/* =========================================
   FactCheck AI — Design System
   Aesthetic: Dark Editorial / Intelligence Briefing
   ========================================= */

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

:root {
    --bg-deep:        #0b0d0f;
    --bg-surface:     #111418;
    --bg-elevated:    #181d23;
    --bg-hover:       #1e242c;
    --border:         rgba(255,255,255,0.07);
    --border-bright:  rgba(255,255,255,0.14);

    --text-primary:   #e8e6e1;
    --text-secondary: #7a8898;
    --text-muted:     #4a5568;

    --accent:         #e8c547;
    --accent-dim:     rgba(232,197,71,0.12);
    --accent-glow:    rgba(232,197,71,0.25);

    --green:          #3ecf8e;
    --red:            #e85d4a;
    --blue:           #5b9cf6;

    --font-display:   'Playfair Display', Georgia, serif;
    --font-mono:      'IBM Plex Mono', 'Courier New', monospace;
    --font-body:      'IBM Plex Sans', system-ui, sans-serif;

    --radius-sm:      4px;
    --radius-md:      8px;
    --radius-lg:      14px;

    --sidebar-w:      230px;
    --transition:     0.18s ease;
}

html, body {
    height: 100%;
    background: var(--bg-deep);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 15px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ── Background ── */
.bg-grid {
    position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background-image:
        linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 80% 80% at 50% 0%, black 40%, transparent 100%);
}

.bg-noise {
    position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: 0.025;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
}

/* ── Layout ── */
.app-wrapper {
    position: relative;
    display: flex;
    height: 100dvh;
    max-width: 1400px;
    margin: 0 auto;
}

/* =========================================
   SIDEBAR
   ========================================= */
.sidebar {
    width: var(--sidebar-w);
    flex-shrink: 0;
    background: var(--bg-surface);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 24px 16px;
    gap: 0;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 0 6px 20px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 20px;
}

.brand-mark {
    font-size: 22px;
    color: var(--accent);
    line-height: 1;
}

.brand-name {
    font-family: var(--font-mono);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.03em;
    color: var(--text-primary);
}

.brand-name em { font-style: normal; color: var(--accent); }

.sidebar-info {
    margin-bottom: 24px;
    padding: 0 4px;
}

.sidebar-desc {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.65;
}

/* How it works tips */
.sidebar-tips {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding: 16px 12px;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    margin-bottom: 20px;
}

.tips-label {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-muted);
    display: block;
    margin-bottom: 2px;
}

.tip-item {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    font-size: 12.5px;
    color: var(--text-secondary);
    line-height: 1.5;
}

.tip-icon { font-size: 13px; flex-shrink: 0; margin-top: 1px; }
.tip-item strong { color: var(--text-primary); font-weight: 500; }

/* Bottom */
.sidebar-status {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 12px;
    margin-top: auto;
}

.status-dot {
    width: 7px; height: 7px;
    border-radius: 50%;
    background: var(--red);
    box-shadow: 0 0 8px var(--red);
    animation: pulse-dot 2.5s ease-in-out infinite;
    transition: background 0.3s ease, box-shadow 0.3s ease;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50%       { opacity: 0.4; }
}

.status-text {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.04em;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-radius: var(--radius-md);
    color: var(--text-muted);
    text-decoration: none;
    font-size: 12px;
    font-family: var(--font-mono);
    transition: color var(--transition);
}

.sidebar-link:hover { color: var(--text-secondary); }

/* =========================================
   CHAT AREA
   ========================================= */
.chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg-deep);
}

.chat-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 28px;
    border-bottom: 1px solid var(--border);
    background: rgba(11,13,15,0.8);
    backdrop-filter: blur(12px);
    flex-shrink: 0;
}

.header-left { display: flex; align-items: baseline; gap: 14px; }

.header-title {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.header-session {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.06em;
}

.clear-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-muted);
    font-size: 12px;
    font-family: var(--font-mono);
    cursor: pointer;
    transition: all var(--transition);
    letter-spacing: 0.04em;
}

