/* ==========================================================================
   TRIGNOVA - AURORA MINT & SUNSET CORAL DESIGN SYSTEM & STYLESHEET
   Aesthetics: Deep Obsidian Emerald / Forest Slate (#070d0a, #0c1612),
               Hyper Mint (#00f5a0), Electric Emerald (#10b981),
               Sunset Coral (#ff6b6b / #fa5252), Solar Amber (#facc15),
               Arctic Sky Blue (#38bdf8)
   Features: Dual Theme (Aurora Dark / Pristine Sage Light), Glassmorphism,
             Rich Diagrams & Visual Geometries
   ========================================================================== */

:root {
  /* Dark Mode Palette (Default: Aurora Obsidian & Hyper Mint) */
  --bg-cosmos: #070d0a;
  --bg-surface: #0b1511;
  --bg-card: rgba(12, 23, 19, 0.78);
  --bg-card-hover: rgba(18, 34, 28, 0.9);
  --bg-glass: rgba(11, 21, 17, 0.7);
  --bg-card-solid: #0e1c16;
  --bg-input: rgba(15, 29, 23, 0.85);
  --bg-inset: rgba(6, 12, 9, 0.65);

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-card: rgba(0, 245, 160, 0.16);
  --border-focus: #00f5a0;
  --border-hover: rgba(0, 245, 160, 0.45);

  --text-primary: #f0fdf4;
  --text-secondary: #cbd5e1;
  --text-muted: #86efac;
  --text-dim: #64748b;

  /* Vibrant Aurora Brand Colors */
  --mint-primary: #00f5a0;
  --mint-secondary: #10b981;
  --mint-dark: #059669;
  --mint-glow: rgba(0, 245, 160, 0.35);

  --coral-accent: #ff6b6b;
  --coral-light: #ff8787;
  --coral-glow: rgba(255, 107, 107, 0.35);

  --solar-amber: #facc15;
  --solar-light: #fde047;
  --solar-glow: rgba(250, 204, 21, 0.3);

  --arctic-sky: #38bdf8;
  --arctic-glow: rgba(56, 189, 248, 0.3);

  --purple-accent: #a855f7;

  /* Typography */
  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;

  /* Shadows & Glows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.65);
  --shadow-mint: 0 0 25px rgba(0, 245, 160, 0.22);
  --shadow-coral: 0 0 25px rgba(255, 107, 107, 0.22);

  /* Spacing & Radii */
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);

  --container-max: 1340px;
}

/* Light Theme (Pristine Sage & Arctic Forest Slate) */
[data-theme="light"] {
  --bg-cosmos: #f2f7f4;
  --bg-surface: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-card-hover: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.88);
  --bg-card-solid: #ffffff;
  --bg-input: #f8fafc;
  --bg-inset: #e8f0ec;

  --border-subtle: #d1e0d7;
  --border-card: rgba(16, 185, 129, 0.3);
  --border-focus: #059669;
  --border-hover: rgba(16, 185, 129, 0.6);

  --text-primary: #064e3b;
  --text-secondary: #1e293b;
  --text-muted: #059669;
  --text-dim: #64748b;

  --mint-primary: #059669;
  --mint-secondary: #10b981;
  --mint-dark: #047857;
  --mint-glow: rgba(5, 150, 105, 0.2);

  --coral-accent: #e11d48;
  --coral-light: #f43f5e;
  --coral-glow: rgba(225, 29, 72, 0.2);

  --solar-amber: #d97706;
  --solar-light: #f59e0b;
  --solar-glow: rgba(217, 119, 6, 0.2);

  --arctic-sky: #0284c7;

  --shadow-sm: 0 2px 8px rgba(6, 78, 59, 0.05);
  --shadow-md: 0 8px 20px rgba(6, 78, 59, 0.08);
  --shadow-lg: 0 16px 36px rgba(6, 78, 59, 0.12);
  --shadow-mint: 0 0 20px rgba(5, 150, 105, 0.15);
  --shadow-coral: 0 0 20px rgba(225, 29, 72, 0.15);
}

