diff --git a/web/src/i18n/en.js b/web/src/i18n/en.js
index 50ad835..edfb481 100644
--- a/web/src/i18n/en.js
+++ b/web/src/i18n/en.js
@@ -46,11 +46,13 @@ const en = {
 
   studio: {
     welcome: 'Welcome to Studio! Chat with your AI assistant here.',
+    welcomeNew: 'Welcome to Muyue Studio. I am your AI orchestrator. Describe your project and I will create a plan, propose agents, and track each step.',
     configureHint: 'Configure agents and workflows from the sidebar.',
     chat: 'Chat',
     agents: 'Agents',
     workflows: 'Workflows',
     placeholder: 'Type a message... (Enter to send)',
+    placeholderNew: 'Describe your project or ask a question...',
     send: 'Send',
     commands: 'Commands',
     planGoal: '/plan <goal>',
@@ -64,6 +66,16 @@ const en = {
     usePlan: 'Use /plan <goal> in chat to start.',
     noResponse: 'No response',
     error: 'Error',
+    inputHint: 'Enter to send, Shift+Enter for new line',
+    context: 'Context',
+    plans: 'Plans',
+    activity: 'Activity',
+    noPlansYet: 'No plans detected. Ask the AI to create a plan.',
+    noAgentsYet: 'No agents mentioned.',
+    planDetail: 'Plan detail',
+    steps: 'steps',
+    you: 'You',
+    mentioned: 'mentioned',
   },
 
   shell: {
diff --git a/web/src/styles/global.css b/web/src/styles/global.css
index 1de6109..36e978b 100644
--- a/web/src/styles/global.css
+++ b/web/src/styles/global.css
@@ -396,3 +396,143 @@ input::placeholder { color: var(--text-disabled); }
 .spinner { width: 16px; height: 16px; border: 2px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.6s linear infinite; display: inline-block; vertical-align: middle; }
 @keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }
 .fade-in { animation: fadeIn 0.2s ease-out; }
+
+/* ── Studio ── */
+.studio-layout { display: flex; height: 100%; overflow: hidden; }
+.studio-chat-area { display: flex; flex-direction: column; flex: 1; min-width: 0; }
+.studio-messages { flex: 1; overflow-y: auto; padding: 24px 20px; display: flex; flex-direction: column; gap: 16px; }
+
+.studio-msg { display: flex; gap: 10px; max-width: 85%; animation: fadeIn 0.2s ease-out; }
+.studio-msg.user { align-self: flex-end; flex-direction: row-reverse; }
+.studio-msg.ai { align-self: flex-start; }
+
+.studio-msg-avatar {
+  width: 28px; height: 28px; border-radius: 50%; background: var(--accent-bg); color: var(--accent);
+  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
+}
+.studio-msg-body { display: flex; flex-direction: column; gap: 0; }
+.studio-msg-content { font-size: 14px; line-height: 1.7; color: var(--text-primary); word-break: break-word; }
+
+.studio-code-block {
+  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
+  overflow: hidden; margin: 8px 0;
+}
+.studio-code-block pre { padding: 12px 16px; font-family: var(--font-mono); font-size: 13px; line-height: 1.5; overflow-x: auto; color: var(--text-primary); margin: 0; }
+.studio-code-lang {
+  padding: 4px 12px; font-size: 11px; font-weight: 600; color: var(--text-tertiary);
+  background: var(--bg-surface); border-bottom: 1px solid var(--border); text-transform: uppercase; letter-spacing: 0.5px;
+}
+.inline-code { background: var(--bg-input); padding: 2px 6px; border-radius: 4px; font-family: var(--font-mono); font-size: 13px; color: var(--accent-muted); }
+
+.msg-h3 { font-size: 16px; font-weight: 700; color: var(--text-primary); margin: 16px 0 8px; display: block; }
+.msg-h4 { font-size: 14px; font-weight: 700; color: var(--text-secondary); margin: 12px 0 6px; display: block; }
+.msg-bullet { display: block; padding-left: 16px; position: relative; margin: 2px 0; }
+.msg-bullet::before { content: '\2022'; position: absolute; left: 4px; color: var(--accent); }
