:root {
    /* 核心调色盘:完美同步清爽的天空蓝与白云明亮色调 */
    --bg-color: #f0f7ff;          /* 极浅的天空蓝底色 */
    --text-color: #1e293b;        /* 深蓝灰文本,保证高清晰度 */
    --text-muted: #64748b;        /* 次要文本 */
    --primary: #0284c7;           /* 天空主蓝色 */
    --primary-glow: rgba(56, 189, 248, 0.25);
    --accent: #0369a1;            /* 强调深蓝色 */
    --card-bg: rgba(255, 255, 255, 0.75); /* 半透明白云感卡片 */
    --border-color: rgba(2, 132, 199, 0.15);

    /* 状态调色:配合明亮风格进行微调 */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;

    /* 高级拟物阴影 */
    --shadow-sm: 0 4px 6px -1px rgba(2, 132, 199, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(2, 132, 199, 0.08);
    --shadow-lg: 0 20px 40px -4px rgba(2, 132, 199, 0.12);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 
                 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow-x: hidden;
}

/* 极简网格背景 */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image:
            linear-gradient(rgba(2, 132, 199, 0.04) 1px, transparent 1px),
            linear-gradient(90deg, rgba(2, 132, 199, 0.04) 1px, transparent 1px);
    background-size: 40px 40px;
    z-index: -2;
}

/* 核心光晕:明亮的蔚蓝云雾感 */
body::after {
    content: '';
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(56, 189, 248, 0.3) 0%, transparent 70%);
    z-index: -1;
    pointer-events: none;
}

.login-container {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.6);
    box-shadow: var(--shadow-lg);
    padding: 40px;
    width: 100%;
    max-width: 420px;
    animation: slideUp 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.logo {
    text-align: center;
    margin-bottom: 30px;
}

.logo img {
    max-width: 120px;
    height: auto;
    margin-bottom: 15px;
    filter: drop-shadow(0 4px 6px rgba(2, 132, 199, 0.15));
}

.logo h1 {
    color: var(--text-color);
    font-size: 28px;
    margin-bottom: 8px;
    background: linear-gradient(135deg, #0f172a 40%, var(--primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo p {
    color: var(--text-muted);
    font-size: 14px;
    letter-spacing: 1px;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-color);
    font-weight: 600;
    font-size: 14px;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    color: var(--text-color);
    transition: all 0.2s ease;
}

input[type="text"]:focus,
input[type="password"]:focus {
    outline: none;
    background: rgba(255, 255, 255, 0.9);
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

input[type="text"].error,
input[type="password"].error {
    border-color: var(--error);
    background: rgba(239, 68, 68, 0.03);
}

.login-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 14px rgba(2, 132, 199, 0.3);
}

.login-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(2, 132, 199, 0.45);
    filter: brightness(1.05);
}

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

.login-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.error-message {
    background: rgba(239, 68, 68, 0.08);
    border-left: 3px solid var(--error);
    color: var(--error);
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 20px;
    font-size: 14px;
    display: none;
    align-items: center;
    gap: 0.25rem;
}

.error-message.show {
    display: flex;
}

.info-text {
    text-align: center;
    margin-top: 20px;
    color: var(--text-muted);
    font-size: 12px;
    letter-spacing: 0.5px;
}