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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Malgun Gothic', sans-serif;
    background: linear-gradient(135deg, rgba(245, 247, 250, 0.98) 0%, rgba(237, 242, 247, 0.98) 100%),
                url('https://iabyg.top/static/images/bgc.png') center/cover fixed;
    color: #2d3748;
    line-height: 1.6;
    padding-bottom: 80px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    background: rgba(255, 255, 255, 0.98);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    border-bottom: 1px solid #e2e8f0;
}

.header-content {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #3182ce 0%, #2c5282 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: white;
    font-size: 18px;
    box-shadow: 0 2px 8px rgba(49, 130, 206, 0.3);
}

.logo-text h1 {
    font-size: 16px;
    color: #2c5282;
    margin-bottom: 2px;
    font-weight: 600;
}

.logo-text p {
    font-size: 11px;
    color: #718096;
}

nav a {
    color: #4a5568;
    text-decoration: none;
    margin-left: 20px;
    font-size: 14px;
    transition: color 0.3s;
    font-weight: 500;
}

nav a:hover {
    color: #3182ce;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.95) 0%, rgba(247, 250, 252, 0.95) 100%);
    border-radius: 20px;
    padding: 40px;
    margin: 30px 0;
    backdrop-filter: blur(10px);
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.hero-content {
    display: flex;
    gap: 30px;
    align-items: center;
}

.hero-text h2 {
    color: #2c5282;
    font-size: 24px;
    margin-bottom: 10px;
    font-weight: 700;
}

.hero-text p {
    color: #4a5568;
    font-size: 15px;
    line-height: 1.8;
}

.hero-features {
    display: flex;
    gap: 20px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.feature-badge {
    background: linear-gradient(135deg, rgba(49, 130, 206, 0.1) 0%, rgba(66, 153, 225, 0.05) 100%);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    color: #2c5282;
    border: 1px solid rgba(49, 130, 206, 0.2);
    font-weight: 500;
}

.feature-badge i {
    color: #3182ce;
}

/* Content Section */
.content-section {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 35px;
    margin: 25px 0;
    backdrop-filter: blur(10px);
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.content-section h3 {
    color: #2c5282;
    font-size: 20px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #e2e8f0;
    font-weight: 600;
}

/* Image Text Sections */
.image-text-section {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 40px;
    margin: 25px 0;
    backdrop-filter: blur(10px);
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    display: flex;
    gap: 40px;
    align-items: center;
}

.image-text-section.reverse {
    flex-direction: row-reverse;
}

.section-image {
    flex: 0 0 45%;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
    border: 1px solid #e2e8f0;
}

.section-image img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.3s;
}

.section-image:hover img {
    transform: scale(1.05);
}

.section-text {
    flex: 1;
}

.section-text h3 {
    color: #2c5282;
    font-size: 24px;
    margin-bottom: 20px;
    font-weight: 700;
}

.section-text p {
    color: #4a5568;
    font-size: 15px;
    line-height: 1.8;
    margin-bottom: 20px;
}

.section-text ul {
    list-style: none;
    padding: 0;
}

.section-text ul li {
    padding: 10px 0;
    color: #4a5568;
    font-size: 15px;
}

.section-text ul li i {
    color: #3182ce;
    margin-right: 10px;
}

/* Curriculum List */
.curriculum-list {
    list-style: none;
}

.curriculum-list li {
    padding: 15px 20px;
    background: linear-gradient(135deg, rgba(237, 242, 247, 0.5) 0%, rgba(247, 250, 252, 0.5) 100%);
    margin-bottom: 10px;
    border-radius: 10px;
    border-left: 3px solid #3182ce;
    transition: all 0.3s;
    color: #4a5568;
}

.curriculum-list li:hover {
    background: linear-gradient(135deg, rgba(49, 130, 206, 0.1) 0%, rgba(66, 153, 225, 0.05) 100%);
    transform: translateX(5px);
    box-shadow: 0 2px 8px rgba(49, 130, 206, 0.15);
}

/* Quiz Section */
.quiz-section {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.95) 0%, rgba(255, 253, 247, 0.95) 100%);
    border-radius: 20px;
    padding: 35px;
    margin: 25px 0;
    backdrop-filter: blur(10px);
    border: 1px solid #fbd38d;
    box-shadow: 0 4px 20px rgba(237, 137, 54, 0.1);
}

.quiz-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
}

.quiz-header h3 {
    color: #c05621;
    font-size: 20px;
    margin: 0;
    font-weight: 600;
}

.quiz-description {
    color: #744210;
    font-size: 14px;
    margin-bottom: 25px;
    padding: 15px;
    background: rgba(251, 211, 141, 0.2);
    border-radius: 10px;
    border-left: 3px solid #ed8936;
}

.question-block {
    background: rgba(255, 255, 255, 0.8);
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 20px;
    border: 2px solid #e2e8f0;
    transition: all 0.3s;
}

.question-block.answered {
    border-color: #3182ce;
    background: rgba(237, 242, 247, 0.5);
}

