feat: enhance LaTeX editing and compilation features

- Added summary field to history entries for better tracking of edits.
- Updated prompts to return both LaTeX and a summary in specific tags.
- Implemented compile cooldown mechanism to prevent rapid recompilation.
- Improved compile state management with JSON file storage.
- Enhanced error handling and user feedback for compilation status.
- Updated CSS for a neobrutalist design with improved button styles and dropzone support.
- Refactored HTML templates to support new features and improve user experience.

main.py

@@ -1,4 +1,5 @@
 import base64
+import hashlib
 import json
 import logging
 import mimetypes
@@ -78,6 +79,7 @@ class HistoryEntry(TypedDict, total=False):
     instructions: str
     model: str
     status: str
+    summary: str
 
 
 RUNS_DIR.mkdir(parents=True, exist_ok=True)
@@ -106,6 +108,7 @@ def _append_history_entry(run_dir: Path, entry: HistoryEntry) -> None:
         "instructions": entry.get("instructions", ""),
         "model": entry.get("model", ""),
         "status": entry.get("status", ""),
+        "summary": entry.get("summary", ""),
     }
     path = _history_path(run_dir)
     with path.open("a", encoding="utf-8") as f:
@@ -140,6 +143,7 @@ def _load_history_for_ip(run_dir: Path, ip: str) -> list[HistoryEntry]:
                         "instructions": obj.get("instructions", ""),
                         "model": obj.get("model", ""),
                         "status": obj.get("status", ""),
+                        "summary": obj.get("summary", ""),
                     }
                 )
     except Exception:
@@ -271,10 +275,11 @@ CONVERT_PROMPT = (
 
 EDIT_SYSTEM_PROMPT = (
     "You are an expert LaTeX/TikZ editor. "
-    "Given an existing standalone LaTeX/TikZ document and an edit request, return EXACTLY ONE updated complete LaTeX document. "
+    "Given an existing standalone LaTeX/TikZ document and an edit request, return EXACTLY TWO elements: "
-    "Return ONLY raw LaTeX source: no markdown, no code fences, no commentary, no extra text. "
+    "a complete LaTeX document wrapped in <latex>...</latex> and a very generic summary (less than 7 words, all lowercase) wrapped in <summary>...</summary>. "
-    "The output must compile with pdflatex. "
+    "Return ONLY these tags and their contents: no markdown, no code fences, no commentary, no extra text. "
-    "Wrap LaTeX to roughly 80 characters per line, keep formatting tidy, and add brief LaTeX comments to clarify sections when helpful."
+    "The LaTeX must compile with pdflatex. "
+    "Wrap LaTeX to roughly 80 characters per line, keep formatting tidy, and add brief LaTeX comments where helpful."
 )
 
 EDIT_PROMPT_TEMPLATE = (
@@ -282,7 +287,7 @@ EDIT_PROMPT_TEMPLATE = (
     "Rules:\n"
     "- Return a complete standalone LaTeX document (\\documentclass{{standalone}} ... \\end{{document}}).\n"
     "- Make minimal changes necessary to satisfy the instructions.\n"
-    "- Do not add external files or assets.\n\n"
+    "- Do not add external files or assets.\n"
     "INSTRUCTIONS:\n{instructions}\n\n"
     "LATEX:\n{latex}\n"
 )
@@ -326,6 +331,22 @@ def _extract_text_from_litellm(resp: Any) -> str:
     return str(resp).strip()
 
 
+def _parse_latex_and_summary(raw_text: str) -> tuple[str, str]:
+    """Extracts <latex>...</latex> and <summary>...</summary> from raw_text.
+
+    Falls back to treating the whole raw_text as LaTeX if tags are missing.
+    """
+    latex_re = re.compile(r"<latex>(.*?)</latex>", re.DOTALL | re.IGNORECASE)
+    summary_re = re.compile(r"<summary>(.*?)</summary>", re.DOTALL | re.IGNORECASE)
+
+    latex_match = latex_re.search(raw_text or "")
+    summary_match = summary_re.search(raw_text or "")
+
+    latex = (latex_match.group(1) if latex_match else (raw_text or "")).strip()
+    summary = (summary_match.group(1) if summary_match else "").strip()
+    return latex, summary
+
+
 def _litellm_call(*, model: str, messages: list[dict[str, Any]], **kwargs: Any) -> Any:
     return completion(model=model, messages=messages, **kwargs)
 
@@ -439,6 +460,46 @@ def _render_png_with_magick(
     return None
 
 
+COMPILE_COOLDOWN_SECS = 3
+COMPILE_STATE_FILE = "compile_state.json"
+
+
+def _load_compile_state(run_dir: Path) -> dict[str, Any]:
+    path = run_dir / COMPILE_STATE_FILE
+    if not path.exists():
+        return {}
+    try:
+        data = json.loads(path.read_text(encoding="utf-8", errors="replace"))
+        return data if isinstance(data, dict) else {}
+    except Exception:
+        return {}
+
+
+def _save_compile_state(run_dir: Path, state: dict[str, Any]) -> None:
+    path = run_dir / COMPILE_STATE_FILE
+    path.write_text(json.dumps(state, indent=2, sort_keys=True) + "\n", encoding="utf-8")
+
+
+def _tex_digest(text: str) -> str:
+    return hashlib.sha256(text.encode("utf-8", errors="replace")).hexdigest()
+
+
+def _should_compile(
+    run_dir: Path, tex_text: str, *, cooldown_s: int = COMPILE_COOLDOWN_SECS
+) -> tuple[bool, str, str]:
+    state = _load_compile_state(run_dir)
+    last_ts = float(state.get("last_ts", 0.0) or 0.0)
+    last_hash = state.get("last_hash") if isinstance(state.get("last_hash"), str) else ""
+    now = time.time()
+    digest = _tex_digest(tex_text)
+
+    if now - last_ts < cooldown_s:
+        return False, "cooldown", digest
+    if last_hash and last_hash == digest:
+        return False, "unchanged", digest
+    return True, "ok", digest
+
+
 def _render_svg_with_pdf2svg(
     run_dir: Path, pdf_path: Path, run_logger: RunLogger, section_title: str, svg_name: str = "diagram.svg"
 ) -> Optional[Path]:
@@ -468,7 +529,27 @@ def _compile_latex_to_png(
 
