GPT-5 Nano

by OpenAIReasoningClean

Running live in a sandboxed frame. Click inside it before using the keyboard.

How it went

Total time: 1 min 56 s
Cost: $0.0059
Output tokens: 14,633
Spent thinking: 11,712 tokens
Speed: 136.3 tok/s
Console errors: 0

First token after: 8.2 s
First visible text after: 1 min 32 s
Prompt tokens: 522
Code size: 8.1 KB
Finish reason: stop
Served by: OpenAI
Model id: openai/gpt-5-nano
Reasoning sent: model default
Max output: 128,000 tokens
Generated: Nov 12, 2026

What it was asked

The prompt

Create a standalone SVG illustration of a fox sitting on a hill, looking at the moon on a starry night, with a few subtle animations. Requirements: - Output a single valid .svg file (```svg code block) with a viewBox of 0 0 800 600. - Hand-written shapes and paths only: no embedded raster images, no external references, no JavaScript. - The fox must be clearly recognizable (pointy ears, snout, bushy tail with a white tip). - Include the moon with a soft glow, many stars, the hill and some background elements (trees, distant hills). - Use a coherent color palette and at least one gradient. - Animations (SMIL or CSS inside the SVG), all looping seamlessly: stars twinkling, the fox's tail swaying gently, and a shooting star crossing the sky every 4 seconds (the first one within 2 seconds).

System prompt, sent with every prompt

You are generating a self-contained web demo. It will be rendered automatically in a sandboxed iframe and compared side by side with the output of other AI models given the exact same task.

Output rules:
- Reply with exactly ONE fenced code block containing the complete file: ```html (or ```svg when the task asks for an SVG). No text before or after the code block.
- Everything must be inline: CSS in <style>, JavaScript in <script>. No external files, images, fonts or network requests, except the CDN URLs explicitly allowed by the task.
- Do not use localStorage, sessionStorage, cookies, IndexedDB, alert(), confirm(), prompt() or window.open(): they are blocked in the sandbox and will throw.
- The page must look right in a 1280×800 viewport and adapt gracefully down to 375px wide. No horizontal scrollbar.
- Something meaningful must be visible on first paint: a screenshot is taken automatically about 3 seconds after load, without any interaction.
- Everything that makes the demo interesting must be visible within the first seconds: nothing hidden behind a high score, a later level or a long play session.
- Games must start in a self-playing demo mode (a simple AI plays) behind a "Click or press a key to start" message, so the game can be judged in action without playing.
- The iframe only receives keyboard events after the user clicks it: if the demo uses the keyboard, display a clear "Click or press a key to start" message.
- The code must run with zero errors in the console of the latest Chrome.

Code run-1.svg · 180 lines

Download

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 800 600" width="800" height="600" role="img" aria-label="Night scene with a fox on a hill watching the moon">
  <defs>
    <!-- Color palette gradients -->
    <linearGradient id="skyGrad" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#0b1a32"/>
      <stop offset="60%" stop-color="#0a2a4a"/>
      <stop offset="100%" stop-color="#071a33"/>
    </linearGradient>

    <linearGradient id="hillGrad" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#2e7a28"/>
      <stop offset="100%" stop-color="#1b5b21"/>
    </linearGradient>

    <linearGradient id="hillDistant" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#284e2b"/>
      <stop offset="100%" stop-color="#122b14"/>
    </linearGradient>

    <linearGradient id="fur" x1="0" y1="0" x2="1" y2="0">
      <stop offset="0%" stop-color="#f28a1f"/>
      <stop offset="100%" stop-color="#e5741a"/>
    </linearGradient>

    <!-- Moon surface -->
    <radialGradient id="moonGrad" cx="50%" cy="50%" r="60%">
      <stop offset="0%" stop-color="#ffffff"/>
      <stop offset="60%" stop-color="#f4f1e0"/>
      <stop offset="100%" stop-color="#dfe6ff"/>
    </radialGradient>

    <!-- Moon glow filter -->
    <filter id="moonGlow" x="-50%" y="-50%" width="200%" height="200%">
      <feGaussianBlur stdDeviation="6" result="blur"/>
      <feMerge>
        <feMergeNode in="blur"/>
        <feMergeNode in="SourceGraphic"/>
      </feMerge>
    </filter>

