/* ==========================================================================
   Mobile App Official Website
   Modern, minimal, mobile-first design
   ========================================================================== */

:root {
  --bg: #ffffff;
  --surface: #f7f9fc;
  --surface-strong: #eef2f9;
  --text: #101828;
  --text-muted: #52607a;
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --accent-contrast: #ffffff;
  --accent-soft: #e9f0fd;
  --border: #e2e8f0;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.05), 0 6px 20px rgba(16, 24, 40, 0.06);
  --content-max: 800px;
  --header-height: 64px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1220;
    --surface: #111a2e;
    --surface-strong: #16213a;
    --text: #e7edf7;
    --text-muted: #9fb0c9;
    --accent: #60a5fa;
    --accent-strong: #93c5fd;
    --accent-contrast: #0b1220;
    --accent-soft: #1c2b47;
    --border: #1f2b42;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 6px 20px rgba(0, 0, 0, 0.35);
  }
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
}

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

a:hover {
  text-decoration: underline;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* --------------------------------------------------------------------------
   Accessibility: skip-to-content link
   -------------------------------------------------------------------------- */

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 10px 16px;
  border-radius: 0 0 var(--radius-sm) 0;
  font-weight: 600;
}

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

/* --------------------------------------------------------------------------
   Layout
   -------------------------------------------------------------------------- */

.container {
  max-width: var(--content-max);
  margin: 0 auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* --------------------------------------------------------------------------
   Header and navigation
   -------------------------------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: var(--header-height);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.01em;
}

.brand:hover {
  text-decoration: none;
  color: var(--accent);
}

.brand-icon {
  display: block;
  border-radius: 7px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-menu a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.98rem;
}

.nav-menu a:hover {
  color: var(--text);
  background: var(--surface);
  text-decoration: none;
}

.nav-menu a.active {
  color: var(--accent);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: var(--text);
}

/* Mobile: hamburger menu when JavaScript is enabled */
@media (max-width: 719px) {
  .js .nav-toggle {
    display: inline-flex;
  }

  .js .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    padding: 10px 16px 14px;
  }

  .js .nav-menu.open {
    display: flex;
  }

  /* Without JavaScript, the menu stays visible */
  .no-js .nav-toggle {
    display: none;
  }

  .no-js .nav-menu {
    flex-wrap: wrap;
    justify-content: flex-end;
  }

  .no-js .nav-menu a {
    padding: 8px 10px;
    min-height: 40px;
  }
}

/* --------------------------------------------------------------------------
   Home page: hero
   -------------------------------------------------------------------------- */

.hero {
  padding: 56px 0 40px;
  text-align: center;
  background: linear-gradient(180deg, var(--accent-soft), transparent 72%);
}

.hero-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.hero-icon {
  width: 128px;
  height: 128px;
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  margin: 4px 0 0;
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
}

.hero-title {
  margin: 4px 0 0;
  font-size: clamp(2rem, 6vw, 3rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.hero-description {
  margin: 0;
  max-width: 620px;
  color: var(--text-muted);
  font-size: 1.12rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 10px;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 10px 22px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-contrast);
  font-weight: 600;
  font-size: 1rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 0.15s ease;
}

.btn:hover {
  background: var(--accent-strong);
  text-decoration: none;
}

.btn:active {
  transform: translateY(1px);
}

.btn-store {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border);
}

.btn-store:hover {
  background: var(--surface-strong);
  color: var(--text);
}

/* --------------------------------------------------------------------------
   Sections and cards
   -------------------------------------------------------------------------- */

.section {
  padding: 40px 0;
}

.section-title {
  margin: 0 0 22px;
  font-size: 1.5rem;
  letter-spacing: -0.01em;
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 640px) {
  .features-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}

.feature h3 {
  margin: 12px 0 6px;
  font-size: 1.1rem;
  line-height: 1.3;
}

.feature p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.98rem;
}

.feature-icon {
  color: var(--accent);
}

.privacy-card,
.support-card {
  text-align: center;
}

.privacy-card p,
.support-card p {
  margin: 8px 0;
}

.link-arrow {
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   Content pages (Privacy, Terms, Support)
   -------------------------------------------------------------------------- */

main.container {
  padding-top: 36px;
  padding-bottom: 64px;
}

h1 {
  margin: 0 0 8px;
  font-size: 2rem;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.page-meta {
  margin: 0 0 24px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.legal h2 {
  margin: 2.2em 0 0.6em;
  font-size: 1.3rem;
  line-height: 1.3;
}

.legal h3 {
  margin: 1.6em 0 0.5em;
  font-size: 1.08rem;
  line-height: 1.3;
}

.legal p {
  margin: 0 0 1em;
}

.legal ul {
  padding-left: 1.2em;
}

.legal li {
  margin: 0.35em 0;
}

.check-list {
  list-style: none;
  padding-left: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  margin: 1em 0 1.5em;
}

@media (min-width: 560px) {
  .check-list {
    grid-template-columns: 1fr 1fr;
  }
}

.check-list li {
  position: relative;
  padding-left: 32px;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0.1em;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 700;
}

.contact-line {
  font-size: 1.05rem;
}

.contact-line a {
  font-weight: 600;
}

.contact-card {
  margin: 24px 0 36px;
}

.notfound-card {
  margin-top: 48px;
  text-align: center;
}

/* --------------------------------------------------------------------------
   FAQ
   -------------------------------------------------------------------------- */

.faq {
  display: grid;
  gap: 12px;
  margin: 0 0 32px;
}

.faq details {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0 18px;
}

.faq summary {
  cursor: pointer;
  padding: 14px 0;
  font-weight: 600;
}

.faq details p {
  margin: 0 0 14px;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  text-align: center;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 22px;
  margin-bottom: 12px;
}

.footer-nav a {
  color: var(--text-muted);
  font-weight: 500;
  padding: 6px 4px;
}

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

.footer-copy {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.92rem;
}

/* --------------------------------------------------------------------------
   Small touches
   -------------------------------------------------------------------------- */

::selection {
  background: var(--accent);
  color: var(--accent-contrast);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}