semester-info {
    font-size: 1rem;
    font-weight: 700;
    margin-top: 0.8rem;
    padding-top: 0.8rem;
    border-top: 2px solid rgba(255, 255, 255, 0.4);
    letter-spacing: 0.5px;
}

.price-badge .disclaimer {
    font-size: 0.7rem;
    margin-top: 1.2rem;
    opacity: 0.85;
    line-height: 1.4;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .hero-section {
        grid-template-columns: 1fr;
        gap: 3rem;
        padding: 3rem 2rem;
        text-align: center;
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-image {
        justify-content: center;
    }
    
    .price-badge {
        position: static;
        transform: none;
        margin-top: 2rem;
        min-width: auto;
        max-width: 400px;
        margin-left: auto;
        margin-right: auto;
    }
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 1.5rem;
    }
    
    .container {
        padding: 0 1rem;
        justify-content: center;
        text-align: center;
    }
    
    .whatsapp-btn {
        padding: 0.8rem 1.5rem;
        font-size: 0.95rem;
    }
    
    .hero-content h2 {
        font-size: 2rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .course-selector {
        padding: 2rem 1.5rem;
    }
    
    .course-tabs {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .search-box {
        flex-direction: column;
    }
    
    .search-btn {
        width: 100%;
    }
    
    .student-image {
        width: 280px;
        height: 360px;
    }
    
    .price-badge {
        min-width: auto;
        padding: 1.5rem;
    }
    
    .price-badge .price {
        font-size: 3.5rem;
    }
}

@media (max-width: 480px) {
    .hero-section {
        padding: 2rem 1rem;
    }
    
    .hero-content h2 {
        font-size: 1.6rem;
    }
    
    .course-selector h3 {
        font-size: 1.2rem;
    }
}