:root {
    --primary-color: #00d2ff;
    --secondary-color: #3a7bd5;
    --bg-dark: #0f172a;
    --bg-chat: #1e293b;
    --text-light: #f1f5f9;
    --text-dim: #94a3b8;
    --user-bubble: #3a7bd5;
    --bot-bubble: #334155;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-light);
    height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    padding: 1rem;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    position: sticky;
    top: 0;
    z-index: 10;
}

header h1 {
    font-size: 1.25rem;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 800;
}

#chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message {
    max-width: 80%;
    padding: 0.75rem 1rem;
    border-radius: 1rem;
    font-size: 0.95rem;
    line-height: 1.4;
    position: relative;
    animation: fadeIn 0.3s ease;
}

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

.user-message {
    align-self: flex-end;
    background: var(--user-bubble);
    border-bottom-right-radius: 0.25rem;
    box-shadow: 0 4px 15px rgba(58, 123, 213, 0.3);
}

.bot-message {
    align-self: flex-start;
    background: var(--bot-bubble);
    border-bottom-left-radius: 0.25rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.typing-indicator {
    font-style: italic;
    font-size: 0.8rem;
    color: var(--text-dim);
    margin-bottom: 0.5rem;
}

footer {
    padding: 1rem;
    background: var(--bg-chat);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.input-group {
    display: flex;
    gap: 0.5rem;
    max-width: 800px;
    margin: 0 auto;
}

input[type="text"] {
    flex: 1;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 2rem;
    padding: 0.75rem 1.25rem;
    color: white;
    outline: none;
    transition: 0.2s;
}

input[type="text"]:focus {
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.1);
}

button {
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    border: none;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 2rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.1s, opacity 0.2s;
}

button:active {
    transform: scale(0.95);
}

button:hover {
    opacity: 0.9;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
}