/* ==================== Reset & 基础 ==================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

/* ==================== 登录卡片 ==================== */
.login-container {
    background-color: #fff;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    text-align: center;
    max-width: 400px;
    width: 90%;
    transition: all 0.3s ease;
}

.login-container:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

.login-container h1 {
    margin-bottom: 30px;
    color: #333;
    font-size: 28px;
    font-weight: 600;
}

/* ==================== Logo ==================== */
.logo {
    width: 80px;
    height: 80px;
    margin-bottom: 20px;
}

/* ==================== 二维码 ==================== */
.qr-code {
    margin: 30px 0;
    position: relative;
}

.qr-code img {
    width: 200px;
    height: 200px;
    border-radius: 10px;
    transition: all 0.3s ease;
}

.qr-code::before {
    content: "";
    position: absolute;
    inset: -5px;
    background: linear-gradient(45deg, #12c2e9, #c471ed, #f64f59);
    z-index: -1;
    filter: blur(20px);
    border-radius: 15px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.qr-code:hover::before {
    opacity: 1;
}

/* ==================== 说明文字 ==================== */
.instructions {
    color: #666;
    font-size: 16px;
    margin-top: 20px;
    line-height: 1.5;
}

/* ==================== 动画 ==================== */
@keyframes pulse {
    0%   { transform: scale(1); }
    50%  { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.pulse {
    animation: pulse 2s infinite;
}

/* ==================== 无痕登录按钮 ==================== */
.stealth-login-btn {
    margin-top: 25px;
    padding: 12px 24px;
    background-color: #007bff;   /* 蓝底 */
    color: #fff;                 /* 白字 */
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0, 123, 255, 0.25);
    transition: background-color 0.25s ease, transform 0.25s ease;
}

.stealth-login-btn:hover {
    background-color: #0056b3;   /* 深一点的蓝 */
    transform: translateY(-2px);
}

.stealth-login-btn:active {
    transform: translateY(0);
}
