:root {
    /* Base Typography */
    --font-family: 'Inter', sans-serif;
    
    /* Dark Theme Colors (Default from uploaded image palette) */
    --bg-main: #161638;
    --bg-sidebar: #1B435E;
    --bg-input: #1B435E;
    --bg-hover: #38667E;
    --text-primary: #FFFFFF;
    --text-secondary: #A0B0C0;
    --border-color: #38667E;
    --msg-user: #563457;
    --msg-ai: #3A2B50;
    --accent: #38667E;
    --accent-hover: #5289A5;
}

.light-mode {
    --bg-main: #F4F7F9;
    --bg-sidebar: #E5EBF1;
    --bg-input: #FFFFFF;
    --bg-hover: #D1DCE5;
    --text-primary: #161638;
    --text-secondary: #5C6A79;
    --border-color: #C0CDD9;
    --msg-user: #E2D3E5; /* Lighter tint of #563457 */
    --msg-ai: #FFFFFF;
    --accent: #38667E;
    --accent-hover: #1B435E;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-main);
    color: var(--text-primary);
    display: flex;
    height: 100vh;
    overflow: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

/* Sidebar */
.sidebar {
    width: 260px;
    background-color: var(--bg-sidebar);
    display: flex;
    flex-direction: column;
    padding: 1rem;
    transition: background-color 0.3s ease, transform 0.3s ease;
    border-right: 1px solid var(--border-color);
}

.sidebar-header {
    margin-bottom: 1.5rem;
}

.new-chat-btn {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background-color: transparent;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.95rem;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.new-chat-btn:hover {
    background-color: var(--bg-hover);
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
}

.history-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
    padding-left: 0.5rem;
}

.history-list {
    list-style: none;
}

.history-item {
    padding: 0.75rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: background-color 0.2s ease;
}

.history-item:hover, .history-item.active {
    background-color: var(--bg-hover);
}

.sidebar-footer {
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.theme-toggle {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
    padding: 0.75rem;
    background: transparent;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    border-radius: 8px;
    text-align: left;
    font-size: 0.95rem;
    transition: background-color 0.2s ease;
}

.theme-toggle:hover {
    background-color: var(--bg-hover);
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
    background-color: var(--bg-main);
}

.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    height: 60px;
    border-bottom: 1px solid transparent;
}

.model-selector {
    position: relative;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: background-color 0.2s ease;
    font-weight: 500;
    font-size: 1.1rem;
    user-select: none;
}

.model-selector:hover {
    background-color: var(--bg-hover);
}

.model-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    margin-top: 0.5rem;
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    list-style: none;
    width: 200px;
    padding: 0.5rem 0;
    display: none;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    z-index: 100;
}

.model-selector.open .model-dropdown {
    display: block;
}

.model-dropdown li {
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    cursor: pointer;
}

.model-dropdown li:hover {
    background-color: var(--bg-hover);
}

.model-dropdown li.active {
    background-color: var(--bg-hover);
    font-weight: 600;
    color: var(--text-primary);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.login-btn {
    padding: 0.5rem 1rem;
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.login-btn:hover {
    background-color: var(--bg-hover);
    border-color: var(--accent);
}

.user-profile .avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--msg-user), var(--accent));
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: white;
}

/* Chat Area */
.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    scroll-behavior: smooth;
}

.chat-container::-webkit-scrollbar {
    width: 8px;
}
.chat-container::-webkit-scrollbar-track {
    background: transparent;
}
.chat-container::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 10px;
}

.welcome-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    padding-bottom: 10vh;
}

.logo-area {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.logo-image {
    width: 100px;
    height: 100px;
    border-radius: 20px;
    object-fit: cover;
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.logo-icon {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    background: linear-gradient(135deg, #1B435E, #563457);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    font-weight: bold;
    color: white;
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.welcome-screen h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    background: linear-gradient(to right, var(--text-primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

.suggestions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
    max-width: 600px;
}

.suggestion-btn {
    padding: 0.75rem 1.5rem;
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.95rem;
    transition: all 0.2s ease;
}

.suggestion-btn:hover {
    background-color: var(--bg-hover);
    transform: translateY(-2px);
    border-color: var(--accent);
}

.chat-messages {
    width: 100%;
    max-width: 800px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    padding-bottom: 2rem;
}

.message {
    display: flex;
    gap: 1rem;
    width: 100%;
    opacity: 0;
    animation: fadeIn 0.4s forwards ease-out;
}

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

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

.message-content {
    max-width: 80%;
    padding: 1rem 1.25rem;
    border-radius: 16px;
    line-height: 1.5;
    font-size: 1rem;
}

.message.user .message-content {
    background-color: var(--msg-user);
    border-bottom-right-radius: 4px;
    color: #fff; /* Ensure text is always legible */
}
.light-mode .message.user .message-content {
    color: var(--text-primary);
}

