.chat-login-modal {
    --chat-login-brand: #2e91f6;
    --chat-login-brand-hover: #1f7ad4;
    --chat-login-text: #1f2937;
    --chat-login-muted: #6b7280;
    --chat-login-border: #e5e7eb;
    position: fixed;
    inset: 0;
    z-index: 10050;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: rgba(15, 23, 42, 0.48);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.28s ease, visibility 0.28s ease;
}

.chat-login-modal.is-open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

body.chat-login-open {
    overflow: hidden;
}

.chat-login-dialog {
    position: relative;
    width: min(420px, 100%);
    max-height: calc(100vh - 40px);
    overflow-y: auto;
    padding: 30px;
    border-radius: 12px;
    background: #fff;
    color: var(--chat-login-text);
    opacity: 0;
    transform: translateY(12px) scale(0.98);
    transition: opacity 0.28s ease, transform 0.28s ease;
}

.chat-login-modal.is-open .chat-login-dialog {
    opacity: 1;
    transform: translateY(0) scale(1);
}

.chat-login-close {
    position: absolute;
    top: 10px;
    right: 12px;
    width: 34px;
    height: 34px;
    border: 0;
    background: transparent;
    color: #9ca3af;
    font-size: 26px;
    line-height: 1;
    cursor: pointer;
}

.chat-login-close:hover {
    color: var(--chat-login-text);
}

.chat-login-dialog .auth-tabs {
    display: flex;
    margin-bottom: 22px;
    border-bottom: 1px solid var(--chat-login-border);
}

.chat-login-dialog .auth-tab {
    flex: 1;
    padding: 10px 8px;
    border: 0;
    border-bottom: 2px solid transparent;
    background: transparent;
    color: var(--chat-login-muted);
    font-size: 14px;
    cursor: pointer;
}

.chat-login-dialog .auth-tab.is-active {
    border-bottom-color: var(--chat-login-brand);
    color: var(--chat-login-brand);
    font-weight: 600;
}

.chat-login-dialog .auth-form[hidden] {
    display: none;
}

.chat-login-dialog .auth-field {
    margin-bottom: 16px;
}

.chat-login-dialog .auth-label {
    display: block;
    margin-bottom: 7px;
    color: var(--chat-login-text);
    font-size: 14px;
    font-weight: 500;
}

.chat-login-dialog .auth-input,
.chat-login-dialog .auth-input-wrap input {
    width: 100%;
    height: 42px;
    padding: 0 12px;
    border: 1px solid var(--chat-login-border);
    border-radius: 8px;
    outline: none;
    background: #fff;
    color: var(--chat-login-text);
    font-size: 14px;
    box-sizing: border-box;
}

.chat-login-dialog .auth-input:focus,
.chat-login-dialog .auth-input-wrap input:focus {
    border-color: var(--chat-login-brand);
    box-shadow: 0 0 0 3px rgba(46, 145, 246, 0.14);
}

.chat-login-dialog .is-invalid {
    border-color: #dc2626 !important;
}

.chat-login-dialog .auth-code-row {
    display: flex;
    gap: 10px;
}

.chat-login-dialog .auth-code-row .auth-input {
    min-width: 0;
    flex: 1;
}

.chat-login-dialog .auth-code-btn {
    flex: 0 0 112px;
    height: 42px;
    border: 1px solid var(--chat-login-brand);
    border-radius: 8px;
    background: #fff;
    color: var(--chat-login-brand);
    font-size: 13px;
    cursor: pointer;
}

.chat-login-dialog .auth-code-btn:disabled {
    border-color: var(--chat-login-border);
    color: #9ca3af;
    cursor: not-allowed;
}

.chat-login-dialog .auth-input-wrap {
    position: relative;
}

.chat-login-dialog .auth-input-wrap input {
    padding-right: 42px;
}

.chat-login-dialog .auth-toggle-password {
    position: absolute;
    top: 0;
    right: 0;
    width: 42px;
    height: 42px;
    border: 0;
    background: transparent;
    color: #9ca3af;
    cursor: pointer;
}

.chat-login-dialog .auth-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 24px;
    margin-bottom: 16px;
    gap: 12px;
}

.chat-login-dialog .auth-remember {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--chat-login-muted);
    font-size: 13px;
    cursor: pointer;
}

.chat-login-dialog .auth-link {
    color: var(--chat-login-brand);
    text-decoration: none;
}

.chat-login-dialog .auth-submit {
    width: 100%;
    height: 42px;
    border: 0;
    border-radius: 8px;
    background: var(--chat-login-brand);
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
}

.chat-login-dialog .auth-submit:hover {
    background: var(--chat-login-brand-hover);
}

.chat-login-dialog .auth-submit:disabled {
    cursor: wait;
    opacity: 0.7;
}

.chat-login-dialog .auth-switch {
    margin: 18px 0 0;
    text-align: center;
    color: var(--chat-login-muted);
    font-size: 13px;
}

@media (max-width: 480px) {
    .chat-login-modal {
        align-items: flex-end;
        padding: 0;
    }

    .chat-login-dialog {
        width: 100%;
        max-height: 92vh;
        padding: 26px 20px calc(20px + env(safe-area-inset-bottom));
        border-radius: 14px 14px 0 0;
        transform: translateY(16px);
    }

    .chat-login-modal.is-open .chat-login-dialog {
        transform: translateY(0);
    }
}