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

html {
  font-display: swap;
}

body {
  font-family:
    "Inter",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    Oxygen,
    Ubuntu,
    Cantarell,
    sans-serif;
  background: #24273a;
  min-height: 100vh;
  line-height: 1.6;
  color: #cad3f5;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem;
}

.header {
  text-align: center;
  margin-bottom: 3rem;
  color: #cad3f5;
}

.header-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.header-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0;
  background: none;
  -webkit-background-clip: unset;
  background-clip: unset;
  -webkit-text-fill-color: unset;
  color: #f5f7ff;
}

.header-subtitle {
  margin-top: 0.4rem;
  font-size: 0.9rem;
  opacity: 0.85;
}

.header h1 {
  font-size: 3.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #f5bde6, #8bd5ca, #8aadf4);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header p {
  font-size: 1.25rem;
  opacity: 0.9;
  font-weight: 300;
  margin-bottom: 1.5rem;
}

.install-btn {
  display: inline-block;
  margin-top: 0;
  background: linear-gradient(135deg, #7dc4e4, #91d7e3);
  color: #1e2030;
  border: none;
  padding: 0.6rem 1.1rem;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(125, 196, 228, 0.18);
}

.install-btn[disabled] {
  opacity: 0.6;
  cursor: not-allowed;
}

.simple-calculator-btn {
  background: linear-gradient(135deg, #7dc4e4, #91d7e3);
  color: #1e2030;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
  box-shadow: 0 4px 15px rgba(125, 196, 228, 0.3);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.simple-calculator-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(125, 196, 228, 0.4);
}

.calculator-card {
  background: #1e2030;
  border-radius: 24px;
  padding: 4rem 3rem;
  box-shadow: 0 25px 50px rgba(0, 0, 0, 0.5);
  margin-bottom: 2rem;
  border: 1px solid #363a4f;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.calculator-container {
  margin-bottom: 3rem;
}

.input-section {
  background: #181926;
  border-radius: 16px;
  padding: 2rem;
  margin-bottom: 2rem;
  border: 1px solid #363a4f;
}

.input-section h2 {
  color: #8aadf4;
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  text-align: center;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  color: #b8c0e0;
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.5rem;
}

.form-group input {
  width: 100%;
  padding: 1rem 1.5rem;
  border: 2px solid #5b6078;
  border-radius: 12px;
  background: #181926;
  color: #cad3f5;
  font-size: 1rem;
  font-weight: 500;
  transition: border-color 0.2s ease;
  font-family: inherit;
}

.form-group input:focus {
  outline: none;
  border-color: #8aadf4;
  background: #1e2030;
}

.form-group input:hover {
  border-color: #6e738d;
}

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

input[type="number"] {
  -moz-appearance: textfield;
  appearance: textfield;
}

.generate-btn,
.calculate-btn {
  background: linear-gradient(135deg, #8aadf4, #c6a0f6);
  color: #1e2030;
  border: none;
  padding: 1rem 2rem;
  border-radius: 12px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
  box-shadow: 0 4px 15px rgba(138, 173, 244, 0.3);
  width: 100%;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.generate-btn:hover,
.calculate-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(138, 173, 244, 0.4);
}

.course-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
  padding: 1rem;
  background: #1e2030;
  border: 1px solid #363a4f;
  border-radius: 12px;
  transition: transform 0.2s ease;
}

.course-row:hover {
  transform: translateY(-2px);
}

.course-row label {
  color: #8aadf4;
  font-weight: 600;
  margin: 0;
  min-width: 120px;
}

.course-row input,
.course-row select {
  padding: 0.75rem 1rem;
  border: 2px solid #5b6078;
  border-radius: 8px;
  background: #181926;
  color: #cad3f5;
  font-size: 1rem;
  transition: border-color 0.2s ease;
}

.course-row input:focus,
.course-row select:focus {
  outline: none;
  border-color: #8aadf4;
  background: #1e2030;
}

.course-row select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23cad3f5' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6,9 12,15 18,9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1rem;
  padding-right: 2.5rem;
}

.loading-section {
  text-align: center;
  margin: 2rem 0;
  padding: 2rem;
  background: #181926;
  border-radius: 12px;
  border: 1px solid #363a4f;
}

.loading-content {
  display: inline-flex;
  align-items: center;
  color: #cad3f5;
  font-weight: 600;
  gap: 0.75rem;
}

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid #5b6078;
  border-top: 3px solid #8aadf4;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.result-section {
  background: linear-gradient(135deg, #a6da95, #94e2d5);
  color: #1e2030;
  padding: 2rem;
  border-radius: 16px;
  text-align: center;
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 2rem;
  box-shadow: 0 8px 25px rgba(166, 218, 149, 0.3);
}

.error-message {
  background: rgba(237, 135, 150, 0.1);
  border: 1px solid rgba(237, 135, 150, 0.3);
  color: #ed8796;
  padding: 1rem 1.5rem;
  border-radius: 12px;
  text-align: center;
  font-weight: 600;
  margin-top: 2rem;
}

.how-to-use-card {
  background: #1e2030;
  border-radius: 16px;
  padding: 2rem;
  border: 1px solid #363a4f;
  margin-top: 2rem;
}

.how-to-use-card h2 {
  color: #f5bde6;
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  text-align: center;
}

.steps-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.5rem;
  background: #181926;
  border: 1px solid #363a4f;
  border-radius: 12px;
}

.step-number {
  background: linear-gradient(135deg, #f5bde6, #c6a0f6);
  color: #1e2030;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.step-content p {
  margin: 0;
  color: #b8c0e0;
  line-height: 1.6;
  font-size: 1rem;
}

.step-content a {
  color: #7dc4e4;
  text-decoration: none;
  font-weight: 600;
}

.step-content a:hover {
  text-decoration: underline;
}

@media (max-width: 768px) {
  .container {
    padding: 1rem;
    max-width: 100%;
  }

  .header-row {
    justify-content: space-between;
    gap: 0.5rem;
  }

  .header-title {
    font-size: 1rem;
  }

  .install-btn {
    padding: 0.45rem 0.8rem;
    font-size: 0.85rem;
    margin-top: 0;
  }

  .header h1 {
    font-size: 2.5rem;
  }

  .calculator-card {
    padding: 2rem 1.5rem;
    max-width: 100%;
    margin: 0 auto 2rem auto;
  }

  .input-section {
    padding: 1.5rem;
  }

  .course-row {
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
  }

  .course-row input,
  .course-row select {
    width: 100%;
  }

  .course-row label {
    min-width: auto;
    text-align: center;
  }

  .step {
    padding: 1rem;
    gap: 0.8rem;
  }

  .step-number {
    width: 2rem;
    height: 2rem;
    font-size: 0.9rem;
  }

  .step-content p {
    font-size: 0.9rem;
  }
}

@media (max-width: 480px) {
  .header h1 {
    font-size: 2rem;
  }

  .calculator-card {
    padding: 1.5rem 1rem;
  }

  .input-section {
    padding: 1rem;
  }

  .generate-btn,
  .calculate-btn {
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

button:focus,
input:focus,
select:focus {
  outline: 2px solid #8aadf4;
  outline-offset: 2px;
}

::selection {
  background: rgba(138, 173, 244, 0.3);
  color: #cad3f5;
}