:root{
      --bg-1: #f3f6fb;
      --bg-2: #e8eff9;
      --card-bg: #ffffff;
      --primary: #1f6feb;
      --muted: #f1f5f9;
      --danger: #ef4444;
      --text-strong: #0b2545;
      --text-muted: #475569;
      --radius-lg: 14px;
      --radius-md: 10px;
      --shadow: 0 10px 30px rgba(8, 30, 66, 0.08);
    }

    *{
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: 'Poppins', system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
    }

    html,body{
      height: 100%;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      font-size: 16px;
      background-color: var(--bg-1);
    }

    body{
      background-image:
        linear-gradient(180deg, rgba(7, 32, 70, 0.60), rgba(7, 32, 70, 0.32)),
        url('https://images.unsplash.com/photo-1503264116251-35a269479413?auto=format&fit=crop&w=1350&q=80');
      background-size: cover;
      background-position: center;
      background-attachment: fixed;
      color: var(--text-strong);
    }

    #main{
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 2.25rem;
    }

    .box{
      width: 100%;
      max-width: 420px;
      background: linear-gradient(180deg, rgba(255,255,255,0.98), rgba(250,250,252,0.98));
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow);
      padding: 1.5rem;
      display: flex;
      flex-direction: column;
      align-items: stretch;
      gap: 1.25rem;
      backdrop-filter: blur(6px);
      border: 1px solid rgba(11,37,69,0.06);
    }

    h1{
      font-size: 2.5rem;
      line-height: 1;
      font-weight: 700;
      color: var(--text-strong);
      background: linear-gradient(90deg, rgba(31,111,235,0.06), rgba(31,111,235,0.02));
      border-radius: var(--radius-md);
      padding: 1.25rem;
      text-align: center;
      width: 100%;
      display: flex;
      align-items: center;
      justify-content: center;
      letter-spacing: 0.01em;
      box-shadow: inset 0 -1px 0 rgba(8,30,66,0.03);
    }

    .controls{
      width: 100%;
      display: flex;
      gap: 0.75rem;
      justify-content: center;
      flex-wrap: wrap;
    }

    button{
      border: none;
      cursor: pointer;
      padding: 0.9rem 1.15rem;
      border-radius: 10px;
      font-weight: 600;
      font-size: 1rem;
      min-width: 110px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: transform 120ms ease, box-shadow 120ms ease, opacity 120ms ease;
      box-shadow: 0 4px 10px rgba(8,30,66,0.04);
    }

    button:active{
      transform: translateY(1px);
    }

    button:focus{
      outline: 3px solid rgba(31,111,235,0.15);
      outline-offset: 3px;
    }

    .inc{
      background: var(--primary);
      color: #ffffff;
      box-shadow: 0 8px 24px rgba(31,111,235,0.16);
    }

    .inc:hover{
      transform: translateY(-3px);
      opacity: 0.98;
    }

    .reset{
      background: var(--muted);
      color: var(--text-strong);
    }

    .reset:hover{
      transform: translateY(-3px);
      opacity: 0.98;
    }

    .dec{
      background: var(--danger);
      color: #ffffff;
      box-shadow: 0 8px 24px rgba(239,68,68,0.12);
    }

    .dec:hover{
      transform: translateY(-3px);
      opacity: 0.98;
    }

    @media (max-width: 420px){
      .box{
        padding: 1rem;
        gap: 0.75rem;
      }
      h1{
        font-size: 2rem;
        padding: 1rem;
      }
      button{
        min-width: 95px;
        padding: 0.75rem 0.9rem;
        font-size: 0.95rem;
      }
    }