 def _compile_phase(
     run_dir: Path, tex_path: Path, run_log: RunLogger, phase: str, start_msg: str = "compile.start"
-) -> tuple[Optional[Path], Optional[Path], Optional[Path], int]:
+) -> tuple[Optional[Path], Optional[Path], Optional[Path], int, str]:
+    try:
+        tex_text = tex_path.read_text(encoding="utf-8", errors="replace")
+    except Exception:
+        tex_text = ""
+
+    allowed, reason, digest = _should_compile(run_dir, tex_text, cooldown_s=COMPILE_COOLDOWN_SECS)
+
+    pdf_path_existing = run_dir / Path(tex_path.name).with_suffix(".pdf").name
+    png_path_existing = run_dir / "preview.png"
+    svg_path_existing = run_dir / "diagram.svg"
+
+    if not allowed:
+        pdf_path = pdf_path_existing if pdf_path_existing.exists() else None
+        png_path = png_path_existing if png_path_existing.exists() else None
+        svg_path = svg_path_existing if svg_path_existing.exists() else None
+        run_log.line(
+            f"{start_msg}.skip reason={reason} has_pdf={pdf_path is not None} has_png={png_path is not None} has_svg={svg_path is not None}"
+        )
+        return pdf_path, png_path, svg_path, 0, reason
+
     run_log.line(start_msg)
     started = time.monotonic()
     pdf_path, png_path = _compile_latex_to_png(run_dir, tex_path, run_log, phase=phase)
@@ -478,17 +559,38 @@ def _compile_phase(
         else None
     )
     elapsed_ms = int((time.monotonic() - started) * 1000)
+
+    _save_compile_state(
+        run_dir,
+        {
+            "last_ts": time.time(),
+            "last_hash": digest,
+        },
+    )
+
     run_log.line(
         f"compile.end elapsed_ms={elapsed_ms} ok_pdf={pdf_path is not None} ok_png={png_path is not None} ok_svg={svg_path is not None}"
     )
-    return pdf_path, png_path, svg_path, elapsed_ms
+    return pdf_path, png_path, svg_path, elapsed_ms, "compiled"
+
+
+BASE62_ALPHABET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+RUN_ID_RE = re.compile(r"(\d{4}-\d{2}-\d{2}-[0-9a-f]{32}|[0-9A-Za-z]{22})")
 
 
-RUN_ID_RE = re.compile(r"\d{4}-\d{2}-\d{2}-[0-9a-f]{32}")
+def _uuid_to_base62(u: uuid.UUID) -> str:
+    n: int = int.from_bytes(u.bytes, "big", signed=False)
+    base = len(BASE62_ALPHABET)
+    chars: list[str] = []
+    while n > 0:
+        n, rem = divmod(n, base)
+        chars.append(BASE62_ALPHABET[rem])
+    encoded = "".join(reversed(chars or [BASE62_ALPHABET[0]]))
+    return encoded.rjust(22, BASE62_ALPHABET[0])
 
 
 def _new_run_id() -> str:
-    return f"{time.strftime('%Y-%m-%d')}-{uuid.uuid4().hex}"
+    return _uuid_to_base62(uuid.uuid4())
 
 
 def _write_run_meta(run_dir: Path, meta: dict[str, Any]) -> None:
@@ -674,8 +776,11 @@ async def convert(request: Request, image: UploadFile = File(...), notes: str =
     png_path: Optional[Path] = None
     svg_path: Optional[Path] = None
 
+    cp_elapsed_ms = 0
+    cp_reason = ""
+
     if tex:
-        pdf_path, png_path, svg_path, cp_elapsed_ms = _compile_phase(
+        pdf_path, png_path, svg_path, cp_elapsed_ms, cp_reason = _compile_phase(
             run_dir, tex_path, run_log, phase="convert"
         )
         logger.info(
@@ -724,11 +829,12 @@ async def convert(request: Request, image: UploadFile = File(...), notes: str =
         f"convert.end elapsed_ms={elapsed_ms} ok_pdf={pdf_path is not None} ok_png={png_path is not None}",
     )
 
-    return RedirectResponse(url=f"{BASE_PATH}/{run_id}", status_code=303)
+    warn_qs = f"?warn={cp_reason}" if cp_elapsed_ms == 0 and cp_reason else ""
+    return RedirectResponse(url=f"{BASE_PATH}/d/{run_id}{warn_qs}", status_code=303)
 
