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

html,
body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', Roboto, sans-serif;
    background: #ffffff;
    color: #333333;
    display: flex;
    align-items: center;
    justify-content: center;
}

.security-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    width: 100%;
    height: 100vh;
    animation: fadeIn 0.6s ease-out;
}

.security-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    max-width: 500px;
    padding: 40px 20px;
}

.shield-wrapper {
    display: grid;
    place-items: center;
    width: 600px;
    height: 600px;
    background: radial-gradient(closest-side, #fff 40%, rgba(168, 205, 255, .4) 40%, #fff);
    border-radius: 50%;
    overflow: hidden;
}

.shield-icon {
    width: 120px;
    height: auto;
}

.security-content-text {
    margin-top: -100px;
}

.main-title {
    font-size: 26px;
    font-weight: 600;
    color: #333333;
    letter-spacing: 1px;
    margin: 0;
    line-height: 1.4;
}

.subtitle {
    font-size: 16px;
    font-weight: 400;
    color: #888888;
    letter-spacing: 0.5px;
    margin: 0 0 20px 0;
}

.enter-btn {
    background: #2196F3;
    color: #ffffff;
    border: none;
    padding: 16px 100px;
    font-size: 18px;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
    box-shadow: 0 4px 15px rgba(33, 150, 243, 0.3);
    letter-spacing: 2px;
}

.enter-btn:hover {
    background: #1976D2;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(33, 150, 243, 0.4);
}

.enter-btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(33, 150, 243, 0.3);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 768px) {
    .security-content-text {
        margin-top: -40px;
    }

    .security-content {
        gap: 15px;
        padding: 30px 15px;
    }

    .shield-wrapper {
        width: 140px;
        height: 140px;
    }

    .shield-icon {
        width: 70px;
    }

    .main-title {
        font-size: 22px;
    }

    .subtitle {
        font-size: 14px;
    }

    .enter-btn {
        padding: 14px 80px;
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .security-content-text {
        margin-top: 0px;
    }

    .shield-wrapper {
        width: 120px;
        height: 120px;
    }

    .shield-icon {
        width: 60px;
    }

    .main-title {
        font-size: 20px;
    }

    .subtitle {
        font-size: 13px;
    }

    .enter-btn {
        padding: 12px 60px;
        font-size: 15px;
    }
}

::selection {
    background: rgba(33, 150, 243, 0.2);
    color: #333333;
}