body {
    margin: 0;
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #ffffff;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    padding: 20px;
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    backdrop-filter: blur(10px);
    z-index: 1000;
}
.logo {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: flex-start;
    padding-left: 20px;
}
.logo img {
    height: 40px;
    width: auto;
}
.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    background: #ffffff;
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    backdrop-filter: blur(10px);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    max-width: 90%;
    width: 400px;
    margin: 80px auto 0;
}
.container:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
}
.text {
    font-size: 16px;
    color: #2c3e50;
    line-height: 1.6;
    text-align: center;
    margin-top: 20px;
    font-weight: 500;
}
.loading-circle {
    width: 48px;
    height: 48px;
    border: 3px solid #eef2f7;
    border-top: 3px solid #3498db;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 24px;
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.2);
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@media screen and (min-width: 1440px) {
    header {
        padding: 25px;
    }
    .logo img {
        height: 45px;
    }
    .container {
        padding: 50px;
        width: 500px;
    }
    .text {
        font-size: 18px;
        line-height: 1.7;
    }
    .loading-circle {
        width: 60px;
        height: 60px;
        border-width: 4px;
    }
}

@media screen and (min-width: 768px) and (max-width: 1439px) {
    header {
        padding: 20px;
    }
    .logo img {
        height: 40px;
    }
    .container {
        padding: 45px;
        width: 450px;
    }
    .text {
        font-size: 17px;
    }
    .loading-circle {
        width: 54px;
        height: 54px;
    }
}

@media screen and (min-width: 481px) and (max-width: 767px) {
    header {
        padding: 15px;
    }
    .logo img {
        height: 35px;
    }
    .container {
        padding: 35px 25px;
        width: 400px;
    }
    .text {
        font-size: 16px;
    }
    .loading-circle {
        width: 48px;
        height: 48px;
    }
}

@media screen and (max-width: 480px) {
    header {
        padding: 12px;
    }
    .logo img {
        height: 30px;
    }
    body {
        padding: 15px;
    }
    .container {
        padding: 30px 20px;
        width: 100%;
    }
    .text {
        font-size: 14px;
        line-height: 1.5;
    }
    .loading-circle {
        width: 40px;
        height: 40px;
        border-width: 2.5px;
    }
}

@media screen and (max-width: 320px) {
    header {
        padding: 10px;
    }
    .logo img {
        height: 28px;
    }
    body {
        padding: 10px;
    }
    .container {
        padding: 25px 15px;
    }
    .text {
        font-size: 13px;
    }
    .loading-circle {
        width: 36px;
        height: 36px;
        border-width: 2px;
    }
}