body {
  font-family: 'Segoe UI', Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f7f7f7;
}

#app {
  max-width: 500px;
  margin: 2rem auto;
  background: #fff;
  min-height: 100vh;
  box-shadow: 0 2px 16px rgba(0,0,0,0.10);
  padding: 2rem 1.5rem 2rem 1.5rem;
  border-radius: 14px;
}

h2 {
  font-size: 2rem;
  margin-bottom: 1.2rem;
  font-weight: 700;
}

label {
  display: block;
  margin: 1.1em 0 0.3em 0.1em;
  font-size: 1.08em;
  font-weight: 500;
}

input, select {
  width: 100%;
  padding: 0.9em 1em;
  margin-bottom: 0.7em;
  border-radius: 6px;
  border: 1.5px solid #d0d0d0;
  font-size: 1.08em;
  background: #f9f9f9;
  box-sizing: border-box;
  transition: border 0.2s;
}
input:focus, select:focus {
  border: 1.5px solid #222;
  outline: none;
}

button {
  width: 100%;
  background: #222;
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 1em 0;
  font-size: 1.15em;
  font-weight: 600;
  margin-top: 1.2em;
  margin-bottom: 0.5em;
  cursor: pointer;
  transition: background 0.2s;
}
button:active {
  background: #444;
}


.bill-preview {
  background: #fff;
  border: 1.5px solid #e0e6ef;
  padding: 2.2em 0.7em 2em 0.7em;
  margin: 2em 0 1.5em 0;
  border-radius: 18px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.07);
  max-width: 100%;
}

.bill-preview h3 {
  font-size: 1.7em;
  margin-bottom: 1.2em;
  color: #1a1a1a;
  letter-spacing: 1px;
  text-align: center;
}

.bill-preview table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.2em 0 1.5em 0;
  font-size: 1.08em;
  min-width: 480px;
  background: #fff;
}
.bill-preview th, .bill-preview td {
  border: 1px solid #dbe3ef;
  padding: 0.9em 0.7em;
  text-align: left;
  word-break: break-word;
}
.bill-preview th {
  background: #eaf1fb;
  font-weight: 600;
  color: #222;
}
.bill-preview td {
  background: #fff;
}
.bill-preview .totals {
  text-align: right;
  margin-top: 1.2em;
  font-size: 1.13em;
  background: #f5f8fc;
  border-radius: 10px;
  padding: 1.2em 1em;
  margin-bottom: 1.2em;
}
.bill-preview .totals div {
  margin-bottom: 0.3em;
}
.bill-preview .notes {
  margin-top: 1.5em;
  font-size: 1.05em;
  color: #666;
}
.bill-preview .bill-section {
  background: #f5f8fc;
  border-radius: 10px;
  padding: 1.2em 1em 1em 1em;
  margin-bottom: 1.7em;
}
.bill-preview .bill-header {
  text-align: center;
  margin-bottom: 1.5em;
}
.bill-preview .bill-header .biller-name {
  font-size: 1.5em;
  font-weight: 800;
  color: #1a1a1a;
  letter-spacing: 1px;
  margin-bottom: 0.2em;
}
.bill-preview .bill-header .biller-contact,
.bill-preview .bill-header .biller-address {
  font-size: 1.08em;
  color: #222;
  margin-bottom: 0.2em;
}
.bill-preview .bill-header .biller-gstin {
  font-size: 1em;
  color: #555;
}
.bill-preview .invoice-title {
  text-align: center;
  font-size: 1.25em;
  font-weight: 700;
  color: #222;
  letter-spacing: 1px;
  margin-bottom: 1.2em;
}
.bill-preview .bill-dates {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 1.2em;
  font-size: 1.08em;
  color: #222;
}
.bill-preview .bill-dates div {
  margin-bottom: 0.2em;
}
.bill-preview .bill-section .bill-to-label {
  font-weight: 700;
  margin-bottom: 0.3em;
  color: #1a1a1a;
  font-size: 1.08em;
}
.bill-preview .bill-section .bill-to-name,
.bill-preview .bill-section .bill-to-address {
  margin-bottom: 0.2em;
  font-size: 1.08em;
  color: #222;
}
.bill-preview .bill-section .bill-to-gstin {
  font-size: 1em;
  color: #555;
}

@media (max-width: 700px) {
  .bill-preview {
    padding: 1.2em 0.2em 1.2em 0.2em;
    border-radius: 10px;
  }
  .bill-preview table {
    font-size: 0.98em;
    min-width: 340px;
  }
}
@media (max-width: 480px) {
  .bill-preview {
    padding: 0.7em 0.1em 0.7em 0.1em;
    border-radius: 7px;
  }
  .bill-preview table {
    font-size: 0.92em;
    min-width: 260px;
  }
}

@media (max-width: 600px) {
  #app { padding: 0.5rem; }
  .bill-preview { padding: 1em 0.5em; }
  h2 { font-size: 1.3rem; }
}