/* ============================================================
   Nursemate Design Tokens — Apple-inspired dark system
   Shared across home, chat, care plan generator, about
   ============================================================ */

:root {
  /* Surfaces */
  --bg-0: #0a0c0f;
  --bg-1: #0f1115;
  --bg-2: #161a21;
  --bg-3: #1d222b;
  --glass: rgba(255, 255, 255, 0.04);
  --glass-strong: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);

  /* Text */
  --text-1: #f5f7fa;
  --text-2: #a8b1bd;
  --text-3: #858fa0;

  /* Accent — signature blue→teal gradient */
  --accent: #4d9fff;
  --accent-2: #38d2c0;
  --accent-soft: rgba(77, 159, 255, 0.14);
  --accent-2-soft: rgba(56, 210, 192, 0.14);
  --gradient: linear-gradient(135deg, #4d9fff 0%, #38d2c0 100%);

  /* Feedback */
  --success: #34c98f;
  --warning: #f0b429;
  --danger: #ff6b6b;

  /* Radius */
  --r-sm: 10px;
  --r: 14px;
  --r-lg: 20px;
  --r-xl: 28px;
  --r-pill: 999px;

  /* Shadow */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.45);
  --glow: 0 0 0 1px rgba(77, 159, 255, 0.25), 0 8px 32px rgba(77, 159, 255, 0.15);

  /* Type */
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI",
    Roboto, "Helvetica Neue", Inter, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, monospace;

  /* Spacing (8pt grid) */
  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 16px;
  --s-5: 24px;
  --s-6: 32px;
  --s-7: 48px;
  --s-8: 64px;
  --s-9: 96px;

  /* Motion */
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --t-fast: 150ms;
  --t: 250ms;
  --t-slow: 400ms;
}

/* ============ Light mode ============ */
:root[data-theme="light"] {
  --bg-0: #f6f7f9;
  --bg-1: #ffffff;
  --bg-2: #f0f2f5;
  --bg-3: #e8ebf0;
  --glass: rgba(15, 17, 21, 0.035);
  --glass-strong: rgba(15, 17, 21, 0.06);
  --border: rgba(15, 17, 21, 0.08);
  --border-strong: rgba(15, 17, 21, 0.16);

  --text-1: #13161b;
  --text-2: #49525e;
  --text-3: #67707d;

  --accent-soft: rgba(77, 159, 255, 0.12);
  --accent-2-soft: rgba(56, 210, 192, 0.12);

  --shadow-sm: 0 1px 2px rgba(15, 17, 21, 0.08);
  --shadow-md: 0 8px 24px rgba(15, 17, 21, 0.1);
  --shadow-lg: 0 20px 60px rgba(15, 17, 21, 0.14);
  --glow: 0 0 0 1px rgba(77, 159, 255, 0.22), 0 8px 32px rgba(77, 159, 255, 0.14);
}

:root[data-theme="light"] .site-header {
  background: rgba(255, 255, 255, 0.75);
}

:root[data-theme="light"] ::selection {
  background: rgba(77, 159, 255, 0.3);
  color: #111;
}

:root[data-theme="light"] ::-webkit-scrollbar-thumb {
  background: rgba(15, 17, 21, 0.2);
  background-clip: content-box;
  border: 2px solid transparent;
}

:root[data-theme="light"] ::-webkit-scrollbar-thumb:hover {
  background: rgba(15, 17, 21, 0.3);
  background-clip: content-box;
  border: 2px solid transparent;
}

/* ============ Theme toggle ============ */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--glass);
  color: var(--text-2);
  cursor: pointer;
  flex-shrink: 0;
  transition: background var(--t-fast) var(--ease), color var(--t-fast) var(--ease),
    border-color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease-spring);
}

.theme-toggle:hover {
  background: var(--glass-strong);
  color: var(--text-1);
  transform: translateY(-1px);
}

.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }

:root[data-theme="light"] .theme-toggle .icon-sun { display: block; }
:root[data-theme="light"] .theme-toggle .icon-moon { display: none; }

/* ============ Base ============ */
* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-1);
  background: var(--bg-0);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img {
  max-width: 100%;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--t-fast) var(--ease);
}

a:hover {
  color: #8fc3ff;
}

::selection {
  background: rgba(77, 159, 255, 0.35);
  color: #fff;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.12);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: content-box;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.22);
  background-clip: content-box;
  border: 2px solid transparent;
}

/* ============ Layout ============ */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--s-5);
}