/* Base Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-cosmos);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Background Aurora Ambient Lights */
.bg-ambient-layer {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.ambient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(130px);
  opacity: 0.25;
  transition: all 1s ease;
}

.orb-1 {
  width: 580px;
  height: 580px;
  background: radial-gradient(circle, var(--mint-primary), transparent 70%);
  top: -160px;
  right: -120px;
}

.orb-2 {
  width: 620px;
  height: 620px;
  background: radial-gradient(circle, var(--coral-accent), transparent 70%);
  bottom: 15%;
  left: -220px;
  opacity: 0.2;
}

.orb-3 {
  width: 460px;
  height: 460px;
  background: radial-gradient(circle, var(--solar-amber), transparent 70%);
  top: 40%;
  right: 5%;
  opacity: 0.14;
}

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(to right, var(--border-subtle) 1px, transparent 1px),
    linear-gradient(to bottom, var(--border-subtle) 1px, transparent 1px);
  background-size: 38px 38px;
  opacity: 0.3;
  mask-image: radial-gradient(ellipse at center, black 45%, transparent 85%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 45%, transparent 85%);
}

/* Typography Helpers */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--text-primary);
  line-height: 1.25;
  font-weight: 700;
}

p {
  color: var(--text-secondary);
}

a {
  color: var(--mint-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  text-decoration: underline;
}

code, kbd, pre {
  font-family: var(--font-mono);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
  position: relative;
  z-index: 1;
}

/* ==========================================================================
   NAVIGATION BAR
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: var(--bg-glass);
  border-bottom: 1px solid var(--border-subtle);
  transition: all var(--transition-normal);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 16px;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(0, 245, 160, 0.22), rgba(255, 107, 107, 0.18));
  border: 1px solid rgba(0, 245, 160, 0.35);
  box-shadow: 0 0 18px var(--mint-glow);
}

.brand-icon svg {
  width: 26px;
  height: 26px;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.28rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #ffffff 25%, var(--mint-primary) 70%, var(--coral-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="light"] .brand-title {
  background: linear-gradient(135deg, #064e3b 30%, var(--mint-primary) 80%, var(--coral-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-subtitle {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.nav-center-menu {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 8px 14px;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav-link:hover, .nav-link.active {
  color: #ffffff;
  background: rgba(0, 245, 160, 0.14);
  text-decoration: none;
}

[data-theme="light"] .nav-link:hover,
[data-theme="light"] .nav-link.active {
  color: var(--mint-dark);
  background: rgba(16, 185, 129, 0.12);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Global Angle Mode Pill (DEG / RAD / GRAD) */
.angle-mode-selector {
  display: flex;
  background: var(--bg-inset);
  padding: 3px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-subtle);
}

.angle-btn {
  background: transparent;
  border: none;
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--text-dim);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.angle-btn.active {
  background: linear-gradient(135deg, var(--mint-primary), var(--mint-dark));
  color: #070d0a;
  box-shadow: 0 0 12px var(--mint-glow);
}

/* Icon Buttons (Theme toggle, etc.) */
.icon-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  color: var(--mint-primary);
  border-color: var(--mint-primary);
  transform: translateY(-1px);
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero-section {
  padding: 46px 0 30px;
  text-align: center;
  position: relative;
}

.hero-badge-wrap {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(0, 245, 160, 0.08);
  border: 1px solid rgba(0, 245, 160, 0.3);
  padding: 6px 18px;
  border-radius: var(--radius-full);
  margin-bottom: 20px;
  backdrop-filter: blur(8px);
}

.badge-pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--mint-primary);
  box-shadow: 0 0 10px var(--mint-primary);
  animation: pulseGlow 2s infinite;
}

@keyframes pulseGlow {
  0% { transform: scale(0.9); opacity: 0.7; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.9); opacity: 0.7; }
}

