frontend/style.css

/* ═══════════════════════════════════════════════════════════════
   ConsultAI — Premium Dark-Mode Chat UI
   ═══════════════════════════════════════════════════════════════ */

/* --- CSS Variables / Design Tokens --- */
:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-tertiary: #1a2038;
    --bg-surface: rgba(255, 255, 255, 0.04);
    --bg-glass: rgba(255, 255, 255, 0.06);
    --bg-glass-hover: rgba(255, 255, 255, 0.10);

    --text-primary: #f0f2f5;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;

    --accent-primary: #6366f1;
    --accent-secondary: #818cf8;
    --accent-glow: rgba(99, 102, 241, 0.25);
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a78bfa 100%);

    --phase-discovery: #3b82f6;
    --phase-exploration: #8b5cf6;
    --phase-constraints: #f59e0b;
    --phase-solution: #10b981;
    --phase-refinement: #06d6a0;

    --border-color: rgba(255, 255, 255, 0.08);
    --border-accent: rgba(99, 102, 241, 0.3);

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px var(--accent-glow);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;

    --sidebar-width: 280px;
    --topbar-height: 60px;

    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Reset --- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.12);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* ═══════════════════════════════════════════════════
   SIDEBAR
   ═══════════════════════════════════════════════════ */
.sidebar {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
    z-index: 100;
}

.sidebar.hidden {
    transform: translateX(-100%);
    position: absolute;
    height: 100%;
    opacity: 0;
    pointer-events: none;
}

.sidebar-header {
    padding: 16px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    font-size: 22px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-text {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.btn-new-chat {
    background: var(--bg-glass);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: var(--radius-sm);
    padding: 8px;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-new-chat:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
}

.session-list {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.session-item {
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 2px;
    font-size: 13px;
    color: var(--text-secondary);
}

.session-item:hover {
    background: var(--bg-glass-hover);
    color: var(--text-primary);
}

.session-item.active {
    background: var(--accent-glow);
    color: var(--text-primary);
    border: 1px solid var(--border-accent);
}

.session-item-label {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1;
}

.session-item-delete {
    opacity: 0;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 2px 4px;
    font-size: 16px;
    line-height: 1;
    transition: all var(--transition-fast);
}

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

.session-item-delete:hover {
    color: #ef4444;
}

.sidebar-footer {
    padding: 12px 20px;
    border-top: 1px solid var(--border-color);
}

.sidebar-footer-text {
    font-size: 11px;
    color: var(--text-muted);
    text-align: center;
}

/* ═══════════════════════════════════════════════════
   MAIN AREA
   ═══════════════════════════════════════════════════ */
.main-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    position: relative;
}

/* --- Top Bar --- */
.topbar {
    height: var(--topbar-height);
    padding: 0 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    border-bottom: 1px solid var(--border-color);
    background: rgba(10, 14, 26, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 10;
}

.btn-toggle-sidebar {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 6px;
    border-radius: var(--radius-sm);
    display: flex;
    transition: all var(--transition-fast);
}

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

.topbar-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

/* ═══════════════════════════════════════════════════
   MESSAGES
   ═══════════════════════════════════════════════════ */
.messages-container {
    flex: 1;
    overflow-y: auto;
    scroll-behavior: smooth;
}

.messages {
    max-width: 820px;
    margin: 0 auto;
    padding: 24px 20px 100px;
}

/* --- Welcome Screen --- */
.welcome-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 80px 20px 40px;
    animation: fadeInUp 0.6s ease-out;
}

.welcome-icon {
    font-size: 48px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 16px;
}

.welcome-screen h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.welcome-screen p {
    color: var(--text-secondary);
    font-size: 15px;
    max-width: 500px;
    line-height: 1.6;
    margin-bottom: 32px;
}

.welcome-suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
}

.suggestion-chip {
    background: var(--bg-glass);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 10px 18px;
    border-radius: 100px;
    font-size: 13px;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: var(--font-family);
}

.suggestion-chip:hover {
    background: var(--bg-glass-hover);
    color: var(--text-primary);
    border-color: var(--border-accent);
    box-shadow: var(--shadow-glow);
}

/* --- Message Bubbles --- */
.message {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
    animation: fadeInUp 0.35s ease-out;
}

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

.message.assistant-message {
    justify-content: flex-start;
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 2px;
}

.assistant-message .message-avatar {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-glow);
}

.user-message .message-avatar {
    background: var(--bg-glass);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    order: 2;
}

.message-bubble {
    max-width: 75%;
    padding: 14px 18px;
    border-radius: var(--radius-lg);
    line-height: 1.65;
    font-size: 14px;
}

