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

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --dark-color: #1e293b;
    --light-color: #f8fafc;
    --text-color: #334155;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --warning-color: #f59e0b;
}

html {
    scroll-behavior: auto;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    overflow-x: hidden;
}

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

/* 헤더 & 네비게이션 */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.header.scrolled {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
}

.navbar {
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    color: var(--primary-color);
    font-size: 1.8rem;
    cursor: pointer;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after {
    width: 100%;
}

.nav-menu a:hover {
    color: var(--primary-color);
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.7rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(99,102,241,0.3);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    transition: all 0.3s ease;
}

/* 히어로 섹션 */
.hero {
    margin-top: 80px;
    padding: 100px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,144C960,149,1056,139,1152,128C1248,117,1344,107,1392,101.3L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content h2 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.btn-large {
    background: white;
    color: var(--primary-color);
    border: none;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-large:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.hero-image {
    position: relative;
}

.code-animation {
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 2rem;
    border: 2px solid rgba(255,255,255,0.2);
}

.code-line {
    height: 20px;
    background: rgba(255,255,255,0.3);
    margin-bottom: 15px;
    border-radius: 10px;
    animation: codeTyping 2s infinite;
}

.code-line:nth-child(1) {
    width: 80%;
    animation-delay: 0s;
}

.code-line:nth-child(2) {
    width: 60%;
    animation-delay: 0.5s;
}

.code-line:nth-child(3) {
    width: 90%;
    animation-delay: 1s;
}

@keyframes codeTyping {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* 페이드인 애니메이션 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
}

.fade-in.visible {
    animation: fadeInUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 섹션 공통 스타일 */
section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--dark-color);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: var(--primary-color);
    margin: 1rem auto;
    border-radius: 2px;
}

/* 강의 슬라이더 */
.course-slider {
    position: relative;
    overflow: hidden;
    padding: 20px 50px;
}

.course-wrapper {
    display: flex;
    gap: 2rem;
    transition: transform 0.5s ease;
}

.course-card {
    min-width: calc(33.333% - 1.5rem);
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

.course-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.2);
}

.course-image {
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    position: relative;
}

.course-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--accent-color);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.course-content {
    padding: 1.5rem;
}

.course-content h3 {
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.course-content p {
    color: var(--text-color);
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.course-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.rating {
    color: var(--warning-color);
}

.students {
    color: var(--text-color);
}

.course-price {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.btn-enroll {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-enroll:hover {
    background: var(--secondary-color);
    transform: scale(1.05);
}

.slider-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    z-index: 10;
}

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

.slider-btn.prev {
    left: 0;
}

.slider-btn.next {
    right: 0;
}

/* 카테고리 섹션 */
.categories {
    background: var(--light-color);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.category-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    cursor: pointer;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.category-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.category-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

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

/* 통계 섹션 */
.stats {
    background: var(--dark-color);
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
}

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

.stat-number {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* FAQ 섹션 */
.faq {
    background: var(--light-color);
}

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

.faq-item {
    background: white;
    margin-bottom: 1rem;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.faq-question {
    padding: 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
}

.faq-question:hover {
    background: var(--light-color);
}

.faq-question h3 {
    font-size: 1.1rem;
    color: var(--dark-color);
}

.faq-icon {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 300;
    transition: transform 0.3s ease;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 1.5rem 1.5rem;
}

.faq-answer p {
    color: var(--text-color);
    line-height: 1.8;
}

/* 푸터 */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.social-links {
    display: flex;
    gap: 1rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.6);
}

/* 모달 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    z-index: 2000;
    justify-content: center;
    align-items: center;
}

.modal.show {
    display: flex;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: white;
    padding: 2.5rem;
    border-radius: 15px;
    max-width: 400px;
    width: 90%;
    position: relative;
    animation: slideDown 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

.close {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-color);
    transition: color 0.3s ease;
}

.close:hover {
    color: var(--primary-color);
}

.modal-content h2 {
    margin-bottom: 1.5rem;
    color: var(--dark-color);
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
    color: var(--dark-color);
}

.form-group input {
    padding: 0.8rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

.btn-block {
    width: 100%;
    margin-top: 1rem;
}

.form-footer {
    text-align: center;
    margin-top: 1rem;
    color: var(--text-color);
}

.form-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

/* Scroll to Top 버튼 */
.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--primary-color);
    color: white;
    border: none;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
}

.scroll-top.show {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    background: var(--secondary-color);
    transform: translateY(-5px);
}

/* 반응형 디자인 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0,0,0,0.05);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(8px, -8px);
    }

    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content h2 {
        font-size: 2.5rem;
    }

    .course-card {
        min-width: 100%;
    }

    .slider-btn {
        display: none;
    }

    .stat-number {
        font-size: 2.5rem;
    }
}

@media (max-width: 480px) {
    .hero-content h2 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 2rem;
    }
}

