:root {
  --color-pink: #ea0069;
  --color-blue: #5271ff;
  --color-yellow: #fdae00;
  --color-bg: #f0f4ff;
  --color-text: #333;
  --color-header-bg: #fff;
  --color-footer-bg: var(--color-blue);
  --color-footer-text: #fff;
  --font-family-base: 'Poppins', sans-serif;
  --nav-width: 240px;
}

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

body {
  font-family: var(--font-family-base);
  background: var(--color-bg);
  color: var(--color-text);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header */
header {
  background: var(--color-header-bg);
  padding: 10px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
header .logo img {
  height: 45px;
}

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 24px;
  height: 18px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 1100;
}
.nav-toggle .bar {
  width: 100%;
  height: 3px;
  background: var(--color-pink);
  border-radius: 2px;
  transition: transform 0.3s, background 0.3s, opacity 0.3s;
}
.nav-toggle.open .bar:nth-child(1) {
  transform: translateY(7.5px) rotate(45deg);
  background: var(--color-blue);
}
.nav-toggle.open .bar:nth-child(2) {
  opacity: 0;
}
.nav-toggle.open .bar:nth-child(3) {
  transform: translateY(-7.5px) rotate(-45deg);
  background: var(--color-blue);
}

/* Desktop navigation */
.desktop-nav ul {
  list-style: none;
  display: flex;
  gap: 20px;
}
.desktop-nav ul li a {
  display: flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  color: var(--color-pink);
  font-weight: 500;
  position: relative;
  transition: color 0.2s;
}
.desktop-nav ul li a svg {
  fill: currentColor;
  transition: transform 0.2s;
}
.desktop-nav ul li a:hover {
  color: var(--color-blue);
}
.desktop-nav ul li a:hover svg {
  transform: translateY(-2px);
}
.desktop-nav ul li a.active {
  color: var(--color-yellow);
}
.desktop-nav ul li a.active::after {
  content: "";
  position: absolute;
  left: 0; bottom: -4px; width: 100%; height: 2px;
  background: var(--color-yellow);
}

/* Mobile side nav */
.mobile-nav {
  position: fixed;
  top: 0; right: calc(-1 * var(--nav-width));
  width: var(--nav-width);
  height: 100%;
  background: #fff;
  box-shadow: -2px 0 5px rgba(0,0,0,0.2);
  transition: right 0.3s ease;
  z-index: 1001;
  display: flex;
  flex-direction: column;
}
.mobile-nav.open {
  right: 0;
}
.mobile-nav .nav-close {
  align-self: flex-end;
  margin: 10px;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--color-text);
}
.mobile-nav ul {
  list-style: none;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.mobile-nav ul li a {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--color-pink);
  font-weight: 500;
  transition: color 0.2s;
}
.mobile-nav ul li a svg {
  fill: currentColor;
}
.mobile-nav ul li a:hover {
  color: var(--color-blue);
}
.mobile-nav ul li a.active {
  color: var(--color-yellow);
}

/* Overlay */
.overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.4);
  opacity: 0; visibility: hidden;
  transition: opacity 0.3s ease;
  z-index: 1000;
}
.overlay.open {
  opacity: 1; visibility: visible;
}

/* Main container */
.container {
  max-width: 900px;
  width: 100%;
  margin: 20px auto;
  background: #fff;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
  flex: 1 0 auto;
}
h2, h3 {
  margin-bottom: 12px;
  color: var(--color-pink);
}
p {
  margin-bottom: 16px;
  font-size: 0.95rem;
}

/* Error message */
.error-msg {
  color: var(--color-pink);
  margin-bottom: 12px;
  font-size: 0.95rem;
  min-height: 1.2em;
}

/* Table styling */
.table-wrapper {
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 20px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
table {
  width: 100%; border-collapse: collapse; font-size: 0.95rem;
}
thead {
  background: var(--color-blue); color: #fff;
}
thead th {
  padding: 12px; text-align: left; font-weight: 500;
}
tbody tr:nth-child(even) { background: #fafafa; }
tbody tr:nth-child(odd)  { background: #fff; }
td, th {
  padding: 10px; border-bottom: 1px solid #e0e0e0;
}
tbody tr:last-child td { border-bottom: none; }

/* Inputs */
input[type="number"] {
  width: 80px; padding: 5px 8px; border: 1px solid #ccc;
  border-radius: 4px; font-family: var(--font-family-base);
  font-size: 0.9rem; transition: border-color 0.2s, box-shadow 0.2s;
}
input[type="number"]:focus {
  outline: none; border-color: var(--color-blue);
  box-shadow: 0 0 3px rgba(82,113,255,0.5);
}
input.input-error {
  border-color: var(--color-pink); background: #ffe6ec;
}

/* Button */
.btn {
  background: var(--color-pink); color: #fff; border: none;
  padding: 12px 20px; font-size: 1rem; border-radius: 6px;
  cursor: pointer; margin-bottom: 20px;
  transition: background 0.2s, transform 0.1s;
  font-family: var(--font-family-base);
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.btn:hover {
  background: var(--color-yellow); color: var(--color-text);
  transform: translateY(-1px);
}

.button-row {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 15px;
}

.return-btn {
  background-color: #007BFF;
  color: #fff;
  padding: 10px 16px;
  text-decoration: none;
  border-radius: 6px;
  transition: background-color 0.3s ease;
  font-size: 16px;
}

.return-btn:hover {
  background-color: #0056b3;
}

/* Results */
.results {
  font-size: 1.05rem; margin-top: 10px; padding: 15px;
  background: var(--color-yellow); border-radius: 6px;
  color: var(--color-text); box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.results p { margin-bottom: 8px; }

/* Footer */
footer {
  background: var(--color-footer-bg); color: var(--color-footer-text);
  text-align: center; padding: 12px 0; flex-shrink: 0;
}
footer p { font-size: 0.9rem; }

/* Responsive */
@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .desktop-nav { display: none; }
}
@media (min-width: 769px) {
  .mobile-nav, .overlay { display: none; }
}