.clear-btn:hover {
    border-color: var(--red);
    color: var(--red);
    background: rgba(232,93,74,0.08);
}

/* ── Messages ── */
.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 32px 28px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.messages-container::-webkit-scrollbar { width: 4px; }
.messages-container::-webkit-scrollbar-track { background: transparent; }
.messages-container::-webkit-scrollbar-thumb { background: var(--border-bright); border-radius: 2px; }

.message {
    max-width: 760px;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.25s ease, transform 0.25s ease;
}

.message.visible,
.intro-message { opacity: 1; transform: translateY(0); }

.fade-out {
    opacity: 0 !important;
    transform: translateY(-6px) !important;
    transition: opacity 0.25s ease, transform 0.25s ease !important;
}

.message-meta {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 6px;
}

.msg-sender {
    font-family: var(--font-mono);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.msg-time {
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-muted);
}

.message-body {
    padding: 16px 20px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    line-height: 1.7;
    font-size: 14.5px;
}

.message-body p + p { margin-top: 10px; }

.bot-message { align-self: flex-start; }
.bot-message .msg-sender { color: var(--accent); }
.bot-message .message-body {
    background: var(--bg-elevated);
    border-color: var(--border-bright);
    color: var(--text-primary);
}

.user-message { align-self: flex-end; }
.user-message .msg-sender { color: var(--blue); }
.user-message .message-body {
    background: rgba(91,156,246,0.08);
    border-color: rgba(91,156,246,0.2);
    color: var(--text-primary);
}

.error-message .message-body {
    background: rgba(232,93,74,0.07);
    border-color: rgba(232,93,74,0.25);
}

/* No-key message — amber tint to signal action needed */
.no-key-message .message-body {
    background: var(--accent-dim);
    border-color: rgba(232,197,71,0.22);
}

/* ── "Enter API Key" inline button ── */
.enter-key-btn {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    margin-top: 14px;
    padding: 8px 16px;
    background: var(--accent);
    color: var(--bg-deep);
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.04em;
    cursor: pointer;
    transition: all var(--transition);
}

.enter-key-btn:hover {
    background: #f0d060;
    transform: translateY(-1px);
    box-shadow: 0 4px 14px var(--accent-glow);
}

.enter-key-btn:active { transform: translateY(0); }

/* Loading */
.loading-message .message-body {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
}

.typing-indicator { display: flex; align-items: center; gap: 5px; }

.typing-indicator span {
    display: block;
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--accent);
    animation: bounce-dot 1.2s ease-in-out infinite;
}

.typing-indicator span:nth-child(2) { animation-delay: 0.15s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.3s; }

@keyframes bounce-dot {
    0%, 80%, 100% { transform: scale(0.7); opacity: 0.4; }
    40%            { transform: scale(1);   opacity: 1;   }
}

.loading-text {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    letter-spacing: 0.06em;
    animation: flicker 1.5s ease-in-out infinite;
}

@keyframes flicker {
    0%, 100% { opacity: 1; }
    50%       { opacity: 0.4; }
}

/* =========================================
   INPUT AREA
   ========================================= */
.input-area {
    padding: 16px 28px 20px;
    border-top: 1px solid var(--border);
    background: rgba(11,13,15,0.88);
    backdrop-filter: blur(12px);
    flex-shrink: 0;
}

/* ── The main input box ── */
.input-form {
    display: flex;
    align-items: center;
    gap: 0;
    background: var(--bg-elevated);
    border: 1px solid var(--border-bright);
    border-radius: var(--radius-lg);
    padding: 8px 10px 8px 10px;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.input-form:focus-within {
    border-color: rgba(232,197,71,0.35);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

/* ── Mode pill toggle (inside input box) ── */
.mode-pill {
    display: flex;
    align-items: center;
    gap: 2px;
    background: var(--bg-hover);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 3px;
    flex-shrink: 0;
}

