/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #f59e0b;
    --dark: #1e1e2e;
    --darker: #13131d;
    --gray: #6b7280;
    --gray-light: #9ca3af;
    --white: #ffffff;
    --bg-card: #252536;
    --bg-card-hover: #2d2d42;
    --border: #3f3f5a;
    --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
}

body {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--darker);
    color: var(--white);
    line-height: 1.6;
}

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

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(19, 19, 29, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--border);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--white);
    text-decoration: none;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    color: var(--gray-light);
    text-decoration: none;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--white);
}

/* Hero */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(180deg, var(--darker) 0%, var(--dark) 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.badge {
    display: inline-block;
    background: var(--gradient);
    color: var(--white);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 900;
    line-height: 1.2;
    margin-bottom: 15px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.3rem;
    color: var(--gray-light);
    margin-bottom: 20px;
}

.description {
    font-size: 1.1rem;
    color: var(--gray);
    margin-bottom: 30px;
}

.description strong {
    color: var(--secondary);
}

.hero-buttons {
    display: flex;
    gap: 15px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 14px 28px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient);
    color: var(--white);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--border);
}

.btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--white);
}

.btn-large {
    padding: 18px 40px;
    font-size: 1.1rem;
}

/* Code Preview */
.code-preview {
    background: var(--bg-card);
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--border);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
}

.code-header {
    background: var(--dark);
    padding: 12px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot.red { background: #ff5f56; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #27c93f; }

.filename {
    margin-left: 10px;
    color: var(--gray-light);
    font-size: 0.85rem;
}

.code-body {
    padding: 20px;
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    line-height: 1.8;
    overflow-x: auto;
}

.code-body code {
    color: var(--gray-light);
}

.keyword { color: #c678dd; }
.function { color: #61afef; }
.type { color: #e5c07b; }
.string { color: #98c379; }
.comment { color: #5c6370; font-style: italic; }

/* Recommend Section */
.recommend {
    padding: 80px 0;
    background: var(--dark);
}

.recommend h2, .courses h2, .reviews h2, .pricing h2, .instructor h2, .faq h2 {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 50px;
}

.section-desc {
    text-align: center;
    color: var(--gray-light);
    margin-top: -30px;
    margin-bottom: 40px;
}

.recommend-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.recommend-card {
    background: var(--bg-card);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.recommend-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary);
}

.recommend-card .icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.recommend-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.recommend-card p {
    color: var(--gray-light);
    font-size: 0.95rem;
}

/* Courses Section */
.courses {
    padding: 80px 0;
    background: var(--darker);
}

.course-module {
    background: var(--bg-card);
    border-radius: 16px;
    margin-bottom: 30px;
    overflow: hidden;
    border: 1px solid var(--border);
}

.course-module.bonus {
    border-color: var(--secondary);
}

.module-header {
    padding: 25px 30px;
    background: var(--dark);
    display: flex;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
}

.module-badge {
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
}

.module-badge.basic { background: #10b981; }
.module-badge.advanced { background: #3b82f6; }
.module-badge.pro { background: #8b5cf6; }
.module-badge.bonus-badge { background: var(--secondary); }

.module-header h3 {
    flex: 1;
    font-size: 1.3rem;
}

.duration {
    color: var(--gray-light);
    font-size: 0.9rem;
}

.lecture-list {
    list-style: none;
}

.lecture-list li {
    display: flex;
    align-items: center;
    padding: 20px 30px;
    border-bottom: 1px solid var(--border);
    transition: background 0.3s;
}

.lecture-list li:last-child {
    border-bottom: none;
}

.lecture-list li:hover {
    background: var(--bg-card-hover);
}

.lecture-num {
    width: 40px;
    height: 40px;
    background: var(--dark);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: var(--primary);
    margin-right: 20px;
    flex-shrink: 0;
}

.lecture-info {
    flex: 1;
}

.lecture-info h4 {
    font-size: 1.05rem;
    margin-bottom: 5px;
}

.lecture-info p {
    color: var(--gray-light);
    font-size: 0.9rem;
}

.lecture-time {
    color: var(--gray);
    font-size: 0.9rem;
    flex-shrink: 0;
}

/* Reviews */
.reviews {
    padding: 80px 0;
    background: var(--dark);
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.review-card {
    background: var(--bg-card);
    padding: 30px;
    border-radius: 16px;
    border: 1px solid var(--border);
}

.review-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
}

.avatar {
    width: 50px;
    height: 50px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
}

.review-header h4 {
    font-size: 1.1rem;
}

.review-header span {
    color: var(--gray-light);
    font-size: 0.9rem;
}

.review-card p {
    color: var(--gray-light);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 15px;
}

.stars {
    color: var(--secondary);
    font-size: 1.1rem;
}

/* Pricing */
.pricing {
    padding: 80px 0;
    background: var(--darker);
}

.pricing-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.pricing-card {
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid var(--border);
    overflow: hidden;
    position: relative;
    transition: transform 0.3s;
}

.pricing-card:hover {
    transform: translateY(-5px);
}

.pricing-card.featured {
    border-color: var(--primary);
    transform: scale(1.05);
}

.pricing-card.featured:hover {
    transform: scale(1.08);
}

.ribbon {
    position: absolute;
    top: 20px;
    right: -30px;
    background: var(--secondary);
    color: var(--darker);
    padding: 5px 40px;
    font-size: 0.8rem;
    font-weight: 700;
    transform: rotate(45deg);
}

.pricing-header {
    padding: 30px;
    background: var(--dark);
    text-align: center;
}

