/* =========================================================================
   Nadi Design System — Base Stylesheet (Light Theme / Public Pages)
   Version: 1.0.0
   Phase 1 build — locked decisions from p21_nadi_execution_checklist.md
   ========================================================================= */

/* -------------------------------------------------------------------------
   1. Design Tokens (CSS Custom Properties)
   ------------------------------------------------------------------------- */
:root {
  /* Colors — Light theme (public) */
  --nadi-bg:            #FAFAF8;
  --nadi-surface:       #FFFFFF;
  --nadi-text:          #111827;
  --nadi-text-muted:    #6B7280;
  --nadi-border:        #E5E7EB;
  --nadi-emerald:       #059669;
  --nadi-emerald-hover: #047857;
  --nadi-amber:         #F59E0B;
  --nadi-amber-hover:   #D97706;
  --nadi-error:         #EF4444;
  --nadi-success:       #059669;

  /* Typography */
  --nadi-font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  --nadi-size-hero:      clamp(40px, 5vw, 64px);
  --nadi-size-h2:        clamp(30px, 3.5vw, 40px);
  --nadi-size-h3:        clamp(20px, 2vw, 24px);
  --nadi-size-body:      17px;
  --nadi-size-body-sm:   15px;
  --nadi-size-caption:   14px;

  --nadi-weight-regular: 400;
  --nadi-weight-medium:  500;
  --nadi-weight-semi:    600;
  --nadi-weight-bold:    700;

  --nadi-line-tight:  1.1;
  --nadi-line-snug:   1.3;
  --nadi-line-normal: 1.6;

  /* 8px grid spacing */
  --nadi-s-1:   8px;
  --nadi-s-2:  16px;
  --nadi-s-3:  24px;
  --nadi-s-4:  32px;
  --nadi-s-6:  48px;
  --nadi-s-8:  64px;
  --nadi-s-12: 96px;
  --nadi-s-16: 128px;

  /* Radius */
  --nadi-radius-sm: 8px;
  --nadi-radius-md: 12px;
  --nadi-radius-lg: 16px;
  --nadi-radius-pill: 999px;

  /* Shadows — subtle only */
  --nadi-shadow-sm: 0 1px 2px rgba(17, 24, 39, 0.04);
  --nadi-shadow-md: 0 4px 12px rgba(17, 24, 39, 0.06);
  --nadi-shadow-lg: 0 8px 24px rgba(17, 24, 39, 0.08);

  /* Motion */
  --nadi-ease: cubic-bezier(0.22, 1, 0.36, 1);
  --nadi-dur-fast:   120ms;
  --nadi-dur-base:   200ms;
  --nadi-dur-slow:   400ms;

  /* Layout */
  --nadi-container:    1200px;
  --nadi-container-sm:  720px;
  --nadi-nav-h:         72px;
}

/* -------------------------------------------------------------------------
   2. Reset + Base
   ------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--nadi-bg);
  color: var(--nadi-text);
  font-family: var(--nadi-font);
  font-size: var(--nadi-size-body);
  font-weight: var(--nadi-weight-regular);
  line-height: var(--nadi-line-normal);
}

img, svg, video { display: block; max-width: 100%; height: auto; }

a {
  color: var(--nadi-emerald);
  text-decoration: none;
  transition: color var(--nadi-dur-fast) var(--nadi-ease);
}
a:hover { color: var(--nadi-emerald-hover); }

::selection {
  background: var(--nadi-emerald);
  color: #fff;
}

/* -------------------------------------------------------------------------
   3. Typography
   ------------------------------------------------------------------------- */
.nadi-hero {
  font-size: var(--nadi-size-hero);
  font-weight: var(--nadi-weight-bold);
  line-height: var(--nadi-line-tight);
  letter-spacing: -0.02em;
  margin: 0 0 var(--nadi-s-3) 0;
  color: var(--nadi-text);
}

.nadi-h2 {
  font-size: var(--nadi-size-h2);
  font-weight: var(--nadi-weight-semi);
  line-height: var(--nadi-line-snug);
  letter-spacing: -0.01em;
  margin: 0 0 var(--nadi-s-2) 0;
}

.nadi-h3 {
  font-size: var(--nadi-size-h3);
  font-weight: var(--nadi-weight-medium);
  line-height: var(--nadi-line-snug);
  margin: 0 0 var(--nadi-s-2) 0;
}

.nadi-body     { font-size: var(--nadi-size-body);    line-height: var(--nadi-line-normal); }
.nadi-body-sm  { font-size: var(--nadi-size-body-sm); line-height: var(--nadi-line-normal); }
.nadi-caption  { font-size: var(--nadi-size-caption); color: var(--nadi-text-muted); }
.nadi-muted    { color: var(--nadi-text-muted); }