 
-@app.get("/{run_id}", response_class=HTMLResponse)
+@app.get("/d/{run_id}", response_class=HTMLResponse)
-async def get_run_result(request: Request, run_id: str):
+async def get_run_result(request: Request, run_id: str, warn: str | None = None):
     run_dir = _run_dir_for_id(run_id)
     if run_dir is None:
         return HTMLResponse("Not found", status_code=404)
@@ -765,6 +871,15 @@ async def get_run_result(request: Request, run_id: str):
     download_pdf_url = file_url(pdf_path.name) if pdf_path.exists() else file_url("diagram.pdf")
     download_svg_url = file_url(svg_path.name) if svg_path.exists() else file_url("diagram.svg")
 
+    def _warn_text(reason: str | None) -> str:
+        if not reason:
+            return ""
+        if reason == "cooldown":
+            return "Please wait a few seconds before compiling again."
+        if reason == "unchanged":
+            return "Source unchanged; compile skipped."
+        return "Compilation skipped."
+
     return templates.TemplateResponse(
         "edit.html",
         {
@@ -783,11 +898,12 @@ async def get_run_result(request: Request, run_id: str):
             "base_path": BASE_PATH,
             "edit_remaining": rate_status["edit_remaining"],
             "edit_limit": rate_status["edit_limit"],
+            "compile_warning": _warn_text(warn),
         },
     )
 
 
-@app.post("/{run_id}", response_class=HTMLResponse)
+@app.post("/d/{run_id}", response_class=HTMLResponse)
 async def edit_tex(request: Request, run_id: str, instructions: str = Form(...), latex: str = Form(...)):
     run_dir = _run_dir_for_id(run_id)
     if run_dir is None:
@@ -800,7 +916,7 @@ async def edit_tex(request: Request, run_id: str, instructions: str = Form(...),
     instructions = (instructions or "").strip()
     if not instructions:
         _write_run_error(run_dir, "Edit instructions are empty.")
-        return RedirectResponse(url=f"{BASE_PATH}/{run_id}", status_code=303)
+        return RedirectResponse(url=f"{BASE_PATH}/d/{run_id}", status_code=303)
 
     tex_path = run_dir / "diagram.tex"
     current_tex = latex
@@ -825,6 +941,7 @@ async def edit_tex(request: Request, run_id: str, instructions: str = Form(...),
     raw_text = ""
     new_tex = ""
     used_model = ""
+    summary_text = ""
     try:
         llm_started = time.monotonic()
         run_log.line("llm.start")
@@ -836,7 +953,7 @@ async def edit_tex(request: Request, run_id: str, instructions: str = Form(...),
             ],
             run_log=run_log,
         )
-        new_tex = (raw_text or "").strip()
+        new_tex, summary_text = _parse_latex_and_summary(raw_text or "")
         llm_elapsed_ms = int((time.monotonic() - llm_started) * 1000)
         logger.info(
             "edit.llm.ok run_id=%s elapsed_ms=%s raw_chars=%s tex_chars=%s",
@@ -861,8 +978,13 @@ async def edit_tex(request: Request, run_id: str, instructions: str = Form(...),
     png_path: Optional[Path] = None
     svg_path: Optional[Path] = None
 
+    cp_elapsed_ms = 0
+    cp_reason = ""
+
     if new_tex:
-        pdf_path, png_path, svg_path, cp_elapsed_ms = _compile_phase(run_dir, tex_path, run_log, phase="edit")
+        pdf_path, png_path, svg_path, cp_elapsed_ms, cp_reason = _compile_phase(
+            run_dir, tex_path, run_log, phase="edit"
+        )
         logger.info(
             "edit.compile.done run_id=%s elapsed_ms=%s ok_pdf=%s ok_png=%s ok_svg=%s",
             run_id,
@@ -872,19 +994,21 @@ async def edit_tex(request: Request, run_id: str, instructions: str = Form(...),
             svg_path is not None,
         )
 
-        history_status = "ok" if pdf_path else "error"
+        if cp_elapsed_ms > 0:
-        _append_history_entry(
+            history_status = "ok" if pdf_path else "error"
-            run_dir,
+            _append_history_entry(
-            {
+                run_dir,
-                "ts": time.time(),
+                {
-                "ip": client_ip,
+                    "ts": time.time(),
-                "action": "edit",
+                    "ip": client_ip,
-                "latex": new_tex,
+                    "action": "edit",
-                "instructions": instructions,
+                    "latex": new_tex,
-                "model": used_model or (EDIT_MODELS[0] if EDIT_MODELS else ""),
+                    "instructions": instructions,
-                "status": history_status,
+                    "model": used_model or (EDIT_MODELS[0] if EDIT_MODELS else ""),
-            },
+                    "status": history_status,
-        )
+                    "summary": summary_text,
+                },
+            )
 
     run_log.section("edit.llm_raw", raw_text or "")
 
@@ -941,10 +1065,11 @@ async def edit_tex(request: Request, run_id: str, instructions: str = Form(...),
         f"edit.end elapsed_ms={elapsed_ms} ok_pdf={pdf_path is not None} ok_png={png_path is not None}",
     )
 
-    return RedirectResponse(url=f"{BASE_PATH}/{run_id}", status_code=303)
+    warn_qs = f"?warn={cp_reason}" if cp_elapsed_ms == 0 and cp_reason else ""
+    return RedirectResponse(url=f"{BASE_PATH}/d/{run_id}{warn_qs}", status_code=303)
 
