:root {
    /* Colors - Purple & Black Theme */
    --primary-color: #8B5CF6;
    --primary-dark: #7C3AED;
    --primary-light: #A78BFA;
    --primary-glow: rgba(139, 92, 246, 0.3);
    --secondary-color: #6366F1;
    --accent-color: #C084FC;
    
    --bg-color: #F8F7FC;
    --bg-secondary: #EDE9FE;
    --card-bg: #ffffff;
    --text-main: #1F1F1F;
    --text-muted: #6B7280;
    --border-color: #E5E7EB;
    --input-bg: #ffffff;
    
    --msg-user-bg: linear-gradient(135deg, #8B5CF6 0%, #7C3AED 100%);
    --msg-user-text: #ffffff;
    --msg-ai-bg: #ffffff;
    --msg-ai-text: #1F1F1F;
    
    --code-bg: #1a1a2e;
    --code-header: #252540;
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
    --shadow-purple: 0 8px 30px rgba(139, 92, 246, 0.25);
    
    --font-family: 'Poppins', sans-serif;
    --radius: 16px;
    --radius-lg: 24px;
}

/* Dark Mode Colors */
[data-theme="dark"] {
    --bg-color: #0D0D0D;
    --bg-secondary: #1A1A2E;
    --card-bg: #161622;
    --text-main: #F3F4F6;
    --text-muted: #9CA3AF;
    --border-color: #2D2D44;
    --input-bg: #1E1E2E;
    
    --msg-user-bg: linear-gradient(135deg, #8B5CF6 0%, #7C3AED 100%);
    --msg-ai-bg: #1E1E2E;
    --msg-ai-text: #F3F4F6;
    
    --code-bg: #0d0d1a;
    --code-header: #1a1a2e;
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.4);
}

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Header */
header {
    background: var(--card-bg);
    padding: 12px 20px;
    box-shadow: var(--shadow-sm);
    z-index: 100;
    flex-shrink: 0;
    border-bottom: 1px solid var(--border-color);
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

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

.logo {
    font-size: 1.3rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-main);
}

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

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

.icon-btn, .theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: all 0.25s ease;
}

.icon-btn:hover, .theme-toggle:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-purple);
}

.icon-btn:active, .theme-toggle:active {
    transform: translateY(0);
}

/* Main Chat Layout */
.main-chat-layout {
    flex: 1;
    display: flex;
    flex-direction: column;
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
    overflow: hidden;
    position: relative;
}

/* Chat Container */
.chat-container {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
}

/* Scrollbar Styling */
.chat-container::-webkit-scrollbar {
    width: 6px;
}
.chat-container::-webkit-scrollbar-track {
    background: transparent;
}
.chat-container::-webkit-scrollbar-thumb {
    background: var(--primary-light);
    border-radius: 3px;
}
.chat-container::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

/* Welcome Screen */
.welcome-screen {
    text-align: center;
    margin: auto;
    padding: 40px 20px;
    animation: fadeIn 0.6s ease;
    max-width: 500px;
}

.welcome-icon {
    width: 90px;
    height: 90px;
    margin: 0 auto 24px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.8rem;
    color: white;
    box-shadow: var(--shadow-purple);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.welcome-title {
    font-size: 2rem;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome-description {
    margin-bottom: 32px;
}

.welcome-description .desc-main {
    font-size: 1.1rem;
    color: var(--text-main);
    margin-bottom: 8px;
    font-weight: 500;
}

.welcome-description .desc-sub {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.welcome-features {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: all 0.3s ease;
}

.feature-item:hover {
    border-color: var(--primary-color);
    transform: translateX(5px);
}

.feature-item i {
    width: 36px;
    height: 36px;
    background: var(--bg-secondary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1rem;
}

.feature-item span {
    color: var(--text-main);
    font-size: 0.95rem;
}

/* Messages */
.message {
    display: flex;
    gap: 12px;
    animation: slideUp 0.3s ease;
    max-width: 100%;
}

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

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 0.9rem;
}

.message.ai .message-avatar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: white;
    box-shadow: var(--shadow-purple);
}

.message.user .message-avatar {
    background: var(--bg-secondary);
    color: var(--text-muted);
    order: 2;
}

.message-wrapper {
    max-width: 80%;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.message.user .message-wrapper {
    order: 1;
    align-items: flex-end;
}