+.msg-step { display: flex; gap: 8px; align-items: baseline; margin: 3px 0; }
+.msg-step-num { color: var(--accent); font-weight: 700; font-family: var(--font-mono); font-size: 13px; flex-shrink: 0; min-width: 20px; }
+
+.studio-msg-meta { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
+
+.studio-plan-chip {
+  display: inline-flex; align-items: center; gap: 6px; padding: 5px 10px; border-radius: var(--radius);
+  background: var(--bg-card); border: 1px solid var(--border); font-size: 12px; color: var(--text-secondary);
+  cursor: pointer; transition: all 0.15s; user-select: none;
+}
+.studio-plan-chip:hover { border-color: var(--accent-dark); background: var(--bg-hover); color: var(--text-primary); }
+.studio-expand-icon { font-size: 9px; color: var(--text-tertiary); margin-left: 4px; }
+
+.studio-agent-tag {
+  display: inline-flex; align-items: center; padding: 3px 8px; border-radius: 99px;
+  background: rgba(68,138,255,0.12); color: var(--info); font-size: 11px; font-weight: 600;
+}
+
+.studio-plan-detail {
+  margin-top: 8px; border: 1px solid var(--border); border-radius: var(--radius);
+  background: var(--bg-surface); overflow: hidden;
+}
+.studio-plan-detail-header { padding: 10px 14px; font-size: 12px; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: 0.5px; border-bottom: 1px solid var(--border); }
+.studio-steps { display: flex; flex-direction: column; gap: 2px; padding: 8px 0; }
+.studio-step { display: flex; gap: 10px; align-items: baseline; padding: 4px 14px; }
+.studio-step-num { color: var(--accent); font-weight: 700; font-family: var(--font-mono); font-size: 13px; flex-shrink: 0; min-width: 24px; }
+.studio-step-text { font-size: 13px; color: var(--text-secondary); line-height: 1.5; }
+.studio-plan-raw { padding: 8px 14px 12px; border-top: 1px solid var(--border); }
+.studio-plan-raw pre { font-family: var(--font-mono); font-size: 12px; color: var(--text-tertiary); white-space: pre-wrap; word-break: break-word; margin: 0; line-height: 1.5; }
+
+.studio-cursor { display: inline-block; width: 8px; height: 16px; background: var(--accent); margin-left: 2px; vertical-align: text-bottom; animation: blink 0.8s step-end infinite; }
+@keyframes blink { 50% { opacity: 0; } }
+
+.studio-thinking { display: flex; gap: 4px; padding: 8px 0; }
+.studio-thinking span { width: 6px; height: 6px; border-radius: 50%; background: var(--accent-dim); animation: bounce 1.2s ease-in-out infinite; }
+.studio-thinking span:nth-child(2) { animation-delay: 0.15s; }
+.studio-thinking span:nth-child(3) { animation-delay: 0.3s; }
+@keyframes bounce { 0%, 80%, 100% { transform: translateY(0); opacity: 0.4; } 40% { transform: translateY(-6px); opacity: 1; } }
+
+.studio-input-area { padding: 12px 20px 8px; border-top: 1px solid var(--border); background: var(--bg-surface); }
+.studio-input-row { display: flex; gap: 8px; align-items: flex-end; }
+.studio-input-row textarea {
+  flex: 1; resize: none; min-height: 42px; max-height: 200px; padding: 10px 14px;
+  font-size: 14px; line-height: 1.5; border-radius: var(--radius);
+  background: var(--bg-input); color: var(--text-primary); border: 1px solid var(--border);
+  font-family: var(--font-sans); outline: none; transition: border-color 0.2s, box-shadow 0.2s;
+}
+.studio-input-row textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--border-accent); }
+.studio-input-row textarea::placeholder { color: var(--text-disabled); }
+
+.studio-send-btn {
+  width: 42px; height: 42px; padding: 0; display: flex; align-items: center; justify-content: center;
+  border-radius: var(--radius); background: var(--accent); color: #fff; border: 1px solid var(--accent);
