:root {
    --bg-primary: #0d0d0d;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #262626;
    --bg-glass: rgba(38, 38, 38, 0.6);
    --bg-glass-hover: rgba(51, 51, 51, 0.8);
    --border-glass: rgba(255, 255, 255, 0.08);
    --border-glass-strong: rgba(255, 255, 255, 0.15);
    --text-primary: #ffffff;
    --text-secondary: #a3a3a3;
    --text-tertiary: #737373;
    --accent-primary: #10a37f;
    --accent-secondary: #19c59f;
    --accent-glow: rgba(16, 163, 127, 0.3);
    --gradient-start: #10a37f;
    --gradient-end: #0d8b6b;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --blur: blur(20px);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}


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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow: hidden;
    line-height: 1.5;
}


.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
    overflow: hidden;
}


.sidebar {
    width: 280px;
    background: var(--bg-glass);
    backdrop-filter: var(--blur);
    -webkit-backdrop-filter: var(--blur);
    border-right: 1px solid var(--border-glass);
    display: flex;
    flex-direction: column;
    position: relative;
    z-index: 100;
    transition: var(--transition);
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-glass);
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo i {
    font-size: 1.5rem;
    -webkit-text-fill-color: var(--accent-primary);
}

.btn-new-chat {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: var(--transition);
}

.btn-new-chat:hover {
    background: var(--bg-glass-hover);
    border-color: var(--border-glass-strong);
    transform: translateY(-1px);
}

.chat-history {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
}

.history-section {
    margin-bottom: 24px;
}

.history-title {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
    padding-left: 12px;
}

.chat-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.chat-item:hover {
    background: var(--bg-glass-hover);
    color: var(--text-primary);
}

.chat-item.active {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.chat-item i {
    font-size: 0.875rem;
    opacity: 0.7;
}

.chat-item span {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
}

.sidebar-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--border-glass);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
}

.user-profile:hover {
    background: var(--bg-glass-hover);
}

.avatar {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
}

.user-profile span {
    flex: 1;
    font-size: 0.875rem;
    font-weight: 500;
}


.sidebar-toggle {
    display: none;
    position: fixed;
    top: 16px;
    left: 16px;
    z-index: 200;
    width: 44px;
    height: 44px;
    background: var(--bg-glass);
    backdrop-filter: var(--blur);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1.125rem;
    cursor: pointer;
    transition: var(--transition);
}

.sidebar-toggle:hover {
    background: var(--bg-glass-hover);
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.sidebar-overlay.active {
    display: block;
    opacity: 1;
}


.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
    background: var(--bg-primary);
    overflow: hidden;
}


.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-glass);
    background: var(--bg-glass);
    backdrop-filter: var(--blur);
}

.model-selector {
    position: relative;
}

.model-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-xl);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.model-btn:hover {
    background: var(--bg-glass-hover);
    border-color: var(--border-glass-strong);
}

.model-btn i:first-child {
    color: var(--accent-primary);
}

.model-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    min-width: 280px;
    background: var(--bg-glass);
    backdrop-filter: var(--blur);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    box-shadow: var(--shadow-lg);
    z-index: 50;
}

.model-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.model-option {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
}

.model-option:hover {
    background: var(--bg-glass-hover);
}

.model-option i {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    color: var(--accent-primary);
    font-size: 1rem;
}

.model-info {
    display: flex;
    flex-direction: column;
}

.model-name {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
}

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

.header-actions {
    display: flex;
    gap: 8px;
}

.action-btn {
    width: 40px;
    height: 40px;
    background: transparent;
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.action-btn:hover {
    background: var(--bg-glass);
    color: var(--text-primary);
    border-color: var(--border-glass-strong);
}


.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    scroll-behavior: smooth;
}


.welcome-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100%;
}

.welcome-content {
    text-align: center;
    max-width: 800px;
    padding: 40px 20px;
}

.welcome-title {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 12px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start), var(--accent-secondary), var(--gradient-end));
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: gradient-shift 5s ease infinite;
}

@keyframes gradient-shift {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.welcome-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 48px;
}

.suggestions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    max-width: 700px;
    margin: 0 auto;
}

