/* 通用样式 */
body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #f0f0f0, #e0e0e0); /* 渐变背景 */
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

/* 页眉样式 */
header {
    background: #007bff; /* 更鲜明的背景色 */
    color: #fff;
    padding: 2rem 2.5rem; /* 更宽的内边距 */
    text-align: center;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.2); /* 更柔和的阴影 */
    border-bottom: 5px solid #0056b3; /* 更厚的底部边框 */
    border-radius: 0 0 20px 20px; /* 圆角效果 */
}

header h1 {
    margin: 0;
    font-size: 3rem; /* 更大的字体大小 */
    letter-spacing: 1.5px;
    animation: fadeIn 1s ease-out;
    font-weight: bold;
}

/* 主要内容区样式 */
main {
    max-width: 900px; /* 更宽的主要内容区域 */
    margin: 0;
    padding: 2.5rem;
    background: #fff;
    border-radius: 20px; /* 更圆角的边框 */
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2); /* 更柔和的阴影 */
    animation: fadeIn 1s ease-out;
    width: 100%;
    box-sizing: border-box; /* 包含边距和内边距 */
}

/* 鉴权和上传区样式 */
#auth-section, #upload-section {
    margin-bottom: 2.5rem;
}

/* 按钮样式 */
button {
    background: linear-gradient(135deg, #007bff, #0056b3);
    color: #fff;
    border: none;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    cursor: pointer;
    border-radius: 12px;
    transition: background 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.2); /* 更柔和的阴影 */
}

button:hover {
    background: linear-gradient(135deg, #0056b3, #004494);
    transform: translateY(-3px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.25); /* 更强的阴影 */
}

button:active {
    transform: translateY(0);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.2);
}

button:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(38, 143, 255, 0.5);
}

/* 文件输入框样式 */
input[type="file"] {
    margin-bottom: 1.5rem;
    padding: 0.75rem;
    border-radius: 12px;
    border: 1px solid #007bff;
    background: #fff;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1); /* 更柔和的阴影 */
}

/* 进度条样式 */
#progress-container {
    background: #e9ecef;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2); /* 更柔和的阴影 */
    margin-bottom: 1.5rem;
}

#progress-bar {
    height: 35px; /* 更高的进度条 */
    background: linear-gradient(to right, #007bff, #0056b3);
    color: #fff;
    text-align: center;
    line-height: 35px;
    width: 0;
    border-radius: 12px;
    transition: width 0.5s ease, background 0.5s ease;
}

/* 状态和空间使用样式 */
#status, #space-used {
    margin-bottom: 1.5rem;
    font-weight: bold;
    animation: fadeIn 1s ease-out;
}

#error {
    color: #dc3545;
    font-weight: bold;
    margin-top: 1.5rem;
}

#success {
    color: #28a745;
    font-weight: bold;
    margin-top: 1.5rem;
}

/* 链接列表样式 */
#links {
    display: flex;
    flex-direction: column;
}

#links .file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    padding: 1rem; /* 更大的内边距 */
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15); /* 更柔和的阴影 */
}

#links a {
    color: #007bff;
    text-decoration: none;
    margin-right: 12px;
    font-size: 1.1rem; /* 更大的字体 */
}

#links a:hover {
    color: #0056b3;
}

/* 删除按钮样式 */
.delete-btn {
    background: #dc3545;
    color: #fff;
    border: none;
    padding: 0.75rem 1.25rem;
    font-size: 0.9rem;
    cursor: pointer;
    border-radius: 12px;
    transition: background 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15); /* 更柔和的阴影 */
}

.delete-btn:hover {
    background: #c82333;
    transform: translateY(-3px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2); /* 更强的阴影 */
}

.delete-btn:active {
    transform: translateY(0);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

/* 页脚样式 */
footer {
    text-align: center;
    padding: 1.5rem;
    background: #333;
    color: #fff;
    position: fixed;
    bottom: 0;
    width: 100%;
    box-shadow: 0 -6px 12px rgba(0, 0, 0, 0.15); /* 更柔和的阴影 */
}

footer a {
    color: #fff;
    transition: color 0.3s ease;
}

footer a:hover {
    color: #007bff;
}

/* 隐藏按钮的样式 */
button.hidden {
    display: none;
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}