body {
    font-family: "Segoe UI", Arial, sans-serif;
    margin: 20px;
    background: #1e1e1e; /* 深色背景 */
    color: #e0e0e0;      /* 淺灰文字 */
}

.container {
    max-width: 800px;
    margin: auto;
    background: #2b2b2b; /* 深灰容器 */
    padding: 10px;
    border-radius: 4px;
    border: 1px solid #444;
}

h2 {
    text-align: left;
    font-size: 14px;
    margin: 6px 0;
    color: #e0e0e0;
}

/* 控制輸入元件 */
input,
select,
button {
    margin: 6px 0;
    padding: 6px;
    width: 100%;
    font-size: 13px;
    background: #3a3a3a;
    border: 1px solid #555;
    color: #e0e0e0;
}

input:focus,
select:focus,
button:hover {
    border-color: #3399ff;
    outline: none;
}

/* 檔案總管清單 */
.file-list {
    margin-top: 10px;
    border: 1px solid #444;
    background: #1e1e1e;
    font-size: 13px;
}

/* 每列檔案 */
.file-item {
    display: grid;
    grid-template-columns: 60% 40%; /* 左邊檔名 / 右邊操作 */
    align-items: center;
    padding: 6px 10px;
    border-bottom: 1px solid #333;
    cursor: default;
    color: #e0e0e0;
}

/* 檔名樣式 */
.file-item a {
    color: #e0e0e0;
    text-decoration: none;
    display: flex;
    align-items: center;
}

/* 檔案圖示 */
.file-item a::before {
    content: "📄";
    margin-right: 6px;
}

/* 操作按鈕靠右 */
.file-item button {
    justify-self: end;
    padding: 2px 6px;
    font-size: 12px;
    background: #3a3a3a;
    border: 1px solid #555;
    color: #e0e0e0;
}

.file-item button:hover {
    background: #444;
    border-color: #3399ff;
}

/* hover 效果 */
.file-item:hover {
    background: #2a2a2a; /* 深灰 hover */
}

/* 選取效果 */
.file-item.selected {
    background: #094771; /* Windows 深色模式選取藍 */
    color: #fff;
}

.short-url {
    color: #3399ff;
    text-decoration: underline;
    cursor: pointer;
}

.upload-area {
    border: 2px dashed #555;
    border-radius: 4px;
    padding: 20px;
    text-align: center;
    cursor: pointer;
    transition: background 0.3s, border-color 0.3s;
    background: #2b2b2b;
    color: #aaa;
}

.upload-area.dragover {
    background: #094771;
    border-color: #3399ff;
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(51,153,255,0.6); }
    70% { box-shadow: 0 0 8px 12px rgba(51,153,255,0); }
    100% { box-shadow: 0 0 0 0 rgba(51,153,255,0); }
}

#deleteAll {
    display: none;
}