:root {
    /* Brand Colors */
    --color-primary: #010A3A;
    /* Deep Navy */
    --color-accent: #461DDD;
    /* Vivid Blue/Purple */
    --color-secondary: #D9D9D9;
    /* Light Silver */

    /* Text Colors */
    --text-main: #FFFFFF;
    --text-muted: #A0A0A0;

    /* Spacing & Layout */
    --container-width: 1200px;
    --header-height: 80px;
    --section-padding: 100px 0;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
}

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

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
    background-color: var(--color-primary);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: opacity 0.3s;
}

ul {
    list-style: none;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Typography Helpers */
.text-gradient {
    background: linear-gradient(135deg, #FFFFFF 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

/* Hero Info */
.hero-info {
    font-size: 1.1rem;
    color: #fff;
    margin-bottom: 32px;
    font-weight: 500;
    opacity: 0.9;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--color-accent);
    color: #fff;
    border: 1px solid var(--color-accent);
    box-shadow: 0 4px 15px rgba(70, 29, 221, 0.4);
}

.btn-primary:hover {
    background-color: #3515A8;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(70, 29, 221, 0.6);
}

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--color-secondary);
    color: var(--color-secondary);
}

.btn-outline:hover {
    background-color: rgba(217, 217, 217, 0.1);
    color: #fff;
    border-color: #fff;
}

.btn-lg {
    padding: 16px 32px;
    font-size: 1.1rem;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: rgba(1, 10, 58, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-container {
    height: 100%;
    display: flex;
    align-items: center;
}

.logo {
    flex: 1;
    display: flex;
    align-items: center;
}

.nav {
    flex: 2;
    display: flex;
    justify-content: center;
}

.header-actions {
    flex: 1;
    display: flex;
    justify-content: flex-end;
    gap: 12px;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-list a {
    color: var(--color-secondary);
    font-size: 0.95rem;
}

.nav-list a:hover {
    color: #fff;
}

/* Hero Section */
.hero {
    position: relative;
    padding-top: calc(var(--header-height) + 80px);
    padding-bottom: 120px;
    text-align: center;
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 4rem;
    line-height: 1.2;
    margin-bottom: 24px;
    font-weight: 800;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-secondary);
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.badge {
    display: inline-block;
    padding: 8px 16px;
    background-color: rgba(70, 29, 221, 0.2);
    color: #aaa;
    border: 1px solid rgba(70, 29, 221, 0.5);
    border-radius: 50px;
    margin-bottom: 24px;
    font-size: 0.9rem;
    font-weight: 600;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
}

.hero-bg-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(70, 29, 221, 0.4) 0%, rgba(1, 10, 58, 0) 70%);
    filter: blur(80px);
    z-index: 1;
    pointer-events: none;
}

/* Sections General */
.section {
    padding: var(--section-padding);
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--text-muted);
}

/* Mission Grid (Cards) */
.mission-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.card {
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 32px;
    border-radius: var(--radius-md);
    transition: transform 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    background-color: rgba(255, 255, 255, 0.08);
}

.icon-box {
    font-size: 2rem;
    margin-bottom: 24px;
}

.card h3 {
    margin-bottom: 12px;
    font-size: 1.25rem;
    color: #fff;
}

.card p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

/* Footer */
.footer {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 60px 0 24px;
    margin-top: 80px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 40px;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 8px;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: #fff;
}

.footer-bottom {
    text-align: center;
    font-size: 0.8rem;
    color: #555;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-actions {
        flex-direction: column;
    }

    .nav-list {
        display: none;
        /* Mobile menu implementation needed later */
    }

    .footer-content {
        flex-direction: column;
        gap: 32px;
        text-align: center;
        align-items: center;
    }
}

/* Curriculum Section */
.curriculum-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
    margin-top: 48px;
}

.curriculum-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md);
    padding: 32px;
    position: relative;
    overflow: hidden;
}

.curriculum-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--color-accent);
}

.curriculum-step {
    font-size: 0.9rem;
    color: var(--color-accent);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
    display: block;
}

.curriculum-title {
    font-size: 1.5rem;
    color: #fff;
    margin-bottom: 16px;
}

.curriculum-desc {
    color: var(--text-muted);
    font-size: 1rem;
    margin-bottom: 24px;
}

.curriculum-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag {
    background: rgba(255, 255, 255, 0.1);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    color: #ddd;
}

/* FAQ Section */
.faq-grid {
    display: grid;
    gap: 24px;
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-sm);
    padding: 24px;
}

.faq-question {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: #fff;
    display: flex;
    align-items: center;
    gap: 12px;
}

.faq-question::before {
    content: 'Q.';
    color: var(--color-accent);
    font-weight: 800;
}

.faq-answer {
    color: var(--text-muted);
    font-size: 0.95rem;
    padding-left: 30px;
}

/* CTA Section */
.cta-section {
    position: relative;
    text-align: center;
    padding: 120px 0;
    background: linear-gradient(to top, rgba(1, 10, 58, 1), rgba(70, 29, 221, 0.1));
}

