diff --git a/crates/tui/src/palette.rs b/crates/tui/src/palette.rs
index 6fbd13e0..b56a6393 100644
--- a/crates/tui/src/palette.rs
+++ b/crates/tui/src/palette.rs
@@ -82,6 +82,9 @@ pub const SURFACE_TOOL_ACTIVE: Color = Color::Rgb(29, 48, 73); // #1D3049
 pub const SURFACE_SUCCESS: Color = Color::Rgb(22, 56, 63); // #16383F
 #[allow(dead_code)]
 pub const SURFACE_ERROR: Color = Color::Rgb(63, 27, 36); // #3F1B24
+pub const DIFF_ADDED_BG: Color = Color::Rgb(18, 52, 38); // #123426 dark green tint
+pub const DIFF_DELETED_BG: Color = Color::Rgb(52, 22, 28); // #34161C dark red tint
+pub const DIFF_ADDED: Color = Color::Rgb(87, 199, 133); // #57C785
 pub const ACCENT_REASONING_LIVE: Color = Color::Rgb(146, 198, 248); // #92C6F8
 pub const ACCENT_TOOL_LIVE: Color = Color::Rgb(133, 184, 234); // #85B8EA
 pub const ACCENT_TOOL_ISSUE: Color = Color::Rgb(192, 143, 153); // #C08F99
diff --git a/crates/tui/src/tui/diff_render.rs b/crates/tui/src/tui/diff_render.rs
index e05b4029..7303c4fd 100644
--- a/crates/tui/src/tui/diff_render.rs
+++ b/crates/tui/src/tui/diff_render.rs
@@ -54,7 +54,9 @@ pub fn render_diff(diff: &str, width: u16) -> Vec<Line<'static>> {
                 old_line,
                 new_line,
                 '+',
-                Style::default().fg(palette::STATUS_SUCCESS),
+                Style::default()
+                    .fg(palette::DIFF_ADDED)
+                    .bg(palette::DIFF_ADDED_BG),
             ));
             if let Some(line) = new_line.as_mut() {
                 *line = line.saturating_add(1);
@@ -70,7 +72,9 @@ pub fn render_diff(diff: &str, width: u16) -> Vec<Line<'static>> {
                 old_line,
                 new_line,
                 '-',
-                Style::default().fg(palette::STATUS_ERROR),
+                Style::default()
+                    .fg(palette::STATUS_ERROR)
+                    .bg(palette::DIFF_DELETED_BG),
             ));
             if let Some(line) = old_line.as_mut() {
                 *line = line.saturating_add(1);
diff --git a/crates/tui/src/tui/history.rs b/crates/tui/src/tui/history.rs
index 0e7d107d..6d9572c2 100644
--- a/crates/tui/src/tui/history.rs
+++ b/crates/tui/src/tui/history.rs
@@ -6,7 +6,7 @@ use std::time::Instant;
 use ratatui::style::{Color, Modifier, Style, Stylize};
 use ratatui::text::{Line, Span};
 use serde_json::Value;
-use unicode_width::{UnicodeWidthChar, UnicodeWidthStr};
+use unicode_width::UnicodeWidthStr;
 