.suggestion-card {
    background: var(--bg-glass);
    backdrop-filter: var(--blur);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    padding: 24px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.suggestion-card:hover {
    background: var(--bg-glass-hover);
    border-color: var(--border-glass-strong);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.suggestion-card i {
    font-size: 1.5rem;
    color: var(--accent-primary);
}

.suggestion-card span {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}


.messages-area {
    display: none;
    flex-direction: column;
    gap: 24px;
    max-width: 900px;
    margin: 0 auto;
    width: 100%;
    padding-bottom: 24px;
}

.messages-area.active {
    display: flex;
}

.message {
    display: flex;
    gap: 16px;
    padding: 24px;
    border-radius: var(--radius-lg);
    animation: message-in 0.3s ease;
}

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

.message.user {
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
}

.message.assistant {
    background: transparent;
}

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

.message.user .message-avatar {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.message.assistant .message-avatar {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
}

.message-content {
    flex: 1;
    font-size: 0.9375rem;
    line-height: 1.7;
    color: var(--text-primary);
}

.message-content p {
    margin-bottom: 12px;
}

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


.input-container {
    padding: 24px;
    background: linear-gradient(to top, var(--bg-primary) 60%, transparent);
}

.input-wrapper {
    display: flex;
    align-items: flex-end;
    gap: 12px;
    max-width: 900px;
    margin: 0 auto;
    background: var(--bg-glass);
    backdrop-filter: var(--blur);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-xl);
    padding: 14px 18px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.input-wrapper:focus-within {
    border-color: var(--border-glass-strong);
    box-shadow: var(--shadow-lg), 0 0 0 3px var(--accent-glow);
}

.input-actions {
    display: flex;
    gap: 8px;
}

.input-btn {
    width: 36px;
    height: 36px;
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    color: var(--text-tertiary);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.input-btn:hover {
    color: var(--text-primary);
    background: var(--bg-glass-hover);
}

.message-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 0.9375rem;
    font-family: inherit;
    resize: none;
    min-height: 24px;
    max-height: 200px;
    line-height: 1.5;
}

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

.send-btn {
    width: 36px;
    height: 36px;
    background: var(--accent-primary);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.send-btn:hover:not(:disabled) {
    background: var(--accent-secondary);
    transform: scale(1.05);
}

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

.input-footer {
    text-align: center;
    margin-top: 12px;
    font-size: 0.75rem;
    color: var(--text-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}


::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

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

::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}


@media (max-width: 1024px) {
    .sidebar {
        position: fixed;
        left: -280px;
        height: 100vh;
    }
    
    .sidebar.active {
        left: 0;
    }
    
    .sidebar-toggle {
        display: flex;
    }
    
    .header {
        padding-left: 72px;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 12px 16px;
        padding-left: 64px;
    }
    
    .model-btn span {
        display: none;
    }
    
    .chat-container {
        padding: 16px;
    }
    
    .welcome-content {
        padding: 20px 16px;
    }
    
    .suggestions-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    .suggestion-card {
        flex-direction: row;
        justify-content: flex-start;
        padding: 16px 20px;
    }
    
    .input-container {
        padding: 16px;
    }
    
    .input-wrapper {
        padding: 12px 14px;
    }
    
    .message {
        padding: 16px;
    }
    
    .message-avatar {
        width: 32px;
        height: 32px;
    }
}

@media (max-width: 480px) {
    .input-btn:not(.send-btn) {
        display: none;
    }
    
    .input-footer {
        display: none;
    }
}


.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 4px 0;
}

.typing-indicator span {
    width: 8px;
    height: 8px;
    background: var(--accent-primary);
    border-radius: 50%;
    animation: typing 1.4s infinite;
}

.typing-indicator span:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {
    0%, 60%, 100% {
        transform: translateY(0);
        opacity: 0.4;
    }
    30% {
        transform: translateY(-8px);
        opacity: 1;
    }
}


.code-block {
    background: var(--bg-secondary);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    padding: 16px;
    margin: 16px 0;
    overflow-x: auto;
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.875rem;
}

.code-block code {
    color: var(--text-primary);
}


::selection {
    background: var(--accent-primary);
    color: white;
}