.message-content {
    background: var(--msg-ai-bg);
    color: var(--msg-ai-text);
    padding: 14px 18px;
    border-radius: 18px;
    border-top-left-radius: 4px;
    font-size: 0.95rem;
    line-height: 1.7;
    box-shadow: var(--shadow-sm);
    overflow-wrap: break-word;
    word-wrap: break-word;
    border: 1px solid var(--border-color);
}

.message.user .message-content {
    background: var(--msg-user-bg);
    color: var(--msg-user-text);
    border-radius: 18px;
    border-top-right-radius: 4px;
    border: none;
    box-shadow: var(--shadow-purple);
}

/* Message Actions */
.message-actions {
    display: flex;
    gap: 8px;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.message:hover .message-actions {
    opacity: 1;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-muted);
    font-size: 0.8rem;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.action-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.action-btn.copied {
    background: #10B981;
    color: white;
    border-color: #10B981;
}

/* Code Block Styling */
.message-content pre {
    position: relative;
    background: var(--code-bg);
    border-radius: 12px;
    margin: 12px 0;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    background: var(--code-header);
    border-bottom: 1px solid var(--border-color);
}

.code-lang {
    font-size: 0.8rem;
    color: var(--primary-light);
    font-weight: 500;
    text-transform: uppercase;
}

.copy-code-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: #9CA3AF;
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.copy-code-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.copy-code-btn.copied {
    background: #10B981;
    color: white;
    border-color: #10B981;
}

.message-content pre code {
    display: block;
    padding: 14px;
    overflow-x: auto;
    font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
    color: #e0e0e0;
}

.message-content code {
    font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.85em;
}

/* Inline code */
.message-content p code,
.message-content li code {
    background: var(--bg-secondary);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.85em;
    color: var(--primary-color);
}

.message-content p {
    margin-bottom: 10px;
}

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

.message-content ul, .message-content ol {
    margin-left: 20px;
    margin-bottom: 10px;
}

.message-content li {
    margin-bottom: 4px;
}

.message-content a {
    color: var(--primary-color);
    text-decoration: none;
}

.message-content a:hover {
    text-decoration: underline;
}

.message-content blockquote {
    border-left: 3px solid var(--primary-color);
    padding-left: 12px;
    margin: 10px 0;
    color: var(--text-muted);
}

.message-content h1, 
.message-content h2, 
.message-content h3 {
    margin: 16px 0 10px;
    color: var(--text-main);
}

.message-content h1 { font-size: 1.4rem; }
.message-content h2 { font-size: 1.2rem; }
.message-content h3 { font-size: 1.1rem; }

/* Typing Indicator */
.typing-indicator {
    padding: 0 20px 10px;
    display: none;
}

.typing-indicator.show {
    display: block;
}

.typing-content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.typing-avatar {
    width: 36px;
    height: 36px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

.typing-dots {
    display: flex;
    gap: 4px;
    padding: 12px 16px;
    background: var(--card-bg);
    border-radius: 18px;
    border-top-left-radius: 4px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

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

.typing-dots span:nth-child(1) { animation-delay: -0.32s; }
.typing-dots span:nth-child(2) { animation-delay: -0.16s; }

/* Input Area */
.input-area-wrapper {
    background: linear-gradient(to top, var(--bg-color) 85%, transparent);
    padding: 15px 20px 20px;
    flex-shrink: 0;
}

.input-container {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 28px;
    padding: 8px 12px;
    display: flex;
    align-items: flex-end;
    gap: 10px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.input-container:focus-within {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-purple);
}

textarea {
    flex: 1;
    border: none;
    background: transparent;
    padding: 12px 8px;
    resize: none;
    font-family: inherit;
    font-size: 1rem;
    color: var(--text-main);
    max-height: 120px;
    min-height: 24px;
    outline: none;
    line-height: 1.5;
}

textarea::placeholder {
    color: var(--text-muted);
}

.send-btn {
    width: 46px;
    height: 46px;
    border: none;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    transition: all 0.25s ease;
    flex-shrink: 0;
    box-shadow: var(--shadow-purple);
}

.send-btn:hover {
    transform: scale(1.08);
    box-shadow: 0 8px 25px rgba(139, 92, 246, 0.4);
}

.send-btn:active {
    transform: scale(1);
}

.send-btn:disabled {
    background: var(--text-muted);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.footer-info {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 10px;
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    padding: 20px;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--card-bg);
    padding: 24px;
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 420px;
    transform: translateY(30px) scale(0.95);
    transition: transform 0.3s cubic-bezier(0.18, 0.89, 0.32, 1.28);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
}

