/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    background: #ffffff;
    color: #111827;
    height: 100vh;
    overflow: hidden;
}

.font-ibm-plex {
    font-family: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
}

/* App Container */
.app-container {
    min-height: 100vh;
    background: #ffffff;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid #e5e7eb;
}

.header-content {
    max-width: 1024px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-title {
    color: #111827;
    font-size: 18px;
    font-weight: 500;
    line-height: 1.5;
}

.clear-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    border: none;
    border-radius: 6px;
    background: transparent;
    color: #6b7280;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.clear-btn:hover {
    background: #f3f4f6;
    color: #111827;
}

/* Chat Container */
.chat-container {
    display: flex;
    flex-direction: column;
    height: calc(100vh - 80px);
}

.messages-area {
    flex: 1;
    overflow-y: auto;
}

.messages-content {
    max-width: 1024px;
    margin: 0 auto;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    min-height: 100%;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    height: 100%;
    min-height: 400px;
}

.welcome-icon {
    background: #f3f4f6;
    border: 1px solid #e5e7eb;
    border-radius: 32px;
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    color: #6b7280;
}

.welcome-title {
    color: #111827;
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 16px;
    line-height: 1.5;
}

.welcome-text {
    color: #6b7280;
    max-width: 448px;
    font-size: 14px;
    line-height: 1.5;
}

/* Messages Container */
.messages-container {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Message Styles */
.message {
    display: flex;
    width: 100%;
}

.message.user { justify-content: flex-end; }
.message.ai { justify-content: flex-start; }

.message-wrapper {
    max-width: 512px;
    display: flex;
    flex-direction: column;
}

.message.user .message-wrapper { align-items: flex-end; }
.message.ai .message-wrapper { align-items: flex-start; }

.message-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.message.user .message-header { flex-direction: row-reverse; }

.message-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: #111827;
    border-color: #111827;
    color: #ffffff;
}

.message.ai .message-avatar {
    background: #f3f4f6;
    border-color: #e5e7eb;
    color: #6b7280;
}

.message-info {
    display: flex;
    align-items: center;
    gap: 8px;
}

.message.user .message-info { flex-direction: row-reverse; }

.message-sender {
    color: #6b7280;
    font-size: 14px;
    font-weight: 500;
}


/* Language Selector */
.language-section {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 8px;
}

.language-label {
    color: #6b7280;
    font-size: 14px;
    font-weight: 500;
    white-space: nowrap;
}

.select-wrapper {
    position: relative;
    display: inline-flex;
    align-items: center;
}

.select-wrapper::after {
    content: '';
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    width: 0;
    height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 5px solid #6b7280;
    pointer-events: none;
}

.language-select {
    width: 128px;
    height: 36px;
    background: #ffffff;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    color: #111827;
    padding: 0 30px 0 12px;
    font-size: 14px;
    font-family: inherit;
    cursor: pointer;
    outline: none;
    transition: all 0.2s ease;
    appearance: none;
    -webkit-appearance: none;
}

.language-select:focus {
    border-color: #9ca3af;
    box-shadow: 0 0 0 3px rgba(156, 163, 175, 0.1);
}

.language-select:hover {
    border-color: #9ca3af;
}


/* Language badge - reuses model badge style */
.message-model {
    background: #f3f4f6;
    color: #6b7280;
    border: 1px solid #e5e7eb;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 400;
}

.message-bubble {
    border-radius: 12px;
    padding: 12px 16px;
    word-wrap: break-word;
    max-width: 100%;
}

.message.user .message-bubble {
    background: #111827;
    color: #ffffff;
}

.message.ai .message-bubble {
    background: #f9fafb;
    border: 1px solid #e5e7eb;
    color: #111827;
}

.message-text {
    white-space: pre-wrap;
    word-break: break-words;
    font-size: 14px;
    line-height: 1.6;
}

.message-footer {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-top: 4px;
    font-size: 12px;
    color: #9ca3af;
}

.message.user .message-footer { justify-content: flex-end; }
.message.ai .message-footer { justify-content: flex-start; }

/* Meter Validity Badges */
.meter-badge {
    font-size: 11px;
    font-weight: 500;
    padding: 2px 7px;
    border-radius: 10px;
}

.meter-valid {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.meter-invalid {
    background: #fef3c7;
    color: #92400e;
    border: 1px solid #fde68a;
}

/* Loading Indicator */
.loading-indicator {
    display: flex;
    justify-content: flex-start;
}

.loading-bubble {
    background: #f9fafb;
    border: 1px solid #e5e7eb;
    border-radius: 32px;
    padding: 24px;
    max-width: 320px;
}

.loading-content {
    display: flex;
    align-items: center;
    gap: 8px;
}

.loading-dots {
    display: flex;
    gap: 4px;
}

.dot {
    width: 8px;
    height: 8px;
    background: #9ca3af;
    border-radius: 50%;
    animation: pulse 1.5s ease-in-out infinite;
}

.dot:nth-child(2) { animation-delay: 0.2s; }
.dot:nth-child(3) { animation-delay: 0.4s; }

.loading-text {
    color: #6b7280;
    font-size: 14px;
}

@keyframes pulse {
    0%, 80%, 100% { opacity: 0.3; }
    40% { opacity: 1; }
}

/* Input Area */
.input-area {
    border-top: 1px solid #e5e7eb;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(16px);
}

.input-content {
    max-width: 1024px;
    margin: 0 auto;
    padding: 16px 24px;
}

.chat-form {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.input-section {
    display: flex;
    align-items: flex-end;
    gap: 8px;
}

.textarea-container {
    flex: 1;
    position: relative;
}

.message-textarea {
    width: 100%;
    min-height: 44px;
    max-height: 128px;
    background: #ffffff;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    padding: 12px 16px;
    color: #111827;
    font-size: 14px;
    font-family: inherit;
    line-height: 1.4;
    resize: none;
    outline: none;
    transition: all 0.2s ease;
}

.message-textarea::placeholder { color: #9ca3af; }

.message-textarea:focus {
    border-color: #9ca3af;
    box-shadow: 0 0 0 3px rgba(156, 163, 175, 0.1);
}

.message-textarea:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    background: #f9fafb;
}

.send-button {
    height: 44px;
    width: 44px;
    background: #111827;
    border: none;
    border-radius: 8px;
    color: #ffffff;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    flex-shrink: 0;
    position: relative;
}

.send-button:hover:not(:disabled) { background: #1f2937; }
.send-button:disabled { opacity: 0.5; cursor: not-allowed; }

.loading-spinner { position: absolute; }

.spinner {
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top: 2px solid #ffffff;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Scrollbar Styling */
.messages-area::-webkit-scrollbar { width: 6px; }
.messages-area::-webkit-scrollbar-track { background: transparent; }
.messages-area::-webkit-scrollbar-thumb { background: #e5e7eb; border-radius: 3px; }
.messages-area::-webkit-scrollbar-thumb:hover { background: #d1d5db; }

/* Responsive Design */
@media (max-width: 768px) {
    .header-content { padding: 16px; }
    .messages-content { padding: 16px; gap: 20px; }
    .message-wrapper { max-width: 85%; }
    .input-content { padding: 16px; }
    .chat-form { gap: 10px; }
    .language-section { flex-direction: row; } /* keep inline on mobile */
}

@media (max-width: 480px) {
    .header-title { font-size: 16px; }
    .welcome-title { font-size: 18px; }
    .message-wrapper { max-width: 90%; }
    .message-bubble { padding: 10px 12px; }
    .header-content { padding: 12px; }
    .messages-content { padding: 12px; }
    .input-content { padding: 12px; }
}