body {
      --bg:#0b1220; --fg:#e8eefc; --muted:#a6b1cf;
      --card:rgba(255,255,255,0.06); --card-border:rgba(255,255,255,0.12);
      --accent:#3b82f6;
      font-family: 'Inter', sans-serif;
      font-weight: 400;
      background: var(--bg);
      color: var(--fg);
    }

    body.theme-light {
      --bg:#f7f8fb; --fg:#0e1320; --muted:#485068;
      --card:#ffffff; --card-border:rgba(14,19,32,0.08);
      --accent:#2563eb;
    }

    h1, h2, h3, h4, h5 {
      font-family: 'Poppins', sans-serif;
      font-weight: 600;
      letter-spacing: 0.3px;
      text-transform: none;
    }

    strong, b {
      font-weight: 500 !important;
    }

    .hover-scale { transition: transform .25s ease; }
    .hover-scale:hover { transform: translateY(-2px) scale(1.02); }
    .inverted-radius{ border-radius: 18px 18px 28px 28px / 18px 18px 10px 10px; }

    ::selection {
      background: var(--accent);
      color: #fff;
    }

    #copyBtn {
      position: absolute;
      background: var(--card);
      border: 1px solid var(--card-border);
      color: var(--accent);
      padding: 4px 10px;
      border-radius: 8px;
      font-size: 13px;
      cursor: pointer;
      display: none;
      z-index: 9999;
      box-shadow: 0 4px 10px rgba(0,0,0,0.2);
      backdrop-filter: blur(6px);
      transition: opacity .2s ease, transform .2s ease;
    }

    #toast {
      position: fixed;
      bottom: 25px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--card);
      border: 1px solid var(--card-border);
      color: var(--fg);
      padding: 8px 14px;
      border-radius: 10px;
      font-size: 14px;
      opacity: 0;
      pointer-events: none;
      transition: opacity .3s ease;
      z-index: 9999;
    }
    #toast.show { opacity: 1; }