 use crate::deepseek_theme::active_theme;
 use crate::models::{ContentBlock, Message};
@@ -37,6 +37,11 @@ const USER_GLYPH: &str = "\u{258E}"; // ▎
 /// Visual marker for the assistant role. Solid bullet that pulses at 2s
 /// cycle while the response is streaming, holds full brightness when idle.
 const ASSISTANT_GLYPH: &str = "\u{25CF}"; // ●
+/// Transcript body left rail. Solid 1/8 block (`▏`) followed by a space —
+/// used as a visual left-margin anchor for continuation lines, tool-card
+/// detail rows, and affordance lines. Dimmed so it guides the eye without
+/// competing with content.
+const TRANSCRIPT_RAIL: &str = "\u{258F} "; // ▏ + space
 /// Reasoning header opener. Replaces the spinner glyph on thinking cells —
 /// reasoning is a slow exhale, not a tool spin.
 const REASONING_OPENER: &str = "\u{2026}"; // …
@@ -478,7 +483,10 @@ fn render_archived_context(
     let rendered = crate::tui::markdown_render::render_markdown(&body, content_width, body_style);
     for (idx, line) in rendered.into_iter().enumerate() {
         if idx == 0 {
-            let mut spans = vec![Span::styled("▏ ", Style::default().fg(palette::TEXT_DIM))];
+            let mut spans = vec![Span::styled(
+                TRANSCRIPT_RAIL.to_string(),
+                Style::default().fg(palette::TEXT_DIM),
+            )];
             spans.extend(line.spans);
             lines.push(Line::from(spans));
         } else {
@@ -1608,7 +1616,7 @@ fn render_checklist_change_card(
     let (marker, marker_color) = checklist_status_marker(&change.status);
     let prefix = format!("{marker} ");
     let prefix_width =
-        UnicodeWidthStr::width("\u{258F} ") + UnicodeWidthStr::width(prefix.as_str());
+        UnicodeWidthStr::width(TRANSCRIPT_RAIL) + UnicodeWidthStr::width(prefix.as_str());
     let id_label = format!("Todo #{}", change.id);
     let arrow = " \u{2192} ";
     let status_label = change.status.clone();
@@ -1702,7 +1710,7 @@ fn render_checklist_card(
         let prefix = format!("{marker} ");
         // Reserve room for the rail + marker prefix when wrapping content.
         let prefix_width =
-            UnicodeWidthStr::width("\u{258F} ") + UnicodeWidthStr::width(prefix.as_str());
+            UnicodeWidthStr::width(TRANSCRIPT_RAIL) + UnicodeWidthStr::width(prefix.as_str());
         let content_width = usize::from(width).saturating_sub(prefix_width).max(1);
         for (idx, part) in wrap_text(item.content.trim(), content_width)
             .into_iter()
@@ -2044,7 +2052,7 @@ fn render_thinking(
     // 12% reasoning surface tint over the app ink — the only deliberately
     // warm element in the transcript. Dropped on Ansi-16 terminals where the
     // tint would distort the named palette.
-    let depth = palette::ColorDepth::detect();
+    let depth = cached_color_depth();
     let body_bg = palette::reasoning_surface_tint(depth);
     let body_style = match body_bg {
         Some(bg) => style.italic().bg(bg),
@@ -2153,9 +2161,13 @@ fn render_message(
             let indent = if prefix.is_empty() {
                 String::new()
             } else {
-                " ".repeat(prefix_width + 1)
+                let mut s = String::with_capacity(prefix_width + 1);
+                s.push('\u{258F}');
+                s.extend(std::iter::repeat_n(' ', prefix_width));
+                s
             };
-            let mut spans = vec![Span::raw(indent)];
+            let rail_style = Style::default().fg(palette::TEXT_DIM);
+            let mut spans = vec![Span::styled(indent, rail_style)];
             spans.extend(line.spans);
             lines.push(Line::from(spans));
         }
@@ -2485,16 +2497,16 @@ fn file_line_style(text: &str) -> Option<Style> {
 /// Apply inline diff highlighting to a single text line.
 ///
 /// Returns the appropriate style for the line based on its prefix:
-/// - Lines starting with `+` (after trimming) => `palette::STATUS_SUCCESS` (green)
+/// - Lines starting with `+` (after trimming) => `palette::DIFF_ADDED` (green)
 /// - Lines starting with `-` (after trimming) => `palette::STATUS_ERROR` (red)
 /// - Lines starting with `@@` => `palette::DEEPSEEK_SKY` (cyan/blue)
 /// - All other lines => None (use default style)
 fn diff_line_style(text: &str) -> Option<Style> {
     let trimmed = text.trim_start();
     if trimmed.starts_with("@@") {
-        Some(Style::default().fg(palette::DEEPSEEK_SKY))
+        Some(Style::default().fg(palette::DEEPSEEK_BLUE))
     } else if trimmed.starts_with('+') && !trimmed.starts_with("+++") {
-        Some(Style::default().fg(palette::STATUS_SUCCESS))
+        Some(Style::default().fg(palette::DIFF_ADDED))
     } else if trimmed.starts_with('-') && !trimmed.starts_with("---") {
         Some(Style::default().fg(palette::STATUS_ERROR))
     } else {
@@ -2549,22 +2561,21 @@ fn wrap_text(text: &str, width: usize) -> Vec<String> {
 
