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

:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --border-color: #e5e7eb;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: var(--gray-50);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    position: relative;
    z-index: 1;
}

.row {
    width: 100%;
    margin: 0;
}

.auth-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 2rem;
}

.auth-container {
    width: 100%;
    max-width: 440px;
}

.auth-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.auth-header {
    padding: 2rem 2rem 1.5rem;
    text-align: center;
    background: var(--gray-50);
    border-bottom: 1px solid var(--border-color);
}

.auth-logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    background: var(--primary);
    border-radius: 8px;
    margin-bottom: 1rem;
}

.auth-logo i {
    font-size: 2rem;
    color: var(--white);
}

.auth-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.5rem;
}

.auth-subtitle {
    font-size: 0.9rem;
    color: var(--gray-500);
    margin: 0;
}

.auth-body {
    padding: 2rem 2rem 2rem;
}

.alert {
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 12px 16px;
    margin-bottom: 1rem;
    font-size: 14px;
}

.alert-danger {
    background: #fef2f2;
    color: #991b1b;
    border-color: #fecaca;
}

.alert-success {
    background: #f0fdf4;
    color: #166534;
    border-color: #bbf7d0;
}

.form-label {
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: 6px;
    display: block;
}

.input-group {
    position: relative;
    margin-bottom: 1rem;
}

.input-group-text {
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 44px;
    background: var(--gray-100);
    border: 1px solid var(--border-color);
    border-right: none;
    border-radius: 6px 0 0 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gray-500);
    z-index: 2;
}

.form-control {
    width: 100%;
    padding: 10px 12px 10px 3rem;
    font-size: 14px;
    color: var(--gray-800);
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    outline: none;
}

.form-control:hover {
    border-color: var(--gray-300);
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-control::placeholder {
    color: var(--gray-400);
}

.input-group .form-control {
    border-radius: 6px;
    padding-left: 3rem;
}

.form-text {
    font-size: 12px;
    color: var(--gray-500);
    margin-top: 0.5rem;
}

.btn-primary {
    width: 100%;
    padding: 12px 1.5rem;
    font-size: 14px;
    font-weight: 500;
    color: var(--white);
    background: var(--primary);
    border: 1px solid var(--primary);
    border-radius: 6px;
    cursor: pointer;
}

.btn-primary:hover {
    background: var(--primary-hover);
    border-color: var(--primary-hover);
    color: var(--white);
}

.btn-primary i {
    margin-right: 0.5rem;
}

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

.auth-footer a {
    color: var(--gray-500);
    font-size: 14px;
    text-decoration: none;
}

.auth-footer a:hover {
    color: var(--primary);
    text-decoration: underline;
}

.auth-divider {
    display: inline-block;
    width: 4px;
    height: 4px;
    background: var(--gray-300);
    border-radius: 50%;
    margin: 0 0.75rem;
    vertical-align: middle;
}

.captcha-wrapper {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

.captcha-display {
    flex: 1;
    padding: 10px 12px;
    background: var(--gray-100);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--gray-700);
    text-align: center;
    letter-spacing: 0.05em;
    user-select: none;
}

.captcha-input {
    flex: 1;
}

.captcha-input .form-control {
    padding-left: 12px;
}

@media (max-width: 576px) {
    .auth-container {
        max-width: 100%;
    }
    
    .auth-header {
        padding: 1.5rem 1.5rem 1.25rem;
    }
    
    .auth-body {
        padding: 1.5rem;
    }
    
    .auth-title {
        font-size: 1.25rem;
    }
    
    .form-control {
        font-size: 16px;
    }
}

.bg-gradient-primary {
    background: transparent !important;
}

.min-vh-100 {
    min-height: 100vh;
}

.card {
    border: none;
    box-shadow: none;
    background: transparent;
}

.card-header {
    display: none;
}

.card-body {
    padding: 0;
    background: transparent;
}

.shadow-lg {
    box-shadow: none !important;
}

.border-0 {
    border: none !important;
}

.rounded-lg {
    border-radius: 0 !important;
}