/* -------------------------------------------------------------------------
   4. Layout
   ------------------------------------------------------------------------- */
.nadi-container {
  width: 100%;
  max-width: var(--nadi-container);
  margin: 0 auto;
  padding: 0 var(--nadi-s-3);
}
.nadi-container--sm { max-width: var(--nadi-container-sm); }

.nadi-section {
  padding: var(--nadi-s-12) 0;
}
@media (min-width: 900px) {
  .nadi-section { padding: var(--nadi-s-16) 0; }
}

.nadi-stack > * + * { margin-top: var(--nadi-s-2); }
.nadi-stack-lg > * + * { margin-top: var(--nadi-s-3); }

/* -------------------------------------------------------------------------
   5. Buttons — pill style
   ------------------------------------------------------------------------- */
.nadi-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-family: var(--nadi-font);
  font-size: var(--nadi-size-body);
  font-weight: var(--nadi-weight-semi);
  line-height: 1;
  border-radius: var(--nadi-radius-pill);
  border: 2px solid transparent;
  cursor: pointer;
  transition:
    background var(--nadi-dur-base) var(--nadi-ease),
    color var(--nadi-dur-base) var(--nadi-ease),
    border-color var(--nadi-dur-base) var(--nadi-ease),
    transform var(--nadi-dur-fast) var(--nadi-ease),
    box-shadow var(--nadi-dur-base) var(--nadi-ease);
  text-decoration: none;
  white-space: nowrap;
  user-select: none;
}

.nadi-btn:active { transform: translateY(1px); }
.nadi-btn:focus-visible {
  outline: 3px solid rgba(5, 150, 105, 0.25);
  outline-offset: 2px;
}

/* Primary — amber pill */
.nadi-btn--primary {
  background: var(--nadi-amber);
  color: #1F1300;
  box-shadow: var(--nadi-shadow-sm);
}
.nadi-btn--primary:hover {
  background: var(--nadi-amber-hover);
  box-shadow: var(--nadi-shadow-md);
}

/* Secondary — emerald outlined pill */
.nadi-btn--secondary {
  background: transparent;
  color: var(--nadi-emerald);
  border-color: var(--nadi-emerald);
}
.nadi-btn--secondary:hover {
  background: var(--nadi-emerald);
  color: #fff;
}

/* Ghost — text only */
.nadi-btn--ghost {
  background: transparent;
  color: var(--nadi-text);
  padding: 10px 16px;
  border-radius: var(--nadi-radius-md);
}
.nadi-btn--ghost:hover {
  background: rgba(17, 24, 39, 0.06);
  color: var(--nadi-text);
}

.nadi-btn--lg { padding: 18px 36px; font-size: 18px; }
.nadi-btn--sm { padding: 10px 20px; font-size: 14px; }

.nadi-btn[disabled],
.nadi-btn--disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* -------------------------------------------------------------------------
   6. Cards
   ------------------------------------------------------------------------- */
.nadi-card {
  background: var(--nadi-surface);
  border: 1px solid var(--nadi-border);
  border-radius: var(--nadi-radius-lg);
  padding: var(--nadi-s-4);
  transition: border-color var(--nadi-dur-base) var(--nadi-ease),
              box-shadow var(--nadi-dur-base) var(--nadi-ease);
}
.nadi-card:hover {
  box-shadow: var(--nadi-shadow-md);
}

.nadi-card--recommended {
  border: 2px solid var(--nadi-emerald);
  position: relative;
}
.nadi-card--recommended::before {
  content: 'Recommended';
  position: absolute;
  top: -12px;
  left: 24px;
  background: var(--nadi-emerald);
  color: #fff;
  padding: 4px 12px;
  border-radius: var(--nadi-radius-pill);
  font-size: 12px;
  font-weight: var(--nadi-weight-semi);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.nadi-card--flush {
  padding: var(--nadi-s-3);
}

/* -------------------------------------------------------------------------
   7. Form inputs
   ------------------------------------------------------------------------- */
.nadi-field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.nadi-label {
  font-size: var(--nadi-size-body-sm);
  font-weight: var(--nadi-weight-medium);
  color: var(--nadi-text);
}

.nadi-input,
.nadi-textarea,
.nadi-select {
  width: 100%;
  height: 52px;
  padding: 0 16px;
  background: var(--nadi-surface);
  border: 2px solid var(--nadi-border);
  border-radius: var(--nadi-radius-md);
  font-family: var(--nadi-font);
  font-size: var(--nadi-size-body);
  color: var(--nadi-text);
  transition: border-color var(--nadi-dur-base) var(--nadi-ease),
              box-shadow var(--nadi-dur-base) var(--nadi-ease);
}

.nadi-textarea {
  height: auto;
  min-height: 120px;
  padding: 14px 16px;
  resize: vertical;
  line-height: var(--nadi-line-normal);
}

.nadi-input::placeholder,
.nadi-textarea::placeholder { color: var(--nadi-text-muted); }

