:root {
    --aikb-primary: #4F46E5;
    --aikb-primary-hover: #4338CA;
    --aikb-bg: #FFFFFF;
    --aikb-surface: #F9FAFB;
    --aikb-text: #111827;
    --aikb-text-secondary: #6B7280;
    --aikb-border: #E5E7EB;
    --aikb-shadow: 0 4px 24px rgba(0, 0, 0, 0.12);
    --aikb-radius: 12px;
    --aikb-radius-lg: 20px;
    --aikb-font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --aikb-user-bubble: #4F46E5;
    --aikb-user-text: #FFFFFF;
    --aikb-bot-bubble: #F3F4F6;
    --aikb-bot-text: #111827;
    --aikb-code-bg: #1F2937;
    --aikb-code-text: #F9FAFB;
    --aikb-toggle-shadow: 0 4px 16px rgba(79, 70, 229, 0.4);
}

.aikb-dark {
    --aikb-bg: #1F2937;
    --aikb-surface: #374151;
    --aikb-text: #F9FAFB;
    --aikb-text-secondary: #9CA3AF;
    --aikb-border: #4B5563;
    --aikb-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
    --aikb-bot-bubble: #374151;
    --aikb-bot-text: #F9FAFB;
    --aikb-code-bg: #111827;
    --aikb-code-text: #F9FAFB;
}

.aikb-widget *,
.aikb-widget *::before,
.aikb-widget *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

.aikb-widget {
    font-family: var(--aikb-font);
    font-size: 14px;
    line-height: 1.5;
    color: var(--aikb-text);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.aikb-toggle-button {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 999998;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    border: none;
    border-radius: 50%;
    background: var(--aikb-primary);
    color: #fff;
    cursor: pointer;
    box-shadow: var(--aikb-toggle-shadow);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.aikb-toggle-button:hover {
    transform: scale(1.05);
    background: var(--aikb-primary-hover);
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.5);
}

.aikb-toggle-button:focus-visible {
    outline: 2px solid var(--aikb-primary);
    outline-offset: 2px;
}

.aikb-toggle-button svg {
    width: 24px;
    height: 24px;
}

.aikb-icon-close {
    display: none;
}

.aikb-widget.aikb-open .aikb-icon-chat {
    display: none;
}

.aikb-widget.aikb-open .aikb-icon-close {
    display: block;
}

.aikb-popup {
    position: fixed;
    bottom: 92px;
    right: 24px;
    z-index: 999997;
    width: 380px;
    max-width: calc(100vw - 48px);
    max-height: min(600px, calc(100vh - 120px));
    background: var(--aikb-bg);
    border-radius: var(--aikb-radius-lg);
    box-shadow: var(--aikb-shadow);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border: 1px solid var(--aikb-border);
    animation: aikb-slide-up 0.25s ease;
}

@keyframes aikb-slide-up {
    from {
        opacity: 0;
        transform: translateY(12px) scale(0.96);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.aikb-popup[hidden] {
    display: none !important;
}

.aikb-popup-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    background: var(--aikb-primary);
    color: #fff;
    flex-shrink: 0;
}

.aikb-header-title {
    font-weight: 600;
    font-size: 15px;
}

.aikb-header-actions {
    display: flex;
    align-items: center;
    gap: 4px;
}

.aikb-theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border: none;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.15);
    color: #fff;
    cursor: pointer;
    transition: background 0.2s ease;
}

.aikb-theme-toggle:hover {
    background: rgba(255, 255, 255, 0.25);
}

.aikb-theme-toggle:focus-visible {
    outline: 2px solid rgba(255, 255, 255, 0.6);
    outline-offset: 2px;
}

.aikb-theme-toggle svg {
    width: 16px;
    height: 16px;
}

.aikb-icon-sun {
    display: none;
}

.aikb-dark .aikb-icon-sun {
    display: block;
}

.aikb-dark .aikb-icon-moon {
    display: none;
}

.aikb-messages {
    flex: 1;
    overflow-y: auto;
    padding: 16px 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    scroll-behavior: smooth;
    background: var(--aikb-surface);
}

.aikb-message {
    display: flex;
    flex-direction: column;
    max-width: 85%;
    animation: aikb-fade-in 0.2s ease;
}

@keyframes aikb-fade-in {
    from {
        opacity: 0;
        transform: translateY(4px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.aikb-user-message {
    align-self: flex-end;
}

.aikb-bot-message {
    align-self: flex-start;
}

.aikb-message-content {
    padding: 10px 14px;
    border-radius: var(--aikb-radius);
    font-size: 14px;
    line-height: 1.6;
    word-wrap: break-word;
    white-space: pre-wrap;
}

.aikb-user-message .aikb-message-content {
    background: var(--aikb-user-bubble);
    color: var(--aikb-user-text);
    border-bottom-right-radius: 4px;
}

.aikb-bot-message .aikb-message-content {
    background: var(--aikb-bot-bubble);
    color: var(--aikb-bot-text);
    border-bottom-left-radius: 4px;
}

.aikb-message-meta {
    font-size: 11px;
    color: var(--aikb-text-secondary);
    margin-top: 4px;
    padding: 0 4px;
}

