body {
    font-family: "Arial", sans-serif;
    background: linear-gradient(to bottom, #e0e5ec, #f8f9fb);
    color: #222;
    text-align: center;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 950px;
    margin: 50px auto;
    padding: 30px;
    background: #fdfdfd;
    border-radius: 12px;
    box-shadow: 0 0 15px rgba(0,0,0,0.08);
}

h1 {
    font-size: 50px;
    color: #34495e;
    text-shadow: 1px 1px 0 #ccc;
    margin-bottom: 25px;
    font-family:Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
}

.flash p {
    color: lightsteelblue; 
    font-weight: bold;
}

form {
    margin: 20px 0;
}

.upload-box {
    border: 3px dashed #34495e;
    padding: 50px;
    margin: 0 auto 20px;
    cursor: pointer;
    position: relative;
    border-radius: 12px;
    transition: background 0.2s, border-color 0.2s;
    background: #f0f3f7;
}

.upload-box:hover {
    background: #e0e5ec;
    border-color: #2c3e50;
}

.upload-box p {
    margin: 0;
    font-size: 16px;
}

.upload-box input[type="file"] {
    position: absolute;
    width: 100%;
    height: 100%;
    top:0;
    left:0;
    opacity:0;
    cursor:pointer;
}

.filter-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    margin: 15px 0;
}

.filter-btn {
    padding: 10px 15px;
    margin: 5px;
    border: 2px solid #34495e;
    border-radius: 8px;
    background: #f0f3f7;
    cursor: pointer;
    font-size: 14px;
    transition: background 0.2s, color 0.2s;
}

.filter-btn.selected {
    background: #34495e;
    color: #fff;
}

.filter-btn:hover {
    background: #2c3e50;
    color: #fff;
}

.generate-btn {
    /* 修改后的样式 */
    padding: 15px 30px;
    margin-top: 20px;
    border: 3px solid #34495e;
    border-radius: 10px;
    background: #34495e;
    color: #fff;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
}

.generate-btn:hover {
    background: #2c3e50;
}

.preview {
    display: flex;
    justify-content: center;
    margin-top: 30px;
    flex-wrap: wrap;
}

.preview div {
    margin: 15px;
}

.preview img {
    max-width: 350px;
    border-radius: 10px;
    box-shadow: 0 0 8px rgba(0,0,0,0.15);
}

.processed-placeholder, .generating-message {
    width: 350px;
    height: auto;
    min-height: 200px;
    background-color: #f0f3f7;
    border-radius: 10px;
    box-shadow: 0 0 8px rgba(0,0,0,0.15);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
}

.processed-placeholder p {
    color: #888;
    font-style: italic;
    padding: 20px;
}

.generating-message p {
    color: #34495e;
    font-weight: bold;
}

.download-btn {
    display: block;
    width: 80%;
    margin: 15px auto 0;
    padding: 12px;
    background-color: #4a90e2;
    color: white;
    text-decoration: none;
    font-weight: bold;
    border-radius: 8px;
    transition: background-color 0.2s;
}

.download-btn:hover {
    background-color: #3870b2;
}