.hero-badge-text {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--mint-primary);
  text-transform: uppercase;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
  max-width: 950px;
  margin-left: auto;
  margin-right: auto;
}

.gradient-text-aurora {
  background: linear-gradient(135deg, var(--mint-primary) 0%, #34d399 40%, var(--coral-accent) 85%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto 26px;
}

/* Quick Jump Feature Ribbon */
.hero-pills-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 26px;
}

.quick-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.quick-pill:hover {
  background: var(--bg-card-hover);
  border-color: var(--mint-primary);
  color: #ffffff;
  transform: translateY(-2px);
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(0, 245, 160, 0.2);
}

[data-theme="light"] .quick-pill:hover {
  color: var(--mint-dark);
}

/* Main Hub Tab Navigation */
.hub-nav-wrapper {
  position: sticky;
  top: 72px;
  z-index: 90;
  background: var(--bg-cosmos);
  padding: 12px 0 16px;
  border-bottom: 1px solid var(--border-subtle);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  margin-bottom: 32px;
}

.hub-nav-scroll {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  padding: 4px 2px;
  scrollbar-width: thin;
  scrollbar-color: var(--mint-secondary) transparent;
}

.hub-nav-scroll::-webkit-scrollbar {
  height: 4px;
}
.hub-nav-scroll::-webkit-scrollbar-thumb {
  background: var(--mint-secondary);
  border-radius: 4px;
}

.tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.tab-btn svg {
  width: 18px;
  height: 18px;
  opacity: 0.85;
}

.tab-btn:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--border-hover);
}

.tab-btn.active {
  background: linear-gradient(135deg, rgba(0, 245, 160, 0.18), rgba(255, 107, 107, 0.12));
  color: #ffffff;
  border-color: var(--mint-primary);
  box-shadow: 0 0 16px var(--mint-glow);
}

[data-theme="light"] .tab-btn.active {
  color: var(--mint-dark);
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.18), rgba(255, 107, 107, 0.12));
}

.tab-btn.active svg {
  opacity: 1;
  stroke: var(--mint-primary);
}

/* ==========================================================================
   TAB PANELS & CALCULATOR CARDS
   ========================================================================== */
.tab-content-area {
  margin-bottom: 60px;
}

.tab-panel {
  display: none;
  animation: fadeIn 0.3s ease;
}

.tab-panel.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.calc-split-grid {
  display: grid;
  grid-template-columns: 1.05fr 1.05fr;
  gap: 28px;
  align-items: start;
}

@media (max-width: 1024px) {
  .calc-split-grid {
    grid-template-columns: 1fr;
  }
}

/* Calculator Card Styling */
.calc-card {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 26px;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
  transition: border-color var(--transition-normal);
}

.calc-card:hover {
  border-color: var(--border-hover);
}

.card-header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-subtle);
  flex-wrap: wrap;
  gap: 12px;
}

.card-title-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.card-icon-badge {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 245, 160, 0.14);
  border: 1px solid rgba(0, 245, 160, 0.35);
  color: var(--mint-primary);
}

.card-icon-badge.coral {
  background: rgba(255, 107, 107, 0.14);
  border-color: rgba(255, 107, 107, 0.35);
  color: var(--coral-accent);
}

.card-icon-badge.amber {
  background: rgba(250, 204, 21, 0.14);
  border-color: rgba(250, 204, 21, 0.35);
  color: var(--solar-amber);
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
}

.card-subtitle {
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* Presets Bar */
.presets-group {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.preset-label {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-right: 4px;
}

.preset-chip {
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.preset-chip:hover, .preset-chip.active {
  background: var(--bg-card-hover);
  color: var(--mint-primary);
  border-color: var(--mint-primary);
}

/* Inputs & Forms */
.input-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 14px;
  margin-bottom: 18px;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.label-hint {
  font-size: 0.74rem;
  color: var(--text-dim);
  font-weight: 400;
}

