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

:root {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #252525;
    --bg-message-user: #2563eb;
    --bg-message-ai: #1f1f1f;
    --text-primary: #e5e5e5;
    --text-secondary: #a3a3a3;
    --text-tertiary: #737373;
    --border-color: #333333;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --success-color: #10b981;
    --shadow: rgba(0, 0, 0, 0.5);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', sans-serif;
    background: linear-gradient(135deg, #0f0f0f 0%, #1a1a1a 100%);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

.container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 1400px;
    margin: 0 auto;
}

/* Header Styles */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
    box-shadow: 0 2px 10px var(--shadow);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-icon {
    width: 32px;
    height: 32px;
    stroke: #3b82f6;
}

.model-selector-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.model-selector-wrapper label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.model-select {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
    min-width: 200px;
}

.model-select:hover {
    border-color: var(--accent-color);
}

.model-select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* Chat Container */
.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 2rem 1.5rem;
    position: relative;
}

.chat-container::-webkit-scrollbar {
    width: 8px;
}

.chat-container::-webkit-scrollbar-track {
    background: transparent;
}

.chat-container::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

.chat-container::-webkit-scrollbar-thumb:hover {
    background: var(--border-color);
}

.chat-messages {
    max-width: 900px;
    margin: 0 auto;
}

/* Welcome Message */
.welcome-message {
    text-align: center;
    padding: 3rem 2rem;
    opacity: 0.9;
}

.welcome-icon {
    display: inline-block;
    width: 80px;
    height: 80px;
    margin-bottom: 1.5rem;
}

.welcome-icon svg {
    width: 100%;
    height: 100%;
    stroke: var(--accent-color);
}

.welcome-message h2 {
    font-size: 2rem;
    margin-bottom: 0.75rem;
    background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome-message p {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* Message Styles */
.message {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-weight: 600;
    font-size: 0.875rem;
}

.message.user .message-avatar {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    color: white;
}

.message.ai .message-avatar {
    background: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
    color: white;
}

.message-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.message-role {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.message-text {
    background: var(--bg-message-ai);
    padding: 1rem 1.25rem;
    border-radius: 12px;
    line-height: 1.6;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.message.user .message-text {
    background: var(--bg-message-user);
    border-color: transparent;
}

/* Loading Indicator */
.loading-indicator {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-left: 56px;
}

.loading-indicator.hidden {
    display: none;
}

.loading-dots {
    display: flex;
    gap: 0.5rem;
}

.loading-dots span {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent-color);
    animation: bounce 1.4s infinite ease-in-out both;
}

.loading-dots span:nth-child(1) {
    animation-delay: -0.32s;
}

.loading-dots span:nth-child(2) {
    animation-delay: -0.16s;
}

@keyframes bounce {
    0%, 80%, 100% {
        transform: scale(0);
        opacity: 0.5;
    }
    40% {
        transform: scale(1);
        opacity: 1;
    }
}

/* Input Container */
.input-container {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem;
}

.input-wrapper {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    gap: 0.75rem;
    align-items: flex-end;
}

.message-input {
    flex: 1;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.875rem 1rem;
    font-size: 1rem;
    font-family: inherit;
    resize: none;
    max-height: 150px;
    transition: all 0.2s;
}

.message-input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.message-input::placeholder {
    color: var(--text-tertiary);
}

.send-button {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--accent-color);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    flex-shrink: 0;
}

.send-button:hover:not(:disabled) {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

.send-button:active:not(:disabled) {
    transform: translateY(0);
}

.send-button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.send-button svg {
    width: 20px;
    height: 20px;
}

.input-footer {
    max-width: 900px;
    margin: 0.75rem auto 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.status-text {
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        align-items: stretch;
    }

    .logo {
        justify-content: center;
    }

    .model-selector-wrapper {
        justify-content: center;
    }

    .model-select {
        flex: 1;
    }

    .chat-container {
        padding: 1rem;
    }

    .welcome-message {
        padding: 2rem 1rem;
    }

    .welcome-message h2 {
        font-size: 1.5rem;
    }

    .welcome-message p {
        font-size: 1rem;
    }
}