.aikb-user-message .aikb-message-meta {
    text-align: right;
}

.aikb-message-sources {
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px solid var(--aikb-border);
}

.aikb-message-sources-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--aikb-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 4px;
}

.aikb-message-sources-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.aikb-message-sources-list li {
    font-size: 12px;
    color: var(--aikb-primary);
    padding: 2px 0;
}

.aikb-message-confidence {
    font-size: 11px;
    color: var(--aikb-text-secondary);
    margin-top: 4px;
}

.aikb-fallback-button {
    margin-top: 8px;
}

.aikb-fallback-button button {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    font-size: 13px;
    font-weight: 500;
    font-family: var(--aikb-font);
    background: var(--aikb-primary);
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.2s ease;
}

.aikb-fallback-button button:hover {
    background: var(--aikb-primary-hover);
}

.aikb-fallback-button button:focus-visible {
    outline: 2px solid var(--aikb-primary);
    outline-offset: 2px;
}

.aikb-typing {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 10px 14px;
    background: var(--aikb-bot-bubble);
    border-radius: var(--aikb-radius);
    border-bottom-left-radius: 4px;
    align-self: flex-start;
    max-width: 70px;
}

.aikb-typing-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--aikb-text-secondary);
    animation: aikb-bounce 1.4s infinite ease-in-out both;
}

.aikb-typing-dot:nth-child(1) {
    animation-delay: -0.32s;
}

.aikb-typing-dot:nth-child(2) {
    animation-delay: -0.16s;
}

.aikb-typing-dot:nth-child(3) {
    animation-delay: 0s;
}

@keyframes aikb-bounce {
    0%, 80%, 100% {
        transform: scale(0.6);
    }
    40% {
        transform: scale(1);
    }
}

.aikb-input-area {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    padding: 12px 16px;
    background: var(--aikb-bg);
    border-top: 1px solid var(--aikb-border);
    flex-shrink: 0;
}

.aikb-input {
    flex: 1;
    padding: 10px 14px;
    font-size: 14px;
    font-family: var(--aikb-font);
    line-height: 1.5;
    color: var(--aikb-text);
    background: var(--aikb-surface);
    border: 1px solid var(--aikb-border);
    border-radius: var(--aikb-radius);
    resize: none;
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    max-height: 120px;
    min-height: 40px;
}

.aikb-input:focus {
    border-color: var(--aikb-primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.aikb-input::placeholder {
    color: var(--aikb-text-secondary);
}

.aikb-send-button {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 10px;
    background: var(--aikb-primary);
    color: #fff;
    cursor: pointer;
    flex-shrink: 0;
    transition: background 0.2s ease, transform 0.15s ease;
}

.aikb-send-button:hover {
    background: var(--aikb-primary-hover);
    transform: scale(1.05);
}

.aikb-send-button:active {
    transform: scale(0.95);
}

.aikb-send-button:focus-visible {
    outline: 2px solid var(--aikb-primary);
    outline-offset: 2px;
}

.aikb-send-button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.aikb-send-button svg {
    width: 18px;
    height: 18px;
}

.aikb-message-content p {
    margin: 0 0 8px;
}

.aikb-message-content p:last-child {
    margin-bottom: 0;
}

.aikb-message-content ul,
.aikb-message-content ol {
    margin: 4px 0;
    padding-left: 20px;
}

.aikb-message-content li {
    margin: 2px 0;
}

.aikb-message-content code {
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    font-size: 13px;
    background: var(--aikb-code-bg);
    color: var(--aikb-code-text);
    padding: 2px 6px;
    border-radius: 4px;
}

.aikb-message-content pre {
    background: var(--aikb-code-bg);
    color: var(--aikb-code-text);
    padding: 12px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 8px 0;
    font-size: 13px;
    line-height: 1.5;
}

.aikb-message-content pre code {
    background: none;
    padding: 0;
    font-size: 13px;
}

.aikb-message-content strong {
    font-weight: 600;
}

.aikb-message-content a {
    color: var(--aikb-primary);
    text-decoration: underline;
}

.aikb-message-content blockquote {
    border-left: 3px solid var(--aikb-primary);
    padding-left: 12px;
    margin: 8px 0;
    color: var(--aikb-text-secondary);
}

.aikb-error-message .aikb-message-content {
    background: #FEF2F2;
    color: #991B1B;
    border: 1px solid #FECACA;
}

.aikb-dark .aikb-error-message .aikb-message-content {
    background: #451A1A;
    color: #FCA5A5;
    border-color: #7F1D1D;
}

@media (max-width: 480px) {
    .aikb-popup {
        right: 12px;
        left: 12px;
        bottom: 80px;
        max-width: none;
        width: auto;
        height: auto;
        max-height: calc(100vh - 110px);
    }

    .aikb-toggle-button {
        bottom: 16px;
        right: 16px;
        width: 52px;
        height: 52px;
    }

    .aikb-messages {
        padding: 12px 14px;
    }

    .aikb-message {
        max-width: 90%;
    }
}

@media (prefers-reduced-motion: reduce) {
    .aikb-popup {
        animation: none;
    }

    .aikb-message {
        animation: none;
    }

    .aikb-typing-dot {
        animation: none;
    }

    .aikb-toggle-button {
        transition: none;
    }
}