.input-with-addons {
  display: flex;
  align-items: center;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  overflow: hidden;
}

.input-with-addons:focus-within {
  border-color: var(--mint-primary);
  box-shadow: 0 0 0 3px var(--mint-glow);
}

.addon-prefix {
  padding: 0 12px;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.03);
  border-right: 1px solid var(--border-subtle);
  user-select: none;
}

.form-control {
  width: 100%;
  background: transparent;
  border: none;
  padding: 11px 14px;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-primary);
  outline: none;
}

.addon-select {
  padding: 0 12px;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--mint-primary);
  background: rgba(0, 245, 160, 0.08);
  border: none;
  border-left: 1px solid var(--border-subtle);
  height: 100%;
  cursor: pointer;
  outline: none;
}

/* Sliders */
.slider-group {
  margin-bottom: 16px;
}

.slider-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  margin-bottom: 6px;
  font-weight: 600;
}

.slider-val-badge {
  font-family: var(--font-mono);
  background: var(--bg-inset);
  padding: 2px 8px;
  border-radius: var(--radius-xs);
  color: var(--mint-primary);
  border: 1px solid var(--border-subtle);
}

.custom-range {
  width: 100%;
  height: 6px;
  background: var(--bg-inset);
  border-radius: var(--radius-full);
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
}

.custom-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--mint-primary);
  box-shadow: 0 0 12px var(--mint-primary);
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.custom-range::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

/* Action Buttons */
.action-buttons-row {
  display: flex;
  gap: 12px;
  margin-top: 20px;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--mint-primary), var(--mint-dark));
  color: #070d0a;
  font-weight: 700;
  font-size: 0.95rem;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 16px var(--mint-glow);
  transition: all var(--transition-fast);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--mint-glow);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--bg-inset);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.92rem;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--border-hover);
}

/* ==========================================================================
   DIAGRAM VISUALIZATION PANELS & TOOLBARS
   ========================================================================== */
.results-card {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

/* Diagram Container Box */
.diagram-canvas-box {
  width: 100%;
  height: 300px;
  background: radial-gradient(circle at center, rgba(0, 245, 160, 0.05), transparent 70%), var(--bg-inset);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.diagram-canvas-box svg,
.diagram-canvas-box canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.diagram-watermark {
  position: absolute;
  bottom: 8px;
  right: 12px;
  font-size: 0.7rem;
  font-family: var(--font-mono);
  color: var(--text-dim);
  pointer-events: none;
}

/* Diagram Interactive Toolbar / Toggle Chips */
.diagram-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  padding: 8px 12px;
  background: var(--bg-inset);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.diagram-tool-chip {
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  font-size: 0.74rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: var(--radius-xs);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: all var(--transition-fast);
}

.diagram-tool-chip:hover {
  border-color: var(--mint-primary);
  color: var(--mint-primary);
}

.diagram-tool-chip.active {
  background: rgba(0, 245, 160, 0.18);
  border-color: var(--mint-primary);
  color: #ffffff;
}

[data-theme="light"] .diagram-tool-chip.active {
  color: var(--mint-dark);
}

/* Primary Metric Hero Card */
.metric-hero {
  display: flex;
  flex-direction: column;
  background: linear-gradient(135deg, rgba(0, 245, 160, 0.1), rgba(255, 107, 107, 0.08));
  border: 1px solid rgba(0, 245, 160, 0.3);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  position: relative;
}

.metric-hero-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--mint-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.metric-hero-value {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.02em;
  margin: 6px 0;
  word-break: break-all;
}

[data-theme="light"] .metric-hero-value {
  color: #064e3b;
}

.metric-hero-exact {
  font-size: 0.95rem;
  color: var(--coral-accent);
  font-family: var(--font-mono);
  font-weight: 600;
}

/* Metric Multi-Grid */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 12px;
}

.metric-box {
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 12px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-fast);
}

.metric-box:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
}

.metric-label {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.metric-val {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

