* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

body {
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
    padding: 0;
    margin: 0;
    min-height: 100vh;
    padding-top: var(--header-height, 80px);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    background-color: #4a5568;
    color: white;
    padding: 24px 16px;
    text-align: center;
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

h1 {
    font-size: 1.5rem;
    margin-bottom: 8px;
    font-weight: 600;
}

.subtitle {
    font-size: 0.9rem;
    opacity: 0.9;
}

.content {
    background-color: #ffffff;
    border-radius: 8px;
    padding: 24px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

h2 {
    font-size: 1.25rem;
    margin: 24px 0 16px 0;
    color: #2d3748;
    border-bottom: 1px solid #e2e8f0;
    padding-bottom: 8px;
    font-weight: 600;
}

h2:first-child {
    margin-top: 0;
}

p {
    margin-bottom: 16px;
    font-size: 0.95rem;
    text-align: left;
    line-height: 1.7;
    color: #4a5568;
}

/* 中文版本使用两端对齐 */
html:lang(zh) p {
    text-align: justify;
}

ul {
    margin: 0 0 16px 24px;
}

li {
    margin-bottom: 10px;
    font-size: 0.95rem;
    line-height: 1.6;
    color: #4a5568;
}

.highlight {
    background-color: #f7fafc;
    border-left: 3px solid #4a5568;
    padding: 16px 20px;
    margin: 20px 0;
    border-radius: 4px;
}

.actions {
    display: flex;
    gap: 12px;
    margin-top: 24px;
    position: sticky;
    bottom: 0;
    background-color: #f5f5f5;
    padding: 16px;
    margin: 0 -16px -16px -16px;
    border-top: 1px solid #e2e8f0;
}

button {
    flex: 1;
    padding: 14px;
    border: none;
    border-radius: 6px;
    font-weight: 500;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.2s ease;
    -webkit-tap-highlight-color: transparent;
}

.accept {
    background-color: #4a5568;
    color: white;
}

.accept:hover {
    background-color: #2d3748;
}

.accept:active {
    background-color: #2d3748;
}

.decline {
    background-color: #e2e8f0;
    color: #4a5568;
}

.decline:hover {
    background-color: #cbd5e0;
}

.decline:active {
    background-color: #cbd5e0;
}

.back-to-top {
    position: fixed;
    bottom: 80px;
    right: 20px;
    width: 48px;
    height: 48px;
    background-color: #4a5568;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    cursor: pointer;
    z-index: 100;
    opacity: 0;
    transition: opacity 0.3s ease;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.back-to-top svg {
    width: 20px;
    height: 20px;
    stroke: white;
    stroke-width: 2.5;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.back-to-top.visible {
    opacity: 1;
}

.back-to-top:hover {
    background-color: #2d3748;
}

.back-to-top:active {
    background-color: #2d3748;
}

footer {
    text-align: center;
    padding: 20px 0;
    color: #718096;
    font-size: 0.85rem;
}

.contact {
    color: #4a5568;
    text-decoration: none;
}

.contact:hover {
    text-decoration: underline;
}

/* 平板设备适配 */
@media (min-width: 481px) and (max-width: 768px) {
    body {
        padding-top: var(--header-height, 90px);
    }
    
    .container {
        padding: 20px;
    }
    
    header {
        padding: 28px 20px;
    }
    
    h1 {
        font-size: 1.6rem;
    }
    
    .content {
        padding: 28px;
    }
    
    h2 {
        font-size: 1.3rem;
    }
    
    .back-to-top {
        width: 50px;
        height: 50px;
        bottom: 50px;
        right: 24px;
    }
    
    .back-to-top svg {
        width: 22px;
        height: 22px;
    }
}

/* PC端适配 */
@media (min-width: 769px) {
    body {
        padding-top: var(--header-height, 100px);
    }
    
    .container {
        padding: 24px;
    }
    
    header {
        padding: 32px 24px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    .content {
        padding: 32px 40px;
    }
    
    h2 {
        font-size: 1.4rem;
        margin: 28px 0 20px 0;
    }
    
    p {
        font-size: 1rem;
        margin-bottom: 18px;
    }
    
    li {
        font-size: 1rem;
    }
    
    .back-to-top {
        width: 52px;
        height: 52px;
        bottom: 50px;
        right: 32px;
    }
    
    .back-to-top svg {
        width: 24px;
        height: 24px;
    }
    
    button {
        padding: 16px;
        font-size: 1.05rem;
    }
}

/* 移动端适配 */
@media (max-width: 480px) {
    body {
        padding-top: var(--header-height, 70px);
    }
    
    .container {
        padding: 12px;
    }
    
    header {
        padding: 20px 12px;
    }
    
    h1 {
        font-size: 1.3rem;
    }
    
    .content {
        padding: 16px;
    }
    
    h2 {
        font-size: 1.1rem;
        margin: 20px 0 12px 0;
        padding-bottom: 8px;
    }
    
    p {
        font-size: 0.9rem;
        margin-bottom: 14px;
    }
    
    ul {
        margin-left: 20px;
    }
    
    li {
        font-size: 0.9rem;
        margin-bottom: 8px;
    }
    
    button {
        padding: 12px;
        font-size: 0.95rem;
    }
    
    .back-to-top {
        width: 44px;
        height: 44px;
        bottom: 50px;
        right: 16px;
    }
    
    .back-to-top svg {
        width: 18px;
        height: 18px;
    }
    
    .actions {
        padding: 12px;
        margin: 0 -12px -12px -12px;
    }
}

/* 大屏幕PC端优化 */
@media (min-width: 1400px) {
    .container {
        max-width: 1400px;
    }
    
    .content {
        padding: 40px 48px;
    }
}