 
-@app.post("/{run_id}/compile", response_class=HTMLResponse)
+@app.post("/d/{run_id}/compile", response_class=HTMLResponse)
 async def compile_tex(request: Request, run_id: str, latex: str = Form(...)):
     run_dir = _run_dir_for_id(run_id)
     if run_dir is None:
@@ -964,8 +1089,11 @@ async def compile_tex(request: Request, run_id: str, latex: str = Form(...)):
     png_path: Optional[Path] = None
     svg_path: Optional[Path] = None
 
+    cp_elapsed_ms = 0
+    cp_reason = ""
+
     if tex.strip():
-        pdf_path, png_path, svg_path, cp_elapsed_ms = _compile_phase(
+        pdf_path, png_path, svg_path, cp_elapsed_ms, cp_reason = _compile_phase(
             run_dir, tex_path, run_log, phase="compile", start_msg="compile.invoke"
         )
         logger.info(
@@ -977,19 +1105,20 @@ async def compile_tex(request: Request, run_id: str, latex: str = Form(...)):
             svg_path is not None,
         )
 
-        history_status = "ok" if pdf_path else "error"
+        if cp_elapsed_ms > 0:
-        _append_history_entry(
+            history_status = "ok" if pdf_path else "error"
-            run_dir,
+            _append_history_entry(
-            {
+                run_dir,
-                "ts": time.time(),
+                {
-                "ip": client_ip,
+                    "ts": time.time(),
-                "action": "compile",
+                    "ip": client_ip,
-                "latex": tex,
+                    "action": "compile",
-                "instructions": "",
+                    "latex": tex,
-                "model": "",
+                    "instructions": "",
-                "status": history_status,
+                    "model": "",
-            },
+                    "status": history_status,
-        )
+                },
+            )
 
     meta = _read_run_meta(run_dir)
     model_label = _get_meta_string(meta, "model")
@@ -1028,10 +1157,11 @@ async def compile_tex(request: Request, run_id: str, latex: str = Form(...)):
     logger.info("compile.end run_id=%s elapsed_ms=%s", run_id, elapsed_ms)
     run_log.line(f"compile.finish elapsed_ms={elapsed_ms}")
 
-    return RedirectResponse(url=f"{BASE_PATH}/{run_id}", status_code=303)
+    warn_qs = f"?warn={cp_reason}" if cp_elapsed_ms == 0 and cp_reason else ""
+    return RedirectResponse(url=f"{BASE_PATH}/d/{run_id}{warn_qs}", status_code=303)
 
 
-@app.get("/{run_id}/history")
+@app.get("/d/{run_id}/history")
 async def get_history(request: Request, run_id: str):
     run_dir = _run_dir_for_id(run_id)
     if run_dir is None:
@@ -1051,6 +1181,7 @@ async def get_history(request: Request, run_id: str):
                 "instructions": entry.get("instructions", ""),
                 "model": entry.get("model", ""),
                 "status": entry.get("status", ""),
+                "summary": entry.get("summary", ""),
             }
         )
 

public/styles.css

@@ -6,155 +6,152 @@
     *::after {
         box-sizing: border-box;
     }
-
+    html {
-    html,
+        height: 100%;
+        color-scheme: light dark;
+    }
     body {
         height: 100%;
     }
-
     body {
         margin: 0;
     }
-
     img {
         max-width: 100%;
         height: auto;
         display: block;
     }
-
+    textarea,
-    textarea {
+    input,
+    select,
+    button {
         font: inherit;
     }
 }
 
 @layer base {
     :root {
-        color-scheme: light dark;
+        --bg: #e0e0e0;
-
+        --fg: #121212;
-        --border: 1px solid rgba(127, 127, 127, 0.35);
+        --border-color: #000000;
-        --border-danger: 1px solid rgba(255, 0, 0, 0.35);
+
-
+        /* Neobrutalist Palette */
-        --radius-lg: 0.75rem;
+        --c-primary: #a390e4; /* Purple */
-        --radius-md: 0.625rem;
+        --c-secondary: #90e4c1; /* Mint */
-
+        --c-accent: #ffc900; /* Yellow */
-        --pad-1: 0.5rem;
+        --c-danger: #ff6b6b; /* Red */
-        --pad-2: 0.75rem;
+        --c-surface: #ffffff;
-        --pad-3: 1rem;
+
-        --pad-4: 1.5rem;
+        --border-width: 2px;
-
+        --border: var(--border-width) solid var(--border-color);
-        --text-dim: 0.78;
+        --shadow: 4px 4px 0 0 var(--border-color);
-
+        --shadow-sm: 2px 2px 0 0 var(--border-color);
-        --btn-bg: #f2f3f5;
+        --shadow-hover: 6px 6px 0 0 var(--border-color);
-        --btn-bg-hover: #e7e8ec;
+
-        --btn-bg-active: #d9dbe0;
+        --pad-xs: 0.25rem;
-        --btn-border: #d0d4db;
+        --pad-sm: 0.5rem;
-        --btn-text: #20242c;
+        --pad-md: 0.75rem;
-
+        --pad-lg: 1.5rem;
-        --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
+
-        --sans: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, sans-serif;
+        --font-sans: "Inter", system-ui, -apple-system, sans-serif;
+        --font-mono: "JetBrains Mono", "Fira Code", monospace;
+        --checkerboard-color: light-dark(rgb(from #000 r g b / 0.2), rgb(from #fff r g b / 0.2));
     }
 
