* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #000000;
    min-height: 100vh;
    color: #1a1a1a;
    overflow-x: hidden;
}

.container {
    width: 100%;
    margin: 0 auto;
    background: #ffffff;
    min-height: 100vh;
    position: relative;
}

.video-section {
    position: relative;
    width: 100%;
    height: 100vh;
    overflow: hidden;
}

.video-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.video-background video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: 30% center;
}

.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0,0,0,0.3), rgba(0,0,0,0.7));
    z-index: 1;
}

.hero-content {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 30px 25px;
    color: white;
    z-index: 2;
}

.hero-top {
    text-align: center;
    animation: fadeInUp 1s ease-out;
}

.logo {
    font-size: 36px;
    font-weight: 900;
    margin-bottom: 8px;
    letter-spacing: -1px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.7);
}

.tagline {
    font-size: 14px;
    opacity: 0.9;
    font-weight: 500;
    text-shadow: 0 1px 5px rgba(0, 0, 0, 0.5);
}

.hero-bottom {
    text-align: center;
    animation: fadeInUp 1s ease-out 0.3s both;
    margin-bottom: 60px;
}

.main-headline {
    font-size: 40px;
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 16px;
    letter-spacing: -2px;
    text-shadow: 0 2px 15px rgba(0, 0, 0, 0.8);
}

.sub-headline {
    font-size: 18px;
    font-weight: 500;
    opacity: 0.95;
    line-height: 1.3;
    text-shadow: 0 1px 8px rgba(0, 0, 0, 0.6);
    margin-bottom: 40px;
}

/* 시작하기 버튼 */
.next-button {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50px;
    padding: 16px 32px;
    font-size: 18px;
    font-weight: 700;
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    width: 100%;
    margin-bottom: 20px;
    display: block;
    animation: fadeInUp 1s ease-out 0.6s both;
}

.next-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.6s;
}

.next-button:hover {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.next-button:hover::before {
    left: 100%;
}

.next-button:active {
    transform: translateY(-1px);
}

/* 로딩 도트 */
.loading-dots {
    display: flex;
    gap: 8px;
    justify-content: center;
    animation: fadeIn 1s ease-out 0.9s both;
}

.dot {
    width: 8px;
    height: 8px;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 50%;
    animation: dotPulse 1.5s infinite ease-in-out;
}

.dot:nth-child(2) {
    animation-delay: 0.2s;
}

.dot:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes dotPulse {
    0%, 80%, 100% {
        opacity: 0.3;
        transform: scale(0.8);
    }
    40% {
        opacity: 1;
        transform: scale(1);
    }
}

/* Skip 버튼 */
.skip-button {
    position: absolute;
    top: 40px;
    right: 30px;
    background: none;
    border: none;
    color: rgba(255, 255, 255, 0.7);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    z-index: 10;
    animation: fadeIn 1s ease-out 1.2s both;
    padding: 8px 16px;
}

.skip-button:hover {
    color: white;
    transform: scale(1.05);
}

/* 자동 진행 바 */
.progress-container {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 200px;
    height: 4px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 2px;
    overflow: hidden;
    animation: fadeIn 1s ease-out 1.5s both;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 2px;
    width: 0%;
    animation: progressFill 5s linear infinite;
}

/* 애니메이션 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes progressFill {
    from {
        width: 0%;
    }
    to {
        width: 100%;
    }
}

/* 페이드 아웃 애니메이션 */
.fade-out {
    animation: fadeOut 0.8s ease-in-out forwards;
}

@keyframes fadeOut {
    to {
        opacity: 0;
        transform: scale(1.05);
    }
}

/* 작은 모바일 최적화 */
@media (max-width: 375px) {
    .hero-content {
        padding: 25px 20px;
    }
    
    .logo {
        font-size: 32px;
    }
    
    .main-headline {
        font-size: 36px;
    }
    
    .sub-headline {
        font-size: 16px;
    }
    
    .next-button {
        padding: 14px 28px;
        font-size: 16px;
    }
    
    .progress-container {
        width: 160px;
    }
}

/* 낮은 높이 화면 */
@media (max-height: 650px) {
    .hero-content {
        padding: 20px 25px;
    }
    
    .logo {
        font-size: 32px;
        margin-bottom: 6px;
    }
    
    .main-headline {
        font-size: 36px;
        margin-bottom: 12px;
    }
    
    .sub-headline {
        margin-bottom: 30px;
    }
}

/* 터치 피드백 및 사용자 선택 방지 */
.next-button, .skip-button {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-touch-callout: none;
}

/* iOS Safari 최적화 */
@supports (-webkit-touch-callout: none) {
    .container {
        min-height: -webkit-fill-available;
    }
    
    .video-section {
        height: -webkit-fill-available;
    }
}

/* 포커스 스타일 */
.next-button:focus,
.skip-button:focus {
    outline: 2px solid rgba(255, 255, 255, 0.8);
    outline-offset: 4px;
}

/* 접근성: 모션 감소 설정 */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 고해상도 디스플레이 최적화 */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    .video-background video {
        image-rendering: -webkit-optimize-contrast;
    }
}