/* 기본 설정 */
:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-color: #1f2937;
    --light-color: #f9fafb;
    --text-color: #374151;
    --border-color: #e5e7eb;
    --gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.15);
}

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

body {
    font-family: 'Noto Sans KR', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background-attachment: fixed;
    min-height: 100vh;
}

/* 모달 스타일 */
.modal {
    position: fixed;
    z-index: 9999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.6);
    display: none;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: #fefefe;
    margin: auto;
    padding: 30px;
    border-radius: 12px;
    width: 90%;
    max-width: 700px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.modal-close {
    position: absolute;
    right: 20px;
    top: 20px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    color: #999;
    transition: color 0.3s;
}

.modal-close:hover {
    color: #333;
}

.modal-content h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
}

.modal-content h3 {
    color: var(--dark-color);
    margin-top: 20px;
    margin-bottom: 10px;
}

.modal-content p {
    margin-bottom: 10px;
    line-height: 1.6;
}

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

/* 네비게이션 */
.navbar {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

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

.logo {
    font-size: 1.8rem;
    font-weight: 900;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.beta-badge {
    background: var(--warning-color);
    color: white;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
}

.nav-auth {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* 버튼 */
.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: #5558e3;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

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

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

.btn-gradient:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

/* 히어로 섹션 */
.hero {
    padding: 4rem 0;
    background: white;
    border-radius: 0 0 50px 50px;
}

.hero-content {
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    font-weight: 900;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: #6b7280;
    margin-bottom: 3rem;
}

.quick-convert {
    display: flex;
    gap: 1rem;
    max-width: 700px;
    margin: 0 auto 3rem;
}

.input-url {
    flex: 1;
    padding: 1rem 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s;
}

.input-url:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
}

.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 900;
    color: var(--primary-color);
}

.stat-label {
    color: #6b7280;
    font-size: 0.9rem;
}

/* 섹션 공통 */
.section-title {
    font-size: 2.5rem;
    font-weight: 900;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--dark-color);
}

/* 특징 섹션 */
.features {
    padding: 5rem 0;
    background: rgba(255, 255, 255, 0.95);
    margin: 3rem 20px;
    border-radius: 30px;
}

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

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    text-align: center;
    transition: all 0.3s;
    border: 2px solid transparent;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.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: #6b7280;
}

/* 사용 방법 */
.how-to {
    padding: 5rem 0;
    background: rgba(255, 255, 255, 0.95);
    margin: 3rem 20px;
    border-radius: 30px;
}

.steps {
    display: flex;
    justify-content: space-around;
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.step {
    text-align: center;
    flex: 1;
}

.step-number {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--gradient);
    color: white;
    font-size: 2rem;
    font-weight: 900;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
}

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

.step p {
    color: #6b7280;
}

/* 리뷰 섹션 */
.reviews {
    padding: 5rem 0;
    background: rgba(255, 255, 255, 0.95);
    margin: 3rem 20px;
    border-radius: 30px;
}

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

.review-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.review-stars {
    color: #fbbf24;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.review-card p {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.review-author {
    color: #6b7280;
    font-weight: 600;
}

/* CTA 섹션 */
.cta {
    padding: 5rem 0;
    background: white;
    margin: 3rem 20px;
    border-radius: 30px;
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.cta p {
    font-size: 1.2rem;
    color: #6b7280;
    margin-bottom: 2rem;
}

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

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
}

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

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

.footer-section a {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.copyright {
    margin-top: 1rem;
    color: #6b7280;
}

/* 로딩 애니메이션 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 알림 메시지 */
.alert {
    padding: 1rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.alert-info {
    background: #dbeafe;
    color: #1e40af;
    border: 1px solid #93c5fd;
}

/* 모달 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 9999;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #6b7280;
}

/* 반응형 디자인 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .quick-convert {
        flex-direction: column;
    }
    
    .hero-stats {
        gap: 2rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .steps {
        flex-direction: column;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}