:root {
    --primary: #C8102E;
    --primary-dark: #9a0c24;
    --secondary: #1E3A8A;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --bg-page: #f5f5f7;
    --border: #e5e7eb;
    --error-bg: #fef2f2;
    --error-text: #991b1b;
    --error-border: #fca5a5;
    --flash-bg: #eff6ff;
    --flash-text: #1e40af;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Microsoft Yahei', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}
body {
    background: var(--bg-page);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}
.login-page {
    width: 100%;
    max-width: 420px;
}
.login-card {
    background: #fff;
    padding: 40px 32px 28px;
    border-radius: 12px;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    border-top: 4px solid var(--primary);
}
.login-brand {
    text-align: center;
    margin-bottom: 28px;
}
.brand-mark {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    margin-bottom: 14px;
}
.brand-red,
.brand-blue {
    display: inline-block;
    width: 28px;
    height: 6px;
    border-radius: 2px;
}
.brand-red {
    background: var(--primary);
}
.brand-blue {
    background: var(--secondary);
}
.brand-title {
    font-size: 22px;
    color: var(--text-main);
    font-weight: 600;
    letter-spacing: 1px;
    margin-bottom: 4px;
}
.brand-subtitle {
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 2px;
    text-transform: uppercase;
}
.flash-msg,
.error-msg {
    padding: 10px 14px;
    border-radius: 6px;
    font-size: 13px;
    margin-bottom: 18px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.flash-msg {
    background: var(--flash-bg);
    color: var(--flash-text);
    border: 1px solid #bfdbfe;
}
.error-msg {
    background: var(--error-bg);
    color: var(--error-text);
    border: 1px solid var(--error-border);
}
.form-group {
    margin-bottom: 18px;
}
.form-label {
    display: block;
    font-size: 13px;
    color: var(--text-main);
    margin-bottom: 8px;
    font-weight: 500;
}
.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}
.input-icon {
    position: absolute;
    left: 12px;
    color: var(--text-muted);
    font-size: 16px;
    pointer-events: none;
}
.form-input {
    width: 100%;
    padding: 11px 40px 11px 38px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 14px;
    color: var(--text-main);
    background: #fff;
    transition: border-color 0.15s, box-shadow 0.15s;
}
.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(200, 16, 46, 0.08);
}
.password-toggle {
    position: absolute;
    right: 12px;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 16px;
    user-select: none;
}
.password-toggle:hover {
    color: var(--primary);
}
.login-btn {
    width: 100%;
    padding: 12px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    letter-spacing: 4px;
    transition: background 0.15s;
    margin-top: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.login-btn:hover {
    background: var(--primary-dark);
}
.login-btn:active {
    transform: translateY(1px);
}
.btn-loading {
    display: none;
}
.spin {
    animation: spin 0.8s linear infinite;
    display: inline-block;
}
@keyframes spin {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}
.login-btn.loading .btn-text {
    display: none;
}
.login-btn.loading .btn-loading {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.login-footer {
    text-align: center;
    margin-top: 22px;
    color: var(--text-muted);
    font-size: 12px;
}

@media (max-width: 480px) {
    .login-card {
        padding: 28px 22px 22px;
    }
    .brand-title {
        font-size: 20px;
    }
}