/* ==================== 새 페이지 스타일 ==================== */

/* 로고 링크 스타일 */
.logo a {
    text-decoration: none;
    color: inherit;
}

/* 활성 네비게이션 링크 */
.nav-menu a.active {
    color: var(--primary-color);
}

.nav-menu a.active::after {
    width: 100%;
}

/* 페이지 헤더 */
.page-header {
    margin-top: 80px;
    padding: 60px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* 텍스트 센터 정렬 */
.text-center {
    text-align: center;
    margin-top: 2rem;
}

/* 특징 섹션 (index.html) */
.features {
    padding: 80px 0;
    background: var(--light-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

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

/* 인기 강의 미리보기 */
.courses-preview {
    padding: 80px 0;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

/* 버튼 아웃라인 스타일 */
.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

/* 필터 섹션 (courses.html) */
.filter-section {
    padding: 2rem 0;
    background: var(--light-color);
}

.filter-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-group label {
    font-weight: 600;
    color: var(--dark-color);
}

.filter-btn {
    padding: 0.5rem 1.2rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

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

.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.search-box {
    flex: 1;
    max-width: 300px;
}

.search-box input {
    width: 100%;
    padding: 0.7rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* 강의 목록 그리드 */
.courses-list {
    padding: 60px 0;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

/* 강의 레벨 뱃지 */
.course-level {
    display: inline-block;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.course-level.beginner {
    background: #dbeafe;
    color: #1e40af;
}

.course-level.intermediate {
    background: #fef3c7;
    color: #92400e;
}

.course-level.advanced {
    background: #fee2e2;
    color: #991b1b;
}

/* 카테고리 페이지 (categories.html) */
.categories-page {
    padding: 60px 0;
}

.category-grid-large {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.category-card-large {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    gap: 1.5rem;
}

.category-card-large:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.2);
}

.category-icon-large {
    font-size: 3.5rem;
    flex-shrink: 0;
}

.category-content h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.category-desc {
    color: var(--text-color);
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.category-stats {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    color: var(--text-color);
}

.btn-category {
    display: inline-block;
    padding: 0.6rem 1.5rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-category:hover {
    background: var(--secondary-color);
    transform: scale(1.05);
}

/* 학습 경로 섹션 */
.learning-path {
    padding: 80px 0;
    background: var(--light-color);
}

.path-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.path-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.path-card h3 {
    font-size: 1.4rem;
    margin-bottom: 1.5rem;
    color: var(--dark-color);
}

.path-steps {
    margin-bottom: 1.5rem;
}

.path-step {
    padding: 0.8rem;
    background: var(--light-color);
    border-radius: 8px;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.btn-path {
    width: 100%;
    padding: 0.8rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-path:hover {
    background: var(--secondary-color);
    transform: scale(1.05);
}

/* About 페이지 (about.html) */
.about-vision {
    padding: 80px 0;
}

.vision-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.vision-text h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.vision-text p {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: var(--text-color);
}

.vision-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.vision-placeholder {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.vision-icon {
    font-size: 8rem;
}

/* 핵심 가치 */
.core-values {
    padding: 80px 0;
    background: var(--light-color);
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.value-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

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

.value-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.value-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

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

/* 강사진 */
.instructors {
    padding: 80px 0;
}

.instructors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.instructor-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

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

.instructor-image {
    margin-bottom: 1rem;
}

.instructor-placeholder {
    width: 120px;
    height: 120px;
    background: var(--light-color);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 4rem;
    margin: 0 auto;
}

.instructor-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.3rem;
    color: var(--dark-color);
}

.instructor-title {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.instructor-desc {
    color: var(--text-color);
    font-size: 0.9rem;
}

/* 연혁 타임라인 */
.timeline {
    padding: 80px 0;
    background: var(--light-color);
}

.timeline-container {
    max-width: 800px;
    margin: 3rem auto;
    position: relative;
}

.timeline-container::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
    transform: translateX(-50%);
}

.timeline-item {
    display: flex;
    margin-bottom: 3rem;
    position: relative;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.timeline-year {
    width: 100px;
    text-align: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.timeline-content {
    flex: 1;
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    margin: 0 2rem;
}

.timeline-content h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.timeline-content p {
    color: var(--text-color);
}

/* CTA 섹션 */
.cta-section {
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta-section p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* FAQ 페이지 (faq.html) */
.faq-tabs-section {
    padding: 2rem 0;
    background: var(--light-color);
}

.faq-tabs {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.faq-tab {
    padding: 0.7rem 1.5rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.faq-tab:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.faq-tab.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* 문의하기 섹션 */
.contact-section {
    padding: 80px 0;
    background: var(--light-color);
    text-align: center;
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.contact-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
}

.contact-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.contact-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.contact-card p {
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.contact-time {
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.8;
}

.btn-contact {
    margin-top: 1rem;
    padding: 0.7rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-contact:hover {
    background: var(--secondary-color);
    transform: scale(1.05);
}

/* 반응형 디자인 추가 */
@media (max-width: 768px) {
    .page-header h1 {
        font-size: 2rem;
    }

    .filter-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        max-width: 100%;
    }

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

    .category-grid-large {
        grid-template-columns: 1fr;
    }

    .category-card-large {
        flex-direction: column;
        text-align: center;
    }

