/* 自定义额外样式：保持与 Bootstrap 搭配，只增强视觉 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: linear-gradient(145deg, #0b1120 0%, #1a2538 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    position: relative;
}

    /* 装饰性光晕 (背景氛围) */
    body::before {
        content: '';
        position: fixed;
        pointer-events: none;
        width: 300px;
        height: 300px;
        background: radial-gradient(circle, rgba(79, 70, 229, 0.25) 0%, rgba(79, 70, 229, 0) 70%);
        border-radius: 50%;
        top: -80px;
        left: -80px;
        z-index: 0;
    }

    body::after {
        content: '';
        position: fixed;
        pointer-events: none;
        width: 500px;
        height: 500px;
        background: radial-gradient(circle, rgba(139, 92, 246, 0.2) 0%, rgba(139, 92, 246, 0) 70%);
        border-radius: 50%;
        bottom: -150px;
        right: -120px;
        z-index: 0;
    }

.ab-top-left {
    position: absolute;
    top: 20px;
    left: 20px;
}
/* 卡片容器：增加 Bootstrap 没有的玻璃质感细节 */
.login-card {
    background: rgba(255, 255, 255, 0.98);
    border-radius: 1.75rem;
    box-shadow: 0 25px 45px -12px rgba(0, 0, 0, 0.4), 0 4px 12px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    border: 1px solid rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(0px);
}

/* 自定义表单控件增强 (保持 Bootstrap 原生但更协调) */
.form-control {
    border-radius: 1rem;
    padding: 0.7rem 1rem 0.7rem 2.6rem;
    font-weight: 500;
    border: 1.5px solid #e2e8f0;
    font-size: 0.95rem;
    transition: all 0.2s;
}

    .form-control:focus {
        border-color: #6366f1;
        box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
    }

/* 输入框图标定位 (使用Bootstrap 搭配绝对位置) */
.input-icon {
    position: relative;
}

    .input-icon i {
        position: absolute;
        left: 1rem;
        top: 50%;
        transform: translateY(-50%);
        color: #94a3b8;
        font-size: 1.1rem;
        z-index: 4;
        pointer-events: none;
    }

/* 按钮样式: 渐变风格并保留 Bootstrap 按钮特性 */
.btn-login {
    background: linear-gradient(105deg, #4f46e5, #7c3aed);
    border: none;
    padding: 0.75rem 0;
    border-radius: 2rem;
    font-weight: 700;
    font-size: 1rem;
    letter-spacing: 0.3px;
    color: white;
    transition: all 0.25s;
    box-shadow: 0 8px 18px -6px rgba(79, 70, 229, 0.4);
}

    .btn-login:hover {
        background: linear-gradient(105deg, #6366f1, #8b5cf6);
        transform: scale(0.98);
        box-shadow: 0 4px 12px -4px rgba(79, 70, 229, 0.6);
        color: white;
    }

    .btn-login:active {
        transform: scale(0.97);
    }

/* 辅助链接样式 */
.forgot-link, .signup-link {
    color: #4f46e5;
    font-weight: 600;
    text-decoration: none;
    transition: color 0.2s;
    cursor: pointer;
}

    .forgot-link:hover, .signup-link:hover {
        color: #7c3aed;
        text-decoration: underline;
    }

/* 分割线样式 */
.divider {
    display: flex;
    align-items: center;
    color: #a0afc3;
    font-size: 0.75rem;
    font-weight: 500;
    gap: 1rem;
}

.divider-line {
    flex: 1;
    height: 1px;
    background: #e2e8f0;
}

/* 社交图标圆角按钮增强 */
.social-icon {
    width: 46px;
    height: 46px;
    background-color: #f8fafc;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    color: #334155;
    transition: all 0.2s;
    border: 1px solid #eef2ff;
    text-decoration: none;
}

    .social-icon:hover {
        background-color: #ffffff;
        color: #4f46e5;
        border-color: #c7d2fe;
        transform: translateY(-3px);
        box-shadow: 0 6px 12px -6px rgba(0, 0, 0, 0.1);
    }

/* 复选框样式优化 */
.form-check-input:checked {
    background-color: #4f46e5;
    border-color: #4f46e5;
}

.form-check-input:focus {
    box-shadow: 0 0 0 0.2rem rgba(79, 70, 229, 0.25);
}

/* 响应式微调 */
@media (max-width: 480px) {
    body {
        padding: 0;
    }

    .login-card {
        padding: 1.8rem !important;
    }

    .social-icon {
        width: 42px;
        height: 42px;
        font-size: 1.2rem;
    }
}

/* 辅助文字 */
.helper-note {
    font-size: 0.7rem;
    color: #94a3b8;
    border-top: 1px solid #edf2f7;
    padding-top: 1.2rem;
    margin-top: 0.5rem;
}

/* 保持所有交互元素仅为视觉，无实际动作 */
.no-action {
    cursor: pointer;
}