.question-number {
    display: inline-block;
    width: 30px;
    height: 30px;
    background: linear-gradient(135deg, #3182ce 0%, #2c5282 100%);
    color: white;
    border-radius: 50%;
    text-align: center;
    line-height: 30px;
    font-weight: bold;
    margin-right: 10px;
    box-shadow: 0 2px 8px rgba(49, 130, 206, 0.3);
}

.question-text {
    color: #2d3748;
    font-size: 16px;
    margin-bottom: 15px;
    font-weight: 600;
}

.options {
    list-style: none;
}

.option-item {
    background: rgba(247, 250, 252, 0.5);
    padding: 15px 20px;
    margin-bottom: 10px;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
    border: 2px solid #e2e8f0;
    display: flex;
    align-items: center;
    gap: 10px;
    color: #4a5568;
}

.option-item:hover {
    background: rgba(237, 242, 247, 0.8);
    border-color: #3182ce;
    box-shadow: 0 2px 8px rgba(49, 130, 206, 0.15);
}

.option-item.selected {
    background: linear-gradient(135deg, rgba(49, 130, 206, 0.15) 0%, rgba(66, 153, 225, 0.1) 100%);
    border-color: #3182ce;
    color: #2c5282;
    font-weight: 500;
}

.option-checkbox {
    width: 20px;
    height: 20px;
    border: 2px solid #3182ce;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    background: white;
}

.option-item.selected .option-checkbox {
    background: linear-gradient(135deg, #3182ce 0%, #2c5282 100%);
    box-shadow: 0 2px 4px rgba(49, 130, 206, 0.3);
}

.option-item.selected .option-checkbox::after {
    content: '✓';
    color: white;
    font-weight: bold;
}

/* CTA Button */
.cta-button {
    display: block;
    width: 100%;
    padding: 18px;
    background: linear-gradient(135deg, #3182ce 0%, #2c5282 100%);
    color: white;
    text-align: center;
    text-decoration: none;
    border-radius: 50px;
    font-size: 16px;
    font-weight: bold;
    margin: 25px 0;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(49, 130, 206, 0.4);
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(49, 130, 206, 0.5);
    background: linear-gradient(135deg, #2c5282 0%, #2b4c7e 100%);
}

.cta-button:disabled {
    background: linear-gradient(135deg, #cbd5e0 0%, #a0aec0 100%);
    cursor: not-allowed;
    opacity: 0.6;
    box-shadow: none;
}

.cta-button i {
    margin-right: 8px;
}

/* Fixed Bottom CTA Button */
.cta-button-fixed {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: auto;
    max-width: 90%;
    min-width: 280px;
    margin: 0;
    border-radius: 50px;
    padding: 18px 40px;
    z-index: 999;
}

.cta-button-fixed:hover {
    transform: translateX(-50%) translateY(-2px);
}

.button-icon {
    width: 24px;
    height: 24px;
    vertical-align: middle;
    margin-right: 8px;
    display: inline-block;
}

.warning-message {
    text-align: center;
    color: #c05621;
    font-size: 14px;
    margin-top: 15px;
    padding: 10px;
    background: rgba(251, 211, 141, 0.2);
    border-radius: 10px;
    display: none;
    border: 1px solid #fbd38d;
}

.warning-message.show {
    display: block;
}

/* Alert Section */
.alert-section {
    background: linear-gradient(135deg, rgba(254, 252, 191, 0.3) 0%, rgba(255, 255, 255, 0.3) 100%);
    border-radius: 15px;
    padding: 20px;
    margin: 25px 0;
    border-left: 4px solid #d69e2e;
    box-shadow: 0 2px 12px rgba(213, 158, 46, 0.1);
}

.alert-section h4 {
    color: #975a16;
    font-size: 16px;
    margin-bottom: 10px;
    font-weight: 600;
}

.alert-section p {
    color: #4a5568;
    font-size: 14px;
}

/* Footer */
footer {
    background: rgba(255, 255, 255, 0.98);
    padding: 30px 20px;
    margin-top: 50px;
    text-align: center;
    border-top: 1px solid #e2e8f0;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.05);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.footer-links a {
    color: #4a5568;
    text-decoration: none;
    font-size: 14px;
    padding: 8px 15px;
    border-radius: 5px;
    transition: all 0.3s;
    font-weight: 500;
}

.footer-links a:hover {
    color: #3182ce;
    background: rgba(49, 130, 206, 0.1);
}

.copyright {
    color: #a0aec0;
    font-size: 12px;
    margin-top: 15px;
}

.fas, .fab {
    display: inline-block;
}

@media (max-width: 768px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
    }

    .hero-features {
        justify-content: center;
    }

    nav {
        display: none;
    }

    .image-text-section,
    .image-text-section.reverse {
        flex-direction: column;
        padding: 25px;
    }

    .section-image {
        flex: 0 0 100%;
    }

    .section-text h3 {
        font-size: 20px;
    }
}