.cta-content h2 {
    font-size: 3rem;
    margin-bottom: 24px;
}

.cta-content p {
    font-size: 1.25rem;
    margin-bottom: 48px;
}

/* Comparison Section */
.comparison-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
    margin-bottom: 48px;
}

.comparison-card {
    flex: 1;
    min-width: 300px;
    padding: 32px;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.comparison-card.yeontam {
    background: rgba(70, 29, 221, 0.1);
    border-color: var(--color-accent);
}

.comparison-card h3 {
    margin-bottom: 24px;
    font-size: 1.5rem;
    text-align: center;
}

.comparison-card ul li {
    margin-bottom: 12px;
    padding-left: 24px;
    position: relative;
    color: var(--text-muted);
}

.comparison-card.yeontam ul li {
    color: #fff;
}

.comparison-card ul li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-accent);
}

.comparison-icon {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--color-secondary);
}

/* Method / Feature Section */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.feature-card {
    text-align: center;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 8px;
}

.feature-sub {
    color: var(--color-accent);
    font-weight: 700;
    margin-bottom: 16px;
    font-size: 1rem;
}

/* Testimonials */
.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.testimonial-card {
    font-style: italic;
}

.testimonial-text {
    font-size: 1.1rem;
    margin-bottom: 24px;
    line-height: 1.6;
    color: #ddd;
}

.testimonial-author {
    text-align: right;
    font-weight: 600;
    color: var(--color-secondary);
}

/* Pricing Section */
.pricing-card {
    max-width: 500px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--color-accent);
    border-radius: var(--radius-lg);
    padding: 48px;
    text-align: center;
}

.pricing-header h3 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    color: var(--text-muted);
}

.price {
    font-size: 3rem;
    font-weight: 800;
    color: #fff;
    margin-bottom: 8px;
}

.price-desc {
    color: var(--text-muted);
    margin-bottom: 32px;
}

.pricing-body ul {
    text-align: left;
    margin-bottom: 32px;
    padding: 0 20px;
}

.pricing-body ul li {
    margin-bottom: 16px;
    font-size: 1.1rem;
}

.btn-block {
    width: 100%;
    margin-bottom: 16px;
}

.refund-policy {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Curriculum Detail */
.curriculum-detail-container {
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--radius-lg);
    padding: 32px;
    margin-top: 48px;
}

.detail-card {
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: 24px;
    margin-bottom: 24px;
}

.detail-card h4 {
    margin-bottom: 16px;
    color: #00ffcc;
}

.detail-card ul {
    list-style: none;
    padding: 0;
}

.detail-card ul li {
    margin-bottom: 8px;
    font-size: 0.95rem;
    color: #ddd;
    line-height: 1.6;
}

.detail-track-wrapper {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

/* Feature Examples */
.feature-example {
    margin-top: 24px;
    padding-top: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: left;
    font-size: 0.9rem;
}

.feature-example p {
    margin-bottom: 8px;
    color: var(--text-muted);
}

/* Operation Method */
.operation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.operation-card {
    text-align: center;
}

.operation-card .icon-box {
    margin: 0 auto 24px;
}

.operation-card .sub-text {
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: 24px;
}

.operation-card ul {
    text-align: left;
    padding: 0 16px;
    list-style: disc;
    margin-left: 16px;
}

.operation-card ul li {
    margin-bottom: 8px;
    color: var(--text-muted);
}

/* Benefits Section */
.benefits-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

@media (max-width: 900px) {
    .benefits-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .benefits-grid {
        grid-template-columns: 1fr;
    }
}

.benefit-card {
    text-align: center;
}

.benefit-card.highlight {
    border-color: var(--color-secondary);
    background: rgba(217, 217, 217, 0.05);
}

.benefit-card .icon-box {
    margin: 0 auto 16px;
}

/* Testimonial Slider */
.testimonial-slider-container {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 16px;
}

.testimonial-slider {
    overflow: hidden;
    flex: 1;
}

.testimonial-track {
    display: flex;
    transition: transform 0.5s ease;
}

.testimonial-card {
    min-width: 100%;
    box-sizing: border-box;
}

.slider-btn {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: #fff;
    font-size: 1.5rem;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    transition: background 0.3s;
    flex-shrink: 0;
}

.slider-btn:hover {
    background: var(--color-accent);
}

/* Card Images */
.card-image {
    margin-top: 60px;
    margin-bottom: 24px;
    border-radius: 8px;
    overflow: hidden;
    /* aspect-ratio: 16/9; Optional: maintain aspect ratio */
}

.card-image img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 8px;
    background-color: rgba(255, 255, 255, 0.05);
    /* Placeholder background */
}

/* Method Examples Grid */
.method-examples-container {
    margin-top: 60px;
}

.subsection-title {
    font-size: 1.5rem;
    margin-bottom: 32px;
    text-align: center;
    color: #fff;
}

