:root {
    /* Base Palette - Preserved from original */
    --pink-50: #FFFFFF;
    --pink-100: #7D2D56;
    --pink-200: #DC2B5C;
    --pink-300: #222848;
    --pink-400: #7D2D56;
    --pink-500: #F2F2F2;
    --pink-600: #EFA2A5;
    
    /* Extended Palette */
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --bg-elevated: #252545;
    --surface-glass: rgba(125, 45, 86, 0.15);
    --surface-glass-hover: rgba(125, 45, 86, 0.25);
    
    /* Borders */
    --border-color-primary: #491232;
    --border-color-secondary: #222848;
    --border-glass: rgba(220, 43, 92, 0.2);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 20px rgba(220, 43, 92, 0.3);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--pink-100) 0%, var(--pink-200) 100%);
    --gradient-surface: linear-gradient(180deg, rgba(37, 37, 69, 0.8) 0%, rgba(26, 26, 46, 0.9) 100%);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    /* Spacing & Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 400ms ease;
}

/* Import Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--pink-50);
    height: 100vh;
    overflow: hidden;
    line-height: 1.6;
}

/* ====== Main Container ====== */
.chat-container {
    display: flex;
    height: 100vh;
    background: var(--bg-primary);
}

/* ====== Sidebar ====== */
.sidebar {
    width: 280px;
    min-width: 280px;
    background: var(--surface-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-right: 1px solid var(--border-glass);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.sidebar h3 {
    color: var(--pink-50);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    opacity: 0.7;
    margin-bottom: 0.5rem;
}

/* Chat List */
.chat-list {
    flex-grow: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.chat-list::-webkit-scrollbar {
    width: 4px;
}

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

.chat-list::-webkit-scrollbar-thumb {
    background: var(--pink-200);
    border-radius: 2px;
}

.chat-item {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    cursor: pointer;
    border: 1px solid transparent;
}

.chat-item:hover {
    background: var(--surface-glass-hover);
    border-color: var(--border-glass);
}

.chat-item.active {
    background: var(--gradient-primary);
    border-color: var(--pink-200);
    box-shadow: var(--shadow-glow);
}

.chat-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
}

.chat-link {
    flex-grow: 1;
    text-decoration: none;
    color: var(--pink-50);
    font-size: 0.9rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.delete-chat {
    background: none;
    border: none;
    color: var(--pink-600);
    cursor: pointer;
    padding: 4px 8px;
    font-size: 1.1rem;
    border-radius: var(--radius-sm);
    opacity: 0;
    transition: all var(--transition-fast);
}

.chat-item:hover .delete-chat {
    opacity: 1;
}

.delete-chat:hover {
    color: #ff6b6b;
    background: rgba(255, 107, 107, 0.1);
}

/* New Chat Button */
.new-chat-btn {
    width: 100%;
    padding: 1rem;
    background: var(--gradient-primary);
    color: var(--pink-50);
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-primary);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.new-chat-btn::before {
    content: '+';
    font-size: 1.2rem;
    font-weight: 700;
}

.new-chat-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

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

/* ====== Main Chat Area ====== */
.chat-main {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    background: var(--gradient-surface);
    overflow: hidden;
}

/* Header */
header {
    background: var(--surface-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-glass);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.header-avatar {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: var(--shadow-glow);
}

.header-info h1 {
    color: var(--pink-50);
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0;
}

/* Header Container & Logo */
.header-container {
    display: flex;
    align-items: center;
    width: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    transition: all var(--transition-fast);
}

.logo:hover {
    transform: scale(1.02);
}

.logo-icon {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    filter: drop-shadow(0 0 8px rgba(220, 43, 92, 0.5));
}

.logo-icon svg {
    width: 100%;
    height: 100%;
}

.logo-text {
    font-size: 1.4rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--pink-50) 0%, var(--pink-200) 50%, var(--pink-600) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.header-info p {
    color: var(--pink-600);
    font-size: 0.85rem;
    margin: 0.25rem 0 0;
    opacity: 0.8;
}

.header-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-left: auto;
    color: var(--pink-600);
    font-size: 0.8rem;
}

.status-dot {
    width: 8px;
    height: 8px;
    background: #4ade80;
    border-radius: 50%;
    animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.6; transform: scale(0.9); }
}

/* ====== Chat Messages ====== */
.chat-messages {
    flex-grow: 1;
    overflow-y: auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    scroll-behavior: smooth;
}

.chat-messages::-webkit-scrollbar {
    width: 6px;
}

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

.chat-messages::-webkit-scrollbar-thumb {
    background: var(--pink-100);
    border-radius: 3px;
}

/* Empty State */
.empty-state {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem;
    opacity: 0;
    animation: fadeIn var(--transition-slow) forwards;
}

.empty-state-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-glow);
}

.empty-state h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.empty-state p {
    color: var(--pink-600);
    font-size: 1rem;
    max-width: 400px;
    opacity: 0.8;
}

/* Messages */
.message {
    max-width: 75%;
    padding: 1rem 1.25rem;
    border-radius: var(--radius-lg);
    position: relative;
    opacity: 0;
    animation: messageSlideIn var(--transition-normal) forwards;
}

