:root {
  --teach-ink-900: #10212e;
  --teach-ink-700: #2d4354;
  --teach-ink-500: #5d7282;
  --teach-paper: #fbfdff;
  --teach-bg-start: #edf4f7;
  --teach-bg-mid: #f7fbfd;
  --teach-bg-end: #eef5f9;
  --teach-primary: #0f7ea8;
  --teach-primary-2: #1397bf;
  --teach-accent: #f18f01;
  --teach-success: #1d9a62;
  --teach-danger: #c62828;
  --teach-border: #d6e2e8;
  --teach-shadow: 0 20px 45px rgba(16, 33, 46, 0.12);
  --teach-radius-sm: 8px;
  --teach-radius-md: 12px;
  --teach-radius-lg: 18px;
  --teach-action-height: 44px;
  --teach-font: 'Poppins', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --teach-bg:
    radial-gradient(circle at 8% 12%, rgba(19, 151, 191, 0.16), transparent 38%),
    radial-gradient(circle at 92% 84%, rgba(241, 143, 1, 0.14), transparent 34%),
    linear-gradient(160deg, var(--teach-bg-start) 0%, var(--teach-bg-mid) 55%, var(--teach-bg-end) 100%);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  font-family: var(--teach-font);
  color: var(--teach-ink-900);
}

a {
  color: inherit;
}

button,
input,
select,
textarea {
  font: inherit;
}

button,
a[class*="btn"],
a[class*="button"] {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid rgba(19, 151, 191, 0.32);
  outline-offset: 2px;
}

.page-footer {
  color: var(--teach-ink-500);
  font-family: var(--teach-font);
}

.teach-btn,
.teach-icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: var(--teach-action-height);
  border: 1px solid var(--teach-border);
  border-radius: var(--teach-radius-sm);
  padding: 10px 14px;
  background: #fff;
  color: var(--teach-ink-700);
  cursor: pointer;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 700;
  line-height: 1.1;
  text-align: center;
  text-decoration: none;
  white-space: normal;
  overflow-wrap: anywhere;
  transition: border-color 0.12s ease, box-shadow 0.12s ease, transform 0.12s ease;
}

.teach-btn:hover,
.teach-icon-btn:hover {
  border-color: rgba(15, 126, 168, 0.46);
  box-shadow: 0 8px 18px rgba(16, 33, 46, 0.1);
  transform: translateY(-1px);
}

.teach-btn:disabled,
.teach-icon-btn:disabled {
  cursor: not-allowed;
  opacity: 0.48;
  transform: none;
  box-shadow: none;
}

.teach-btn--primary {
  border-color: var(--teach-primary);
  background: var(--teach-primary);
  color: #fff;
}

.teach-btn--secondary {
  background: #fff;
  color: var(--teach-ink-700);
}

.teach-btn--quiet {
  background: rgba(255, 255, 255, 0.72);
  color: var(--teach-ink-500);
}

.teach-icon-btn {
  width: var(--teach-action-height);
  min-width: var(--teach-action-height);
  padding: 0;
  font-size: 1.08rem;
  font-weight: 800;
}