/* Seren marketing site — brand from docs/BRAND.md */

:root {
  --brand: #5B6CF9;
  --primary: #4B55C8;
  --primary-soft: #E0E0FF;
  --on-primary: #FFFFFF;
  --secondary: #006B5E;
  --mint: #7DF0C8;
  --periwinkle: #8FA8FF;
  --bg: #F8F8FC;
  --on: #1A1B21;
  --surface: #FFFFFF;
  --surface-low: #F2F2F8;
  --surface-container: #ECECF3;
  --surface-high: #E6E6EE;
  --on-variant: #46464F;
  --outline: #777680;
  --outline-variant: #C7C5D0;
  --dark: #111318;
  --dark-on: #E3E1E9;
  --dark-muted: #C7C5D0;
  --dark-surface: #1A1B21;
  --dark-high: #282A2F;
  --icon-grad-start: #3A2F8F;
  --icon-grad-mid: #1E2A6B;
  --icon-grad-end: #0E1434;
  --success: #2FBF71;
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-pill: 999px;
  --shadow-soft: 0 1px 2px rgba(26, 27, 33, 0.04), 0 8px 24px rgba(26, 27, 33, 0.06);
  --shadow-phone: 0 12px 40px rgba(14, 20, 52, 0.18), 0 2px 8px rgba(14, 20, 52, 0.08);
  --font: "Roboto", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "Roboto Mono", ui-monospace, monospace;
  --max: 1120px;
  --gutter: clamp(1.25rem, 4vw, 2rem);
  --header-h: 4rem;
  color-scheme: light;
}

[data-theme="dark"] {
  --bg: #111318;
  --on: #E3E1E9;
  --surface: #1A1B21;
  --surface-low: #1E1F25;
  --surface-container: #282A2F;
  --surface-high: #33343A;
  --on-variant: #C7C5D0;
  --outline: #91909A;
  --outline-variant: #46464F;
  --primary: #BFC2FF;
  --primary-soft: #323BAE;
  --on-primary: #151E97;
  --secondary: #82D5C4;
  --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.2), 0 8px 24px rgba(0, 0, 0, 0.28);
  --shadow-phone: 0 12px 40px rgba(0, 0, 0, 0.45), 0 2px 8px rgba(0, 0, 0, 0.25);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111318;
    --on: #E3E1E9;
    --surface: #1A1B21;
    --surface-low: #1E1F25;
    --surface-container: #282A2F;
    --surface-high: #33343A;
    --on-variant: #C7C5D0;
    --outline: #91909A;
    --outline-variant: #46464F;
    --primary: #BFC2FF;
    --primary-soft: #323BAE;
    --on-primary: #151E97;
    --secondary: #82D5C4;
    --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.2), 0 8px 24px rgba(0, 0, 0, 0.28);
    --shadow-phone: 0 12px 40px rgba(0, 0, 0, 0.45), 0 2px 8px rgba(0, 0, 0, 0.25);
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--on);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { color: var(--brand); }
[data-theme="dark"] a:hover,
:root:not([data-theme="light"]) a:hover { color: var(--periwinkle); }

h1, h2, h3, h4 {
  line-height: 1.2;
  font-weight: 500;
  letter-spacing: -0.02em;
  margin: 0 0 0.75rem;
  color: var(--on);
}

h1 { font-size: clamp(2.25rem, 5vw, 3.25rem); font-weight: 500; }
h2 { font-size: clamp(1.6rem, 3vw, 2.1rem); }
h3 { font-size: 1.25rem; font-weight: 500; }

p { margin: 0 0 1rem; }
p:last-child { margin-bottom: 0; }

.muted { color: var(--on-variant); }
.lede { font-size: 1.2rem; line-height: 1.55; color: var(--on-variant); max-width: 38rem; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--brand);
  color: #fff;
  padding: 0.75rem 1rem;
  z-index: 100;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; }

/* —— Layout —— */
.wrap {
  width: min(var(--max), 100% - 2 * var(--gutter));
  margin-inline: auto;
}