     @media (prefers-color-scheme: dark) {
         :root {
-            --btn-bg: #2d3138;
+            /* Gruvbox Dark Palette */
-            --btn-bg-hover: #343944;
+            --bg: #1d2021;
-            --btn-bg-active: #2a2e35;
+            --fg: #ebdbb2;
-            --btn-border: #3c414c;
+            --border-color: #504945;
-            --btn-text: #e8ecf2;
+
+            --c-primary: #d3869b; /* Gruvbox Purple */
+            --c-secondary: #8ec07c; /* Gruvbox Green */
+            --c-accent: #fabd2f; /* Gruvbox Yellow */
+            --c-danger: #fb4934; /* Gruvbox Red */
+            --c-surface: #282828;
         }
     }
 
     body {
-        font-family: var(--sans);
+        font-family: var(--font-sans);
-        min-height: 100vh;
+        background-color: var(--bg);
+        color: var(--fg);
+        line-height: 1.4;
+        /* Dot pattern background */
+        background-image: radial-gradient(rgb(from var(--border-color) r g b / 0.5) 1px, transparent 1px);
+        background-size: 20px 20px;
     }
 
-    code {
+    code,
-        font-family: var(--mono);
+    pre,
-        font-size: 0.95em;
+    textarea,
+    .mono {
+        font-family: var(--font-mono);
+    }
+
+    h1,
+    h2,
+    h3 {
+        margin: 0;
+        font-weight: 900;
+        text-transform: uppercase;
+        letter-spacing: -0.02em;
     }
 }
 
 @layer components {
     .wrap {
-        max-width: 54rem;
+        max-width: 50rem;
-        margin-inline: auto;
+        margin: 0 auto;
-        padding: var(--pad-4);
+        padding: var(--pad-lg);
-    }
-
-    .label {
-        font-size: 0.75rem;
-        opacity: var(--text-dim);
-        font-weight: 600;
-    }
-
-    .hint {
-        font-size: 0.75rem;
-        opacity: var(--text-dim);
     }
 
     .card {
+        background: var(--c-surface);
         border: var(--border);
-        border-radius: var(--radius-lg);
+        box-shadow: var(--shadow);
-        padding: var(--pad-3);
+        padding: var(--pad-md);
-    }
-
-    .field {
         display: grid;
-        grid-template-rows: auto 1fr;
+        gap: var(--pad-md);
-        gap: 0.4rem;
-
-        label {
-            font-size: 0.875rem;
-            opacity: 0.9;
-        }
-
-        input[type="file"],
-        input[type="text"] {
-            width: 100%;
-        }
-
-        input[type="text"] {
-            padding: var(--pad-2);
-            border-radius: var(--radius-lg);
-            border: var(--border);
-            background: transparent;
-            color: inherit;
-        }
-
-        textarea {
-            width: 100%;
-            min-height: 6rem;
-            padding: var(--pad-2);
-            border-radius: var(--radius-lg);
-            border: var(--border);
-            background: transparent;
-            color: inherit;
-            resize: vertical;
-        }
     }
 
+    .btn,
     button,
-    a.button,
+    a.button {
-    .btn {
         display: inline-flex;
         align-items: center;
         justify-content: center;
-        padding: 0.625rem 0.875rem;
+        padding: var(--pad-sm) var(--pad-md);
-        border-radius: var(--radius-md);
+        background: var(--c-primary);
-        border: 1px solid var(--btn-border);
+        color: oklch(from var(--c-primary) calc(1 - l) c h);
-        background: var(--btn-bg);
+        border: var(--border);
-        cursor: pointer;
+        box-shadow: var(--shadow-sm);
+        font-weight: 800;
         text-decoration: none;
-        color: var(--btn-text);
+        cursor: pointer;
-        gap: 0.4rem;
+        transition: all 0.1s;
-        box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.5), inset 0 -1px 0 rgba(0, 0, 0, 0.125);
+        gap: 0.5rem;
+        font-size: 0.85rem;
+        text-transform: uppercase;
+
         &:hover {
-            background: var(--btn-bg-hover);
+            transform: translate(-2px, -2px);
+            box-shadow: var(--shadow);
+            filter: brightness(1.1);
         }
 
         &:active {
-            background: var(--btn-bg-active);
+            transform: translate(2px, 2px);
+            box-shadow: 0 0 0 0 var(--border-color);
+        }
+
+        &[disabled] {
+            opacity: 0.5;
+            cursor: not-allowed;
+            box-shadow: none;
+            transform: none;
+            filter: grayscale(1);
         }
 
