:root{
      --card-bg:#ffffff;
      --page-bg:#f9fafc;
      --text:#222;
      --muted:#6b7280;
      --shadow:0 4px 12px rgba(0,0,0,.08), inset 0 0 6px rgba(0,0,0,0.35);
      --radius:14px;
      --gap:15px;
      --min-col: 150px; 
    }
    *{
        box-sizing: border-box;
    }
    body{
      margin:0; 
      padding:20px;
      font-family: system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,"Helvetica Neue",Arial;
      background:var(--page-bg); 
      color:var(--text);
    }
    header{
        margin-bottom:10px;
        text-align: center;
    }
    h1{
        margin:0 0 10px;
    }

    .sub{
        margin:0 auto 18px;
        color:var(--muted);
        font-size:14px
    }
    .cards{
      width: 100%;
      display:grid;
      grid-template-columns:repeat(auto-fit, minmax(var(--min-col), 1fr));
      gap:var(--gap);
      padding:10px 0;
      align-items:stretch;
      margin: auto;
    }
    .card{
      background:var(--card-bg);
      border-radius:var(--radius);
      box-shadow:var(--shadow);
      padding:14px;
      text-align:center;
    }
    .cost{
        width: 90%;
        max-height: 400px;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        background:var(--card-bg);
        border-radius:var(--radius);
        box-shadow:var(--shadow);
        padding: 30px;
        margin:60px auto;
        text-align: center;
    }
    .cardInfo{
        display: flex;
        width: 100%;
        height: 100%;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        padding: 20px;
    }
    .card h3{
        margin:.25rem 0 .5rem 0;
        font-size: 16px;
    }

    .value{
        font-weight:700;
        margin-top:8px
    }

    .value.small{
        font-weight:600;
        color:var(--muted);
        font-size:14px}
    canvas{ 
        height: auto;
        padding: 10px;
    }
    .controls{
        display:flex;
        justify-content:center;
        gap:10px;
        flex-wrap:wrap; 
        margin-top: 50px auto;}

    .btn{
      padding:10px 16px;
      border:0;
      border-radius:10px;
      cursor:pointer;
      box-shadow:var(--shadow);
      font-weight:600
    }
    .btn.on{
        background:#16a34a;
        color:#fff
    }

    .btn.off{
        background:#dc2626;
        color:#fff
    }
    .btn.reset{
        background: #10b981;
        color:#fff
    }
    .btn:hover{
        box-shadow:inset 0 0 6px rgba(0,0,0,0.75);
        transform:translateY(-2px)
    }
    /* Container styling */
    /* Control panel wrapper */
#history-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin:  1rem auto 0;
  padding: 1rem 1.5rem;
  border-radius: 12px;
  box-shadow: 0 -3px 8px rgba(0, 0, 0, 0.08);
  flex-wrap: wrap;
}

/* Date input */
#datePicker {
  padding: 0.6rem 1rem;
  border: 2px solid #6e7a86;
  border-radius: 8px;
  font-size: 0.95rem;
  color: #333;
  outline: none;
  transition: border-color 0.3s ease;
}

#datePicker:focus {
  border-color: #011120;
  box-shadow: 0 0 4px rgba(19, 47, 77, 0.6);
}

/* Fetch button */
#fetchLogs {
  padding: 0.6rem 1.2rem;
  background: #6e7a86;
  color: white;
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.3s ease, transform 0.2s ease;
}

#fetchLogs:hover {
  background: #6b8fb3;
  transform: translateY(-2px);
}

#fetchLogs:active {
  background: #66a4e2;
  transform: translateY(0);
}

#history {
  margin-top: 2rem;
  overflow-x: auto;
}

#historyTable {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 3px 8px rgba(0, 0, 0, 0.08);
}

#historyTable thead {
  background: #6e7a86;
  color: #fff;
  text-align: left;
}

#historyTable th, #historyTable td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid #ddd;
  font-size: 0.95rem;
}

#historyTable tbody tr:hover {
  background: #f5faff;
}

footer{
    text-align: center;
    color:var(--muted);
    font-size:14px;
    margin-top: 50px;
}

    /* Make charts fit on small screens */                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
    @media (max-width: 768px){
      canvas{
        max-width:100%; 
        width: 100%;
        height: 280px;
        }
        .cost{
            width: 100%;
            max-height: 500px;
            padding: 5px;
            canvas{
                width: 100%;
                height: 300;
            }
        }
        .card.energy{
            grid-column: span 2;
            width: 100%;
            margin: auto;
        }
    }