:root {
  --primary-color: #ffffff;
  --secondary-color: #e0e0e0;
  --accent-color: #00ddeb;
  --background-color: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  --card-background: #2a2a4a;
  --text-color: #e0e0e0;
  --border-color: #3a3a5a;
  --shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
  --button-gradient: linear-gradient(90deg, #00ddeb 0%, #00aacc 100%);
  --button-hover-gradient: linear-gradient(90deg, #00aacc 0%, #0088aa 100%);
  --error-color: #ff4d4d;
  --success-color: #00ddeb;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Poppins", sans-serif;
  background: var(--background-color);
  color: var(--text-color);
  padding: 40px;
  line-height: 1.6;
}

.main-container {
  max-width: 900px;
  margin: 0 auto;
}

header {
  text-align: center;
  margin-bottom: 40px;
}

header h1 {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 2px;
}

header p {
  font-size: 1rem;
  color: var(--secondary-color);
  opacity: 0.8;
}
.header-link {
  color: #007bff; /* Blue color for the link */
  text-decoration: none; /* Remove default underline */
  font-weight: 500; /* Slightly bold for emphasis */
  transition: color 0.3s ease; /* Smooth hover transition */
}

.header-link:hover {
  color: #0056b3; /* Darker blue on hover */
  text-decoration: underline; /* Underline on hover for clarity */
}

.container {
  background: var(--card-background);
  padding: 30px;
  border-radius: 12px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
}

.input-section h3,
.results-section h3 {
  color: var(--accent-color);
  font-size: 1.5rem;
  margin-bottom: 15px;
  text-align: center;
}

.input-section p {
  text-align: center;
  color: var(--secondary-color);
  font-size: 0.9rem;
  margin-bottom: 20px;
}

.grid-controls {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.control-btn {
  padding: 10px 20px;
  background: var(--button-gradient);
  color: var(--primary-color);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  transition: transform 0.2s, background 0.3s;
  display: flex;
  align-items: center;
  gap: 5px;
}

.control-btn:hover {
  background: var(--button-hover-gradient);
  transform: translateY(-2px);
}

.control-btn span {
  font-size: 1.2rem;
}

.add-btn {
  background: linear-gradient(90deg, #00ddeb 0%, #00aacc 100%);
}

.delete-btn {
  background: linear-gradient(90deg, #ff4d4d 0%, #e63946 100%);
}

.delete-btn:hover {
  background: linear-gradient(90deg, #e63946 0%, #cc3333 100%);
}

table#inputGrid {
  width: 100%;
  margin-bottom: 20px;
  border-collapse: collapse;
}

#inputGrid td {
  padding: 8px;
  text-align: center;
}

#inputGrid input {
  width: 100%;
  padding: 10px;
  background: #1a1a2e;
  color: var(--primary-color);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  font-size: 0.9rem;
  transition: border-color 0.3s;
}

#inputGrid input:focus {
  border-color: var(--accent-color);
  outline: none;
}

#inputGrid input.error {
  border-color: var(--error-color);
  animation: shake 0.3s;
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25%,
  75% {
    transform: translateX(-5px);
  }
  50% {
    transform: translateX(5px);
  }
}

.calculate-btn {
  display: block;
  margin: 0 auto;
  padding: 12px 40px;
  background: var(--button-gradient);
  color: var(--primary-color);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  transition: transform 0.2s, background 0.3s;
}

.calculate-btn:hover {
  background: var(--button-hover-gradient);
  transform: translateY(-3px);
}

.results-section {
  margin-top: 40px;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s, transform 0.5s;
}

.results-section.show {
  opacity: 1;
  transform: translateY(0);
}

table.results {
  width: 100%;
  border-collapse: collapse;
  background: #1a1a2e;
  border-radius: 8px;
  overflow: hidden;
}

.results th,
.results td {
  border: 1px solid var(--border-color);
  padding: 12px;
  text-align: center;
  font-size: 0.9rem;
}

.results th {
  background: #3a3a5a;
  color: var(--primary-color);
  text-transform: uppercase;
  font-weight: 600;
}

.results td {
  background: #2a2a4a;
  color: var(--text-color);
}

.results tr:nth-child(even) td {
  background: #25253f;
}

.results tr:hover td {
  background: #3a3a5a;
  transition: background 0.3s;
}
.navbar {
  background-color: #000;
  color: #fff;
  margin: 1rem; /* m-4 equivalent */
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: Arial, sans-serif;
  border-radius: 7px;
}

.navbar-brand {
  font-size: 1.5rem;
  font-weight: bold;
}

.navbar-links {
  display: flex;
  gap: 1.5rem;
}

.nav-link {
  color: #fff;
  text-decoration: none;
  font-size: 1rem;
  transition: color 0.3s ease;
}

.nav-link:hover {
  color: #ddd;
}

.nav-link.active {
  color: #ffd700; /* Gold color for active link */
  font-weight: bold;
}

/* Optional: Style for your calculator cards if you want to keep them consistent */
.calculator-selection {
  margin: 1rem;
}