.user-message .message-bubble {
    background: var(--accent-primary);
    color: white;
    border-bottom-right-radius: 4px;
}

.assistant-message .message-bubble {
    background: var(--bg-glass);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-bottom-left-radius: 4px;
}

/* Markdown inside assistant bubbles */
.message-bubble h1,
.message-bubble h2,
.message-bubble h3 {
    font-size: 15px;
    font-weight: 600;
    margin: 12px 0 6px;
    color: var(--text-primary);
}

.message-bubble h1:first-child,
.message-bubble h2:first-child,
.message-bubble h3:first-child {
    margin-top: 0;
}

.message-bubble p {
    margin: 10px 0;
}

.message-bubble ul,
.message-bubble ol {
    margin: 6px 0;
    padding-left: 20px;
}

.message-bubble li {
    margin: 3px 0;
}

/* Question highlighting */
.message-bubble .question-highlight {
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.25);
    border-left: 3px solid var(--accent-primary);
    border-radius: var(--radius-sm);
    padding: 10px 14px;
    margin: 10px 0;
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.message-bubble .question-highlight p {
    margin: 0;
    color: var(--text-primary);
    font-weight: 500;
}

.message-bubble .question-icon {
    font-size: 16px;
    flex-shrink: 0;
    margin-top: 1px;
}

.message-bubble li.question-item {
    background: rgba(99, 102, 241, 0.06);
    border-left: 2px solid var(--accent-primary);
    padding: 6px 10px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 6px 0;
    list-style: none;
    font-weight: 500;
}

.message-bubble strong {
    color: var(--accent-secondary);
    font-weight: 600;
}

.message-bubble code {
    background: rgba(0, 0, 0, 0.3);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 13px;
    font-family: 'Fira Code', monospace;
}

.message-bubble pre {
    background: rgba(0, 0, 0, 0.3);
    padding: 12px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 8px 0;
}

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

.message-bubble blockquote {
    border-left: 3px solid var(--accent-primary);
    padding-left: 12px;
    color: var(--text-secondary);
    margin: 8px 0;
}

/* --- Typing Indicator --- */
.typing-indicator {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
    animation: fadeInUp 0.3s ease-out;
}

.typing-dots {
    display: flex;
    gap: 5px;
    align-items: center;
    padding: 14px 18px;
    background: var(--bg-glass);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    border-bottom-left-radius: 4px;
    backdrop-filter: blur(8px);
}

.typing-dots span {
    width: 8px;
    height: 8px;
    background: var(--text-muted);
    border-radius: 50%;
    animation: typingBounce 1.4s infinite;
}

.typing-dots span:nth-child(2) {
    animation-delay: 0.15s;
}

.typing-dots span:nth-child(3) {
    animation-delay: 0.3s;
}

/* ═══════════════════════════════════════════════════
   INPUT AREA
   ═══════════════════════════════════════════════════ */
.input-area {
    padding: 12px 20px 16px;
    background: linear-gradient(180deg, transparent 0%, var(--bg-primary) 20%);
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
}

.input-wrapper {
    max-width: 820px;
    margin: 0 auto;
    display: flex;
    align-items: flex-end;
    gap: 10px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 8px 8px 8px 18px;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input-wrapper:focus-within {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-wrapper textarea {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-primary);
    font-family: var(--font-family);
    font-size: 14px;
    line-height: 1.5;
    resize: none;
    outline: none;
    max-height: 150px;
    padding: 6px 0;
}

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

.btn-send {
    background: var(--accent-primary);
    border: none;
    color: white;
    border-radius: var(--radius-sm);
    padding: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.btn-send:hover:not(:disabled) {
    background: var(--accent-secondary);
    box-shadow: var(--shadow-glow);
}

.btn-send:disabled {
    opacity: 0.3;
    cursor: default;
}

.input-hint {
    text-align: center;
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 6px;
}

/* ═══════════════════════════════════════════════════
   ANIMATIONS
   ═══════════════════════════════════════════════════ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes typingBounce {

    0%,
    60%,
    100% {
        transform: translateY(0);
        opacity: 0.4;
    }

    30% {
        transform: translateY(-6px);
        opacity: 1;
    }
}

/* ═══════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════ */
@media (max-width: 768px) {
    .sidebar {
        position: absolute;
        height: 100%;
        z-index: 200;
        box-shadow: var(--shadow-lg);
    }

    .sidebar.hidden {
        transform: translateX(-100%);
    }

    .confidence-bar-container {
        display: none;
    }

    .message-bubble {
        max-width: 88%;
    }

    .welcome-screen {
        padding: 40px 16px 20px;
    }

    .welcome-screen h1 {
        font-size: 22px;
    }
}