style(demo): elevate chat panel visual design

- Glass morphism panel background with gradient + backdrop blur
- Context header with subtle accent gradient sweep
- Pill-shaped chips with accent-tinted borders, hover glow
- Suggestion chips with blue tint, hover shadow aura
- Messages with colored left-border accent (blue for user, purple for AI)
- Tooltip with deep shadow + accent-tinted border, smooth entrance
- Refined spacing, letter-spacing, font weights throughout
- Uses CSS variable system consistently (mission colors, accent, etc.)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

demo/styles/chat.css

@@ -6,16 +6,19 @@
     position: relative;
     max-height: 400px;
     overflow: hidden;
-    transition: max-height 0.3s cubic-bezier(.4, 0, .2, 1);
+    transition: max-height 0.35s cubic-bezier(.4, 0, .2, 1),
+                border-color 0.3s ease;
     display: flex;
     flex-direction: column;
-    background: var(--panel-bg);
-    border-top: 1px solid var(--panel-border);
+    background: linear-gradient(180deg, rgba(2, 6, 23, 0.6) 0%, rgba(2, 6, 23, 0.3) 100%);
+    backdrop-filter: blur(16px);
+    -webkit-backdrop-filter: blur(16px);
+    border-top: 1px solid rgba(59, 130, 246, 0.08);
 }
 
 .chat-panel.collapsed {
     max-height: 0;
-    border-top: none;
+    border-top-color: transparent;
 }
 
 /* Chat Toggle Button */
@@ -34,57 +37,70 @@
     right: 12px;
     top: 50%;
     transform: translateY(-50%);
+    transition: color 0.2s ease;
 }
 
 .chat-toggle:hover {
-    color: var(--text-secondary);
+    color: var(--accent-light);
 }
 
-/* Context Header */
+/* ── Context Header ──────────────────────────────────────────── */
+
 .chat-context-header {
     display: flex;
     align-items: center;
-    gap: 6px;
-    padding: 6px 16px;
-    background: rgba(0,0,0,.15);
-    border-bottom: 1px solid var(--panel-border);
+    gap: 8px;
+    padding: 8px 16px;
+    background: linear-gradient(90deg, rgba(59, 130, 246, 0.04) 0%, transparent 100%);
+    border-bottom: 1px solid rgba(255, 255, 255, 0.04);
     flex-wrap: wrap;
     flex-shrink: 0;
 }
 
 .chat-context-label {
-    color: var(--text-tertiary);
-    font-size: 10px;
+    color: var(--accent);
+    font-size: 9px;
+    font-weight: 700;
     text-transform: uppercase;
-    letter-spacing: 0.5px;
+    letter-spacing: 1.2px;
     flex-shrink: 0;
+    opacity: 0.7;
 }
 
 .chat-context-chips {
     display: flex;
     flex-wrap: wrap;
-    gap: 4px;
+    gap: 5px;
 }
 
 .chat-context-chip {
     display: inline-flex;
     align-items: center;
-    gap: 4px;
-    background: rgba(255,255,255,.04);
-    border: 1px solid var(--panel-border);
+    gap: 5px;
+    background: rgba(59, 130, 246, 0.06);
+    border: 1px solid rgba(59, 130, 246, 0.15);
     color: var(--text-primary);
-    padding: 2px 8px;
-    border-radius: 4px;
+    padding: 3px 10px;
+    border-radius: 20px;
     font-size: 11px;
     font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
+    cursor: default;
+    transition: all 0.2s ease;
+}
+
+.chat-context-chip:hover {
+    background: rgba(59, 130, 246, 0.12);
+    border-color: rgba(59, 130, 246, 0.3);
 }
 
 .chat-context-chip .chip-label {
     color: var(--text-secondary);
+    font-family: 'Inter', sans-serif;
+    font-weight: 500;
 }
 
 .chat-context-chip .chip-status {
-    font-size: 9px;
+    font-size: 8px;
     line-height: 1;
 }
 
@@ -92,27 +108,35 @@
 .chat-context-chip .chip-status.no-match { color: var(--mission-nomatch); }
 .chat-context-chip .chip-status.unassessed { color: var(--text-tertiary); }
 