.metric-sub {
  font-size: 0.72rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* Step Solution Box */
.step-solution-box {
  background: var(--bg-card-solid);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 18px;
}

.step-box-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.step-box-title {
  font-size: 0.95rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--mint-primary);
}

.steps-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.step-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 10px 12px;
  background: var(--bg-inset);
  border-radius: var(--radius-xs);
  border-left: 3px solid var(--mint-secondary);
}

.step-num {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: rgba(0, 245, 160, 0.16);
  color: var(--mint-primary);
  font-size: 0.72rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.step-content {
  flex: 1;
  font-size: 0.88rem;
}

.step-math {
  font-family: var(--font-mono);
  color: var(--mint-primary);
  margin-top: 4px;
  font-weight: 600;
}

.calc-footer-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px solid var(--border-subtle);
  flex-wrap: wrap;
}

.quick-action-link {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 6px 10px;
  border-radius: var(--radius-xs);
  transition: all var(--transition-fast);
}

.quick-action-link:hover {
  color: var(--mint-primary);
  background: rgba(0, 245, 160, 0.1);
}

/* ==========================================================================
   UNIT CIRCLE SPECIFIC ENHANCEMENTS & 6 TRIGONOMETRIC LINES
   ========================================================================== */
.unit-circle-controls {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 12px;
}

@media (max-width: 600px) {
  .unit-circle-controls {
    grid-template-columns: repeat(2, 1fr);
  }
}

.angle-quick-badge {
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  padding: 8px 6px;
  border-radius: var(--radius-sm);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.angle-quick-badge:hover,
.angle-quick-badge.active {
  border-color: var(--mint-primary);
  background: rgba(0, 245, 160, 0.14);
  transform: translateY(-1px);
}

.angle-quick-deg {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
}

.angle-quick-rad {
  font-size: 0.7rem;
  color: var(--mint-primary);
  font-family: var(--font-mono);
}

/* Geometric Lines Color Legend */
.geom-lines-legend {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 8px;
  margin-top: 10px;
  padding: 10px;
  background: var(--bg-inset);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  font-size: 0.76rem;
  font-weight: 600;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.legend-line {
  width: 14px;
  height: 3px;
  border-radius: 2px;
}

/* ASTC Quadrant Rule Cards */
.astc-quadrant-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-top: 16px;
}

@media (max-width: 768px) {
  .astc-quadrant-bar {
    grid-template-columns: repeat(2, 1fr);
  }
}

.astc-box {
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 10px;
  text-align: center;
  transition: all var(--transition-fast);
}

.astc-box.highlight {
  border-color: var(--mint-primary);
  background: rgba(0, 245, 160, 0.16);
  box-shadow: 0 0 16px var(--mint-glow);
}

.astc-letter {
  font-size: 1.25rem;
  font-weight: 900;
  color: var(--mint-primary);
}

.astc-box.q2 .astc-letter { color: var(--coral-accent); }
.astc-box.q3 .astc-letter { color: var(--solar-amber); }
.astc-box.q4 .astc-letter { color: var(--arctic-sky); }

.astc-name {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-primary);
}

.astc-signs {
  font-size: 0.68rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* ==========================================================================
   FORMULA & IDENTITIES
   ========================================================================== */
.formula-search-bar {
  display: flex;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 8px 16px;
  margin-bottom: 24px;
  gap: 12px;
}

.formula-search-input {
  width: 100%;
  background: transparent;
  border: none;
  font-size: 0.95rem;
  color: var(--text-primary);
  outline: none;
}

.formula-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}

.formula-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: all var(--transition-normal);
}

.formula-card:hover {
  border-color: var(--mint-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.formula-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--mint-primary);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.formula-badge {
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: rgba(0, 245, 160, 0.12);
  color: var(--mint-primary);
}

.formula-math-display {
  background: var(--bg-inset);
  padding: 14px;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  margin: 10px 0;
  overflow-x: auto;
  color: #ffffff;
}