    <!-- Subtle shadows for depth -->
    <filter id="softShadow" x="-20%" y="-20%" width="140%" height="140%">
      <feDropShadow dx="0" dy="2" stdDeviation="4" flood-color="#000" flood-opacity="0.25"/>
    </filter>

    <!-- Moon halo behind moon (soft glow) -->
    <radialGradient id="halo" cx="50%" cy="50%" r="60%">
      <stop offset="0%" stop-color="#ffffff" stop-opacity="0.9"/>
      <stop offset="60%" stop-color="#ffffff" stop-opacity="0"/>
      <stop offset="100%" stop-color="#ffffff" stop-opacity="0"/>
    </radialGradient>
  </defs>

  <!-- Background sky -->
  <rect width="800" height="600" fill="url(#skyGrad)"/>

  <!-- Distant hills (layer for depth) -->
  <path d="M0,420 C140,380 260,420 420,420 C520,420 660,410 800,420 L800,520 L0,520Z"
        fill="url(#hillDistant)" opacity="0.8"/>

  <!-- Foreground hill on which the fox sits -->
  <path d="M0,420 C100,480 260,520 460,520 C580,520 730,480 800,440 L800,600 L0,600Z"
        fill="url(#hillGrad)" />

  <!-- Some trees on the horizon for atmosphere -->
  <g fill="#2f5f2f" opacity="0.9" filter="url(#softShadow)">
    <polygon points="60,392 72,350 84,392" />
    <polygon points="110,395 122,350 134,395" />
    <polygon points="170,393 184,352 198,393" />
    <polygon points="240,395 254,352 268,395" />
    <polygon points="310,392 322,350 334,392" />
    <polygon points="380,395 392,350 404,395" />
  </g>

  <!-- Stars: twinkling (SMIL) -->
  <g id="stars" fill="#ffffff">
    <circle cx="50" cy="60" r="1.6" fill="#fff">
      <animate attributeName="opacity" values="0.2;1;0.2" dur="3s" repeatCount="indefinite" begin="0s"/>
    </circle>
    <circle cx="100" cy="40" r="1" fill="#fff">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="2.5s" repeatCount="indefinite" begin="0.5s"/>
    </circle>
    <circle cx="140" cy="90" r="1.4" fill="#fff">
      <animate attributeName="opacity" values="0.3;1;0.3" dur="2.8s" repeatCount="indefinite" begin="1s"/>
    </circle>
    <circle cx="200" cy="50" r="1.2" fill="#fff">
      <animate attributeName="opacity" values="0.2;1;0.2" dur="3.5s" repeatCount="indefinite" begin="0s"/>
    </circle>
    <circle cx="240" cy="85" r="1.8" fill="#fff">
      <animate attributeName="opacity" values="0.6;1;0.6" dur="2s" repeatCount="indefinite" begin="0.8s"/>
    </circle>
    <circle cx="320" cy="60" r="1.2" fill="#fff">
      <animate attributeName="opacity" values="0.3;1;0.3" dur="2.2s" repeatCount="indefinite" begin="0.3s"/>
    </circle>
    <circle cx="360" cy="110" r="1" fill="#fff">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="3s" repeatCount="indefinite" begin="0s"/>
    </circle>
    <circle cx="420" cy="50" r="1.5" fill="#fff">
      <animate attributeName="opacity" values="0.2;1;0.2" dur="2.5s" repeatCount="indefinite" begin="1.2s"/>
    </circle>
    <circle cx="480" cy="90" r="1.6" fill="#fff">
      <animate attributeName="opacity" values="0.5;1;0.5" dur="2.7s" repeatCount="indefinite" begin="0.2s"/>
    </circle>
    <circle cx="540" cy="60" r="1" fill="#fff">
      <animate attributeName="opacity" values="0.3;1;0.3" dur="3s" repeatCount="indefinite" begin="0s"/>
    </circle>
    <circle cx="590" cy="100" r="1.3" fill="#fff">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="2.4s" repeatCount="indefinite" begin="1.5s"/>
    </circle>
    <circle cx="650" cy="70" r="1.2" fill="#fff">
      <animate attributeName="opacity" values="0.2;1;0.2" dur="2.9s" repeatCount="indefinite" begin="0.6s"/>
    </circle>
    <circle cx="700" cy="110" r="1.4" fill="#fff">
      <animate attributeName="opacity" values="0.5;1;0.5" dur="3.1s" repeatCount="indefinite" begin="0s"/>
    </circle>
    <circle cx="760" cy="60" r="1" fill="#fff">
      <animate attributeName="opacity" values="0.3;1;0.3" dur="2.6s" repeatCount="indefinite" begin="0.9s"/>
    </circle>
    <circle cx="770" cy="90" r="1.5" fill="#fff">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="3s" repeatCount="indefinite" begin="0s"/>
    </circle>
    <!-- more subtle small stars -->
    <circle cx="60" cy="120" r="0.8" fill="#fff">
      <animate attributeName="opacity" values="0.2;1;0.2" dur="2s" repeatCount="indefinite" begin="1.7s"/>
    </circle>
    <circle cx="180" cy="140" r="0.9" fill="#fff">
      <animate attributeName="opacity" values="0.3;1;0.3" dur="2.4s" repeatCount="indefinite" begin="0.4s"/>
    </circle>
    <circle cx="260" cy="60" r="0.8" fill="#fff">
      <animate attributeName="opacity" values="0.2;1;0.2" dur="2.2s" repeatCount="indefinite" begin="0s"/>
    </circle>
  </g>