     let mut lines = Vec::new();
     let mut current = String::new();
-    let mut current_width = 0usize;
 
     for ch in text.chars() {
-        let ch_width = if ch == '\t' {
-            4
+        let tentative = if current.is_empty() {
+            ch.to_string()
         } else {
-            UnicodeWidthChar::width(ch).unwrap_or(0).max(1)
+            let mut t = current.clone();
+            t.push(ch);
+            t
         };
 
-        if current_width + ch_width > width && !current.is_empty() {
+        if UnicodeWidthStr::width(tentative.as_str()) > width && !current.is_empty() {
             lines.push(std::mem::take(&mut current));
-            current_width = 0;
         }
 
         current.push(ch);
-        current_width = current_width.saturating_add(ch_width);
     }
 
     lines.push(current);
@@ -2603,7 +2614,10 @@ fn status_symbol(started_at: Option<Instant>, status: ToolStatus, low_motion: bo
 
 fn details_affordance_line(text: &str, style: Style) -> Line<'static> {
     Line::from(vec![
-        Span::styled("▏ ", Style::default().fg(palette::TEXT_DIM)),
+        Span::styled(
+            TRANSCRIPT_RAIL.to_string(),
+            Style::default().fg(palette::TEXT_DIM),
+        ),
         Span::styled(text.to_string(), style),
     ])
 }
@@ -2812,14 +2826,17 @@ fn render_card_detail_line(
     width: u16,
 ) -> Vec<Line<'static>> {
     let label_text = label.map(|text| format!("{text}:"));
-    let prefix_width = UnicodeWidthStr::width("▏ ")
+    let prefix_width = UnicodeWidthStr::width(TRANSCRIPT_RAIL)
         + label_text.as_deref().map_or(0, UnicodeWidthStr::width)
         + usize::from(label.is_some());
     let content_width = usize::from(width).saturating_sub(prefix_width).max(1);
 
     let mut lines = Vec::new();
     for (idx, part) in wrap_text(value, content_width).into_iter().enumerate() {
-        let mut spans = vec![Span::styled("▏ ", Style::default().fg(palette::TEXT_DIM))];
+        let mut spans = vec![Span::styled(
+            TRANSCRIPT_RAIL.to_string(),
+            Style::default().fg(palette::TEXT_DIM),
+        )];
         if idx == 0 {
             if let Some(label_text) = label_text.as_deref() {
                 spans.push(Span::styled(
@@ -2845,7 +2862,10 @@ fn render_card_detail_line_single(
     value_style: Style,
 ) -> Line<'static> {
     let label_text = label.map(|text| format!("{text}:"));
-    let mut spans = vec![Span::styled("▏ ", Style::default().fg(palette::TEXT_DIM))];
+    let mut spans = vec![Span::styled(
+        TRANSCRIPT_RAIL.to_string(),
+        Style::default().fg(palette::TEXT_DIM),
+    )];
     if let Some(label_text) = label_text {
         spans.push(Span::styled(label_text, tool_detail_label_style()));
         spans.push(Span::raw(" "));
@@ -2926,6 +2946,16 @@ fn thinking_state_accent(state: ThinkingVisualState) -> Color {
     }
 }
 