.modal-overlay.active .modal-content {
    transform: translateY(0) scale(1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.modal-header h3 {
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
}

.modal-header h3 i {
    color: var(--primary-color);
}

.close-modal {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: var(--bg-secondary);
    border: none;
    color: var(--text-muted);
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.close-modal:hover {
    background: var(--primary-color);
    color: white;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-main);
    font-weight: 500;
    font-size: 0.95rem;
}

.input-with-icon {
    position: relative;
}

.input-with-icon input {
    padding-right: 45px;
}

.toggle-password {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 5px;
}

.toggle-password:hover {
    color: var(--primary-color);
}

.form-group input, .form-group select {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    background: var(--input-bg);
    color: var(--text-main);
    font-family: inherit;
    font-size: 0.95rem;
    transition: all 0.2s ease;
}

.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.form-group small {
    display: block;
    margin-top: 8px;
    color: var(--text-muted);
    font-size: 0.8rem;
}

.modal-footer {
    margin-top: 24px;
}

.btn-primary {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.25s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    box-shadow: var(--shadow-purple);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(139, 92, 246, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

/* Confirm Modal */
.modal-confirm {
    text-align: center;
    max-width: 360px;
}

.confirm-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, #FEE2E2 0%, #FECACA 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: #EF4444;
}

[data-theme="dark"] .confirm-icon {
    background: linear-gradient(135deg, #7F1D1D 0%, #991B1B 100%);
    color: #FCA5A5;
}

.modal-confirm h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: var(--text-main);
}

.modal-confirm p {
    color: var(--text-muted);
    margin-bottom: 24px;
    font-size: 0.95rem;
}

.confirm-actions {
    display: flex;
    gap: 12px;
}

.btn-cancel, .btn-danger {
    flex: 1;
    padding: 12px 20px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-cancel {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-main);
}

.btn-cancel:hover {
    background: var(--border-color);
}

.btn-danger {
    background: linear-gradient(135deg, #EF4444 0%, #DC2626 100%);
    border: none;
    color: white;
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(239, 68, 68, 0.4);
}

/* Toast */
.toast {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(-100px);
    background: var(--card-bg);
    color: var(--text-main);
    padding: 14px 24px;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 12px;
    z-index: 2000;
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.18, 0.89, 0.32, 1.28);
    border: 1px solid var(--border-color);
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast i {
    font-size: 1.2rem;
}

.toast i.fa-check-circle {
    color: #10B981;
}

.toast i.fa-circle-exclamation {
    color: #EF4444;
}

/* Animations */
@keyframes fadeIn { 
    from { opacity: 0; } 
    to { opacity: 1; } 
}

@keyframes slideUp { 
    from { opacity: 0; transform: translateY(15px); } 
    to { opacity: 1; transform: translateY(0); } 
}

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

/* Responsive */
@media (max-width: 768px) {
    .container { padding: 0 15px; }
    
    .header-content {
        padding: 0 5px;
    }
    
    .logo {
        font-size: 1.1rem;
    }
    
    .logo i {
        font-size: 1.3rem;
    }
    
    .icon-btn, .theme-toggle {
        width: 36px;
        height: 36px;
        border-radius: 10px;
    }
    
    .welcome-title { 
        font-size: 1.6rem; 
    }
    
    .welcome-icon {
        width: 70px;
        height: 70px;
        font-size: 2rem;
    }
    
    .welcome-description .desc-main {
        font-size: 1rem;
    }
    
    .welcome-description .desc-sub {
        font-size: 0.9rem;
    }
    
    .feature-item {
        padding: 12px 16px;
    }
    
    .message-wrapper { 
        max-width: 88%; 
    }
    
    .message-content {
        padding: 12px 14px;
        font-size: 0.9rem;
    }
    
    .chat-container {
        padding: 15px;
        gap: 12px;
    }
    
    .input-area-wrapper {
        padding: 10px 15px 15px;
    }
    
    .input-container {
        padding: 6px 10px;
    }
    
    textarea {
        padding: 10px 6px;
        font-size: 0.95rem;
    }
    
    .send-btn {
        width: 42px;
        height: 42px;
        font-size: 1rem;
    }
    
    .modal-content {
        padding: 20px;
        margin: 15px;
    }
    
    .message-actions {
        opacity: 1;
    }
}

@media (max-width: 480px) {
    .welcome-features {
        gap: 8px;
    }
    
    .confirm-actions {
        flex-direction: column;
    }
}