  <!-- The Moon with soft glow -->
  <g transform="translate(640,120)">
    <circle cx="0" cy="0" r="46" fill="url(#moonGrad)" filter="url(#moonGlow)"/>
    <circle cx="0" cy="0" r="78" fill="url(#halo)" opacity="0.4"/>
  </g>

  <!-- The fox on a hill: stylized, hand-drawn shapes with a swaying tail -->
  <g id="fox" transform="translate(210,320)">
    <!-- Tail (back of the fox) with gentle sway animation around its base -->
    <g id="tail" transform="translate(-20,0)">
      <path d="M50,60 C70,20 130,-10 170,10 C210,32 230,80 190,110 C150,140 90,140 60,120 Z"
            fill="url(#fur)">
        <!-- Tail sway around its base (approx at 60,60) -->
        <animateTransform attributeName="transform" type="rotate"
                          values="-6 60 60; 6 60 60; -6 60 60" dur="2s"
                          repeatCount="indefinite"/>
      </path>
      <!-- white tip overlay for tail -->
      <path d="M150,70 C160,80 170,88 178,96 C168,100 150,98 138,94 C140,86 144,78 150,70 Z"
            fill="#fff" opacity="0.95"/>
    </g>

    <!-- Body and head (fox recognizably with pointy ears, snout) -->
    <ellipse cx="120" cy="110" rx="120" ry="60" fill="url(#fur)" filter="url(#softShadow)"/>
    <!-- Chest / belly (lighter patch) -->
    <ellipse cx="140" cy="140" rx="70" ry="40" fill="#ffffff" opacity="0.85"/>

    <!-- Head and ears -->
    <ellipse cx="40" cy="60" rx="50" ry="40" fill="url(#fur)"/>
    <polygon points="22,28 38,48 60,28" fill="#f28a1f"/> <!-- left ear inner shape -->
    <polygon points="4,42 28,50 30,26" fill="#f28a1f"/> <!-- left ear outer -->
    <polygon points="72,28 90,48 70,60" fill="#f28a1f"/> <!-- right ear -->
    <polygon points="56,34 66,54 48,54" fill="#f28a1f"/>

    <!-- Snout and nose -->
    <ellipse cx="60" cy="78" rx="26" ry="14" fill="#f28a1f"/>
    <circle cx="72" cy="82" r="3" fill="#000"/>

    <!-- Eye -->
    <circle cx="26" cy="56" r="4" fill="#000"/>

    <!-- Front legs (peeking from under chest) -->
    <rect x="60" y="150" width="18" height="40" rx="6" fill="#e07a1f" />
    <rect x="100" y="150" width="18" height="40" rx="6" fill="#e07a1f" />

  </g>
</svg>

Reasoning trace (11,712 tokens)

**Designing animations for a night sky**

I’m working on defining a radial gradient for moonlight. For the shooting star, I envision a small line segment moving across the sky every 4 seconds, with the first appearance within 2 seconds after starting. I’m considering using SMIL animateMotion to move this line across the top of the sky. I want to create a white-glowing line and define an `<animateMotion>` path. It looks like I’ll set the timing to make this visually engaging!**Animating a shooting star in SVG**

