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

body {
    background-color: #f2f5f9;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, Helvetica, Arial, sans-serif;
    height: 100vh;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    color: #1a2639;
    padding-top: 15vh;
}

.login-panel {
    width: 520px;
    background-color: transparent;
    margin-left: 0;
    margin-right: auto;
    padding: 0 24px;
}

.header-left {
    margin-bottom: 44px;
    text-align: left;
}

.header-left h1 {
    font-size: 34px;
    font-weight: 500;
    color: #0c1a2b;
    letter-spacing: -0.4px;
    line-height: 1.2;
}

.header-left .hint {
    font-size: 15px;
    color: #5e6f8d;
    margin-top: 10px;
    font-weight: 400;
}

.input-group {
    margin-bottom: 40px;
    width: 100%;
    text-align: left;
}

.input-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: #2e3b4e;
    margin-bottom: 8px;
    letter-spacing: 0.2px;
}

.input-field {
    width: 100%;
    padding: 16px 20px;
    font-size: 16px;
    background-color: #eef2f6;
    border: none;
    border-radius: 14px;
    outline: none;
    transition: background-color 0.15s ease;
    color: #0c1a2b;
    box-shadow: none;
}

.input-field:focus {
    background-color: #e6ecf3;
}

.input-field::placeholder {
    color: #8f9fb1;
    font-size: 15px;
    font-weight: 400;
}

.action {
    margin-top: 40px;
    text-align: center;
    width: 100%;
}

.submit-btn {
    min-width: 160px;
    padding: 16px 32px;
    background-color: #1e2f42;
    border: none;
    border-radius: 40px;
    font-size: 17px;
    font-weight: 500;
    color: white;
    letter-spacing: 0.3px;
    cursor: pointer;
    transition: background-color 0.15s ease;
    box-shadow: none;
    display: inline-block;
    text-align: center;
    line-height: 1;
}

.submit-btn:hover {
    background-color: #2d4059;
}

.submit-btn:active {
    background-color: #121f2f;
}

.error-alert {
    background: #fef2f2;
    color: #b91c1c;
    padding: 14px 18px;
    border-radius: 14px;
    margin-bottom: 24px;
    font-size: 14px;
    display: none;
    align-items: center;
    gap: 10px;
    border: none;
    font-weight: 500;
    animation: alertSlide 0.2s ease-out;
}

@keyframes alertSlide {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}

.error-icon {
    font-size: 16px;
    flex-shrink: 0;
}

.input-field.input-error {
    background-color: #ffe6e6;
}

.submit-btn.loading {
    background-color: #4b5563;
    cursor: not-allowed;
    opacity: 0.8;
}
.submit-btn.success {
    background-color: #059669;
}
.loading-spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
    vertical-align: middle;
    margin-right: 6px;
}
@keyframes spin { to { transform: rotate(360deg); } }