/* === Global Variables === */
:root {
  --primary-color: #2c3e50;
  --secondary-color: #34495e;
  --accent-color: #3498db;
  --accent-hover: #2980b9;
  --text-color: #1c1c1c;
  --light-text-color: #f5f5f5;
  --border-color: #ddd;
  --background-color: #f5f6fa;
  --card-background: #e1e3e6;
  --header-height: 60px;
  --spacing-unit: 1rem;
  --hover-bg: rgba(52, 152, 219, 0.1);
}

/* === Reset and Base Styles === */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  width: 100%;
  min-height: 100vh;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  scroll-behavior: smooth;
}

a {
  text-decoration: none;
  color: inherit;
}

/* === Header Styles === */
header {
  background-color: var(--primary-color);
  color: var(--light-text-color);
  padding: var(--spacing-unit);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

header h1 {
  font-size: 1.8rem;
}

/* === Layout Container === */
.calculator-container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--spacing-unit);
}

/* === Card Component === */
.card {
  background-color: var(--card-background);
  border-radius: 10px;
  padding: 1.5rem;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
}

/* === Headings === */
h1, h2, h3 {
  color: var(--primary-color);
  margin-bottom: 1rem;
}

h1 { font-size: 2.2rem; }
h2 { font-size: 1.6rem; }
h3 { font-size: 1.2rem; }

/* === Table Styles === */
.excel-table {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
}

th, td {
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  text-align: left;
}

th {
  background-color: var(--secondary-color);
  color: white;
  font-weight: 600;
}

tr:hover {
  background-color: var(--hover-bg);
}

/* === Input & Select Fields === */
input, select {
  width: 100%;
  padding: 0.6rem;
  font-size: 1rem;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  transition: box-shadow 0.3s, border-color 0.3s;
}

input:focus, select:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
  outline: none;
}

/* Hide number spinner */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* === Total Cost Style === */
.total-cost {
  margin-top: 1rem;
  padding: 1rem;
  background-color: #ffffff;
  border-radius: 4px;
  display: flex;
  align-items: center;
  gap: 1rem;
  border: 1px solid var(--border-color);
}

.total-cost label {
  font-weight: bold;
  color: var(--primary-color);
}

.total-cost input {
  width: 200px;
  background-color: white;
  color: black;
}

/* === Cost Row Enhancements === */
section table tr:last-child td[colspan] {
  background-color: #edf0f3;
  font-weight: bold;
}

section table tr:last-child td[colspan] input {
  width: 25%;
  margin-left: 0.5rem;
}

/* === Buttons === */
.btn {
  background-color: var(--accent-color);
  color: white;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 1rem;
  transition: background-color 0.3s ease-in-out, transform 0.2s;
}

.btn:hover {
  background-color: var(--accent-hover);
  transform: scale(1.05);
}

/* === Footer === */
footer {
  background-color: var(--primary-color);
  color: var(--light-text-color);
  padding: 2rem;
  text-align: center;
}

footer a {
  color: var(--light-text-color);
  margin: 0 1rem;
  transition: color 0.3s;
}

footer a:hover {
  color: var(--accent-color);
  text-decoration: underline;
}

/* === Responsive === */
@media (max-width: 768px) {
  .calculator-container {
    padding: 1rem;
  }

  .card {
    padding: 1rem;
  }

  th, td {
    padding: 0.5rem;
  }

  input, select {
    padding: 0.5rem;
  }

  .total-cost input {
    width: 150px;
  }
}

/* === Accessibility Enhancements === */
input[readonly] {
  background-color: #eee !important;
  color: #666 !important;
  border: 1px solid #ccc !important;
  cursor: not-allowed;
}

.total-project-cost {
  background-color: #26292c;
  padding: 0.75rem 1.5rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 500;
  color: #f0f0f0;
}

.total-project-cost .calculated-value {
  font-family: monospace;
  min-width: 100px;
}

html, body {
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 0;
  overflow-x: hidden; /* prevent unwanted horizontal scroll */
}

.calculator-container {
  width: 100%;
  max-width: none; /* disable max-width constraint */
  margin: 0;
  padding: var(--spacing-unit);
  box-sizing: border-box;
}
.table-container {
    overflow-x: auto;
    width: 100%;
}

#staircaseTable {
    min-width: 1500px; /* or wider depending on column count */
    border-collapse: collapse;
}

#staircaseTable th,
#staircaseTable td {
    padding: 8px;
    min-width: 120px;
    text-align: center;
}

#staircaseTable input,
#staircaseTable select {
    width: 100%;
    box-sizing: border-box;
}