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

body {
    font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: #f8f9fa;
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(66, 133, 244, 0.05) 0%, transparent 20%),
        radial-gradient(circle at 90% 80%, rgba(234, 67, 53, 0.05) 0%, transparent 20%),
        radial-gradient(circle at 50% 50%, rgba(251, 188, 5, 0.05) 0%, transparent 30%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    text-align: center;
    background-color: #f8f9fa;
    padding: 60px 40px;
    border-radius: 24px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    max-width: 500px;
    width: 100%;
    position: relative;
    border: 1px solid #e8eaed;
}

/* Case toggle button - using international A/a design */
.case-toggle-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 10px 16px;
    font-size: 0.9em;
    font-weight: 500;
    background-color: #f1f3f4;
    color: #5f6368;
    border: 1px solid #dadce0;
    border-radius: 16px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: 'Roboto', sans-serif;
}

.case-toggle-btn:hover {
    background-color: #e8eaed;
    color: #1a73e8;
    border-color: #d2e3fc;
    box-shadow: 0 1px 2px rgba(66, 133, 244, 0.3);
}

.case-toggle-btn:active {
    transform: translateY(1px);
}

.domain-section {
    margin-bottom: 50px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding-top: 20px;
}

#domain {
    font-size: 3.8em;
    font-weight: 700;
    letter-spacing: -1px;
    transition: all 0.2s ease;
    background: linear-gradient(90deg, #4285f4, #ea4335, #fbbc05, #34a853);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-family: 'Roboto', sans-serif;
}

#domain:hover {
    opacity: 0.95;
    transform: scale(1.02);
}

.email-section {
    margin-top: 20px;
}

.email-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2px;
    cursor: pointer;
    position: relative;
    padding: 10px 16px;
    font-size: 0.9em;
    font-weight: 500;
    background-color: #f1f3f4;
    color: #5f6368;
    border: 1px solid #dadce0;
    border-radius: 16px;
    transition: all 0.2s ease;
    font-family: 'Roboto', sans-serif;
    max-width: 280px;
    margin: 0 auto;
}

.email-container:hover {
    background-color: #e8eaed;
    color: #1a73e8;
    border-color: #d2e3fc;
    box-shadow: 0 1px 2px rgba(66, 133, 244, 0.3);
}

.email-container:active {
    transform: translateY(1px);
}

.email-char {
    font-size: 1em;
    font-weight: inherit;
    color: inherit;
    transition: color 0.2s ease;
    font-family: 'Roboto', sans-serif;
    letter-spacing: normal;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 50px 30px;
        border-radius: 20px;
    }
    
    #domain {
        font-size: 2.8em;
    }
    
    .case-toggle-btn,
    .email-container {
        padding: 8px 12px;
        font-size: 0.85em;
        border-radius: 12px;
    }
    
    .email-container {
        max-width: 240px;
        gap: 2px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 40px 20px;
        border-radius: 16px;
    }
    
    #domain {
        font-size: 2.2em;
        letter-spacing: -0.5px;
    }
    
    .case-toggle-btn,
    .email-container {
        padding: 8px 10px;
        font-size: 0.8em;
        border-radius: 10px;
    }
    
    .email-container {
        max-width: 200px;
        gap: 2px;
    }
}