.section {
  padding: clamp(3.5rem, 8vw, 5.5rem) 0;
}

.section-tight { padding: clamp(2.5rem, 5vw, 3.5rem) 0; }

.section-dark {
  background: var(--dark);
  color: var(--dark-on);
}
.section-dark h1,
.section-dark h2,
.section-dark h3 { color: var(--dark-on); }
.section-dark .muted,
.section-dark .lede { color: var(--dark-muted); }
.section-dark a { color: var(--periwinkle); }
.section-dark a:hover { color: var(--mint); }

/* —— Header —— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid color-mix(in srgb, var(--outline-variant) 55%, transparent);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: min(var(--max), 100% - 2 * var(--gutter));
  margin-inline: auto;
}

.wordmark {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  text-decoration: none;
  color: var(--on);
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}
.wordmark:hover { color: var(--on); }
.wordmark-seren { font-weight: 500; }
.wordmark-app { font-weight: 400; color: var(--primary); }
.wordmark-star {
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 0.35rem;
  background: linear-gradient(135deg, var(--icon-grad-start), var(--icon-grad-mid) 55%, var(--icon-grad-end));
  display: inline-grid;
  place-items: center;
  flex-shrink: 0;
  align-self: center;
}
.wordmark-star svg { width: 0.85rem; height: 0.85rem; }

.nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-links {
  display: none;
  align-items: center;
  gap: 0.15rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  display: inline-block;
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-pill);
  text-decoration: none;
  color: var(--on-variant);
  font-size: 0.95rem;
  font-weight: 500;
}
.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--on);
  background: var(--surface-container);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 2.5rem;
  height: 2.5rem;
  border: none;
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--on-variant);
  cursor: pointer;
  padding: 0;
}
.icon-btn:hover {
  background: var(--surface-container);
  color: var(--on);
}
.icon-btn svg { width: 1.35rem; height: 1.35rem; }

.nav-toggle { display: inline-grid; }
@media (min-width: 860px) {
  .nav-links { display: flex; }
  .nav-toggle { display: none; }
}

.nav-panel {
  display: none;
  position: absolute;
  top: var(--header-h);
  left: 0;
  right: 0;
  background: var(--surface);
  border-bottom: 1px solid var(--outline-variant);
  padding: 0.75rem var(--gutter) 1.25rem;
  box-shadow: var(--shadow-soft);
}
.nav-panel.open { display: block; }
.nav-panel ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.25rem;
}
.nav-panel a {
  display: block;
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--on);
  font-weight: 500;
}
.nav-panel a:hover,
.nav-panel a[aria-current="page"] {
  background: var(--surface-low);
  color: var(--primary);
}
@media (min-width: 860px) {
  .nav-panel { display: none !important; }
}

/* —— Buttons —— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 1.4rem;
  border-radius: var(--radius-pill);
  font-family: inherit;
  font-size: 0.98rem;
  font-weight: 500;
  text-decoration: none;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
  line-height: 1.2;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn svg { width: 1.15rem; height: 1.15rem; flex-shrink: 0; }

.btn-primary {
  background: var(--brand);
  color: #fff;
  border-color: var(--brand);
}
.btn-primary:hover {
  background: #4a5be8;
  color: #fff;
  border-color: #4a5be8;
}
[data-theme="dark"] .btn-primary,
:root:not([data-theme="light"]) .btn-primary {
  background: var(--brand);
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--on);
  border-color: var(--outline-variant);
}
.btn-secondary:hover {
  background: var(--surface-container);
  color: var(--on);
  border-color: var(--outline);
}

.section-dark .btn-secondary {
  color: var(--dark-on);
  border-color: rgba(255, 255, 255, 0.22);
}
.section-dark .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
}

.btn-ghost {
  background: transparent;
  color: var(--primary);
  border-color: transparent;
  padding-inline: 0.75rem;
}
.btn-ghost:hover {
  background: var(--primary-soft);
  color: var(--primary);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.75rem;
}

/* —— Hero —— */
.hero {
  padding: clamp(3rem, 9vw, 5.5rem) 0 clamp(2.5rem, 6vw, 4rem);
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  gap: 2.5rem;
  align-items: center;
}
@media (min-width: 900px) {
  .hero-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 3rem;
  }
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--primary);
  letter-spacing: 0.02em;
  margin-bottom: 1rem;
}
.eyebrow::before {
  content: "";
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--mint) 35%, transparent);
}