+// === Cached colour depth ===
+
+/// Once-initialised colour depth for the terminal session. Avoids re-reading
+/// `COLORTERM` / `TERM` env vars on every frame.
+static COLOR_DEPTH: std::sync::OnceLock<palette::ColorDepth> = std::sync::OnceLock::new();
+
+fn cached_color_depth() -> palette::ColorDepth {
+    *COLOR_DEPTH.get_or_init(palette::ColorDepth::detect)
+}
+
 /// Parse `path:line` patterns from `text` and open the file at the given line
 /// in the user's preferred editor (`$VISUAL` / `$EDITOR` / `vim`).
 ///
diff --git a/crates/tui/src/tui/markdown_render.rs b/crates/tui/src/tui/markdown_render.rs
index 74b5fd41..00bbef65 100644
--- a/crates/tui/src/tui/markdown_render.rs
+++ b/crates/tui/src/tui/markdown_render.rs
@@ -430,10 +430,14 @@ fn render_line_with_links(
 }
 
 /// Parse an entire line into (text, style) segments, handling **bold**,
-/// *italic*, and bare URLs that may span multiple words.
+/// *italic*, `code`, ~~strikethrough~~, [text](url) links, and bare URLs.
 fn parse_inline_spans(line: &str, base_style: Style, link_style: Style) -> Vec<(String, Style)> {
     let bold_style = base_style.add_modifier(Modifier::BOLD);
     let italic_style = base_style.add_modifier(Modifier::ITALIC);
+    let code_style = base_style
+        .add_modifier(Modifier::ITALIC)
+        .bg(palette::SURFACE_ELEVATED);
+    let strike_style = base_style.add_modifier(Modifier::CROSSED_OUT);
     let mut out = Vec::new();
     let mut rest = line;
 
@@ -472,6 +476,40 @@ fn parse_inline_spans(line: &str, base_style: Style, link_style: Style) -> Vec<(
             rest = &rest[1 + end + 1..];
             continue;
         }
+        // `inline code`
+        if let Some(end) = rest.strip_prefix('`').and_then(|s| s.find('`')) {
+            let inner = &rest[1..1 + end];
+            out.push((inner.to_string(), code_style));
+            rest = &rest[1 + end + 1..];
+            continue;
+        }
+        // ~~strikethrough~~
+        if let Some(end) = rest.strip_prefix("~~").and_then(|s| s.find("~~")) {
+            let inner = &rest[2..2 + end];
+            out.push((inner.to_string(), strike_style));
+            rest = &rest[2 + end + 2..];
+            continue;
+        }
+        // [text](url)
+        if rest.starts_with('[')
+            && let Some(bracket_end) = rest.find(']')
+        {
+            let text = &rest[1..bracket_end];
+            let after_bracket = &rest[bracket_end + 1..];
+            if after_bracket.starts_with('(')
+                && let Some(paren_end) = after_bracket.find(')')
+            {
+                let url = &after_bracket[1..paren_end];
+                let content = if osc8::enabled() {
+                    osc8::wrap_link(url, text)
+                } else {
+                    format!("{text} ({url})")
+                };
+                out.push((content, link_style));
+                rest = &after_bracket[paren_end + 1..];
+                continue;
+            }
+        }
         // URL: consume until whitespace
         if rest.starts_with("http://") || rest.starts_with("https://") {
             let end = rest.find(char::is_whitespace).unwrap_or(rest.len());
@@ -503,6 +541,9 @@ fn find_next_marker(s: &str) -> usize {
         let slice = &s[i..];
         if slice.starts_with("**")
             || slice.starts_with("__")
+            || slice.starts_with("~~")
+            || slice.starts_with('`')
+            || slice.starts_with('[')
             || (slice.starts_with('*') && !slice.starts_with("**"))
             || (slice.starts_with('_') && !slice.starts_with("__"))
             || slice.starts_with("http://")
diff --git a/crates/tui/src/tui/ui/tests.rs b/crates/tui/src/tui/ui/tests.rs
index c86658e2..32337bd3 100644
--- a/crates/tui/src/tui/ui/tests.rs
+++ b/crates/tui/src/tui/ui/tests.rs
@@ -139,7 +139,7 @@ fn selection_to_text_handles_multiline_and_reversed_endpoints() {
         column: 6,
     });
 
-    assert_eq!(selection_to_text(&app).as_deref(), Some("a beta\n  gam"));
+    assert_eq!(selection_to_text(&app).as_deref(), Some("a beta\n▏ gam"));
 }
 
 #[test]