.pill-btn {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 5px 10px;
    border: none;
    border-radius: 6px;
    background: transparent;
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.04em;
    cursor: pointer;
    transition: all var(--transition);
    white-space: nowrap;
}

.pill-btn:hover {
    color: var(--text-secondary);
    background: rgba(255,255,255,0.05);
}

.pill-btn.active {
    background: var(--accent);
    color: var(--bg-deep);
}

.pill-btn.active svg { opacity: 1; }
.pill-btn svg { opacity: 0.6; }

/* ── Vertical divider between pill and textarea ── */
.input-divider {
    width: 1px;
    height: 28px;
    background: var(--border-bright);
    margin: 0 12px;
    flex-shrink: 0;
}

.textarea-wrap { flex: 1; }

textarea#user-input {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    resize: none;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 14.5px;
    line-height: 1.6;
    min-height: 26px;
    max-height: 160px;
    overflow-y: auto;
    caret-color: var(--accent);
    padding: 2px 0;
}

textarea#user-input::placeholder { color: var(--text-muted); }

/* ── Send button ── */
#send-btn {
    flex-shrink: 0;
    width: 36px; height: 36px;
    border-radius: var(--radius-md);
    border: none;
    background: var(--accent);
    color: var(--bg-deep);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    margin-left: 10px;
    transition: all var(--transition);
}

#send-btn:hover {
    background: #f0d060;
    transform: scale(1.06);
    box-shadow: 0 4px 16px var(--accent-glow);
}

#send-btn:active { transform: scale(0.96); }

.input-hint {
    margin-top: 8px;
    font-size: 11px;
    font-family: var(--font-mono);
    color: var(--text-muted);
    letter-spacing: 0.03em;
}

kbd {
    display: inline-block;
    padding: 1px 5px;
    background: var(--bg-hover);
    border: 1px solid var(--border-bright);
    border-radius: 3px;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-secondary);
}

/* =========================================
   API KEY MODAL
   ========================================= */
.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 200;
    background: rgba(11, 13, 15, 0.82);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    opacity: 0;
    transition: opacity 0.25s ease;
}

.modal-overlay.visible { opacity: 1; }
.modal-overlay.hidden  { display: none; }

.modal-card {
    position: relative;
    background: var(--bg-elevated);
    border: 1px solid var(--border-bright);
    border-radius: var(--radius-lg);
    padding: 32px 30px 28px;
    width: 100%;
    max-width: 500px;
    box-shadow: 0 32px 80px rgba(0,0,0,0.7), 0 0 0 1px rgba(232,197,71,0.06);
    animation: modal-rise 0.28s ease forwards;
}

@keyframes modal-rise {
    from { transform: translateY(12px); opacity: 0; }
    to   { transform: translateY(0);    opacity: 1; }
}

/* Close button */
.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 28px;
    height: 28px;
    background: var(--bg-hover);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition);
}

.modal-close:hover {
    border-color: var(--red);
    color: var(--red);
    background: rgba(232,93,74,0.08);
}

/* Header */
.modal-header {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    margin-bottom: 20px;
}

.modal-icon {
    font-size: 26px;
    line-height: 1;
    margin-top: 2px;
    flex-shrink: 0;
}

.modal-title {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.01em;
    line-height: 1.2;
}

.modal-subtitle {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 4px;
    letter-spacing: 0.04em;
}

/* Divider */
.modal-divider {
    height: 1px;
    background: var(--border);
    margin-bottom: 20px;
}

/* Description text */
.modal-desc {
    font-size: 13.5px;
    color: var(--text-secondary);
    line-height: 1.65;
    margin-bottom: 18px;
}

.modal-desc strong { color: var(--text-primary); font-weight: 500; }

.modal-link {
    color: var(--accent);
    text-decoration: none;
    border-bottom: 1px solid rgba(232,197,71,0.3);
    transition: border-color var(--transition);
}

