:root {
      --unsw-yellow: #e6b800; 
      --black: #0a0a0a;
      --light-gray: #cfcfcf;
      --white: #f8f8f8;
    }

    * { margin: 0; padding: 0; box-sizing: border-box; }

    body {
      font-family: "Inter", "Helvetica Neue", Arial, sans-serif;
      color: var(--white);
      line-height: 1.6;
      overflow-x: hidden;
      background: var(--black);
      position: relative;
    }

    #grid {
      position: fixed;
      top: 0; left: 0;
      width: 100%; height: 100%;
      z-index: -2;
      overflow: hidden;
      perspective: 800px;
    }

    .nebula {
      position: absolute;
      top: -50%; left: -50%;
      width: 200%; height: 200%;
      background: radial-gradient(circle at 20% 30%, rgba(230, 184, 0, 0.2), transparent 40%),
                  radial-gradient(circle at 80% 70%, rgba(255, 255, 255, 0.1), transparent 40%),
                  radial-gradient(circle at 50% 90%, rgba(230, 184, 0, 0.15), transparent 40%);
      animation: nebulaMove 20s ease-in-out infinite alternate;
      filter: blur(60px);
    }

    @keyframes nebulaMove {
      0%   { transform: translate(0,0) scale(1); }
      50%  { transform: translate(-5%, -5%) scale(1.1); }
      100% { transform: translate(5%, 5%) scale(1); }
    }

    .grid-plane {
      position: absolute;
      top: 50%; left: 50%;
      width: 200%; height: 200%;
      background-image: linear-gradient(rgba(230, 184, 0, 0.35) 1px, transparent 1px),
                        linear-gradient(90deg, rgba(230, 184, 0, 0.35) 1px, transparent 1px);
      background-size: 50px 50px;
      transform: translate(-50%, -50%) perspective(600px) rotateX(70deg);
      opacity: 0.3;
      animation: gridFlow 8s linear infinite, pulseGlow 3s ease-in-out infinite;
      filter: drop-shadow(0 0 6px rgba(230,184,0,0.6));
      will-change: transform;
    }

    @keyframes gridFlow {
      0%   { background-position: 0 0; }
      100% { background-position: 0 50px; }
    }

    @keyframes pulseGlow {
      0%, 100% { opacity: 0.2; }
      50%      { opacity: 0.4; }
    }

    header {
      position: fixed;
      top: 0; width: 100%;
      padding: 1.2rem 3rem;
      display: flex; justify-content: space-between; align-items: center;
      background: rgba(0,0,0,0.75);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid #222;
      z-index: 10;
    }
    header .logo { font-size: 1.3rem; font-weight: 700; color: var(--unsw-yellow); }
    header nav a {
      margin-left: 2rem; color: var(--light-gray);
      text-decoration: none; font-size: 0.95rem;
      transition: color 0.3s ease;
    }
    header nav a:hover { color: var(--unsw-yellow); }

    .hero {
      height: 100vh; display: flex; flex-direction: column;
      justify-content: center; align-items: center; text-align: center;
      padding: 0 2rem;
    }
    .hero h1 {
      font-size: clamp(2.5rem, 6vw, 4rem);
      font-weight: 800; color: var(--unsw-yellow);
      margin-bottom: 1rem;
      text-shadow: 0 0 15px rgba(230,184,0,0.5),
                   0 0 25px rgba(230,184,0,0.3);
    }
    .hero p {
      max-width: 650px; color: var(--light-gray);
      font-size: 1.2rem; margin-bottom: 2rem;
      white-space: normal; 
    }

    .typing {
      border-right: 2px solid var(--unsw-yellow);
      overflow: hidden;
      display: inline-block;
      font-size: 1.2rem;
      animation: blink .8s step-end infinite;
    }
    @keyframes blink {
      from, to { border-color: transparent }
      50% { border-color: var(--unsw-yellow); }
    }

    .hero button {
      background: var(--unsw-yellow); border: none; color: var(--black);
      font-size: 1rem; font-weight: 600;
      padding: 0.9rem 2rem; border-radius: 40px; cursor: pointer;
      transition: all 0.3s ease;
      box-shadow: 0 0 15px rgba(230,184,0,0.6);
    }
    .hero button:hover {
      transform: translateY(-3px);
      box-shadow: 0 0 30px rgba(230,184,0,0.9);
    }

    section {
      min-height: 80vh; display: flex; flex-direction: column;
      justify-content: center; align-items: center; text-align: center;
      padding: 6rem 2rem; border-top: 1px solid #222;
      position: relative;
      z-index: 1;
    }
    section h2 {
      font-size: 2.3rem; margin-bottom: 1rem;
      font-weight: 700; color: var(--unsw-yellow);
      text-shadow: 0 0 12px rgba(230,184,0,0.4);
    }
    section p {
      max-width: 700px; color: var(--light-gray);
      font-size: 1.1rem; margin-bottom: 2rem;
      white-space: normal; 
    }

    .upload-box {
      background: rgba(20, 20, 20, 0.9);
      border: 1px solid #333; border-radius: 20px;
      padding: 2.5rem; margin-top: 2rem;
      width: 100%; max-width: 500px; text-align: center;
      box-shadow: 0 0 25px rgba(230,184,0,0.3);
    }

    .upload-box input[type="file"] { display: none; }
    .custom-file {
      display: flex; align-items: center;
      background: #111; border: 1px solid #333;
      border-radius: 12px; overflow: hidden; margin-bottom: 1rem;
    }
    .custom-file label {
      background: var(--unsw-yellow);
      color: var(--black);
      padding: 0.8rem 1.2rem;
      cursor: pointer; font-weight: 600;
      flex-shrink: 0;
    }
    .custom-file span {
      padding: 0.8rem 1rem; color: var(--light-gray);
      flex-grow: 1;
      text-align: left;
    }

    .upload-box button {
      display: block;
      margin: 0 auto; 
      background: var(--unsw-yellow); border: none;
      padding: 0.8rem 1.8rem; border-radius: 30px;
      font-weight: 600; cursor: pointer; color: var(--black);
      transition: 0.3s; margin-top: 1rem;
      box-shadow: 0 0 18px rgba(230,184,0,0.5);
    }
    .upload-box button:hover {
      background: #ffd633; box-shadow: 0 0 28px rgba(230,184,0,0.8);
    }

    footer {
      padding: 2rem; text-align: center;
      color: #aaa; font-size: 0.9rem; border-top: 1px solid #222;
      z-index: 1;
      position: relative;
    }