:root {
  --primary-color: #29b6f6;
  --primary-color-rgb: 41, 182, 246;
  --primary-hover: #0288d1;
  --success-color: #28a745;
  --success-color-rgb: 40, 167, 69;
  --error-color: #dc3545;
  --error-color-rgb: 220, 53, 69;
  --font-family: "Segoe UI", Tahoma, sans-serif;
  --border-radius: 6px;
  --transition-speed: 0.2s;
  --background-start: #141e30;
  --background-end: #243b55;
}

body {
  font-family: var(--font-family);
  margin: 0;
  background: linear-gradient(135deg, var(--background-start), var(--background-end));
  color: #fff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a,
a:visited {
  color: #fff;
}

.site-header {
  text-align: center;
  padding: 2rem 1rem 1rem;
}

.header-image {
  width: 100%;
  max-height: 200px;
  object-fit: cover;
  border-radius: var(--border-radius);
  margin-bottom: 1rem;
}

.banner-img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  object-position: center center;
  display: block;
}

.instructions {
  margin-top: 0.5rem;
  opacity: 0.85;
}

.app-main {
  flex: 1 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

.response-box {
  width: 100%;
  max-width: 600px;
}

footer {
  text-align: center;
  padding: 1rem;
  color: #fff;
  background: rgba(0, 0, 0, 0.2);
}

.idea-form {
  width: 100%;
  max-width: 600px;
  margin: 2rem auto;
  padding: 1rem;
  box-sizing: border-box;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.4);
  font-family: var(--font-family);
  backdrop-filter: blur(6px);
}

.idea-form__textarea {
  width: 100%;
  padding: 0.75rem;
  margin-bottom: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: rgba(0, 0, 0, 0.2);
  color: #fff;
  border-radius: var(--border-radius);
  font-size: 1rem;
  box-sizing: border-box;
  transition: border-color var(--transition-speed) ease-in-out, background-color var(--transition-speed) ease-in-out;
}

.idea-form__textarea:focus-visible {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(var(--primary-color-rgb), 0.25);
}

.submit-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary-color);
  color: #fff;
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: background-color var(--transition-speed) ease-in-out,
              opacity var(--transition-speed) ease-in-out,
              transform var(--transition-speed) ease-in-out;
  position: relative;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

.submit-btn:hover:not(:disabled) {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
}

.submit-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.submit-btn.loading .spinner {
  display: inline-block;
}

.spinner {
  display: none;
  width: 1rem;
  height: 1rem;
  margin-left: 0.5rem;
  border: 2px solid rgba(255, 255, 255, 0.6);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

#resultContainer {
  margin-top: 1rem;
  opacity: 0;
  transition: opacity 0.3s ease-in-out;
  font-size: 1rem;
  padding: 0.5rem 1rem;
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--border-radius);
  white-space: pre-line;
}

#resultContainer.visible {
  opacity: 1;
}

#resultContainer.success {
  color: var(--success-color);
}

#resultContainer.error {
  color: var(--error-color);
}

@media (max-width: 480px) {
  .submit-btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .idea-form__textarea,
  .submit-btn,
  #resultContainer {
    transition: none !important;
  }
  .spinner {
    animation: none !important;
  }
}