body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
  margin: 0;
  padding: 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

header {
  background-color: #fff;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-top {
  padding: 15px 0;
  border-bottom: 1px solid #eee;
}

.header-top .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
}

.nav-container .container {
  padding: 0 20px;
}

.logo-container {
  display: flex;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: #333;
  font-weight: bold;
  font-size: 1.5rem;
}

.logo i {
  color: #4285f4;
  margin-right: 10px;
}

.header-actions {
  display: flex;
  align-items: center;
}

.mobile-menu-btn {
  cursor: pointer;
  font-size: 1.5rem;
  color: #333;
  display: none;
}

main {
  min-height: calc(100vh - 200px);
  padding: 40px 0;
}

.tool-content {
  background-color: #fff;
  border-radius: 10px;
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.05);
  padding: 30px;
  max-width: 1200px;
  margin: 0 auto;
}

.tool-header {
  text-align: center;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 1px solid #eee;
}

.tool-icon-large {
  font-size: 3rem;
  color: #4285f4;
  margin-bottom: 15px;
}

.tool-header h1 {
  margin: 0;
  font-size: 2.2rem;
  color: #333;
}

.tool-header p {
  margin-top: 10px;
  color: #666;
  font-size: 1.1rem;
}

.calculator-container {
  max-width: 400px;
  margin: 0 auto;
}

.calculator-display {
  background-color: #f9f9f9;
  border: 1px solid #ddd;
  border-radius: 8px;
  padding: 15px;
  margin-bottom: 20px;
  text-align: right;
}

#calculator-input {
  width: 100%;
  border: none;
  background: transparent;
  font-size: 1.5rem;
  font-weight: bold;
  text-align: right;
  outline: none;
}

#calculator-result {
  color: #666;
  font-size: 1rem;
  margin-top: 5px;
  min-height: 20px;
}

.calculator-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.calc-button {
  padding: 15px;
  font-size: 1.2rem;
  border: 1px solid #ddd;
  border-radius: 8px;
  background-color: #f9f9f9;
  cursor: pointer;
  transition: all 0.2s;
}

.calc-button:hover {
  background-color: #e9e9e9;
  transform: translateY(-1px);
}

.calc-button:active {
  transform: translateY(0);
}

.calc-button.operator {
  background-color: #4285f4;
  color: white;
  border-color: #4285f4;
}

.calc-button.operator:hover {
  background-color: #3367d6;
}

.calc-button.clear {
  background-color: #ea4335;
  color: white;
  border-color: #ea4335;
}

.calc-button.clear:hover {
  background-color: #d33b2c;
}

.calc-button.equals {
  background-color: #34a853;
  color: white;
  border-color: #34a853;
}

.calc-button.equals:hover {
  background-color: #2d8e47;
}

.calc-button.zero {
  grid-column: span 2;
}

.notification {
  position: fixed;
  top: 80px;
  right: 20px;
  background-color: #34a853;
  color: white;
  padding: 12px 20px;
  border-radius: 6px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  z-index: 1001;
  opacity: 0;
  transform: translateX(100%);
  transition: all 0.3s ease;
}

.notification.show {
  opacity: 1;
  transform: translateX(0);
}

.notification.error {
  background-color: #ea4335;
}

.notification.info {
  background-color: #4285f4;
}

footer {
  background-color: #fff;
  padding: 30px 0;
  border-top: 1px solid #eee;
}

.footer-bottom {
  text-align: center;
  color: #666;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .mobile-menu-btn {
    display: block;
  }

  nav ul {
    flex-direction: column;
    align-items: center;
  }

  nav ul li {
    margin: 5px 0;
    width: 100%;
    text-align: center;
  }

  .tool-content {
    padding: 20px 15px;
  }

  .tool-header h1 {
    font-size: 1.8rem;
  }

  .calculator-buttons {
    gap: 8px;
  }

  .calc-button {
    padding: 12px;
    font-size: 1.1rem;
  }
}