/* 基础样式重置 */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary-color: #4a6fa5;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --error-color: #dc3545;
    --light-gray: #f8f9fa;
    --border-color: #dee2e6;
    --text-color: #333;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f2f5;
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 450px;
    text-align: center;
}

.logo-container {
    margin-bottom: 2rem;
}

.logo-placeholder {
    width: 80px;
    height: 80px;
    margin: 0 auto 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    font-size: 2.5rem;
}

.logo-placeholder i {
    transition: transform 0.3s ease;
}

.logo-placeholder:hover i {
    transform: scale(1.1);
}

h1 {
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    padding: 2rem;
    margin-bottom: 1.5rem;
}

.description {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

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

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-color);
    font-size: 0.9rem;
}

.input-container {
    position: relative;
    display: flex;
    align-items: center;
}

.input-container i {
    position: absolute;
    left: 15px;
    color: var(--secondary-color);
}

input[type="password"] {
    width: 100%;
    padding: 12px 15px 12px 45px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s;
}

input[type="password"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.1);
}

button {
    width: 100%;
    padding: 12px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

button:hover {
    background: #3a5a8a;
    transform: translateY(-2px);
}

button i {
    font-size: 1.1rem;
}

#errorMessage {
    display: none;
    background: rgba(220, 53, 69, 0.1);
    color: var(--error-color);
    padding: 12px;
    border-radius: 8px;
    margin-top: 1.5rem;
    text-align: left;
    align-items: flex-start;
    gap: 10px;
}

.security-info {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-top: 1.5rem;
    padding: 12px;
    background: rgba(40, 167, 69, 0.08);
    border-radius: 8px;
    color: #28a745;
    font-size: 0.9rem;
}

.security-info i {
    font-size: 1.1rem;
    margin-top: 2px;
}

footer {
    color: var(--secondary-color);
    font-size: 0.85rem;
    padding: 1rem 0;
}

/* 响应式设计 */
@media (max-width: 480px) {
    .card {
        padding: 1.5rem;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    .logo-placeholder {
        width: 70px;
        height: 70px;
        font-size: 2rem;
    }
}