.pronunciation {
  font-style: normal;
  color: var(--on-variant);
  font-weight: 400;
  font-size: 0.55em;
  letter-spacing: 0.02em;
}

.hero-phones {
  display: flex;
  justify-content: center;
  gap: 0.85rem;
  perspective: 900px;
}
.hero-phones .phone:nth-child(1) { transform: rotate(-6deg) translateY(12px); }
.hero-phones .phone:nth-child(2) { transform: rotate(2deg) translateY(-4px); z-index: 2; }
.hero-phones .phone:nth-child(3) { transform: rotate(7deg) translateY(18px); }
@media (max-width: 700px) {
  .hero-phones .phone:nth-child(3) { display: none; }
}
@media (max-width: 480px) {
  .hero-phones .phone:nth-child(1) { display: none; }
  .hero-phones .phone:nth-child(2) { transform: none; }
}

/* —— Phone mockup —— */
.phone {
  width: min(210px, 42vw);
  background: #0C0E13;
  border-radius: 1.55rem;
  padding: 0.55rem;
  box-shadow: var(--shadow-phone);
  border: 1px solid rgba(255, 255, 255, 0.08);
  flex-shrink: 0;
}
.phone-screen {
  border-radius: 1.1rem;
  overflow: hidden;
  background: #111;
  aspect-ratio: 400 / 860;
}
.phone-screen img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
}

.phone-lg { width: min(240px, 55vw); }
.phone-sm { width: min(180px, 38vw); }

/* —— Promises —— */
.promises {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .promises { grid-template-columns: 1fr 1fr; }
}
@media (min-width: 960px) {
  .promises { grid-template-columns: repeat(4, 1fr); }
}

.promise {
  background: var(--surface);
  border: 1px solid color-mix(in srgb, var(--outline-variant) 70%, transparent);
  border-radius: var(--radius-lg);
  padding: 1.35rem 1.4rem;
  box-shadow: var(--shadow-soft);
}
.promise-icon {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 0.75rem;
  background: var(--primary-soft);
  color: var(--primary);
  display: grid;
  place-items: center;
  margin-bottom: 1rem;
}
.promise-icon svg { width: 1.25rem; height: 1.25rem; }
.promise h3 { margin-bottom: 0.4rem; font-size: 1.05rem; }
.promise p { font-size: 0.95rem; color: var(--on-variant); margin: 0; }

/* —— App cards —— */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 2rem;
}
.section-head p { max-width: 32rem; margin: 0; }

.app-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}
@media (min-width: 700px) {
  .app-grid { grid-template-columns: 1fr 1fr; }
}

.app-card {
  display: grid;
  grid-template-rows: auto 1fr;
  background: var(--surface);
  border: 1px solid color-mix(in srgb, var(--outline-variant) 70%, transparent);
  border-radius: var(--radius-xl);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow-soft);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.app-card:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--brand) 40%, var(--outline-variant));
  box-shadow: 0 16px 40px rgba(26, 27, 33, 0.1);
  color: inherit;
  text-decoration: none;
}

.app-card-shots {
  display: flex;
  gap: 0.65rem;
  padding: 1.25rem 1.25rem 0.5rem;
  background: linear-gradient(180deg, var(--surface-low), var(--surface));
  justify-content: center;
  min-height: 220px;
  align-items: flex-end;
}
.app-card-shots .phone {
  width: min(130px, 28vw);
  padding: 0.35rem;
  border-radius: 1.1rem;
}
.app-card-shots .phone-screen { border-radius: 0.85rem; }
.app-card-shots .phone:first-child { transform: rotate(-4deg) translateY(8px); }
.app-card-shots .phone:last-child { transform: rotate(4deg); }

.app-card-body {
  padding: 1.25rem 1.4rem 1.5rem;
}
.app-card-status {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--secondary);
  background: color-mix(in srgb, var(--mint) 22%, transparent);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-pill);
  margin-bottom: 0.65rem;
}
.app-card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.35rem;
}
.app-card h3 .suite {
  font-weight: 500;
}
.app-card h3 .word {
  font-weight: 400;
  color: var(--primary);
}
.app-card p {
  font-size: 0.95rem;
  color: var(--on-variant);
  margin: 0;
}
.app-card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 1rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--primary);
}
.app-card:hover .app-card-link { gap: 0.55rem; }

