* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: 'Poppins', sans-serif;
  background: linear-gradient(135deg, #0a0a0a, #1e1e1e);
  color: #fff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
}
header {
  width: 100%;
  background: rgba(0, 0, 0, 0.85);
  text-align: center;
  padding: 25px 20px 15px;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 0 15px rgba(0, 204, 188, 0.25);
  animation: slideDown 0.6s ease;
}
.header-content {
  display: flex;
  justify-content: center;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 20px;
  position: relative;
}
header h1 {
  font-size: 2.2em;
  color: #00ccbc;
  margin: 0;
  letter-spacing: 1px;
  animation: fadeIn 1s ease;
}
.theme-toggle {
  position: absolute;
  right: 20px;
  width: 70px;
  height: 32px;
  background: rgba(255, 255, 255, 0.1);
  border: 2px solid #00ccbc;
  border-radius: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  padding: 3px;
  transition: all 0.3s ease;
}
.theme-toggle:hover {
  background: rgba(0, 204, 188, 0.2);
  box-shadow: 0 0 15px rgba(0, 204, 188, 0.4);
}
.toggle-slider {
  width: 24px;
  height: 24px;
  background: #00ccbc;
  border-radius: 50%;
  transition: transform 0.3s ease;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}
body.light-mode .toggle-slider {
  transform: translateX(38px);
}
.toggle-text {
  position: absolute;
  right: 8px;
  font-size: 0.7em;
  color: #00ccbc;
  font-weight: 600;
  pointer-events: none;
}
body.light-mode .toggle-text {
  left: 8px;
  right: auto;
}
nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 15px;
}
nav a {
  color: #bbb;
  text-decoration: none;
  margin: 0 15px;
  font-weight: 500;
  transition: all 0.3s ease;
  padding: 5px 10px;
}
nav a:hover,
nav a.active {
  color: #00ccbc;
  text-shadow: 0 0 8px #00ccbc;
  transform: scale(1.05);
}
main {
  flex: 1;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 60px 20px;
}
.cart-box {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 20px;
  box-shadow: 0 0 20px rgba(0, 204, 188, 0.2);
  padding: 40px;
  width: 90%;
  max-width: 750px;
  backdrop-filter: blur(12px);
  animation: slideUp 0.8s ease;
}
.cart-box h2 {
  text-align: center;
  color: #00ccbc;
  margin-bottom: 30px;
  letter-spacing: 1px;
  font-size: 1.8em;
  animation: fadeIn 1.2s ease;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 30px;
  text-align: center;
  color: #eee;
  animation: fadeIn 1.4s ease;
}
th,
td {
  padding: 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
th {
  color: #00ccbc;
  text-transform: uppercase;
  font-weight: 600;
  background: rgba(0, 204, 188, 0.15);
  font-size: 0.9em;
}
tr:nth-child(even) {
  background: rgba(255, 255, 255, 0.05);
}
tbody tr:last-child td {
  border-top: 2px solid #00ccbc;
  font-weight: 600;
  color: #00ccbc;
  font-size: 1.1em;
}
form {
  margin-top: 30px;
  animation: fadeIn 1.6s ease;
}
fieldset {
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  padding: 25px;
  background: rgba(255, 255, 255, 0.05);
}
legend {
  color: #00ccbc;
  font-weight: 600;
  padding: 0 10px;
  font-size: 1.1em;
}
input {
  width: 100%;
  margin: 12px 0;
  padding: 12px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
  font-size: 1em;
  transition: all 0.3s ease;
  font-family: 'Poppins', sans-serif;
}
input:focus {
  border-color: #00ccbc;
  box-shadow: 0 0 10px rgba(0, 204, 188, 0.3);
  outline: none;
  transform: scale(1.02);
}
input[type="submit"] {
  background: linear-gradient(90deg, #00ccbc, #00b2a5);
  color: #000;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 0 15px rgba(0, 204, 188, 0.3);
  margin-top: 10px;
}
input[type="submit"]:hover {
  background: linear-gradient(90deg, #00e0d0, #00ccbc);
  box-shadow: 0 0 20px rgba(0, 204, 188, 0.6);
  transform: translateY(-2px);
}
input[type="submit"]:active {
  transform: translateY(0);
}
footer {
  width: 100%;
  background: rgba(0, 0, 0, 0.9);
  text-align: center;
  padding: 20px;
  color: #aaa;
  font-size: 0.9em;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}
footer p {
  margin: 5px 0;
}
footer a {
  color: #00ccbc;
  text-decoration: none;
  transition: all 0.3s ease;
}
footer a:hover {
  text-decoration: underline;
  color: #00e0d0;
}
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
body.light-mode {
  background: linear-gradient(135deg, #f0f0f0, #ffffff);
  color: #1e1e1e;
}
body.light-mode header {
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}
body.light-mode header h1 {
  color: #00b2a5;
}
body.light-mode nav a {
  color: #555;
}
body.light-mode nav a:hover,
body.light-mode nav a.active {
  color: #00b2a5;
  text-shadow: 0 0 8px rgba(0, 178, 165, 0.3);
}
body.light-mode .cart-box {
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(0, 0, 0, 0.05);
}
body.light-mode .cart-box h2 {
  color: #00b2a5;
}
body.light-mode table {
  color: #333;
}
body.light-mode th {
  color: #00b2a5;
  background: rgba(0, 178, 165, 0.1);
}
body.light-mode td {
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}
body.light-mode tr:nth-child(even) {
  background: rgba(0, 0, 0, 0.03);
}
body.light-mode tbody tr:last-child td {
  border-top: 2px solid #00b2a5;
  color: #00b2a5;
}
body.light-mode fieldset {
  border: 1px solid rgba(0, 0, 0, 0.2);
  background: rgba(0, 0, 0, 0.02);
}
body.light-mode legend {
  color: #00b2a5;
}
body.light-mode input {
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid rgba(0, 0, 0, 0.2);
  color: #1e1e1e;
}
body.light-mode input::placeholder {
  color: #888;
}
body.light-mode input:focus {
  border-color: #00b2a5;
  box-shadow: 0 0 10px rgba(0, 178, 165, 0.3);
}
body.light-mode input[type="submit"] {
  background: linear-gradient(90deg, #00b2a5, #00ccbc);
  color: #fff;
}