.modal-link:hover { border-color: var(--accent); }

/* Input wrapper */
.modal-input-wrap {
    position: relative;
    margin-bottom: 10px;
}

.modal-input {
    width: 100%;
    background: var(--bg-deep);
    border: 1px solid var(--border-bright);
    border-radius: var(--radius-md);
    padding: 11px 44px 11px 14px;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: 0.04em;
    outline: none;
    transition: border-color var(--transition), box-shadow var(--transition);
    caret-color: var(--accent);
}

.modal-input:focus {
    border-color: rgba(232,197,71,0.4);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

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

/* Toggle visibility button */
.modal-eye {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
    display: flex;
    align-items: center;
    transition: color var(--transition);
}

.modal-eye:hover { color: var(--text-secondary); }

/* Status message */
.modal-status {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.03em;
    line-height: 1.5;
    min-height: 18px;
    margin-bottom: 14px;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.modal-status--visible { opacity: 1; }
.modal-status--error   { color: var(--red); }
.modal-status--success { color: var(--green); }

/* Privacy note */
.modal-privacy {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    padding: 10px 12px;
    background: var(--bg-deep);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    color: var(--text-muted);
    font-size: 12px;
    font-family: var(--font-mono);
    line-height: 1.5;
    letter-spacing: 0.02em;
}

.modal-privacy svg { flex-shrink: 0; margin-top: 2px; color: var(--accent); opacity: 0.7; }

/* Actions row */
.modal-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.modal-btn-skip {
    flex: 0 0 auto;
    padding: 9px 18px;
    background: transparent;
    border: 1px solid var(--border-bright);
    border-radius: var(--radius-md);
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 12px;
    cursor: pointer;
    transition: all var(--transition);
    letter-spacing: 0.04em;
}

.modal-btn-skip:hover {
    color: var(--text-secondary);
    border-color: rgba(255,255,255,0.2);
}

.modal-btn-submit {
    flex: 1;
    padding: 10px 20px;
    background: var(--accent);
    border: none;
    border-radius: var(--radius-md);
    color: var(--bg-deep);
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.05em;
    cursor: pointer;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 40px;
}

.modal-btn-submit:hover:not(:disabled) {
    background: #f0d060;
    box-shadow: 0 4px 18px var(--accent-glow);
    transform: translateY(-1px);
}

.modal-btn-submit:disabled {
    opacity: 0.65;
    cursor: not-allowed;
    transform: none;
}

/* Spinner (reuse typing-indicator style) */
.modal-spinner {
    display: none;
    align-items: center;
    gap: 4px;
}

.modal-spinner span {
    display: block;
    width: 5px; height: 5px;
    border-radius: 50%;
    background: var(--bg-deep);
    animation: bounce-dot 1.2s ease-in-out infinite;
}

.modal-spinner span:nth-child(2) { animation-delay: 0.15s; }
.modal-spinner span:nth-child(3) { animation-delay: 0.3s; }

/* =========================================
   TASK 1 — MODAL ADDITIONS (two-section)
   ========================================= */

/* Increase card width slightly for two sections */
.modal-card {
    max-width: 500px;
    max-height: 92vh;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-bright) transparent;
}

.modal-card::-webkit-scrollbar { width: 4px; }
.modal-card::-webkit-scrollbar-track { background: transparent; }
.modal-card::-webkit-scrollbar-thumb { background: var(--border-bright); border-radius: 2px; }

/* Section wrapper */
.modal-section {
    margin-bottom: 4px;
}

.modal-section-head {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 6px;
}

.modal-section-label {
    font-family: var(--font-mono);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-primary);
}

/* Badges */
.modal-badge {
    font-family: var(--font-mono);
    font-size: 9px;
    padding: 2px 7px;
    border-radius: 3px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    font-weight: 600;
}

.modal-badge--required {
    background: rgba(232, 93, 74, 0.12);
    color: var(--red);
    border: 1px solid rgba(232, 93, 74, 0.25);
}