+  cursor: pointer; transition: all 0.15s; flex-shrink: 0;
+}
+.studio-send-btn:hover:not(:disabled) { background: var(--accent-bright); border-color: var(--accent-bright); }
+.studio-send-btn:disabled { opacity: 0.3; cursor: not-allowed; }
+
+.studio-input-hint { font-size: 11px; color: var(--text-disabled); text-align: center; margin-top: 6px; }
+
+/* ── Studio Sidebar ── */
+.studio-sidebar {
+  width: 0; border-left: 1px solid var(--border); background: var(--bg-surface);
+  overflow: hidden; transition: width 0.25s ease; flex-shrink: 0; display: flex; flex-direction: column;
+}
+.studio-sidebar.open { width: 300px; }
+
+.studio-sidebar-header { display: flex; justify-content: space-between; align-items: center; padding: 12px 16px; border-bottom: 1px solid var(--border); flex-shrink: 0; }
+.studio-sidebar-header span { font-size: 13px; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: 0.5px; }
+.studio-sidebar-toggle { font-size: 18px; padding: 0 6px; line-height: 1; }
+
+.studio-context { display: flex; flex-direction: column; flex: 1; overflow: hidden; }
+.studio-context-tabs { display: flex; border-bottom: 1px solid var(--border); flex-shrink: 0; }
+.studio-context-tab {
+  flex: 1; padding: 9px 8px; font-size: 12px; font-weight: 600; color: var(--text-tertiary);
+  cursor: pointer; text-align: center; transition: all 0.15s; border-bottom: 2px solid transparent; user-select: none;
+}
+.studio-context-tab:hover { color: var(--text-primary); background: var(--bg-card); }
+.studio-context-tab.active { color: var(--accent); border-bottom-color: var(--accent); }
+.studio-tab-count { font-size: 10px; padding: 1px 5px; border-radius: 99px; background: var(--bg-card); color: var(--text-tertiary); font-family: var(--font-mono); margin-left: 4px; }
+
+.studio-context-body { flex: 1; overflow-y: auto; padding: 12px; }
+
+.studio-plan-list { display: flex; flex-direction: column; gap: 4px; }
+.studio-plan-item {
+  display: flex; align-items: center; gap: 8px; padding: 8px 10px; border-radius: var(--radius);
+  cursor: pointer; transition: all 0.15s; font-size: 13px; color: var(--text-secondary);
+}
+.studio-plan-item:hover { background: var(--bg-card); color: var(--text-primary); }
+.studio-plan-item.active { background: var(--accent-bg); border-left: 2px solid var(--accent); }
+.studio-plan-item svg { flex-shrink: 0; color: var(--text-tertiary); }
+.studio-plan-item-text { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.studio-plan-item-badge { font-size: 11px; color: var(--text-disabled); font-family: var(--font-mono); flex-shrink: 0; }
+
+.studio-agent-list { display: flex; flex-direction: column; gap: 4px; }
+.studio-agent-item { display: flex; align-items: center; gap: 8px; padding: 8px 10px; border-radius: var(--radius); }
+.studio-agent-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--info); flex-shrink: 0; }
+.studio-agent-name { font-size: 13px; color: var(--text-secondary); flex: 1; }
+
+.studio-empty { display: flex; align-items: center; justify-content: center; padding: 32px 16px; color: var(--text-disabled); font-size: 12px; text-align: center; line-height: 1.6; }
+
+.studio-activity-list { display: flex; flex-direction: column; gap: 2px; }
+.studio-activity-item { display: flex; gap: 8px; padding: 6px 10px; border-radius: var(--radius); font-size: 12px; }
+.studio-activity-item:hover { background: var(--bg-card); }
+.studio-activity-dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; margin-top: 5px; }
+.studio-activity-dot.user { background: var(--accent-muted); }
+.studio-activity-dot.ai { background: var(--info); }
+.studio-activity-text { color: var(--text-tertiary); line-height: 1.4; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }