GPT-5 Nano

by OpenAIReasoningClean

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

How it went

Total time: 28.0 s
Cost: $0.0018
Output tokens: 4,364
Spent thinking: 768 tokens
Speed: 170.9 tok/s
Console errors: 0

First token after: 2.4 s
First visible text after: 8.5 s
Prompt tokens: 522
Code size: 9.7 KB
Finish reason: stop
Served by: OpenAI
Model id: openai/gpt-5-nano
Reasoning sent: {"effort":"low"}
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 · 219 lines

Download

<svg width="100%" height="100%" viewBox="0 0 800 600" xmlns="http://www.w3.org/2000/svg" version="1.1">
  <defs>
    <!-- Sky gradient -->
    <linearGradient id="sky" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#0b1b3a"/>
      <stop offset="60%" stop-color="#182447"/>
      <stop offset="100%" stop-color="#0a1a33"/>
    </linearGradient>

    <!-- Moon glow -->
    <radialGradient id="moonGrad" cx="30%" cy="30%" r="60%">
      <stop offset="0%" stop-color="#f9f9f9"/>
      <stop offset="60%" stop-color="#d8e0f4"/>
      <stop offset="100%" stop-color="#a8b6d0"/>
    </radialGradient>

    <!-- Hills gradient -->
    <linearGradient id="hillGrad" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#2b5d3a"/>
      <stop offset="100%" stop-color="#174b2b"/>
    </linearGradient>

    <!-- Fox colors -->
    <linearGradient id="fur" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#d86a2a"/>
      <stop offset="100%" stop-color="#a8521c"/>
    </linearGradient>
    <linearGradient id="tailGrad" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#e38a50"/>
      <stop offset="100%" stop-color="#b65b1c"/>
    </linearGradient>

    <!-- Subtle white fur tip on tail -->
    <linearGradient id="tailTip" x1="0" y1="0" x2="0" y2="1">
      <stop offset="0%" stop-color="#ffffff"/>
      <stop offset="100%" stop-color="#f6f6f6"/>
    </linearGradient>

    <!-- Stars opacity twinkle (common) -->
    <style>
      /* Allow CSS-only animation as fallback, SMIL is also used for some elements. */
      .twinkle { opacity: 0.8; }
      .fox { transform-origin: 360px 370px; } /* not used by SMIL; for completeness if CSS toggled */
    </style>

    <!-- Subtle glow filter for moon -->
    <filter id="moonGlow" x="-40%" y="-40%" width="180%" height="180%">
      <feGaussianBlur stdDeviation="2.5" result="blur"/>
      <feMerge>
        <feMergeNode in="blur"/>
        <feMergeNode in="SourceGraphic"/>
      </feMerge>
    </filter>
  </defs>

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

  <!-- Stars (many small points) with varied twinkling -->
  <!-- Layer 1: farther stars -->
  <g fill="#e9f7ff" opacity="0.95">
    <circle class="twinkle" cx="60" cy="90" r="1.4">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="3s" repeatCount="indefinite" keyTimes="0;0.5;1"/>
    </circle>
    <circle class="twinkle" cx="140" cy="120" r="1" >
      <animate attributeName="opacity" values="0.25;1;0.25" dur="4s" repeatCount="indefinite" begin="0.2s"/>
    </circle>
    <circle class="twinkle" cx="210" cy="60" r="1.2">
      <animate attributeName="opacity" values="0.5;1;0.5" dur="3.5s" repeatCount="indefinite" begin="0.6s"/>
    </circle>
  </g>

  <!-- Layer 2: mid stars -->
  <g fill="#dbeaff" opacity="0.95">
    <circle cx="320" cy="100" r="1.1">
      <animate attributeName="opacity" values="0.3;1;0.3" dur="2.8s" repeatCount="indefinite" begin="0.15s"/>
    </circle>
    <circle cx="420" cy="150" r="0.9">
      <animate attributeName="opacity" values="0.6;1;0.6" dur="3.2s" repeatCount="indefinite" begin="0.8s"/>
    </circle>
    <circle cx="520" cy="90" r="1.2">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="3.6s" repeatCount="indefinite" begin="1.0s"/>
    </circle>
    <circle cx="600" cy="140" r="1.0">
      <animate attributeName="opacity" values="0.5;1;0.5" dur="2.6s" repeatCount="indefinite" begin="0.3s"/>
    </circle>
  </g>

  <!-- Layer 3: distant stars (tiny dots) -->
  <g fill="#f0f8ff" opacity="0.9">
    <circle cx="70" cy="260" r="0.6">
      <animate attributeName="opacity" values="0.3;0.95;0.3" dur="4s" repeatCount="indefinite" begin="0.4s"/>
    </circle>
    <circle cx="150" cy="260" r="0.7">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="3s" repeatCount="indefinite" begin="0.9s"/>
    </circle>
    <circle cx="250" cy="230" r="0.5">
      <animate attributeName="opacity" values="0.3;0.9;0.3" dur="5s" repeatCount="indefinite" begin="1.5s"/>
    </circle>
    <circle cx="320" cy="280" r="0.6">
      <animate attributeName="opacity" values="0.4;1;0.4" dur="4.5s" repeatCount="indefinite" begin="0.7s"/>
    </circle>
    <circle cx="400" cy="210" r="0.5">
      <animate attributeName="opacity" values="0.2;0.95;0.2" dur="3.5s" repeatCount="indefinite" begin="0.2s"/>
    </circle>
  </g>

  <!-- Moon with glow -->
  <g transform="translate(620,120)">
    <circle cx="0" cy="0" r="40" fill="url(#moonGrad)" filter="url(#moonGlow)"/>
    <!-- subtle crescent shading -->
    <path d="M -35 -6 A 40 40 0 0 1 0 -8 A 25 25 0 0 0 -10 8 Z" fill="#f0f0f0" opacity="0.25"/>
  </g>

  <!-- Distant hills (background) -->
  <path d="M0,420 C80,400 140,420 210,410 C270,400 340,420 420,410 C500,400 560,420 640,410 C700,400 760,420 800,410 L800,600 L0,600 Z" fill="url(#hillGrad)" opacity="0.95"/>

  <!-- Foreground hill where fox sits -->
  <path d="M0,480 C120,440 260,480 400,455 C520,440 660,480 800,460 L800,600 L0,600 Z" fill="#2a6a3b" opacity="0.9"/>

  <!-- Some trees and distant hills for composition -->
  <g fill="#1e5b2b" opacity="0.85">
    <path d="M60,420 L70,420 L75,360 L90,420 Z" />
    <path d="M120,430 L130,430 L140,380 L150,430 Z" />
    <path d="M200,425 L210,425 L215,390 L225,425 Z" />
    <path d="M260,428 L270,428 L275,390 L285,428 Z" />
  </g>

  <!-- Fox sitting on hill -->
  <!-- Body (torso) -->
  <g id="fox" transform="translate(240,360)">
    <!-- Tail (left side) with white tip -->
    <g transform="translate(-40,-20)">
      <path d="M120,90 C160,60 210,60 240,90 C270,125 270,170 210,180 C180,184 140,170 120,150 C110,140 110,110 120,90 Z"
            fill="url(#tailGrad)">
        <!-- tail shadow shading -->
        <animate attributeName="d" dur="6s" repeatCount="indefinite" values="
          M120,90 C160,60 210,60 240,90 C270,125 270,170 210,180 C180,184 140,170 120,150 C110,140 120,110 120,90 Z;
          M122,92 C163,58 213,58 246,92 C274,128 270,172 210,184 C178,188 142,170 120,150 C112,142 120,110 122,92 Z;
          M120,90 C160,60 210,60 240,90 C270,125 270,170 210,180 C180,184 140,170 120,150 C110,140 110,110 120,90 Z"/>
      </path>
      <!-- little white tip -->
      <path d="M210,150 C200,147 196,144 190,140 C196,150 206,158 210,150 Z" fill="white" opacity="0.7">
        <animate attributeName="opacity" values="0.6;1;0.6" dur="2.5s" repeatCount="indefinite" begin="0s"/>
      </path>
    </g>

    <!-- Head (snout and ears) -->
    <g transform="translate(60,-10)">
      <!-- ears -->
      <path d="M25,20 L40,0 L52,20 Z" fill="#d86a2a"/>
      <path d="M60,20 L46,0 L58,20 Z" fill="#d86a2a"/>
      <!-- face -->
      <ellipse cx="40" cy="26" rx="28" ry="22" fill="url(#fur)"/>
      <!-- snout -->
      <path d="M12,28 C18,36 34,40 54,38 C58,37 60,34 60,32 C58,32 54,32 50,32 C40,31 26,29 18,26 Z" fill="#f4b689"/>
      <!-- black nose -->
      <circle cx="48" cy="32" r="4" fill="#1b1b1b"/>
    </g>

    <!-- Neck and chest -->
    <ellipse cx="120" cy="320" rx="60" ry="42" fill="url(#fur)" transform="translate(0,-6)"/>
    <ellipse cx="140" cy="340" rx="50" ry="50" fill="#e29a53" opacity="0.95" transform="translate(0,-8)"/>

    <!-- Body -->
    <path d="M120,320 C170,300 210,310 260,340 C260,360 250,380 230,390 C210,400 170,395 150,380 C130,370 110,360 100,360 Z" fill="url(#fur)"/>

    <!-- Leg (left) -->
    <path d="M110,410 C118,420 126,436 132,448 L140,450 C128,424 118,414 110,410 Z" fill="#b05b2b"/>

    <!-- Leg (right) -->
    <path d="M190,410 C198,420 206,436 212,448 L220,452 C210,426 198,414 190,410 Z" fill="#b05b2b"/>

    <!-- Eye -->
    <circle cx="74" cy="290" r="3" fill="#1a1a1a"/>

    <!-- Tail group (to allow sway) -->
    <g id="tail" transform="translate(0,0)">
      <!-- Tail base connection to body -->
      <path d="M170,350 C210,330 240,310 260,290 C270,286 276,284 278,284 C260,300 232,322 210,336 C190,348 170,350 170,350 Z" fill="url(#tailGrad)"/>
      <!-- White tip on tail -->
      <path d="M236,290 C248,294 254,304 260,314 C260,306 256,296 252,292 C250,291 244,290 236,290 Z" fill="white" opacity="0.9"/>
      <!-- Tail sway animation (rotate around base point near 170,350) -->
      <animateTransform attributeName="transform" type="rotate" values="-6 170 350;6 170 350;-6 170 350" dur="2s" repeatCount="indefinite" begin="0s" />

    </g>
  </g>

  <!-- Subtle horizon glow to separate sky and land -->
  <ellipse cx="400" cy="580" rx="520" ry="60" fill="#000" opacity="0"/>

  <!-- Ground shadow under fox for depth -->
  <ellipse cx="320" cy="460" rx="120" ry="20" fill="#000" opacity="0.15"/>

  <!-- Optional gentle parallax hills for depth (foreground above is hill; add a small crest) -->
  <path d="M0,520 C120,500 240,520 360,500 C480,480 600,510 800,500 L800,600 L0,600 Z" fill="#1e6a3a" opacity="0.25"/>

  <!-- Shooting star (SMIL animation moving across the sky) -->
  <g fill="none" stroke="white" stroke-width="2" opacity="0.95">
    <!-- The shooting star is a small diagonal line with a trailing glow -->
    <path id="shoot1" d="M -60,60 L -20,44" stroke="white" stroke-width="2" />
    <path d="M -60,60 L -20,44" stroke="white" stroke-width="2" opacity="0.6">
      <animateTransform attributeName="transform" attributeType="XML" type="translate" values="0,0;800,0" dur="4s" begin="0s" repeatCount="indefinite"/>
    </path>
  </g>

  <!-- Shooting star tail glow (assistive small glow) -->
  <path d="M -60,60 L -20,44" stroke="white" stroke-width="2" opacity="0.6">
    <animate attributeName="opacity" values="0.0;0.8;0.0" dur="4s" begin="0s" repeatCount="indefinite"/>
  </path>

  <!-- Final ensure the main fox group sits above background elements -->
  <style>
    /* Ensure no accidental overflow on small screens */
    @media (max-width: 420px) {
      svg { max-width: 420px; height: auto; }
    }
  </style>
</svg>

Reasoning trace (768 tokens)

**Creating an animated SVG**

I need to deliver a single SVG with animations using SMIL or CSS, avoiding JS entirely. The animation will include a glowing moon, twinkling stars, a swaying fox tail, and a shooting star every four seconds, with the first appearing within two seconds. I'll set the viewBox to 0 0 800 600 and use hand-drawn shapes. The SVG should feature a night sky gradient and organized groups to facilitate the animations. I'll implement multiple shooting stars to create an engaging effect!**Configuring shooting stars**

The first shooting star should appear within two seconds—0 seconds meets that requirement. I want it to loop indefinitely, so I'll set repeatCount to "indefinite." For the motion, I can create a path element and use animate to move it diagonally across the sky with a duration of 4 seconds, starting immediately. The translate action will need a starting point, and I’ll use translate attributes wisely. Stars will be small circles scattered randomly throughout, giving a nice, manual touch!**Animating the scene elements**

I’ll use `<animate>` to create a twinkling effect for the stars, adjusting opacity between 0.6 and 1 over three seconds, looping indefinitely. For added variety, I can stagger the start times.

For the fox, I’ll design it using simple polygon shapes: triangles for ears, an oval for the head, and polygons for the snout and body. The tail will sway with a rotation animation anchored at its base.

For the moon, I’ll create a soft glow effect using a gradient and a blur filter. I’ll keep the hills and trees simple with curves and triangles.**Setting up the SVG code**

I need to ensure the SVG viewBox is set to 800x600, which is crucial for proper scaling. I'll also provide an accessible color palette to enhance visibility. My focus is on creating a clean code block without any extra text or links. This will keep it straightforward and efficient. Alright, let’s dive in and write the code!