         .icon {
@@ -163,54 +160,164 @@
         }
     }
 
+    /* Variant buttons */
+    .btn-accent {
+        background: var(--c-accent);
+    }
+    .btn-secondary {
+        background: var(--c-secondary);
+    }
+    .btn-danger {
+        background: var(--c-danger);
+        color: oklch(from var(--c-danger) calc(1 - l) c h);
+    }
+
+    input[type="text"],
+    input[type="file"],
+    textarea,
+    select {
+        width: 100%;
+        padding: var(--pad-sm);
+        border: var(--border);
+        background: var(--c-surface);
+        border-radius: 0;
+        outline: none;
+        font-size: 0.9rem;
+        transition: box-shadow 0.1s;
+
+        &:focus {
+            box-shadow: var(--shadow-sm);
+            background: var(--c-surface);
+        }
+    }
+
+    textarea {
+        resize: vertical;
+        min-height: 4rem;
+    }
+
+    .label {
+        font-weight: 800;
+        text-transform: uppercase;
+        font-size: 0.7rem;
+        margin-bottom: 0.25rem;
+        display: block;
+        background: var(--c-accent);
+        color: oklch(from var(--c-accent) calc(1 - l) c h);
+        display: inline-block;
+        padding: 0.1rem 0.3rem;
+        border: var(--border);
+        box-shadow: 2px 2px 0 0 var(--border-color);
+    }
+
+    .hint {
+        font-size: 0.75rem;
+        font-weight: 600;
+        opacity: 0.7;
+        margin-top: 0.25rem;
+    }
+
     .error {
-        border: var(--border-danger);
+        background: var(--c-danger);
-        border-radius: var(--radius-lg);
+        color: var(--fg);
-        padding: var(--pad-3);
+        border: var(--border);
+        padding: var(--pad-sm);
+        font-weight: bold;
+        box-shadow: var(--shadow);
         white-space: pre-wrap;
     }
+
+    .field {
+        display: grid;
+        gap: 0.25rem;
+
+        label {
+            font-size: 0.875rem;
+            font-weight: bold;
+        }
+    }
+
+    /* Visually hidden but accessible (for native input) */
+    .sr-only {
+        position: absolute;
+        width: 1px !important;
+        height: 1px;
+        padding: 0;
+        margin: -1px;
+        overflow: hidden;
+        clip: rect(0, 0, 0, 0);
+        white-space: nowrap;
+        border: 0;
+    }
+
+    /* Dropzone styling (applies to label or div) */
+    .dropzone {
+        cursor: pointer;
+        position: relative;
+        padding: 2rem;
+        text-align: center;
+        border: 2px dashed var(--border-color);
+        background: var(--bg);
+        transition: all 0.2s;
+
+        &:hover {
+            background: oklch(from var(--bg) calc(l - 0.05) c h);
+        }
+
+        &.drag-over {
+            background: var(--c-accent);
+            transform: scale(1.01);
+        }
+    }
 }
 
 @layer pages {
     /* Index page */
     .page-index {
+        display: grid;
+        place-items: center;
+        min-height: 100vh;
+
         .wrap {
-            display: grid;
+            width: 100%;
-            gap: 1rem;
         }
 
         h1 {
-            font-size: 1.25rem;
+            background: var(--c-secondary);
-            margin: 0;
+            border: var(--border);
+            box-shadow: var(--shadow);
+            padding: var(--pad-sm);
+            text-align: center;
+            margin-bottom: var(--pad-md);
+            font-size: 1.5rem;
         }
 
         p {
-            margin: 0;
+            background: var(--c-surface);
-            opacity: 0.88;
+            border: var(--border);
-            line-height: 1.45;
+            padding: var(--pad-sm);
-        }
+            margin-bottom: var(--pad-md);
-
+            font-size: 0.9rem;
-        form {
+            font-weight: 500;
-            display: grid;
-            gap: 0.9rem;
         }
 
         .preview {
             display: none;
-            margin-top: 0.75rem;
+            margin-top: var(--pad-sm);
-            padding: var(--pad-2);
+            padding: var(--pad-sm);
-            border-radius: var(--radius-lg);
             border: var(--border);
+            background: var(--bg);
 
             img {
-                border-radius: var(--radius-md);
+                border: var(--border);
             }
 
             .meta {
-                margin-top: 0.5rem;
+                margin-top: var(--pad-xs);
+                font-family: var(--font-mono);
                 font-size: 0.75rem;
-                opacity: var(--text-dim);
+                border-top: var(--border);
-                word-break: break-word;
+                padding-top: var(--pad-xs);
             }
         }
     }
@@ -219,146 +326,172 @@
     .page-result {
         display: grid;
         grid-template-rows: auto 1fr;
+        min-height: 100vh;
 
         .topbar {
             display: flex;
-            gap: 0.75rem;
+            gap: var(--pad-md);
             align-items: center;
-            padding: var(--pad-2) var(--pad-3);
+            padding: var(--pad-sm) var(--pad-md);
             border-bottom: var(--border);
+            background: var(--c-surface);
+            z-index: 10;
 
             a {
                 text-decoration: none;
+                font-weight: 800;
+                text-transform: uppercase;
+                color: var(--fg);
+                &:hover {
+                    text-decoration: underline;
+                }
+            }
+
+            .label {
+                margin: 0;
+                box-shadow: none;
+                background: var(--c-secondary);
+                color: oklch(from var(--c-secondary) calc(1 - l) c h);
             }
         }
 
         .container {
-            min-height: 0;
             display: grid;
-            grid-template-columns: 1fr 1fr;
+            grid-template-columns: 40% 60%;
+            height: 100%;
         }
 
         .pane {
-            min-width: 0;
+            padding: var(--pad-md);
-            padding: var(--pad-3);
+            overflow-y: auto;
-        }
+            display: flex;
+            flex-direction: column;
+            align-items: start;
+            gap: var(--pad-md);
+            height: 100%;
 
-        .left {
+            &.left {
-            border-right: var(--border);
+                border-right: var(--border);
-            display: grid;
+                background: var(--c-surface);
-            grid-template-rows: auto 1fr;
+            }
-            gap: 0.75rem;
+
+            &.right {
+                background: var(--bg);
+            }
         }
 
         .edit-form {
+            display: flex;
+            flex-direction: column;
+            gap: var(--pad-md);
+            flex: 1;
+            width: 100%;
+            height: 100%;
             min-height: 0;
-            display: grid;
-            grid-template-rows: auto 1fr;
-            gap: 0.75rem;
 