body.light-mode input[type="submit"]:hover {
  background: linear-gradient(90deg, #00ccbc, #00e0d0);
}
body.light-mode footer {
  background: rgba(255, 255, 255, 0.95);
  color: #555;
  border-top: 1px solid rgba(0, 0, 0, 0.1);
}
body.light-mode footer a {
  color: #00b2a5;
}
body.light-mode footer a:hover {
  color: #00ccbc;
}
body.light-mode .theme-toggle {
  background: rgba(0, 0, 0, 0.1);
  border: 2px solid #00b2a5;
}
body.light-mode .theme-toggle:hover {
  background: rgba(0, 178, 165, 0.2);
}
body.light-mode .toggle-slider {
  background: #00b2a5;
}
body.light-mode .toggle-text {
  color: #00b2a5;
}
@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@media (max-width: 768px) {
  .header-content {
    padding: 0 10px;
  }
  header h1 {
    font-size: 1.8em;
  }
  .theme-toggle {
    right: 10px;
    width: 65px;
    height: 30px;
  }
  .toggle-slider {
    width: 22px;
    height: 22px;
  }
  body.light-mode .toggle-slider {
    transform: translateX(35px);
  }
  nav {
    flex-direction: column;
    align-items: center;
  }
  nav a {
    margin: 5px 0;
    display: block;
  }
  .cart-box {
    padding: 25px 20px;
    width: 95%;
  }
  .cart-box h2 {
    font-size: 1.5em;
  }
  table {
    font-size: 0.9em;
  }
  th,
  td {
    padding: 10px 5px;
  }

  fieldset {
    padding: 20px 15px;
  }

  input {
    padding: 10px;
    font-size: 0.95em;
  }
}
@media (max-width: 480px) {
  header {
    padding: 20px 10px 12px;
  }
  .header-content {
    padding: 0 5px;
  }
  header h1 {
    font-size: 1.5em;
  }
  .theme-toggle {
    right: 5px;
    width: 60px;
    height: 28px;
  }
  .toggle-slider {
    width: 20px;
    height: 20px;
  }
  body.light-mode .toggle-slider {
    transform: translateX(32px);
  }
  .toggle-text {
    font-size: 0.65em;
  }
  main {
    padding: 40px 15px;
  }
  .cart-box {
    padding: 20px 15px;
  }
  .cart-box h2 {
    font-size: 1.3em;
    margin-bottom: 20px;
  }
  table {
    font-size: 0.85em;
  }
  th,
  td {
    padding: 8px 3px;
  }
  th {
    font-size: 0.8em;
  }
  fieldset {
    padding: 15px 10px;
  }
  legend {
    font-size: 1em;
  }
  input {
    padding: 10px;
    font-size: 0.9em;
  }
  footer {
    font-size: 0.85em;
    padding: 15px;
  }
}