.message.ai .message-content {
    background-color: var(--msg-ai);
    border-bottom-left-radius: 4px;
    border: 1px solid var(--border-color);
}

.message.ai .avatar-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: linear-gradient(135deg, #1B435E, #563457);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.generated-image-container {
    position: relative;
    display: inline-block;
    max-width: 100%;
}

.generated-image {
    margin-top: 0.5rem;
    max-width: 100%;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    display: block;
}

.download-btn {
    position: absolute;
    top: 1rem;
    right: 0.5rem;
    background-color: rgba(27, 67, 94, 0.8);
    backdrop-filter: blur(4px);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 0.5rem;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.2s ease, background-color 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.generated-image-container:hover .download-btn {
    opacity: 1;
}

.download-btn:hover {
    background-color: var(--accent);
}

.loading-indicator {
    display: flex;
    gap: 4px;
    align-items: center;
    height: 24px;
    padding: 0 0.5rem;
}

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

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

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

/* Input Area */
.input-area-wrapper {
    padding: 0 2rem 2rem 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    background: linear-gradient(to top, var(--bg-main) 80%, transparent);
}

.input-form {
    display: flex;
    align-items: flex-end;
    gap: 0.75rem;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    padding: 0.75rem 1rem;
    border-radius: 20px;
    width: 100%;
    max-width: 800px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.2);
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.input-form:focus-within {
    border-color: var(--accent);
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}

textarea {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    resize: none;
    max-height: 200px;
    min-height: 24px;
    padding: 0.25rem 0;
    outline: none;
    line-height: 1.5;
}

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

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.35rem;
    border-radius: 8px;
    transition: color 0.2s ease, background-color 0.2s ease;
}

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

.send-btn {
    color: #fff;
    background-color: var(--accent);
    padding: 0.5rem;
    border-radius: 10px;
}

.send-btn:hover {
    background-color: var(--accent-hover);
    color: #fff;
}

.send-btn:disabled {
    background-color: var(--bg-sidebar);
    color: var(--text-secondary);
    cursor: not-allowed;
}

.disclaimer {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.75rem;
    text-align: center;
}

@media (max-width: 768px) {
    .sidebar {
        position: absolute;
        transform: translateX(-100%);
        z-index: 1000;
        height: 100%;
        box-shadow: 4px 0 12px rgba(0,0,0,0.3);
    }
    .sidebar.open {
        transform: translateX(0);
    }
    .input-form {
        border-radius: 24px;
    }
    .top-nav {
        padding: 1rem;
    }
    .chat-container {
        padding: 1rem;
    }
    .input-area-wrapper {
        padding: 0 1rem 1rem 1rem;
    }
}

/* File Previews */
.file-previews {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    width: 100%;
    max-width: 800px;
    margin-bottom: 0.5rem;
}

.file-chip {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    padding: 0.25rem 0.5rem;
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--text-primary);
}

.file-chip img {
    width: 24px;
    height: 24px;
    object-fit: cover;
    border-radius: 4px;
}

.file-remove {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1rem;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.file-remove:hover {
    color: #ff4444;
}

/* Auth Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-content {
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 2.5rem;
    width: 100%;
    max-width: 400px;
    position: relative;
    box-shadow: 0 24px 48px rgba(0,0,0,0.4);
    transform: translateY(20px);
    transition: transform 0.3s ease;
}

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

.close-modal {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color 0.2s ease;
}

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

.modal-header {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 2rem;
}

.modal-logo {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    object-fit: cover;
    margin-bottom: 1rem;
}

.modal-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.auth-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.auth-tab {
    flex: 1;
    background: transparent;
    border: none;
    padding: 0.5rem 0;
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
}

.auth-tab.active {
    color: var(--text-primary);
    border-bottom-color: var(--accent);
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.form-group input {
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    padding: 0.75rem 1rem;
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s ease;
}

.form-group input:focus {
    border-color: var(--accent);
}

.auth-submit-btn {
    background-color: var(--accent);
    color: white;
    border: none;
    padding: 0.85rem;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    margin-top: 0.5rem;
    transition: background-color 0.2s ease;
}

.auth-submit-btn:hover {
    background-color: var(--accent-hover);
}

.auth-divider {
    margin: 1.5rem 0;
    display: flex;
    align-items: center;
    color: var(--text-secondary);
    font-size: 0.8rem;
}

.auth-divider::before, .auth-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background-color: var(--border-color);
}

.auth-divider span {
    padding: 0 0.75rem;
}

.social-login {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.social-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    background-color: transparent;
    border: 1px solid var(--border-color);
    padding: 0.75rem;
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.social-btn:hover {
    background-color: var(--bg-hover);
}