.pricing-header h3 {
    font-size: 1.4rem;
    margin-bottom: 5px;
}

.pricing-header p {
    color: var(--gray-light);
    font-size: 0.9rem;
}

.pricing-body {
    padding: 30px;
    text-align: center;
}

.price {
    margin-bottom: 25px;
}

.price .original {
    color: var(--gray);
    text-decoration: line-through;
    font-size: 1rem;
    display: block;
    margin-bottom: 5px;
}

.price .current {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--white);
}

.features {
    list-style: none;
    text-align: left;
    margin-bottom: 30px;
}

.features li {
    padding: 10px 0;
    color: var(--gray-light);
    border-bottom: 1px solid var(--border);
}

.features li:last-child {
    border-bottom: none;
}

/* Earlybird Notice */
.earlybird-notice {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.earlybird-item {
    background: var(--bg-card);
    padding: 15px 25px;
    border-radius: 12px;
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 12px;
    opacity: 0.6;
}

.earlybird-item.active {
    opacity: 1;
    border-color: var(--primary);
    background: linear-gradient(135deg, rgba(138, 43, 226, 0.1), rgba(255, 215, 0, 0.1));
}

.earlybird-item .badge {
    background: var(--primary);
    color: white;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.earlybird-item .badge.upcoming {
    background: var(--gray);
}

.earlybird-item strong {
    font-size: 1rem;
}

.earlybird-item .discount {
    color: var(--secondary);
    font-weight: 700;
}

/* Discount Tag */
.discount-tag {
    display: inline-block;
    background: var(--secondary);
    color: var(--darker);
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 700;
    margin-left: 10px;
    vertical-align: middle;
}

.price .current {
    font-size: 2rem;
}

.pricing-card.featured .price .current {
    font-size: 2.2rem;
    color: var(--secondary);
}


/* Instructor */
.instructor {
    padding: 80px 0;
    background: var(--dark);
}

.instructor-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 60px;
    align-items: center;
}

.placeholder-avatar {
    width: 250px;
    height: 250px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6rem;
    margin: 0 auto;
}

.instructor-info h2 {
    text-align: left;
    margin-bottom: 10px;
}

.instructor-info h3 {
    font-size: 2rem;
    margin-bottom: 5px;
}

.instructor-info .title {
    color: var(--primary);
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.instructor-info .bio {
    color: var(--gray-light);
    font-size: 1rem;
    line-height: 1.8;
}

.instructor-info .bio strong {
    color: var(--white);
}

/* FAQ */
.faq {
    padding: 80px 0;
    background: var(--darker);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-card);
    border-radius: 12px;
    margin-bottom: 15px;
    border: 1px solid var(--border);
    overflow: hidden;
}

.faq-item summary {
    padding: 20px 25px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.05rem;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    font-size: 1.5rem;
    color: var(--primary);
}

.faq-item[open] summary::after {
    content: '-';
}

.faq-item p {
    padding: 0 25px 20px;
    color: var(--gray-light);
    line-height: 1.7;
}

/* CTA */
.cta {
    padding: 100px 0;
    background: var(--gradient);
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.cta .btn-primary {
    background: var(--white);
    color: var(--primary-dark);
}

.cta .btn-primary:hover {
    background: var(--darker);
    color: var(--white);
}

/* Preview Section */
.preview {
    padding: 80px 0;
    background: var(--darker);
}

.preview h2 {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 50px;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.preview-card {
    background: var(--bg-card);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.preview-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary);
}

.preview-thumb {
    font-size: 3rem;
    margin-bottom: 15px;
}

.preview-card h4 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.preview-card p {
    color: var(--gray-light);
    font-size: 0.9rem;
}

@media (max-width: 1024px) {
    .preview-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .preview-grid {
        grid-template-columns: 1fr;
    }
}

/* Footer */
.footer {
    padding: 60px 0 30px;
    background: var(--darker);
    border-top: 1px solid var(--border);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.footer-brand p {
    color: var(--gray-light);
}

.footer-links h4 {
    margin-bottom: 15px;
    font-size: 1rem;
}

.footer-links p, .footer-links a {
    color: var(--gray-light);
    font-size: 0.9rem;
    display: block;
    margin-bottom: 8px;
    text-decoration: none;
}

.footer-links a:hover {
    color: var(--primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--border);
    color: var(--gray);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

    .hero-visual {
        display: none;
    }

    .recommend-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .reviews-grid, .pricing-cards {
        grid-template-columns: 1fr;
    }

    .pricing-card.featured {
        transform: none;
    }

    .instructor-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .instructor-info h2 {
        text-align: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .recommend-grid {
        grid-template-columns: 1fr;
    }

    .module-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .lecture-list li {
        flex-wrap: wrap;
    }

    .lecture-time {
        width: 100%;
        margin-top: 10px;
        margin-left: 60px;
    }
}


/* Inquiry Form */
.inquiry {
    padding: 100px 0;
    background: var(--dark);
}

.inquiry h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.inquiry .section-desc {
    text-align: center;
    color: var(--gray-light);
    margin-bottom: 50px;
}

.inquiry-form {
    max-width: 600px;
    margin: 0 auto;
    background: var(--bg-card);
    padding: 40px;
    border-radius: 16px;
    border: 1px solid var(--border);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--white);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    background: var(--darker);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--white);
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--gray);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.inquiry-form .btn {
    width: 100%;
    margin-top: 10px;
}

.inquiry-form .btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

/* Form success/error messages */
.form-message {
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    text-align: center;
}

.form-message.success {
    background: rgba(34, 197, 94, 0.2);
    border: 1px solid #22c55e;
    color: #22c55e;
}

.form-message.error {
    background: rgba(239, 68, 68, 0.2);
    border: 1px solid #ef4444;
    color: #ef4444;
}

@media (max-width: 768px) {
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .inquiry-form {
        padding: 25px;
    }
}