/* —— CTA band —— */
.cta-band {
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, var(--icon-grad-start), var(--icon-grad-mid) 55%, var(--icon-grad-end));
  color: #E3E1E9;
  padding: clamp(2rem, 5vw, 3rem);
  display: grid;
  gap: 1.5rem;
  align-items: center;
}
@media (min-width: 720px) {
  .cta-band {
    grid-template-columns: 1.4fr auto;
  }
}
.cta-band h2 { color: #fff; margin-bottom: 0.5rem; }
.cta-band p { color: rgba(227, 225, 233, 0.82); margin: 0; max-width: 36rem; }
.cta-band .btn-primary {
  background: var(--mint);
  color: #003730;
  border-color: var(--mint);
}
.cta-band .btn-primary:hover {
  background: #9af5d6;
  border-color: #9af5d6;
  color: #003730;
}
.cta-band .btn-secondary {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.28);
}
.cta-band .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

/* —— App page —— */
.app-hero {
  padding: clamp(2.5rem, 7vw, 4.5rem) 0 clamp(2rem, 4vw, 3rem);
}
.app-hero-grid {
  display: grid;
  gap: 2.5rem;
  align-items: center;
}
@media (min-width: 880px) {
  .app-hero-grid {
    grid-template-columns: 1fr auto;
    gap: 3.5rem;
  }
}
.app-hero-shots {
  display: flex;
  gap: 0.85rem;
  justify-content: center;
}
.app-hero-shots .phone:nth-child(1) { transform: rotate(-5deg) translateY(10px); }
.app-hero-shots .phone:nth-child(2) { transform: rotate(3deg); }

.features {
  display: grid;
  gap: 1rem;
}
@media (min-width: 720px) {
  .features { grid-template-columns: 1fr 1fr; }
}

.feature {
  background: var(--surface);
  border: 1px solid color-mix(in srgb, var(--outline-variant) 70%, transparent);
  border-radius: var(--radius-lg);
  padding: 1.35rem 1.4rem;
}
.feature h3 {
  font-size: 1rem;
  color: var(--primary);
  margin-bottom: 0.75rem;
  font-weight: 500;
}
.feature ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.55rem;
}
.feature li {
  position: relative;
  padding-left: 1.25rem;
  font-size: 0.95rem;
  color: var(--on-variant);
  line-height: 1.45;
}
.feature li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.45em;
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--mint);
}

.shots-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  justify-content: center;
}
.shots-row .phone { width: min(200px, 42vw); }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  color: var(--on-variant);
  margin-bottom: 1.25rem;
}
.back-link:hover { color: var(--primary); }

/* —— Footer —— */
.site-footer {
  border-top: 1px solid color-mix(in srgb, var(--outline-variant) 60%, transparent);
  padding: 2.5rem 0 2rem;
  margin-top: 1rem;
}
.footer-inner {
  display: grid;
  gap: 1.5rem;
}
@media (min-width: 720px) {
  .footer-inner {
    grid-template-columns: 1.4fr 1fr;
    align-items: start;
  }
}
.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}
.footer-brand .wordmark { font-size: 1.1rem; }
.footer-brand p {
  font-size: 0.9rem;
  color: var(--on-variant);
  max-width: 28rem;
  margin: 0;
}
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  font-size: 0.9rem;
}
.footer-nav a {
  color: var(--on-variant);
  text-decoration: none;
}
.footer-nav a:hover { color: var(--primary); }

.footer-meta {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid color-mix(in srgb, var(--outline-variant) 50%, transparent);
  font-size: 0.85rem;
  color: var(--outline);
}
.footer-meta a { color: var(--outline); text-decoration: none; }
.footer-meta a:hover { color: var(--primary); }

/* —— Utilities —— */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.sr-only-focusable:not(:focus):not(:focus-within) {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.theme-icon-dark { display: none; }
[data-theme="dark"] .theme-icon-light { display: none; }
[data-theme="dark"] .theme-icon-dark { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-icon-light { display: none; }
  :root:not([data-theme="light"]) .theme-icon-dark { display: block; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .app-card, .btn, .app-card-link { transition: none; }
}