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

.message.user {
    align-self: flex-end;
    background: var(--gradient-primary);
    color: var(--pink-50);
    border-bottom-right-radius: var(--radius-sm);
    box-shadow: var(--shadow-md), var(--shadow-glow);
}

.message.assistant {
    align-self: flex-start;
    background: var(--bg-elevated);
    color: var(--pink-50);
    border-bottom-left-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-glass);
}

.message-content {
    line-height: 1.6;
    font-size: 0.95rem;
}

.message-content p {
    margin: 0 0 0.5rem;
}

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

.message-content code {
    background: rgba(0, 0, 0, 0.2);
    padding: 0.2rem 0.4rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
}

.message-content pre {
    background: rgba(0, 0, 0, 0.3);
    padding: 1rem;
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin: 0.5rem 0;
}

.message-content pre code {
    background: none;
    padding: 0;
}

.message-timestamp {
    font-size: 0.7rem;
    opacity: 0.6;
    margin-top: 0.5rem;
    text-align: right;
}

/* ====== Typing/Loading Indicator ====== */
.message.thinking {
    background: var(--bg-elevated);
    border: 1px solid var(--border-glass);
    animation: none;
    opacity: 1;
}

.typing-indicator {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

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

.typing-dots span {
    width: 8px;
    height: 8px;
    background: var(--pink-200);
    border-radius: 50%;
    animation: bounce 1.4s ease-in-out infinite;
}

.typing-dots span:nth-child(1) { animation-delay: 0s; }
.typing-dots span:nth-child(2) { animation-delay: 0.2s; }
.typing-dots span:nth-child(3) { animation-delay: 0.4s; }

@keyframes bounce {
    0%, 60%, 100% { transform: translateY(0); }
    30% { transform: translateY(-6px); }
}

.typing-text {
    color: var(--pink-600);
    font-size: 0.9rem;
    font-weight: 500;
}

.state-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.state-step {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    color: var(--pink-600);
    font-size: 0.8rem;
    opacity: 0.5;
    transition: all var(--transition-fast);
}

.state-step.active {
    opacity: 1;
    color: var(--pink-200);
}

.state-step.completed {
    opacity: 0.7;
    color: #4ade80;
}

.state-step-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: currentColor;
}

.state-step.active .state-step-dot {
    animation: pulse-dot 1s ease-in-out infinite;
}

/* ====== Chat Input ====== */
.chat-input {
    display: flex;
    gap: 1rem;
    padding: 1.5rem 2rem;
    background: var(--surface-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--border-glass);
}

.input-wrapper {
    flex-grow: 1;
    position: relative;
}

.chat-input input {
    width: 100%;
    padding: 1rem 1.25rem;
    background: var(--bg-elevated);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    color: var(--pink-50);
    font-family: var(--font-primary);
    font-size: 0.95rem;
    transition: all var(--transition-fast);
}

.chat-input input::placeholder {
    color: var(--pink-600);
    opacity: 0.6;
}

.chat-input input:focus {
    outline: none;
    border-color: var(--pink-200);
    box-shadow: 0 0 0 3px rgba(220, 43, 92, 0.15);
}

.chat-input input:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.chat-input button {
    padding: 1rem 2rem;
    background: var(--gradient-primary);
    color: var(--pink-50);
    border: none;
    border-radius: var(--radius-lg);
    font-family: var(--font-primary);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.chat-input button:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

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

.chat-input button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.send-icon {
    width: 18px;
    height: 18px;
}

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

@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

.shimmer {
    background: linear-gradient(
        90deg,
        rgba(255,255,255,0) 0%,
        rgba(255,255,255,0.1) 50%,
        rgba(255,255,255,0) 100%
    );
    background-size: 200% 100%;
    animation: shimmer 2s infinite;
}

/* ====== Error Message ====== */
.message.error {
    background: rgba(239, 68, 68, 0.2);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: #fca5a5;
    align-self: center;
    text-align: center;
    max-width: 90%;
}

/* ====== Responsive Design ====== */
@media (max-width: 768px) {
    .chat-container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        min-width: 100%;
        max-height: 180px;
        border-right: none;
        border-bottom: 1px solid var(--border-glass);
        padding: 1rem;
    }
    
    .sidebar h3 {
        display: none;
    }
    
    .chat-list {
        flex-direction: row;
        gap: 0.5rem;
        overflow-x: auto;
        overflow-y: hidden;
    }
    
    .chat-item {
        flex-shrink: 0;
        padding: 0.5rem 1rem;
    }
    
    .new-chat-btn {
        padding: 0.75rem;
        font-size: 0.85rem;
    }
    
    .chat-messages {
        padding: 1rem;
    }
    
    .message {
        max-width: 90%;
    }
    
    .chat-input {
        padding: 1rem;
    }
    
    .chat-input button span {
        display: none;
    }
    
    header {
        padding: 1rem;
    }
    
    .header-info h1 {
        font-size: 1.1rem;
    }
}