-            .prompt-row {
+            .field {
                 display: flex;
-                gap: 0.5rem;
+                flex-direction: column;
-                align-items: stretch;
+                gap: 0.25rem;
 
-                input[type="text"] {
+                &:has(textarea) {
                     flex: 1;
-                    min-width: 0;
+                    min-height: 0;
-                }
-
-                .btn {
-                    white-space: nowrap;
                 }
             }
 
-            .actions {
+            .prompt-row {
                 display: flex;
-                flex-wrap: wrap;
+                gap: var(--pad-sm);
-                gap: 0.5rem;
+
-                align-items: center;
+                input {
+                    flex: 1;
+                }
+                button {
+                    white-space: nowrap;
+                }
             }
 
             textarea {
-                min-height: 10rem;
+                flex: 1;
+                min-height: 0;
+                font-family: var(--font-mono);
+                font-size: 0.8rem;
+                line-height: 1.5;
+                white-space: pre;
+                border: var(--border);
+                box-shadow: inset 2px 2px 0 0 rgba(0, 0, 0, 0.05);
             }
-        }
-
-        /* Fallback: ensure layout even without CSS nesting support */
-        .edit-form .prompt-row {
-            display: flex;
-            gap: 0.5rem;
-            align-items: stretch;
-        }
-
-        .edit-form .prompt-row input[type="text"] {
-            flex: 1;
-            min-width: 0;
-        }
-
-        .edit-form .prompt-row .btn {
-            white-space: nowrap;
-        }
-
-        .right {
-            display: grid;
-            grid-template-rows: auto 1fr auto auto;
-            gap: 0.75rem;
-        }
 
-        textarea {
+            .actions {
-            width: 100%;
+                display: flex;
-            height: 100%;
+                gap: var(--pad-sm);
-            resize: none;
+            }
-            font-family: var(--mono);
-            font-size: 0.85rem;
-            line-height: 1.45;
-            padding: var(--pad-2);
-            border-radius: var(--radius-lg);
-            border: var(--border);
-            white-space: pre;
-            overflow: auto;
         }
 
         .preview {
-            min-height: 15rem;
             display: grid;
             place-items: center;
-            border-radius: var(--radius-lg);
             border: var(--border);
+            background: var(--c-surface);
+            background-image: linear-gradient(
+                    45deg,
+                    var(--checkerboard-color) 25%,
+                    transparent 25%,
+                    transparent 75%,
+                    var(--checkerboard-color) 75%,
+                    var(--checkerboard-color)
+                ),
+                linear-gradient(
+                    45deg,
+                    var(--checkerboard-color) 25%,
+                    transparent 25%,
+                    transparent 75%,
+                    var(--checkerboard-color) 75%,
+                    var(--checkerboard-color)
+                );
+            background-size: 12px 12px;
+            background-position: 0 0, 6px 6px;
+            padding: var(--pad-md);
             overflow: auto;
+            box-shadow: var(--shadow);
+
+            img {
+                max-width: 100%;
+            }
         }
 
         .downloads {
             display: flex;
             flex-wrap: wrap;
-            gap: 0.5rem;
+            gap: var(--pad-sm);
-        }
 
-        .error {
+            .button {
-            font-family: var(--mono);
+                font-size: 0.75rem;
-            font-size: 0.85rem;
+                padding: var(--pad-xs) var(--pad-sm);
+                background: var(--c-surface);
+                color: oklch(from var(--c-surface) calc(1 - l) c h);
+                &:hover {
+                    background: var(--c-secondary);
+                    color: oklch(from var(--c-secondary) calc(1 - l) c h);
+                }
+            }
         }
 
         @media (max-width: 60rem) {
             .container {
                 grid-template-columns: 1fr;
+                grid-template-rows: 1fr auto;
             }
-
+            .pane.left {
-            .left {
                 border-right: none;
                 border-bottom: var(--border);
             }
-        }
 
-        @media (max-width: 40rem) {
             .topbar {
-                flex-wrap: wrap;
+                .label {
-                gap: 0.5rem;
+                    display: none;
-                padding: var(--pad-2) var(--pad-2);
+                }
-            }
-
-            .topbar .label {
-                display: none;
             }
         }
     }

templates/edit.html

@@ -17,7 +17,7 @@
         <div class="container">
             <div class="pane left">
                 <div class="label">Standalone LaTeX/TikZ</div>
-                <form action="{{ base_path }}/{{ run_id }}" method="post" class="edit-form">
+                <form action="{{ base_path }}/d/{{ run_id }}" method="post" class="edit-form">
                     <div class="field">
                         <label for="instructions">Edit instructions</label>
                         <div class="prompt-row">
@@ -50,10 +50,13 @@
                         <textarea id="latex-source" name="latex" spellcheck="false" wrap="off">{{ tex }}</textarea>
                     </div>
                     <div class="actions">
-                        <button class="btn" type="submit" formaction="{{ base_path }}/{{ run_id }}/compile">
+                        <button class="btn" type="submit" formaction="{{ base_path }}/d/{{ run_id }}/compile">
                             <i class="fa-solid fa-play icon" aria-hidden="true"></i>
                             <span>Compile</span>
                         </button>
+                        {% if compile_warning %}
+                        <div class="hint warning" id="compile-warning">{{ compile_warning }}</div>
+                        {% endif %}
                     </div>
                 </form>
             </div>
@@ -69,11 +72,26 @@
                 </div>
 
