/* ============================================================
   KeyPrime — Design System
   Style: Minimalism & Swiss / Dark Mode (Developer Tool)
   Type:  Inter (UI) + JetBrains Mono (keys)
   ============================================================ */

:root {
  /* Color tokens — "Developer Tool / IDE" dark palette */
  --color-primary: #1E293B;
  --color-on-primary: #FFFFFF;
  --color-secondary: #334155;
  --color-on-secondary: #FFFFFF;
  --color-accent: #22C55E;
  --color-on-accent: #0F172A;
  --color-background: #0F172A;
  --color-foreground: #F8FAFC;
  --color-card: #1B2336;
  --color-card-foreground: #F8FAFC;
  --color-muted: #272F42;
  --color-muted-foreground: #94A3B8;
  --color-border: rgba(148, 163, 184, 0.16);
  --color-border-strong: rgba(148, 163, 184, 0.32);
  --color-destructive: #EF4444;
  --color-ring: #22C55E;

  /* Strength accents */
  --strength-low: #F59E0B;
  --strength-mid: #3B82F6;
  --strength-high: #22C55E;
  --strength-key: #8B5CF6;
  --strength-legacy: #64748B;

  /* Typography */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-lg: 1.125rem;
  --fs-xl: 1.375rem;
  --fs-2xl: 1.75rem;
  --fs-3xl: 2.5rem;

  /* Spacing — 4/8 rhythm */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  /* Radius & elevation */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 999px;
  --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.25), 0 8px 24px rgba(0, 0, 0, 0.18);
  --shadow-pop: 0 8px 32px rgba(0, 0, 0, 0.4);

  /* Motion */
  --dur-fast: 150ms;
  --dur-base: 220ms;
  --dur-slow: 320ms;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);

  /* Layout */
  --container-max: 1120px;
  --header-h: 64px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + var(--space-4));
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-foreground);
  background-color: var(--color-background);
  background-image:
    radial-gradient(60rem 40rem at 80% -10%, rgba(34, 197, 94, 0.08), transparent 60%),
    radial-gradient(50rem 40rem at -10% 10%, rgba(59, 130, 246, 0.07), transparent 60%);
  background-attachment: fixed;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3 { line-height: 1.25; font-weight: 600; letter-spacing: -0.01em; }

.icon { flex: none; vertical-align: middle; }

/* ---------- Skip link ---------- */
.skip-link {
  position: absolute;
  left: var(--space-4);
  top: -100px;
  z-index: 1000;
  padding: var(--space-3) var(--space-4);
  background: var(--color-accent);
  color: var(--color-on-accent);
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: top var(--dur-fast) var(--ease-out);
}
.skip-link:focus { top: var(--space-4); }

/* ---------- Focus ring (keyboard only) ---------- */
:focus-visible {
  outline: 2px solid var(--color-ring);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(15, 23, 42, 0.72);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--color-border);
}
.site-header__inner {
  max-width: var(--container-max);
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-foreground);
  text-decoration: none;
}
.brand:hover { text-decoration: none; }
.brand__mark {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--color-accent), #16A34A);
  color: var(--color-on-accent);
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: var(--fs-sm);
  letter-spacing: 0.04em;
  box-shadow: 0 4px 14px rgba(34, 197, 94, 0.25);
}
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__title { font-weight: 700; font-size: var(--fs-base); }
.brand__subtitle {
  font-size: var(--fs-xs);
  color: var(--color-muted-foreground);
  letter-spacing: 0.02em;
}
@media (max-width: 560px) {
  .brand__subtitle { display: none; }
}

/* ---------- Tools dropdown ---------- */
.tools-nav__dropdown { position: relative; }
.tools-nav__trigger {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-card);
  color: var(--color-foreground);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  font-size: var(--fs-sm);
  font-weight: 500;
  cursor: pointer;
  list-style: none;
  transition: background var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out);
}
.tools-nav__trigger::-webkit-details-marker { display: none; }
.tools-nav__trigger:hover { background: var(--color-muted); border-color: var(--color-border-strong); }
.tools-nav__menu {
  position: absolute;
  right: 0;
  top: calc(100% + var(--space-2));
  min-width: 280px;
  list-style: none;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-pop);
  padding: var(--space-2);
  z-index: 50;
}
.tools-nav__menu li a {
  display: block;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm);
  color: var(--color-foreground);
  text-decoration: none;
  transition: background var(--dur-fast) var(--ease-out);
}
.tools-nav__menu li a:hover { background: var(--color-muted); text-decoration: none; }
.tools-nav__menu li a strong { display: block; font-weight: 600; font-size: var(--fs-sm); }
.tools-nav__menu li a span { display: block; font-size: var(--fs-xs); color: var(--color-muted-foreground); }
.icon--chev { transition: transform var(--dur-fast) var(--ease-out); }
.tools-nav__dropdown[open] .icon--chev { transform: rotate(180deg); }