.modal-badge--indimodel {
    background: rgba(91, 156, 246, 0.1);
    color: var(--blue);
    border: 1px solid rgba(91, 156, 246, 0.2);
}

/* Provider selector row */
.provider-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 10px;
}

.provider-btn {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 5px 11px;
    border: 1px solid var(--border-bright);
    border-radius: var(--radius-sm);
    background: var(--bg-deep);
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.03em;
    cursor: pointer;
    transition: all var(--transition);
    white-space: nowrap;
}

.provider-btn:hover {
    color: var(--text-secondary);
    border-color: rgba(255, 255, 255, 0.2);
    background: var(--bg-hover);
}

.provider-btn.active {
    background: var(--accent-dim);
    border-color: rgba(232, 197, 71, 0.4);
    color: var(--accent);
}

.rec-tag {
    font-size: 9px;
    padding: 1px 5px;
    background: rgba(232, 197, 71, 0.14);
    border: 1px solid rgba(232, 197, 71, 0.2);
    border-radius: 3px;
    color: var(--accent);
    letter-spacing: 0.04em;
    font-weight: 600;
}

/* =========================================
   TASK 2 — MODEL SELECTOR
   ========================================= */
.model-selector {
    display: flex;
    align-items: center;
    gap: 7px;
}

.model-selector-label {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.model-select {
    font-family: var(--font-mono);
    font-size: 11px;
    background: var(--bg-elevated);
    border: 1px solid var(--border-bright);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    padding: 4px 10px 4px 8px;
    cursor: pointer;
    outline: none;
    letter-spacing: 0.04em;
    transition: border-color var(--transition), box-shadow var(--transition);
    appearance: auto;
}

.model-select:hover {
    border-color: rgba(255, 255, 255, 0.2);
}

.model-select:focus {
    border-color: rgba(232, 197, 71, 0.4);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

/* =========================================
   RESPONSIVE
   ========================================= */
@media (max-width: 700px) {
    /* ── Sidebar: hidden by default on mobile ── */
    .sidebar {
        display: none;
    }

    /* ── Task 3: sidebar slides in when .mobile-open is added ── */
    .sidebar.mobile-open {
        display: flex;
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: var(--sidebar-w);
        z-index: 9999;
        box-shadow: 6px 0 32px rgba(0, 0, 0, 0.6);
        animation: sidebar-slide-in 0.22s ease forwards;
    }

    .sidebar-backdrop.active {
        display: block;
        animation: backdrop-fade-in 0.22s ease forwards;
    }

    /* ── Task 3: make title look tappable ── */
    .header-title {
        cursor: pointer;
        user-select: none;
        -webkit-user-select: none;
    }

    .header-title::after {
        content: ' \2630';
        font-size: 13px;
        opacity: 0.45;
        margin-left: 4px;
    }

    /* ── General mobile tweaks ── */
    .chat-header       { padding: 12px 16px; }
    .messages-container { padding: 20px 16px; }
    .input-area        { padding: 12px 16px 16px; }
    .pill-btn          { padding: 5px 8px; font-size: 10px; }

    .modal-card        { padding: 20px 18px 18px; max-width: 100%; }
    .modal-title       { font-size: 18px; }

    .provider-row      { gap: 5px; }
    .provider-btn      { font-size: 10px; padding: 4px 8px; }
    .rec-tag           { display: none; }
}

/* Desktop: hide backdrop always */
@media (min-width: 701px) {
    .sidebar-backdrop  { display: none !important; }
    .header-title      { cursor: default; }
}

/* ── Sidebar slide animation (global — outside media query for browser compat) ── */
@keyframes sidebar-slide-in {
    from { transform: translateX(-100%); opacity: 0.6; }
    to   { transform: translateX(0);     opacity: 1; }
}

@keyframes backdrop-fade-in {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Backdrop base — hidden on all screens by default, activated via JS class */
.sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 9998;
    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
}

.sidebar-backdrop.active {
    display: block;
    animation: backdrop-fade-in 0.22s ease forwards;
}