body {
    margin: 0;
    font-family: "Microsoft YaHei", Arial, sans-serif;
    background: linear-gradient(135deg, #001f4d, #007bff);
    color: white;
    text-align: center;
}

header {
    padding: 80px 20px;
}

.logo {
    font-size: 80px;
    font-weight: bold;
    letter-spacing: 8px;
}

h1 {
    font-size: 42px;
}

.btn,
button {
    display: inline-block;
    background: white;
    color: #0066ff;
    padding: 15px 35px;
    border-radius: 30px;
    border: none;
    font-size: 18px;
    cursor: pointer;
    margin: 10px;
}

.tool {
    background: white;
    color: #333;
    margin: 30px auto;
    padding: 40px;
    width: 80%;
    max-width: 600px;
    border-radius: 25px;
}


/* =========================
   Canvas 区域
========================= */

.canvas-box {
    width: 100%;
    margin: 25px auto;
    text-align: center;
    overflow: hidden;
}


/* =========================
   图片 Canvas
========================= */

#canvas {
    display: block;

    max-width: 100%;
    height: auto;

    margin: 20px auto;

    border: 2px dashed #007bff;

    background: #eeeeee;

    cursor: crosshair;

    /* 手机触摸框选的关键 */
    touch-action: none;

    /* 防止手机长按选中文字 */
    user-select: none;

    /* 防止部分浏览器拖动图片 */
    -webkit-user-drag: none;

    /* 防止触摸时出现浏览器默认行为 */
    -webkit-touch-callout: none;

    /* 提高触摸操作体验 */
    -webkit-tap-highlight-color: transparent;
}


/* =========================
   图片预览
========================= */

.preview img {
    max-width: 90%;
    margin-top: 20px;
    border-radius: 15px;
}


/* =========================
   功能介绍
========================= */

.features {
    padding: 50px 20px;
}

.box {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.box div {
    background: white;
    color: #333;
    padding: 20px;
    width: 220px;
    border-radius: 20px;
}


/* =========================
   VIP
========================= */

.vip {
    background: #003366;
    padding: 50px;
}

.vip h1 {
    font-size: 70px;
}


/* =========================
   Footer
========================= */

footer {
    padding: 20px;
}


/* =========================
   手机端适配
========================= */

@media (max-width: 768px) {

    header {
        padding: 50px 15px;
    }

    .logo {
        font-size: 55px;
        letter-spacing: 5px;
    }

    h1 {
        font-size: 30px;
    }

    .tool {
        width: 90%;
        padding: 25px 15px;
        box-sizing: border-box;
    }

    .btn,
    button {
        padding: 13px 25px;
        font-size: 16px;
    }

    .canvas-box {
        width: 100%;
        overflow: hidden;
    }

    #canvas {
        width: 100%;
        max-width: 100%;
        height: auto;

        margin: 15px auto;

        border-width: 2px;
    }

    .features {
        padding: 35px 15px;
    }

    .box div {
        width: 90%;
        max-width: 300px;
    }

    .vip {
        padding: 35px 15px;
    }

    .vip h1 {
        font-size: 45px;
    }
}


/* =========================
   小屏手机
========================= */

@media (max-width: 480px) {

    .logo {
        font-size: 45px;
    }

    h1 {
        font-size: 26px;
    }

    .tool {
        width: 94%;
        padding: 20px 10px;
    }

    .btn,
    button {
        width: 90%;
        box-sizing: border-box;
        margin: 8px auto;
    }

}