/* ---------- Layout ---------- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--space-8) var(--space-4) var(--space-16);
}

/* ---------- Hero ---------- */
.hero {
  text-align: center;
  padding: var(--space-8) 0 var(--space-10);
}
.hero h1 {
  font-size: clamp(var(--fs-2xl), 5vw, var(--fs-3xl));
  font-weight: 700;
  letter-spacing: -0.03em;
  background: linear-gradient(180deg, #FFFFFF, #CBD5E1);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: var(--space-4);
}
.hero__lead {
  max-width: 620px;
  margin: 0 auto var(--space-8);
  color: var(--color-muted-foreground);
  font-size: var(--fs-lg);
}
.hero__generate {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
}
.hero__hint {
  font-size: var(--fs-xs);
  color: var(--color-muted-foreground);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 48px;
  padding: 0 var(--space-6);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform var(--dur-fast) var(--ease-out),
              background var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out);
}
.btn--primary {
  background: linear-gradient(135deg, var(--color-accent), #16A34A);
  color: var(--color-on-accent);
  box-shadow: 0 6px 20px rgba(34, 197, 94, 0.3);
}
.btn--primary:hover { transform: translateY(-1px); box-shadow: 0 10px 28px rgba(34, 197, 94, 0.38); }
.btn--primary:active { transform: translateY(0); }
.btn .icon { transition: transform var(--dur-base) var(--ease-out); }
.btn--primary:hover .icon { transform: rotate(-60deg); }

/* ---------- Keys grid ---------- */
.keys {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-5);
  margin-top: var(--space-8);
}
@media (max-width: 880px) {
  .keys { grid-template-columns: 1fr; }
}

.key-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-card);
  transition: border-color var(--dur-base) var(--ease-out),
              transform var(--dur-base) var(--ease-out);
}
.key-card:hover { border-color: var(--color-border-strong); }
.key-card__head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}
.key-card__head h2 {
  font-size: var(--fs-lg);
  font-weight: 600;
}
.key-card__head p {
  font-size: var(--fs-sm);
  color: var(--color-muted-foreground);
  margin-top: var(--space-1);
}

/* ---------- Badges ---------- */
.badge {
  flex: none;
  display: inline-flex;
  align-items: center;
  padding: 0.25rem var(--space-3);
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.03em;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
}
.badge--low { color: var(--strength-low); background: rgba(245, 158, 11, 0.12); border-color: rgba(245, 158, 11, 0.3); }
.badge--mid { color: #60A5FA; background: rgba(59, 130, 246, 0.12); border-color: rgba(59, 130, 246, 0.3); }
.badge--high { color: var(--strength-high); background: rgba(34, 197, 94, 0.12); border-color: rgba(34, 197, 94, 0.3); }
.badge--key { color: #A78BFA; background: rgba(139, 92, 246, 0.12); border-color: rgba(139, 92, 246, 0.3); }
.badge--legacy { color: var(--color-muted-foreground); background: rgba(100, 116, 139, 0.12); border-color: rgba(100, 116, 139, 0.3); }

/* ---------- Key items ---------- */
.key-list {
  display: grid;
  gap: var(--space-2);
}
.key-item {
  position: relative;
  display: flex;
  align-items: center;
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color var(--dur-fast) var(--ease-out),
              background var(--dur-fast) var(--ease-out);
}
.key-item:hover { border-color: var(--color-border-strong); }
.key-item:focus-within { border-color: var(--color-ring); }
.key-item__value {
  flex: 1 1 auto;
  min-width: 0;
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--color-foreground);
  background: transparent;
  border: none;
  outline: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.key-item__value::selection { background: rgba(34, 197, 94, 0.3); }
.key-item__copy {
  flex: none;
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 100%;
  min-height: 44px;
  padding: 0 var(--space-3);
  background: transparent;
  border: none;
  border-left: 1px solid var(--color-border);
  color: var(--color-muted-foreground);
  cursor: pointer;
  transition: color var(--dur-fast) var(--ease-out),
              background var(--dur-fast) var(--ease-out);
}
.key-item__copy:hover { color: var(--color-accent); background: rgba(34, 197, 94, 0.08); }
.key-item__copy.copied { color: var(--color-accent); }
.key-item__copy .icon-check { display: none; }
.key-item__copy.copied .icon-copy { display: none; }
.key-item__copy.copied .icon-check { display: block; }

