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

body {
    font-family: "Noto Sans JP", sans-serif;
    background-color: white;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

a {
    text-decoration: none;
}

img {
    width: 100%;
    height: 100%;
    display: flex;
}

.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #ffffff;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.5s ease-out;
}

.loader.hidden {
    opacity: 0;
    pointer-events: none;
}

.loader-content {
    text-align: center;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid #39A1FF;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

.loading-text {
    font-size: 18px;
    color: #333;
    font-weight: 500;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.container {
    max-width: 1200px;
    width: 100%;
    padding: 30px 15px;
    text-align: center;
}

.year-grid {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
}

.year-column {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.year.black {
    color: #000;
    font-size: 40px;
    font-weight: 600;
    line-height: 0.8;
}

.year.blue {
    color: #39A1FF;
    font-size: 40px;
    font-weight: 600;
    line-height: 0.8;
}

.nagaoka-jc {
    font-size: 24px;
    font-weight: bold;
    color: #000;
    margin-bottom: 10px;
    letter-spacing: 2px;
    line-height: 1;
}

.roots-2025 {
    margin-bottom: 40px;
    max-width: 535px;
    width: 100%;
    margin-inline: auto;
}

.special-o {
    color: #39A1FF;
    position: relative;
}

.subscript {
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 12px;
    color: #000;
    font-weight: normal;
}

.year-2025 {
    color: #000;
    margin-left: 10px;
    line-height: 1;
    font-size: 80px;
}

.japanese-text {
    font-size: 18px;
    color: #000;
    margin-bottom: 10px;
    font-weight: 600;
}

.period-boxes {
    max-width: 1000px;
    width: 100%;
    margin-inline: auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

.period-box {
    background-color: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 240px;
    width: 100%;
    height: 40px;
    margin-inline: auto;
    border-radius: 20px;
}

.period-box span {
    font-size: 14px;
    font-weight: 600;
    color: #39A1FF;
    margin-right: 10px;
}

.period-box .year {
    font-size: 18px;
    color: #fff;
}

.period-box img {
    width: 15px;
    height: auto;
}

@media (max-width: 768px) {

    .year.black,
    .year.blue {
        font-size: 30px;
    }

    .roots-2025 {
        max-width: 300px;
    }

    .period-boxes {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 574px) {

    .year.black,
    .year.blue {
        font-size: 28px;
    }

    .period-boxes {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 450px) {
    .year.black,
    .year.blue {
        font-size: 24px;
    }

    .period-boxes {
        gap: 10px;
    }

    .period-box span {
        margin-right: 5px;
    }
}