I'm working on how to use `<animateMotion>` with the path attribute in SVG. The idea is to create a group for a shooting star that animates from left to right across the sky. I want the first animation to begin at 2 seconds and last 0.9 seconds, repeating indefinitely. To achieve a shooting star every 4 seconds, I plan to use SMIL with `<animateTransform>` for the translation. I’m considering different approaches to ensure the star jumps and resets smoothly. It’s a bit tricky, but I’m figuring it out!**Creating a shooting star animation**

I want the star to appear and move smoothly. To do that, I’ll set its opacity to start at 0 and animate it to 1 quickly as it crosses the sky. I’m thinking of defining a `<circle>` with animations: one for opacity and another for transformation. However, SMIL’s transform and translate can’t apply at the same time. I plan to set the initial values properly and ensure that after 4 seconds, it resets for the next cycle. Let’s see how it unfolds!**Setting up shooting star timing**

I'm focusing on the timing for the shooting star animation. I want the next appearance to begin at 6 seconds, so it'd repeat every 4 seconds after the initial 2 seconds. In SMIL, I can specify multiple start times like "2s;6s;10s." If I set begin to "2s" with a duration of "4s" and a repeat count of "indefinite," it’ll work as expected. This setup means the star will move across the sky every 4 seconds, starting at 2 seconds — perfect for my animation!**Crafting an enchanting night sky scene**

I’m designing a night sky with twinkling stars, a moon glow, and a fox on a hill. The first star will appear 2 seconds after loading, moving across the sky with varying opacities for a twinkling effect. I plan to add 25 stars in random positions, each using different beginning times for their animations. The background will feature a dark blue gradient, with a moon using a radial gradient and a glow effect. The fox will have a stylized shape, with distinct features and a white-tipped tail. I’ll ensure everything remains an inline SVG with consistent colors!**Designing a stylized fox with animations**

I'm working on an SVG illustration featuring a fox sitting on a hill while facing the moon. The fox will have a body made of an orange rounded rectangle, an oval head, triangular ears, and a small snout. I want the tail to be bushy, with a separate white tip, so I'll create a curved path for it. The animations will include subtle movements like a swaying tail and twinkling stars. To make everything cohesive, I'll ensure it adheres to the "no JavaScript" rule and implements SMIL for animations inside the SVG.**Crafting the fox and hill illustration**

I’m drawing a stylized fox with a clear body, head, ears, and a bushy tail. The fox will use simple shapes like an ellipse for the body and circles for the head. I need to add details like the ears, snout, and legs. It’s important to ensure the fox is recognizable. Additionally, I’m crafting a hill using a path with gradients for realism and implementing some stars in the sky with slight animations. The SVG will have a gradient background, and I’ll ensure some visible elements on the initial render.**Designing the SVG scene**

I'm creating an illustration involving a fox on a hill, ensuring the hill shape stays within the viewBox. I'll add smaller hills behind it for depth, using a gradient for the fill. Tree silhouettes will be formed by triangles along the horizon. For the moon's glow, I’ll implement a filter. Animations will involve twinkling stars and a swaying tail for the fox. The SVG will include gradients for the sky and moon, along with a structured layout to ensure clarity and visual appeal. It's a detailed plan, and I’m excited to implement it!**Crafting the SVG code**

I'm defining a gradient for the fox's shading and using a solid color for the squirrel. It's important to ensure that the initial paint displays key elements like the moon, hill, and stars. I plan to animate around 20 stars in the sky with twinkling effects using circles. For a shooting star, I’ll create a group that will move across the sky, adhering to timing to ensure it’s visible at the right moment. I’ll assemble everything into a single SVG code block to keep it organized. Let’s put this all together!**Defining SVG gradients and shapes**

I'm working on setting up SVG gradients for the sky, moon, and hills. I’ve defined various color stops for a pleasing visual effect, like using a dark gradient for the sky and a soft glow for the moon. I'm adding shapes for the hills and designing the stars with twinkling animations. For the fox, I initially planned elaborate details but realized simplifying the design could save time while keeping it clear. I think each element should fit well together in the final composition!**Designing the fox character and landscape**

I’m defining various shapes and paths to construct a fox character with a bushy tail and a white tip. For the body and head, I’m using ellipses, while the ears and snout are represented with polygons and small ellipses. Initially, I considered adding a belly patch but decided to skip that to keep it simple. Now, I'm focusing on ensuring that even a silhouette can be recognized as a fox.

Next, I’ll create elements for the background, including hills and trees, and piece everything together into one cohesive SVG code block!