.example-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.example-card {
    background: #e0e0e0;
    /* 이미지 형태처럼 보이게 배경색 변경 (회색) */
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 24px;
    border-radius: var(--radius-md);
    text-align: center;
    /* 이미지 캡션처럼 중앙 정렬 */
    transition: transform 0.3s ease, border-color 0.3s ease;
    min-height: 200px;
    /* 카드 높이 확보 */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: #333;
    /* 텍스트 가독성을 위해 어두운 색으로 변경 */
}

.example-card h4 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: #000;
    /* 제목 검은색 */
    line-height: 1.4;
}

.example-card .desc {
    font-size: 0.95rem;
    color: #444;
    /* 설명 어두운 회색 */
    line-height: 1.6;
}

.example-card .author {
    color: #666;
}

.example-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.example-card .tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(70, 29, 221, 0.2);
    color: var(--color-accent);
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.example-card h4 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: #fff;
    line-height: 1.4;
}

.example-card .author {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 16px;
    font-weight: 600;
}

.example-card .desc {
    font-size: 0.95rem;
    color: #ddd;
    line-height: 1.6;
}

/* Update Operation Card for Images */
.operation-card .card-image {
    margin-bottom: 20px;
}

/* --- V5 Updates --- */

/* Typography & Layout Improvements */
h1,
h2,
h3,
h4,
.btn {
    letter-spacing: -0.02em;
}

.section-title {
    margin-bottom: 24px;
    font-weight: 700;
    line-height: 1.3;
}

.section-desc {
    margin-bottom: 60px;
    /* Consistent spacing */
    font-size: 1.15rem;
    opacity: 0.8;
}

/* D-Day Badge */
.d-day-badge {
    color: #FF4D4D;
    /* Alert color */
    font-weight: 800;
    margin-left: 8px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        opacity: 1;
        transform: scale(1);
    }

    50% {
        opacity: 0.8;
        transform: scale(1.05);
    }

    100% {
        opacity: 1;
        transform: scale(1);
    }
}

/* Header Actions */
.header-actions {
    display: flex;
    gap: 12px;
    align-items: center;
}

.btn.small {
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-outline-light {
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: #fff;
    background: transparent;
}

.btn-outline-light:hover {
    border-color: #fff;
    background: rgba(255, 255, 255, 0.1);
}

/* Track Supplementary Info */
.track-supplementary-info {
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: left;
}

.track-supplementary-info ul {
    display: inline-block;
    text-align: left;
}

.track-supplementary-info li {
    color: var(--text-muted);
    margin-bottom: 8px;
    font-size: 1rem;
}

.track-supplementary-info strong {
    color: var(--color-accent);
}

/* Final CTA Section */
.section-cta-final {
    padding: 140px 0;
    background: linear-gradient(to top, rgba(1, 10, 58, 1), rgba(70, 29, 221, 0.15));
}

.cta-group {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-top: 48px;
    flex-wrap: wrap;
}

.btn-xl {
    padding: 20px 40px;
    font-size: 1.25rem;
    border-radius: var(--radius-md);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: #fff;
}

.next-batch-alert {
    margin-top: 60px;
    color: var(--text-muted);
}

.next-batch-alert p {
    display: inline;
}

.next-batch-alert .text-link {
    color: var(--text-muted);
    text-decoration: underline;
    text-underline-offset: 4px;
    transition: color 0.3s;
    font-weight: 500;
}

.next-batch-alert .text-link:hover {
    color: var(--color-accent);
}

/* Curriculum Image */
/* Curriculum Image */
.curriculum-image {
    width: 100%;
    max-width: 800px;
    display: block;
    margin: 0 auto;
    cursor: pointer;
    transition: 0.3s;
}

.curriculum-image:hover {
    opacity: 0.9;
}

/* Image Modal Styles */
.modal {
    display: none;
    /* Hidden by default */
    position: fixed;
    /* Stay in place */
    z-index: 2000;
    /* Sit on top */
    padding-top: 50px;
    /* Location of the box */
    left: 0;
    top: 0;
    width: 100%;
    /* Full width */
    height: 100%;
    /* Full height */
    overflow: auto;
    /* Enable scroll if needed */
    background-color: rgb(0, 0, 0);
    /* Fallback color */
    background-color: rgba(0, 0, 0, 0.9);
    /* Black w/ opacity */
}

/* Modal Content (Image) */
.modal-content {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 1000px;
}

/* Caption of Modal Image - Image Text */
#caption {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 700px;
    text-align: center;
    color: #ccc;
    padding: 10px 0;
    height: 150px;
}

/* Add Animation - Zoom in the Modal */
.modal-content,
#caption {
    animation-name: zoom;
    animation-duration: 0.6s;
}

@keyframes zoom {
    from {
        transform: scale(0)
    }

    to {
        transform: scale(1)
    }
}

/* The Close Button */
.close {
    position: absolute;
    top: 15px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    transition: 0.3s;
}

.close:hover,
.close:focus {
    color: #bbb;
    text-decoration: none;
    cursor: pointer;
}

/* 100% Image Width on Smaller Screens */
@media only screen and (max-width: 700px) {
    .modal-content {
        width: 100%;
    }
}