:root {
    --bg-color: #0f172a;
    --sidebar-bg: #1e293b;
    --chat-bg: #131c2d;
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #10b981;
    --secondary-hover: #059669;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --input-bg: #2d384d; /* Slightly lighter for inputs */
    --message-bot-bg: #1e293b;
    --message-user-bg: #3b82f6;
    --font-family: 'Inter', sans-serif;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: 1px solid rgba(255, 255, 255, 0.1);
}

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

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

.app-container {
    display: flex;
    height: 100%;
}

/* Sidebar */
.sidebar {
    width: 320px;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    overflow-y: auto;
    transition: transform 0.3s ease;
}

.sidebar-header {
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sidebar-header h2 {
    font-size: 1.5rem;
    background: linear-gradient(135deg, #60a5fa, #a78bfa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.settings-group {
    margin-bottom: 2rem;
}

.label_title {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.input-wrapper input, .input-wrapper textarea {
    width: 100%;
    padding: 0.75rem;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: var(--text-primary);
    font-family: inherit;
    transition: border-color 0.2s;
}

.input-wrapper input:focus, .input-wrapper textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Accordion */
.accordion {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.accordion-item {
    background-color: rgba(255,255,255,0.03);
    border-radius: 0.5rem;
    overflow: hidden;
}

.accordion-header {
    width: 100%;
    padding: 1rem;
    background: none;
    border: none;
    color: var(--text-primary);
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.2s;
}

.accordion-header:hover {
    background-color: rgba(255,255,255,0.05);
}

.accordion-header .arrow {
    transition: transform 0.3s ease;
}

.accordion-item.active .arrow {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    padding: 0 1rem;
}

.accordion-item.active .accordion-content {
    max-height: 500px; /* Arbitrary large height */
    padding-bottom: 1rem;
}

/* Forms in Sidebar */
.file-upload-wrapper {
    margin-bottom: 1rem;
    position: relative;
    overflow: hidden;
    display:inline-block;
    width: 100%
}

.file-upload-label {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    width: 100%;
    padding: 0.75rem;
    background-color: var(--input-bg);
    border: 1px dashed var(--border-color);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
}

.file-upload-label:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

input[type="file"] {
    position: absolute;
    left: 0;
    top: 0;
    opacity: 0;
    cursor: pointer;
    width: 100%;
    height: 100%;
}

.file-name {
    display: block;
    margin-top: 0.5rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

button[type="submit"] {
    width: 100%;
    padding: 0.75rem;
    border: none;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}

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

.btn-secondary { background-color: var(--secondary-color); color: white; }
.btn-secondary:hover { background-color: var(--secondary-hover); }

.btn-danger { background-color: var(--danger-color); color: white; }
.btn-danger:hover { background-color: var(--danger-hover); }

textarea {
    width: 100%;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: white;
    padding: 0.5rem;
    margin-bottom: 1rem;
    resize: vertical;
}

.sidebar-footer {
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Chat Area */
.chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--chat-bg);
    position: relative;
}

.chat-header {
    height: 60px;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    /* backdrop-filter: blur(10px); background: var(--glass-bg); -- optional glass effect header */
    background-color: var(--bg-color);
}

.header-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.status-dot {
    width: 8px;
    height: 8px;
    background-color: #10b981;
    border-radius: 50%;
}

.status-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    scroll-behavior: smooth;
}

.message {
    display: flex;
    flex-direction: column;
    max-width: 70%;
    animation: fadeIn 0.3s ease;
}

.bot-message {
    align-self: flex-start;
}

.user-message {
    align-self: flex-end;
    align-items: flex-end;
}

.message-content {
    padding: 1rem;
    border-radius: 1rem;
    font-size: 0.95rem;
    line-height: 1.5;
    position: relative;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.bot-message .message-content {
    background-color: var(--message-bot-bg);
    border-top-left-radius: 0;
    color: var(--text-primary);
}

.user-message .message-content {
    background-color: var(--message-user-bg);
    border-top-right-radius: 0;
    color: white;
}

.message-time {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
    margin-left: 0.5rem;
}

.user-message .message-time {
    margin-right: 0.5rem;
}

.input-area {
    padding: 2rem;
    /* background-color: var(--bg-color); */
}

.input-area .input-wrapper {
    display: flex;
    gap: 1rem;
    background-color: var(--input-bg);
    padding: 0.5rem;
    border-radius: 3rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.input-area input {
    flex: 1;
    background: transparent;
    border: none;
    padding: 0.75rem 1.5rem;
    color: white;
    font-size: 1rem;
}

.input-area input:focus {
    outline: none;
}

#send-btn {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s, background-color 0.2s;
}

#send-btn:hover {
    background-color: var(--primary-hover);
    transform: scale(1.05);
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #475569;
}

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

/* Loading Indicator */
.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 0.5rem 0;
}

.typing-dot {
    width: 6px;
    height: 6px;
    background-color: var(--text-secondary);
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out both;
}

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

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

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background-color: #333;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: 0 10px 15px rgba(0,0,0,0.1);
    z-index: 1000;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.toast.hidden {
    opacity: 0;
    pointer-events: none;
    transform: translate(-50%, 20px);
}

.toast.success { background-color: var(--secondary-color); }
.toast.error { background-color: var(--danger-color); }
.toast.info { background-color: var(--primary-color); }

/* Responsive */
@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 1rem;
    }
    .settings-group, .accordion, .sidebar-footer {
        display: none; /* Simplify mobile view for now */
    }
    .sidebar-header { margin-bottom: 0; justify-content: space-between; }
    /* Could add a hamburger menu to show sidebar content on mobile */
    .chat-area { flex: 1; }
}