[data-theme="light"] .formula-math-display {
  color: #064e3b;
}

.formula-card-desc {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ==========================================================================
   TRIGONOMETRIC VALUES TABLE
   ========================================================================== */
.table-responsive-wrapper {
  overflow-x: auto;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: var(--bg-card);
}

.trig-table {
  width: 100%;
  border-collapse: collapse;
  text-align: center;
  font-size: 0.88rem;
}

.trig-table th {
  background: var(--bg-inset);
  color: var(--mint-primary);
  font-weight: 700;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-subtle);
  font-family: var(--font-heading);
}

.trig-table td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  color: var(--text-secondary);
}

.trig-table tr:hover td {
  background: rgba(0, 245, 160, 0.08);
  color: var(--text-primary);
}

/* ==========================================================================
   PRACTICE QUIZ
   ========================================================================== */
.quiz-box {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-top: 20px;
}

.quiz-question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.quiz-score-badge {
  font-size: 0.82rem;
  font-weight: 700;
  padding: 4px 12px;
  background: rgba(0, 245, 160, 0.16);
  color: var(--mint-primary);
  border-radius: var(--radius-full);
}

.quiz-question-text {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 20px;
}

.quiz-options-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 20px;
}

@media (max-width: 650px) {
  .quiz-options-list {
    grid-template-columns: 1fr;
  }
}

.quiz-option-btn {
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  text-align: left;
  font-size: 0.92rem;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.quiz-option-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--mint-primary);
  color: var(--text-primary);
}

.quiz-option-btn.correct {
  background: rgba(0, 245, 160, 0.2);
  border-color: var(--mint-primary);
  color: var(--mint-primary);
  font-weight: 700;
}

.quiz-option-btn.wrong {
  background: rgba(255, 107, 107, 0.2);
  border-color: var(--coral-accent);
  color: var(--coral-accent);
  font-weight: 700;
}

.quiz-feedback-box {
  display: none;
  padding: 14px;
  border-radius: var(--radius-sm);
  background: var(--bg-inset);
  border: 1px solid var(--border-subtle);
  margin-bottom: 16px;
  font-size: 0.9rem;
}

/* ==========================================================================
   FAQS ACCORDION
   ========================================================================== */
.faq-section {
  padding: 60px 0;
  border-top: 1px solid var(--border-subtle);
}

.section-head {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 40px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 10px;
}

.section-sub {
  color: var(--text-dim);
}

.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-question {
  width: 100%;
  padding: 18px 22px;
  background: transparent;
  border: none;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.faq-icon {
  font-size: 1.2rem;
  color: var(--mint-primary);
  transition: transform var(--transition-normal);
}

.faq-item.open .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-smooth);
  padding: 0 22px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.open .faq-answer {
  max-height: 400px;
  padding-bottom: 20px;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  padding: 48px 0 24px;
  margin-top: 60px;
  position: relative;
  z-index: 2;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 40px;
}

@media (max-width: 900px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 600px) {
  .footer-top {
    grid-template-columns: 1fr;
  }
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--text-dim);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--mint-primary);
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid var(--border-subtle);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* Toast */
.toast-notice {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: var(--bg-surface);
  border: 1px solid var(--mint-primary);
  color: #ffffff;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
  z-index: 9999;
  display: flex;
  align-items: center;
  gap: 10px;
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-normal);
  font-size: 0.9rem;
  font-weight: 600;
}

[data-theme="light"] .toast-notice {
  color: #064e3b;
}

.toast-notice.show {
  transform: translateY(0);
  opacity: 1;
}

@media (max-width: 768px) {
  .nav-center-menu {
    display: none;
  }
  .hero-section {
    padding: 32px 0 20px;
  }
}

@media print {
  .site-header, .hub-nav-wrapper, .bg-ambient-layer, .action-buttons-row, .site-footer {
    display: none !important;
  }
  body {
    background: #ffffff !important;
    color: #000000 !important;
  }
}