.container-narrow {
  max-width: 920px;
}

/* ============ Skip link ============ */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--bg-3);
  color: var(--text-1);
  padding: 10px 16px;
  border-radius: 0 0 var(--r-sm) 0;
  z-index: 1000;
  font-size: 14px;
}

.skip-link:focus {
  left: 0;
}

/* ============ Header / Nav ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 12, 15, 0.72);
  -webkit-backdrop-filter: blur(20px) saturate(1.6);
  backdrop-filter: blur(20px) saturate(1.6);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  gap: var(--s-4);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--text-1);
}

.brand:hover {
  color: var(--text-1);
}

.brand-logo {
  width: 26px;
  height: 26px;
  object-fit: contain;
}

.brand-accent {
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: var(--s-1);
}

.main-nav a {
  color: var(--text-2);
  font-size: 14px;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--r-pill);
  transition: color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.main-nav a:hover {
  color: var(--text-1);
  background: var(--glass);
}

.main-nav a.nav-active {
  color: var(--text-1);
  background: var(--glass-strong);
}

.main-nav a.nav-cta {
  color: #fff;
  background: var(--gradient);
  padding: 8px 18px;
  font-weight: 600;
  box-shadow: 0 4px 16px rgba(77, 159, 255, 0.28);
}

.main-nav a.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(77, 159, 255, 0.4);
  background: linear-gradient(135deg, #5da9ff 0%, #45ddc9 100%);
}

/* ============ Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s-2);
  font-family: var(--font);
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  padding: 13px 26px;
  border-radius: var(--r-pill);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: transform var(--t-fast) var(--ease-spring),
    box-shadow var(--t-fast) var(--ease),
    background var(--t-fast) var(--ease),
    border-color var(--t-fast) var(--ease);
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  color: #fff;
  background: var(--gradient);
  box-shadow: 0 6px 24px rgba(77, 159, 255, 0.32);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(77, 159, 255, 0.45);
  color: #fff;
}

.btn-secondary {
  color: var(--text-1);
  background: var(--glass);
  border-color: var(--border-strong);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: var(--glass-strong);
  border-color: rgba(255, 255, 255, 0.24);
  transform: translateY(-2px);
  color: var(--text-1);
}

.btn-light {
  color: #0a0c0f;
  background: #f5f7fa;
}

.btn-light:hover {
  background: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: #0a0c0f;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 13px;
}

.btn[disabled],
.btn.disabled {
  opacity: 0.45;
  pointer-events: none;
}

/* ============ Eyebrow + section titles ============ */
.eyebrow {
  margin: 0 0 var(--s-2);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

.section-title {
  margin: 0 0 var(--s-3);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.section-sub {
  margin: 0 0 var(--s-6);
  font-size: 17px;
  color: var(--text-2);
  max-width: 700px;
}

.gradient-text {
  background: var(--gradient);
  background-size: 200% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  animation: gradient-shift 8s ease-in-out infinite;
}

@keyframes gradient-shift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* ============ Scroll reveal ============ */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
  will-change: opacity, transform;
}

.reveal.in {
  opacity: 1;
  transform: translateY(0);
}

/* Gentle float (hero mockups, decorative) */
.float-slow {
  animation: float-y 7s ease-in-out infinite;
}

@keyframes float-y {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .float-slow {
    animation: none;
  }
}

/* ============ Footer ============ */
.footer-wrap {
  margin-top: var(--s-8);
}

.disclaimer {
  border-top: 1px solid var(--border);
  background: var(--bg-1);
  padding: var(--s-5) 0;
}

.disclaimer p {
  margin: 0;
  font-size: 13px;
  color: var(--text-3);
  max-width: 720px;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-0);
  padding: var(--s-6) 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--s-3);
}

.footer-inner > span {
  font-size: 13px;
  color: var(--text-3);
}

.footer-nav {
  display: flex;
  gap: var(--s-4);
}

.footer-nav a {
  font-size: 13px;
  color: var(--text-2);
}

.footer-nav a:hover {
  color: var(--text-1);
}

/* ============ Focus visibility ============ */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ============ Responsive ============ */
@media (max-width: 900px) {
  .main-nav a:not(.nav-cta) {
    display: none;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 var(--s-4);
  }
  .header-inner {
    height: 56px;
    gap: var(--s-2);
  }
  .main-nav .nav-cta {
    padding: 8px 14px;
    font-size: 13px;
  }
  .theme-toggle {
    width: 34px;
    height: 34px;
  }
}

/* Visually hidden but present for SEO/accessibility (H1s on app pages) */
.sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}