/* 리셋 및 공통 스타일 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.about-history-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
    font-family: 'Noto Sans KR', sans-serif;
}

.about-history-title {
    text-align: center;
    font-size: 36px;
    font-weight: 700;
    color: #0099FF;
    margin-bottom: 80px;
    opacity: 0;
    transform: translateY(30px);
    animation: about-history-fade-in 0.8s ease forwards;
}

.about-history-timeline {
    position: relative;
    padding: 40px 0;
}

.about-history-line {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 50%;
    width: 2px;
    background-color: #e0e0e0;
    transform: translateX(-50%);
}

.about-history-item {
    position: relative;
    margin-bottom: 100px;
    opacity: 0;
    transform: translateY(30px);
    display: flex;
    align-items: flex-start;
}

.about-history-item:last-child {
    margin-bottom: 0;
}

.about-history-dot {
    position: absolute;
    top: 10px;
    left: 50%;
    width: 16px;
    height: 16px;
    background-color: #0099FF;
    border-radius: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.about-history-year-circle {
    display: none;
    width: 80px;
    height: 80px;
    background-color: #f2f4f6;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 20px;
    flex-shrink: 0;
}

.about-history-year-circle span {
    font-size: 28px;
    font-weight: 700;
    color: #191970;
}

.about-history-content {
    width: 45%;
    padding: 0 20px;
}

.about-history-year {
    font-size: 28px;
    font-weight: 700;
    color: #0099FF;
    margin-bottom: 10px;
}

.about-history-description {
    font-size: 16px;
    color: #666666;
    line-height: 1.5;
}

/* 데스크탑 레이아웃 */
@media screen and (min-width: 769px) {
    .about-history-year-circle {
        display: none;
    }
    
    .about-history-item {
        display: block;
    }
    
    .about-history-item:nth-child(odd) .about-history-content {
        margin-left: auto;
        text-align: left;
        margin-right: 0;
    }
    
    .about-history-item:nth-child(even) .about-history-content {
        margin-right: auto;
        text-align: right;
        margin-left: 0;
    }
}

/* 애니메이션 */
@keyframes about-history-fade-in {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 모바일/태블릿용 반응형 스타일 */
@media screen and (max-width: 768px) {
    .about-history-container {
        padding: 40px 20px;
    }
    
    .about-history-title {
        font-size: 28px;
        margin-bottom: 50px;
    }
    
    .about-history-line {
        display: none;
    }
    
    .about-history-dot {
        display: none;
    }
    
    .about-history-timeline {
        display: flex;
        flex-direction: column;
        align-items: center;
        max-width: 500px;
        margin: 0 auto;
        margin-left: calc(50% + 20px); /* Shift slightly to the right */
        transform: translateX(-50%);
    }
    
    .about-history-item {
        margin-bottom: 40px;
        display: flex;
        align-items: center;
        width: 100%;
    }
    
    .about-history-year-circle {
        display: flex;
    }
    
    .about-history-content {
        width: auto;
        flex-grow: 1;
        margin: 0;
        padding: 0;
        text-align: left;
    }
    
    .about-history-year {
        font-size: 24px;
    }
    
    .about-history-description {
        font-size: 16px;
    }
}

@media screen and (max-width: 480px) {
    .about-history-title {
        font-size: 24px;
    }
    
    .about-history-timeline {
        max-width: 320px;
        margin-left: calc(50% + 15px); /* Slightly adjusted for smaller screens */
    }
    
    .about-history-year-circle {
        width: 60px;
        height: 60px;
    }
    
    .about-history-year-circle span {
        font-size: 22px;
    }
    
    .about-history-year {
        font-size: 20px;
    }
    
    .about-history-description {
        font-size: 14px;
    }
}