/* ---------- Info section ---------- */
.info {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-16);
  padding-top: var(--space-10);
  border-top: 1px solid var(--color-border);
}
.info__col h2 { font-size: var(--fs-lg); margin-bottom: var(--space-3); }
.info__col p { color: var(--color-muted-foreground); font-size: var(--fs-sm); }
@media (max-width: 880px) {
  .info { grid-template-columns: 1fr; gap: var(--space-8); }
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  background: rgba(15, 23, 42, 0.5);
}
.site-footer__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--space-6) var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  font-size: var(--fs-sm);
  color: var(--color-muted-foreground);
}
.site-footer nav { display: flex; gap: var(--space-5); }
.site-footer a { color: var(--color-muted-foreground); }
.site-footer a:hover { color: var(--color-foreground); }
@media (max-width: 560px) {
  .site-footer__inner { flex-direction: column; text-align: center; }
}

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: var(--space-6);
  left: 50%;
  transform: translateX(-50%) translateY(140%);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  background: var(--color-card);
  color: var(--color-foreground);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-pop);
  font-size: var(--fs-sm);
  font-weight: 500;
  z-index: 200;
  transition: transform var(--dur-slow) var(--ease-out);
  pointer-events: none;
}
.toast.show { transform: translateX(-50%) translateY(0); }
.toast .icon { color: var(--color-accent); }

/* ---------- Prose (privacy policy) ---------- */
.prose {
  max-width: 760px;
  margin: 0 auto;
}
.prose h1 {
  font-size: clamp(var(--fs-2xl), 4vw, var(--fs-3xl));
  letter-spacing: -0.03em;
  background: linear-gradient(180deg, #FFFFFF, #CBD5E1);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: var(--space-3);
}
.prose__lead {
  font-size: var(--fs-lg);
  color: var(--color-muted-foreground);
  margin-bottom: var(--space-8);
}
.prose h2 {
  font-size: var(--fs-xl);
  margin-top: var(--space-10);
  margin-bottom: var(--space-3);
}
.prose p {
  color: var(--color-muted-foreground);
  font-size: var(--fs-base);
  margin-bottom: var(--space-4);
  line-height: 1.7;
}
.prose a { color: var(--color-accent); }

/* ---------- Theme switcher ---------- */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  padding: 0;
  background: var(--color-card);
  color: var(--color-foreground);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out);
}
.theme-toggle:hover { background: var(--color-muted); border-color: var(--color-border-strong); }
.theme-toggle .icon {
  width: 20px;
  height: 20px;
  transition: transform var(--dur-base) var(--ease-out);
}
.theme-toggle .icon--sun { display: none; }
.theme-toggle .icon--moon { display: block; }
html[data-theme="light"] .theme-toggle .icon--sun { display: block; }
html[data-theme="light"] .theme-toggle .icon--moon { display: none; }

/* ---------- Light mode overrides ---------- */
html[data-theme="light"] {
  --color-background: #FFFFFF;
  --color-foreground: #111827;
  --color-card: #FFFFFF;
  --color-card-foreground: #111827;
  --color-muted: #F9FAFB;
  --color-muted-foreground: #6B7280;
  --color-border: rgba(55, 65, 81, 0.12);
  --color-border-strong: rgba(55, 65, 81, 0.24);
  --color-ring: #3B82F6;
  --strength-low: #D97706;
  --strength-mid: #2563EB;
  --strength-high: #166534;
  --strength-key: #7C3AED;
  --strength-legacy: #6B7280;
}
html[data-theme="light"] .site-header {
  background: rgba(255, 255, 255, 0.8);
  border-bottom: 1px solid var(--color-border);
}
html[data-theme="light"] .key-card {
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08), 0 8px 24px rgba(0, 0, 0, 0.06);
}
html[data-theme="light"] body {
  background-image: none;
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}