.nadi-input:focus,
.nadi-textarea:focus,
.nadi-select:focus {
  outline: none;
  border-color: var(--nadi-emerald);
  box-shadow: 0 0 0 4px rgba(5, 150, 105, 0.12);
}

.nadi-field--error .nadi-input,
.nadi-field--error .nadi-textarea,
.nadi-input--error {
  border-color: var(--nadi-error);
}
.nadi-field--error .nadi-input:focus,
.nadi-input--error:focus {
  box-shadow: 0 0 0 4px rgba(239, 68, 68, 0.12);
}

.nadi-help {
  font-size: var(--nadi-size-caption);
  color: var(--nadi-text-muted);
}
.nadi-help--error { color: var(--nadi-error); }

/* -------------------------------------------------------------------------
   8. Navigation (shared nav)
   ------------------------------------------------------------------------- */
.nadi-nav {
  position: sticky;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nadi-nav-h);
  background: rgba(250, 250, 248, 0.85);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--nadi-dur-base) var(--nadi-ease);
}
.nadi-nav--scrolled {
  border-bottom-color: var(--nadi-border);
}

.nadi-nav__inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--nadi-container);
  margin: 0 auto;
  padding: 0 var(--nadi-s-3);
}

.nadi-nav__logo {
  display: inline-flex;
  align-items: center;
  height: 32px;
}
.nadi-nav__logo svg { height: 28px; width: auto; display: block; }

.nadi-nav__links {
  display: flex;
  align-items: center;
  gap: var(--nadi-s-3);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nadi-nav__link {
  color: var(--nadi-text);
  font-size: var(--nadi-size-body-sm);
  font-weight: var(--nadi-weight-medium);
  padding: 8px 4px;
  position: relative;
}
.nadi-nav__link:hover { color: var(--nadi-emerald); }
.nadi-nav__link--active { color: var(--nadi-emerald); }

.nadi-nav__right {
  display: flex;
  align-items: center;
  gap: var(--nadi-s-2);
}

.nadi-nav__toggle {
  display: none;
  background: transparent;
  border: 0;
  width: 40px;
  height: 40px;
  cursor: pointer;
  padding: 0;
}
.nadi-nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--nadi-text);
  margin: 5px auto;
  border-radius: 2px;
  transition: transform var(--nadi-dur-base) var(--nadi-ease), opacity var(--nadi-dur-base) var(--nadi-ease);
}

/* Mobile nav */
@media (max-width: 820px) {
  .nadi-nav__links,
  .nadi-nav__right .nadi-btn { display: none; }
  .nadi-nav__toggle { display: block; }

  .nadi-nav--open .nadi-nav__links {
    display: flex;
    position: absolute;
    top: var(--nadi-nav-h);
    left: 0; right: 0;
    flex-direction: column;
    background: var(--nadi-surface);
    border-bottom: 1px solid var(--nadi-border);
    padding: var(--nadi-s-3);
    gap: var(--nadi-s-2);
  }
  .nadi-nav--open .nadi-nav__right .nadi-btn { display: inline-flex; }
}

/* -------------------------------------------------------------------------
   9. Footer (shared footer)
   ------------------------------------------------------------------------- */
.nadi-footer {
  border-top: 1px solid var(--nadi-border);
  background: var(--nadi-bg);
  padding: var(--nadi-s-4) 0;
}

.nadi-footer__inner {
  max-width: var(--nadi-container);
  margin: 0 auto;
  padding: 0 var(--nadi-s-3);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--nadi-s-3);
  flex-wrap: wrap;
}

.nadi-footer__logo { height: 24px; width: auto; }
.nadi-footer__logo svg { height: 24px; width: auto; }

.nadi-footer__links {
  display: flex;
  align-items: center;
  gap: var(--nadi-s-3);
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}
.nadi-footer__link {
  color: var(--nadi-text-muted);
  font-size: var(--nadi-size-caption);
}
.nadi-footer__link:hover { color: var(--nadi-text); }

/* -------------------------------------------------------------------------
   10. Logo / wordmark styling (SVG embeds handle animation internally)
   ------------------------------------------------------------------------- */
.nadi-logo { display: inline-flex; align-items: center; height: 28px; }
.nadi-logo svg { height: 28px; width: auto; }

/* -------------------------------------------------------------------------
   11. Utility classes
   ------------------------------------------------------------------------- */
.nadi-center  { text-align: center; }
.nadi-emerald { color: var(--nadi-emerald); }
.nadi-amber   { color: var(--nadi-amber); }

.nadi-hr {
  border: 0;
  border-top: 1px solid var(--nadi-border);
  margin: var(--nadi-s-4) 0;
}

.nadi-badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: var(--nadi-weight-semi);
  border-radius: var(--nadi-radius-pill);
  background: rgba(5, 150, 105, 0.1);
  color: var(--nadi-emerald);
  letter-spacing: 0.02em;
}
.nadi-badge--amber {
  background: rgba(245, 158, 11, 0.12);
  color: var(--nadi-amber-hover);
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}