-/* Chip Hover Tooltip (mini track card) */
+/* ── Chip Hover Tooltip (mini track card) ────────────────────── */
+
 .chip-tooltip {
     position: absolute;
     z-index: 20;
-    background: rgba(2, 6, 23, 0.95);
-    backdrop-filter: blur(12px);
-    -webkit-backdrop-filter: blur(12px);
-    border: 1px solid var(--panel-border);
-    border-radius: 6px;
-    padding: 8px 10px;
-    min-width: 180px;
-    max-width: 280px;
+    background: rgba(2, 6, 23, 0.96);
+    backdrop-filter: blur(20px);
+    -webkit-backdrop-filter: blur(20px);
+    border: 1px solid rgba(59, 130, 246, 0.12);
+    border-radius: 8px;
+    padding: 10px 12px;
+    min-width: 200px;
+    max-width: 300px;
     pointer-events: none;
-    animation: fadeSlideIn 0.15s ease;
+    animation: tooltipIn 0.15s ease;
+    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4),
+                0 0 1px rgba(59, 130, 246, 0.2);
+}
+
+@keyframes tooltipIn {
+    from { opacity: 0; transform: translateY(-4px); }
+    to   { opacity: 1; transform: translateY(0); }
 }
 
 .chip-tooltip .tt-header {
-    font-size: 11px;
+    font-size: 12px;
     font-weight: 600;
     color: var(--text-primary);
-    margin-bottom: 6px;
+    margin-bottom: 8px;
     display: flex;
     align-items: center;
     gap: 6px;
@@ -126,112 +150,125 @@
 
 .chip-tooltip .tt-badge {
     font-size: 9px;
-    font-weight: 600;
-    padding: 1px 5px;
-    border-radius: 3px;
-    letter-spacing: 0.3px;
+    font-weight: 700;
+    padding: 2px 6px;
+    border-radius: 4px;
+    letter-spacing: 0.5px;
 }
 
 .chip-tooltip .tt-match {
-    background: rgba(52, 211, 153, 0.15);
+    background: var(--mission-match-bg);
     color: var(--mission-match);
     border: 1px solid rgba(52, 211, 153, 0.25);
 }
 
 .chip-tooltip .tt-nomatch {
-    background: rgba(248, 113, 113, 0.12);
+    background: var(--mission-nomatch-bg);
     color: var(--mission-nomatch);
     border: 1px solid rgba(248, 113, 113, 0.2);
 }
 
 .chip-tooltip .tt-pending {
-    background: rgba(255, 255, 255, 0.04);
-    color: var(--text-tertiary);
-    border: 1px solid rgba(255, 255, 255, 0.08);
+    background: var(--mission-unassessed-bg);
+    color: var(--mission-unassessed);
+    border: 1px solid rgba(100, 116, 139, 0.2);
 }
 
 .chip-tooltip .tt-metrics {
     display: flex;
-    gap: 10px;
+    gap: 12px;
     font-size: 10px;
     color: var(--text-tertiary);
     font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
     margin-bottom: 4px;
+    padding: 4px 0;
+}
+
+.chip-tooltip .tt-metrics span {
+    display: flex;
+    gap: 3px;
 }
 
 .chip-tooltip .tt-reason {
-    font-size: 10px;
+    font-size: 11px;
     color: var(--text-secondary);
-    line-height: 1.4;
-    margin-top: 4px;
-    border-top: 1px solid var(--panel-border);
-    padding-top: 4px;
+    line-height: 1.5;
+    margin-top: 6px;
+    border-top: 1px solid rgba(255, 255, 255, 0.04);
+    padding-top: 6px;
 }
 
-/* Suggestions */
+/* ── Suggestion Chips ────────────────────────────────────────── */
+
 .chat-suggestions {
     display: flex;
-    gap: 5px;
-    padding: 6px 16px;
-    border-bottom: 1px solid var(--panel-border);
+    gap: 6px;
+    padding: 8px 16px;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.03);
     flex-wrap: wrap;
     flex-shrink: 0;
     overflow-x: auto;
 }
 