    .vision-content {
        grid-template-columns: 1fr;
    }

    .vision-placeholder {
        width: 200px;
        height: 200px;
    }

    .timeline-container::before {
        left: 30px;
    }

    .timeline-item {
        flex-direction: row !important;
        padding-left: 70px;
    }

    .timeline-year {
        position: absolute;
        left: 0;
        width: 60px;
        font-size: 1.2rem;
    }

    .timeline-content {
        margin: 0;
    }

    .cta-section h2 {
        font-size: 2rem;
    }

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

/* ==================== 코딩 데모 페이지 스타일 ==================== */

.container-fluid {
    max-width: 100%;
    padding: 0 20px;
}

/* 데모 컨트롤 */
.demo-section {
    padding: 40px 0 80px;
    background: var(--light-color);
}

.demo-controls {
    background: white;
    padding: 1.5rem;
    border-radius: 15px;
    margin-bottom: 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.step-selector {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.step-btn {
    padding: 0.7rem 1.2rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.step-btn:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.step-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.step-icon {
    font-size: 1.2rem;
}

.step-label {
    font-weight: 600;
}

.playback-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.control-btn {
    padding: 0.7rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.control-btn:hover {
    background: var(--secondary-color);
    transform: scale(1.05);
}

.speed-control {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.speed-control label {
    font-weight: 600;
    color: var(--dark-color);
}

.speed-control select {
    padding: 0.5rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background: white;
    cursor: pointer;
    font-size: 0.9rem;
}

/* 스플릿 뷰 */
.split-view {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.code-panel,
.preview-panel {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    height: 600px;
    display: flex;
    flex-direction: column;
}

.panel-header {
    background: var(--dark-color);
    color: white;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* 코드 에디터 */
.editor-tabs {
    display: flex;
    gap: 0.5rem;
}

.editor-tab {
    padding: 0.5rem 1rem;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.editor-tab:hover {
    background: rgba(255,255,255,0.2);
}

.editor-tab.active {
    background: var(--primary-color);
}

.tab-icon {
    font-size: 1rem;
}

.editor-actions {
    color: rgba(255,255,255,0.7);
    font-size: 0.9rem;
}

.code-editor {
    flex: 1;
    display: flex;
    background: #1e1e1e;
    color: #d4d4d4;
    overflow: auto;
    position: relative;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
}

.line-numbers {
    display: none;
}

.code-content {
    flex: 1;
    padding: 1rem;
    margin: 0;
    overflow: auto;
}

#codeDisplay {
    font-size: 14px;
    line-height: 1.6;
    white-space: pre-wrap;
    word-break: break-word;
}

.typing-cursor {
    position: absolute;
    width: 2px;
    height: 20px;
    background: white;
    animation: blink 1s infinite;
    display: none;
}

.typing-cursor.active {
    display: block;
}

@keyframes blink {
    0%, 49% { opacity: 1; }
    50%, 100% { opacity: 0; }
}

/* 코드 신택스 하이라이팅 */
.code-keyword { color: #569cd6; }
.code-string { color: #ce9178; }
.code-comment { color: #6a9955; }
.code-tag { color: #569cd6; }
.code-attribute { color: #9cdcfe; }
.code-value { color: #ce9178; }
.code-function { color: #dcdcaa; }
.code-number { color: #b5cea8; }

/* 프리뷰 패널 */
.preview-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
}

.browser-dots {
    display: flex;
    gap: 0.5rem;
}

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

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

.preview-content {
    flex: 1;
    background: white;
    padding: 1rem;
    overflow: auto;
}

#previewFrame {
    width: 100%;
    height: 100%;
    border: none;
    background: white;
}

/* 단계 설명 */
.step-description {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
}

.description-content h3 {
    font-size: 1.5rem;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
}

.description-content p {
    color: var(--text-color);
    font-size: 1.1rem;
}

/* 학습 포인트 */
.learning-points {
    padding: 80px 0;
    background: white;
}

.points-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.point-card {
    background: var(--light-color);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.point-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.point-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.point-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

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

/* 반응형 디자인 - 코딩 데모 */
@media (max-width: 1024px) {
    .split-view {
        grid-template-columns: 1fr;
    }

    .code-panel,
    .preview-panel {
        height: 500px;
    }
}

@media (max-width: 768px) {
    .demo-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .step-selector {
        flex-direction: column;
    }

    .step-btn {
        width: 100%;
        justify-content: center;
    }

    .playback-controls {
        flex-direction: column;
        width: 100%;
    }

    .control-btn {
        width: 100%;
        justify-content: center;
    }

    .speed-control {
        width: 100%;
        justify-content: space-between;
    }

    .code-panel,
    .preview-panel {
        height: 400px;
    }

    .editor-tabs {
        flex-wrap: wrap;
    }

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

@media (max-width: 480px) {
    .step-label {
        font-size: 0.8rem;
    }

    .code-editor {
        font-size: 12px;
    }

    #codeDisplay {
        font-size: 12px;
    }
}