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

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --error-color: #ef4444;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

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

.login-container {
    width: 100%;
    min-height: 100vh;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.login-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    opacity: 0.05;
}

.grid-pattern {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(99, 102, 241, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.1) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
    0% {
        transform: translate(0, 0);
    }
    100% {
        transform: translate(50px, 50px);
    }
}

.login-content {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 440px;
}

.login-card {
    background: white;
    border-radius: 1.5rem;
    padding: 3rem;
    box-shadow: var(--shadow-xl);
    backdrop-filter: blur(10px);
}

.login-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 1rem;
    color: white;
    margin: 0 auto 1.5rem;
}

.login-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.login-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
}

.login-form {
    width: 100%;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.form-group input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: all 0.3s;
    background: var(--bg-primary);
    color: var(--text-primary);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group input::placeholder {
    color: var(--text-secondary);
}

.form-message {
    min-height: 1.5rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    text-align: center;
}

.form-message.error {
    color: var(--error-color);
}

.form-message.success {
    color: var(--success-color);
}

.btn-login {
    width: 100%;
    padding: 0.875rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.btn-login:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-login:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.spinner {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.register-hint {
    text-align: center;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
}

.register-hint p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.register-hint p:last-child {
    margin-bottom: 0;
}

.contact-phone {
    font-weight: 600;
    color: var(--text-primary) !important;
}

.contact-phone a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s;
}

.contact-phone a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.login-footer {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.back-home {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.3s;
}

.back-home:hover {
    color: var(--primary-color);
}

/* 响应式设计 */
@media (max-width: 640px) {
    .login-card {
        padding: 2rem 1.5rem;
    }
    
    .login-title {
        font-size: 1.75rem;
    }
}