                 <div class="downloads">
-                    <a class="button" href="{{ download_original_url }}">Download original image</a>
+                    <a class="button" href="{{ download_original_url }}">
-                    <a class="button" href="{{ download_tex_url }}">Download .tex</a>
+                        <i class="fa-solid fa-image icon" aria-hidden="true"></i>
-                    <a class="button" href="{{ download_pdf_url }}">Download .pdf</a>
+                        <span>Original Image</span>
-                    <a class="button" href="{{ download_svg_url }}">Download .svg</a>
+                    </a>
-                    <a class="button" href="{{ download_png_url }}">Download .png</a>
+                    <a class="button" href="{{ download_tex_url }}">
+                        <i class="fa-solid fa-file-code icon" aria-hidden="true"></i>
+                        <span>LaTeX (.tex)</span>
+                    </a>
+                    <a class="button" href="{{ download_pdf_url }}">
+                        <i class="fa-solid fa-file-pdf icon" aria-hidden="true"></i>
+                        <span>PDF</span>
+                    </a>
+                    <a class="button" href="{{ download_svg_url }}">
+                        <i class="fa-solid fa-vector-square icon" aria-hidden="true"></i>
+                        <span>SVG</span>
+                    </a>
+                    <a class="button" href="{{ download_png_url }}">
+                        <i class="fa-solid fa-file-image icon" aria-hidden="true"></i>
+                        <span>PNG</span>
+                    </a>
                 </div>
 
                 {% if error %}
@@ -89,6 +107,7 @@
             const runId = "{{ run_id }}"
             const historySelect = document.getElementById("history-select")
             const latexArea = document.getElementById("latex-source")
+            const compileWarning = document.getElementById("compile-warning")
             const currentTex = latexArea ? latexArea.value : ""
             let historyEntries = []
 
@@ -110,7 +129,8 @@
                     const opt = document.createElement("option")
                     opt.value = String(idx)
                     const statusLabel = entry.status === "error" ? " (error)" : ""
-                    opt.textContent = `${entry.action || "edit"} @ ${formatTs(entry.ts)}${statusLabel}`
+                    const label = entry.summary && entry.summary.trim() ? entry.summary.trim() : entry.action || "edit"
+                    opt.textContent = `${label} @ ${formatTs(entry.ts)}${statusLabel}`
                     frag.appendChild(opt)
                 })
 
@@ -121,7 +141,7 @@
             const loadHistory = async () => {
                 if (!historySelect) return
                 try {
-                    const resp = await fetch(`${basePath}/${runId}/history`)
+                    const resp = await fetch(`${basePath}/d/${runId}/history`)
                     if (!resp.ok) return
                     const data = await resp.json()
                     historyEntries = Array.isArray(data.entries) ? data.entries : []
@@ -148,6 +168,12 @@
 
                 loadHistory()
             }
+
+            if (compileWarning) {
+                setTimeout(() => {
+                    compileWarning.style.display = "none"
+                }, 3500)
+            }
         })()
     </script>
 </html>

templates/index.html

@@ -21,11 +21,11 @@
             <form class="card" action="{{ base_path }}/convert" method="post" enctype="multipart/form-data">
                 <div class="field">
                     <label for="image">Diagram image</label>
-                    <input id="image" name="image" type="file" accept="image/*" required />
+                    <input id="image" class="sr-only" name="image" type="file" accept="image/*" required />
-                    <div class="hint">
+                    <label for="image" id="dropzone" class="dropzone"
-                        Accepted: any format your browser can upload (PNG/JPG recommended). You can also paste an image
+                        >Click here to upload an image (or drag & drop / paste)</label
-                        from the clipboard (Ctrl/Cmd+V).
+                    >
-                    </div>
+                    <div class="hint">Accepted: any format your browser can upload (PNG/JPG recommended).</div>
                     <div class="hint">Daily convert quota: {{ convert_remaining }}/{{ convert_limit }} left today.</div>
 
                     <div id="preview" class="preview" aria-live="polite">
@@ -57,6 +57,7 @@
                 const submitStatus = document.getElementById("submit-status")
                 const convertBtn = document.getElementById("convert-btn")
                 const input = document.getElementById("image")
+                const dropzone = document.getElementById("dropzone")
                 const preview = document.getElementById("preview")
                 const img = document.getElementById("preview-img")
                 const meta = document.getElementById("preview-meta")
@@ -107,6 +108,40 @@
                     showFile(file)
                 })
 
+                // Drag and drop support on label dropzone
+                dropzone.addEventListener("dragenter", e => {
+                    e.preventDefault()
+                    e.stopPropagation()
+                    dropzone.classList.add("drag-over")
+                })
+
+                dropzone.addEventListener("dragleave", e => {
+                    e.preventDefault()
+                    e.stopPropagation()
+                    dropzone.classList.remove("drag-over")
+                })
+
+                dropzone.addEventListener("dragover", e => {
+                    e.preventDefault()
+                    e.stopPropagation()
+                })
+
+                dropzone.addEventListener("drop", e => {
+                    e.preventDefault()
+                    e.stopPropagation()
+                    dropzone.classList.remove("drag-over")
+
+                    const files = e.dataTransfer.files
+                    if (!files || files.length === 0) return
+
+                    for (const file of files) {
+                        if (file.type && file.type.startsWith("image/")) {
+                            setInputFile(file)
+                            return
+                        }
+                    }
+                })
+
                 window.addEventListener("paste", e => {
                     const cd = e.clipboardData
                     if (!cd || !cd.items) return