/* Desmos Scientific Calculator - Global Stylesheet */
:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --primary-accent: #0284c7;
  --primary-hover: #0369a1;
  --calc-display-bg: #f8fafc;
  --calc-btn-bg: #ffffff;
  --calc-btn-text: #1e293b;
  --calc-btn-border: #e2e8f0;
  --calc-btn-hover: #f1f5f9;
  --calc-fn-bg: #f1f5f9;
  --calc-fn-text: #334155;
  --calc-action-bg: #0284c7;
  --calc-action-text: #ffffff;
  --calc-action-hover: #0369a1;
}

html.dark {
  --bg-primary: #0f172a;
  --bg-secondary: #020617;
  --bg-card: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --border-color: #334155;
  --primary-accent: #38bdf8;
  --primary-hover: #0ea5e9;
  --calc-display-bg: #090d16;
  --calc-btn-bg: #1e293b;
  --calc-btn-text: #f8fafc;
  --calc-btn-border: #334155;
  --calc-btn-hover: #334155;
  --calc-fn-bg: #0f172a;
  --calc-fn-text: #cbd5e1;
  --calc-action-bg: #0284c7;
  --calc-action-text: #ffffff;
  --calc-action-hover: #0ea5e9;
}

/* High Contrast Mode */
html.high-contrast {
  --bg-primary: #000000 !important;
  --bg-secondary: #000000 !important;
  --bg-card: #000000 !important;
  --text-main: #ffffff !important;
  --text-muted: #ffff00 !important;
  --border-color: #ffffff !important;
  --primary-accent: #ffff00 !important;
  --calc-display-bg: #000000 !important;
  --calc-btn-bg: #000000 !important;
  --calc-btn-text: #ffffff !important;
  --calc-btn-border: #ffffff !important;
  --calc-btn-hover: #333333 !important;
  --calc-fn-bg: #000000 !important;
  --calc-fn-text: #00ffff !important;
  --calc-action-bg: #ffff00 !important;
  --calc-action-text: #000000 !important;
}

html.high-contrast * {
  border-color: #ffffff !important;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-secondary);
  color: var(--text-main);
  transition: background-color 0.2s ease, color 0.2s ease;
  min-height: 100vh;
  margin: 0;
  display: flex;
  flex-direction: column;
}

/* Calculator Grid and Buttons */
.calc-container {
  max-width: 820px;
  width: 100%;
  margin: 0 auto;
}

.calc-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  user-select: none;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 1.125rem;
  min-height: 48px;
  border-radius: 0.5rem;
  border: 1px solid var(--calc-btn-border);
  background-color: var(--calc-btn-bg);
  color: var(--calc-btn-text);
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  transition: all 0.1s ease-in-out;
  cursor: pointer;
}

.calc-btn:hover {
  background-color: var(--calc-btn-hover);
}

.calc-btn:active {
  transform: translateY(1px);
}

.calc-btn:focus-visible {
  outline: 2px solid var(--primary-accent);
  outline-offset: 2px;
}

.calc-btn-fn {
  background-color: var(--calc-fn-bg);
  color: var(--calc-fn-text);
  font-size: 0.95rem;
  font-family: var(--font-sans);
  font-weight: 600;
}

.calc-btn-op {
  background-color: var(--calc-fn-bg);
  color: #0284c7;
  font-weight: 700;
  font-size: 1.25rem;
}

html.dark .calc-btn-op {
  color: #38bdf8;
}

.calc-btn-action {
  background-color: var(--calc-action-bg);
  color: var(--calc-action-text);
  font-weight: 700;
  font-size: 1.35rem;
}

.calc-btn-action:hover {
  background-color: var(--calc-action-hover);
}

.calc-btn-clear {
  background-color: #fee2e2;
  color: #dc2626;
  font-weight: 600;
}

html.dark .calc-btn-clear {
  background-color: #450a0a;
  color: #f87171;
  border-color: #7f1d1d;
}

.calc-btn-clear:hover {
  background-color: #fecaca;
}

html.dark .calc-btn-clear:hover {
  background-color: #7f1d1d;
}

/* Expression Input Box */
.calc-display-wrapper {
  background-color: var(--calc-display-bg);
  border: 2px solid var(--border-color);
  border-radius: 0.75rem;
  transition: border-color 0.2s ease;
}

.calc-display-wrapper:focus-within {
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
}

#calc-expression {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  line-height: 2rem;
  letter-spacing: -0.025em;
  background: transparent;
  outline: none;
  border: none;
  width: 100%;
  color: var(--text-main);
}

#calc-result {
  font-family: var(--font-mono);
  font-size: 2rem;
  line-height: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.025em;
}

/* History and Variables Scroll Area */
.custom-scroll {
  scrollbar-width: thin;
  scrollbar-color: #cbd5e1 transparent;
}

html.dark .custom-scroll {
  scrollbar-color: #475569 transparent;
}

.custom-scroll::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

.custom-scroll::-webkit-scrollbar-thumb {
  background-color: #cbd5e1;
  border-radius: 9999px;
}

html.dark .custom-scroll::-webkit-scrollbar-thumb {
  background-color: #475569;
}

/* Interactive Math Inputs for Specialized Calculators */
.calc-input-field {
  width: 100%;
  padding: 0.625rem 0.875rem;
  border-radius: 0.5rem;
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  font-family: var(--font-mono);
  font-size: 1rem;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.calc-input-field:focus {
  outline: none;
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
}

/* Mobile Responsiveness adjustments */
@media (max-width: 640px) {
  .calc-btn {
    min-height: 44px;
    font-size: 1rem;
  }
  #calc-expression {
    font-size: 1.25rem;
  }
  #calc-result {
    font-size: 1.6rem;
  }
}