 .chat-suggestion-chip {
-    background: rgba(255,255,255,.03);
-    border: 1px solid var(--panel-border);
-    color: var(--text-secondary);
-    padding: 3px 10px;
-    border-radius: 12px;
-    font-size: 10px;
+    background: rgba(59, 130, 246, 0.04);
+    border: 1px solid rgba(59, 130, 246, 0.12);
+    color: var(--accent-light);
+    padding: 5px 14px;
+    border-radius: 20px;
+    font-size: 11px;
+    font-weight: 500;
     cursor: pointer;
     white-space: nowrap;
-    transition: all 0.15s ease;
+    transition: all 0.2s ease;
+    letter-spacing: 0.1px;
 }
 
 .chat-suggestion-chip:hover {
-    background: rgba(59, 130, 246, .1);
-    border-color: rgba(59, 130, 246, .3);
-    color: var(--text-primary);
+    background: rgba(59, 130, 246, 0.12);
+    border-color: rgba(59, 130, 246, 0.35);
+    color: #fff;
+    box-shadow: 0 0 12px rgba(59, 130, 246, 0.15);
 }
 
-/* Messages Area */
+/* ── Messages Area ───────────────────────────────────────────── */
+
 .chat-messages {
     flex: 1;
     overflow-y: auto;
-    padding: 8px 16px;
+    padding: 10px 16px;
     display: flex;
     flex-direction: column;
-    gap: 6px;
+    gap: 8px;
     min-height: 0;
 }
 
 .chat-msg {
-    padding: 6px 10px;
-    border-radius: 6px;
-    font-size: 12px;
-    line-height: 1.5;
-    animation: fadeSlideIn 0.2s ease;
+    padding: 8px 12px;
+    border-radius: 8px;
+    font-size: 12.5px;
+    line-height: 1.6;
+    animation: msgSlideIn 0.25s ease;
 }
 
-@keyframes fadeSlideIn {
-    from { opacity: 0; transform: translateY(4px); }
+@keyframes msgSlideIn {
+    from { opacity: 0; transform: translateY(6px); }
     to   { opacity: 1; transform: translateY(0); }
 }
 
 .chat-msg.user {
-    background: rgba(59, 130, 246, .08);
-    border: 1px solid rgba(59, 130, 246, .15);
-    margin-left: 24px;
+    background: rgba(59, 130, 246, 0.08);
+    border: 1px solid rgba(59, 130, 246, 0.12);
+    border-left: 2px solid var(--accent);
+    margin-left: 20px;
     color: var(--text-primary);
 }
 
 .chat-msg.assistant {
-    background: rgba(255,255,255,.03);
-    border: 1px solid var(--panel-border);
-    margin-right: 24px;
+    background: rgba(255, 255, 255, 0.02);
+    border: 1px solid rgba(255, 255, 255, 0.04);
+    border-left: 2px solid rgba(139, 92, 246, 0.4);
+    margin-right: 20px;
     color: var(--text-secondary);
 }
 
@@ -240,30 +277,32 @@
     border: none;
     text-align: center;
     color: var(--text-tertiary);
-    font-size: 11px;
-    padding: 2px 0;
+    font-size: 10px;
+    padding: 4px 0;
+    letter-spacing: 0.3px;
 }
 
 .chat-msg .msg-role {
-    font-size: 10px;
-    font-weight: 600;
+    font-size: 9px;
+    font-weight: 700;
     text-transform: uppercase;
-    margin-bottom: 2px;
-    opacity: 0.6;
+    letter-spacing: 0.8px;
+    margin-bottom: 3px;
+    opacity: 0.5;
 }
 
-.chat-msg.user .msg-role { color: var(--accent); }
-.chat-msg.assistant .msg-role { color: #8b5cf6; }
+.chat-msg.user .msg-role { color: var(--accent-light); }
+.chat-msg.assistant .msg-role { color: #a78bfa; }
 
 .chat-msg.loading .msg-text::after {
     content: "";
     display: inline-block;
     width: 10px; height: 10px;
-    border: 2px solid rgba(255,255,255,.1);
+    border: 2px solid rgba(255,255,255,.08);
     border-top-color: var(--accent);
     border-radius: 50%;
     animation: spin 0.6s linear infinite;
-    margin-left: 6px;
+    margin-left: 8px;
     vertical-align: middle;
 }