/* ===== DayTag Landing — styles.css ===== */

:root {
  --primary: #FF6B35;
  --primary-strong: #FF7E4F; /* hover / brighten */
  --primary-soft: #FFF1EA;
  --ink: #1C1C1E;
  --muted: #8E8E93;
  --surface: #FFFFFF;
  --surface-2: #F7F7F8;
  --border: #E5E5EA;
  --dark-bg: #101014;
  --dark-ink: #F2F2F7;

  --bg: var(--surface);
  --text: var(--ink);
  --text-muted: var(--muted);
  --card-bg: var(--surface);
  --nav-bg: rgba(255, 255, 255, 0.72);
  --phone-frame: #1C1C1E;
  --shadow-sm: 0 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 18px 40px rgba(0, 0, 0, 0.10);
  --radius-btn: 12px;
  --radius-card: 16px;
  --maxw: 1080px;
  --pad-x: 24px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: var(--dark-bg);
    --text: var(--dark-ink);
    --text-muted: #98989F;
    --surface: #1A1A20;
    --surface-2: #15151B;
    --border: #2C2C34;
    --primary-soft: #3A241A;
    --card-bg: #1A1A20;
    --nav-bg: rgba(16, 16, 20, 0.72);
    --phone-frame: #2A2A32;
    --shadow-sm: 0 4px 16px rgba(0, 0, 0, 0.40);
    --shadow-md: 0 18px 40px rgba(0, 0, 0, 0.55);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

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

a { color: inherit; text-decoration: none; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

/* Skip link (a11y) */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--primary);
  color: #fff;
  padding: 10px 16px;
  border-radius: 0 0 8px 0;
  z-index: 100;
}
.skip-link:focus { left: 0; }

/* ===== Nav ===== */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  transition: background .3s ease, backdrop-filter .3s ease, border-color .3s ease;
  border-bottom: 1px solid transparent;
}
.site-nav.scrolled {
  background: var(--nav-bg);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--border);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: .2px;
  color: var(--text);
}
.brand-sub {
  color: var(--primary);
  font-weight: 600;
  font-size: .9rem;
  margin-left: 4px;
}
.nav-links { display: flex; gap: 28px; }
.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  transition: color .2s ease;
}
.nav-links a:hover { color: var(--text); }

.lang-toggle {
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--text);
  font-weight: 600;
  font-size: .9rem;
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  min-width: 48px;
  transition: border-color .2s ease, color .2s ease, transform .1s ease;
}
.lang-toggle:hover { border-color: var(--primary); color: var(--primary); }
.lang-toggle:active { transform: scale(0.96); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 1rem;
  padding: 14px 28px;
  border-radius: var(--radius-btn);
  cursor: pointer;
  border: 1px solid transparent;
  transition: background .2s ease, transform .12s ease, border-color .2s ease, color .2s ease;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-strong); transform: translateY(-1px); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }

/* ===== Sections ===== */
.section { padding: 88px 0; }
.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin: 0 0 8px;
  letter-spacing: -.5px;
}
.section-sub {
  color: var(--text-muted);
  margin: 0 0 40px;
  font-size: 1.05rem;
}
#features, #faq, #download { scroll-margin-top: 80px; }

/* ===== Hero ===== */
.hero { padding-top: 56px; padding-bottom: 64px; }
.hero-inner {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: center;
}
.hero-text h1 {
  font-size: 3rem;
  line-height: 1.15;
  font-weight: 700;
  margin: 0 0 18px;
  letter-spacing: -1px;
}
.hero-sub {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin: 0 0 30px;
  max-width: 520px;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* Phone mockup (pure CSS) */
.hero-visual { display: flex; justify-content: center; }
.phone {
  position: relative;
  width: 250px;
  height: 500px;
  background: var(--phone-frame);
  border-radius: 40px;
  padding: 12px;
  box-shadow: var(--shadow-md);
}
.phone-notch {
  position: absolute;
  top: 18px;
  left: 50%;
  transform: translateX(-50%);
  width: 110px;
  height: 22px;
  background: var(--phone-frame);
  border-radius: 0 0 14px 14px;
  z-index: 2;
}
.phone-screen {
  background: var(--surface-2);
  border-radius: 30px;
  height: 100%;
  padding: 40px 16px 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.dt-card {
  background: linear-gradient(135deg, var(--primary-soft), var(--card-bg));
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  box-shadow: var(--shadow-sm);
}
.dt-card-alt { background: linear-gradient(135deg, var(--card-bg), var(--primary-soft)); }
.dt-card-label { font-size: .9rem; color: var(--text-muted); font-weight: 500; }
.dt-card-num { font-size: 2.6rem; font-weight: 700; color: var(--primary); line-height: 1.1; }
.dt-card-unit { font-size: .85rem; color: var(--text-muted); }

/* ===== Trust bar ===== */
.trust {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
}
.trust-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 32px;
  padding: 22px var(--pad-x);
}
.trust-item {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 500;
}
.trust-item svg { color: var(--primary); flex: none; }

/* ===== Features ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 24px;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: color-mix(in srgb, var(--primary) 35%, var(--border));
}
.feature-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--primary-soft);
  color: var(--primary);
  margin-bottom: 14px;
}
.feature-card h3 { margin: 0 0 6px; font-size: 1.1rem; font-weight: 600; }
.feature-card p { margin: 0; color: var(--text-muted); font-size: .95rem; }

/* ===== Showcase ===== */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.shot-placeholder {
  aspect-ratio: 9 / 16;
  border-radius: var(--radius-card);
  border: 1px dashed var(--border);
  background: linear-gradient(160deg, var(--surface-2), var(--card-bg));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-weight: 500;
}

/* ===== Download ===== */
.download { text-align: center; }
.download .section-sub { margin-left: auto; margin-right: auto; }
.badges {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  margin-top: 8px;
}
.store-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--phone-frame);
  color: #fff;
  padding: 12px 20px;
  border-radius: 12px;
  min-width: 180px;
  transition: transform .12s ease, opacity .2s ease;
}
.store-badge:hover { transform: translateY(-2px); opacity: .95; }
.store-badge svg { flex: none; }
.badge-text { display: flex; flex-direction: column; line-height: 1.2; text-align: left; }
.badge-text small { font-size: .7rem; opacity: .8; }
.badge-text strong { font-size: 1rem; font-weight: 600; }

/* ===== FAQ ===== */
.faq-list { max-width: 760px; }
.faq-list details {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 4px 20px;
  margin-bottom: 12px;
}
.faq-list summary {
  list-style: none;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.05rem;
  padding: 16px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--primary);
  line-height: 1;
  flex: none;
}
.faq-list details[open] summary::after { content: "\2212"; }
.faq-list details p { margin: 0 0 16px; color: var(--text-muted); }

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface-2);
  padding: 32px 0;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.footer-links { display: flex; gap: 22px; align-items: center; }
.footer-links a { color: var(--text-muted); transition: color .2s ease; }
.footer-links a:hover { color: var(--primary); }
.footer-copy { margin: 0; color: var(--text-muted); font-size: .9rem; }

/* ===== Focus visibility (a11y) ===== */
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--primary) 60%, transparent);
  outline-offset: 2px;
  border-radius: 6px;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-sub { margin-left: auto; margin-right: auto; }
  .hero-actions { justify-content: center; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .showcase-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  :root { --pad-x: 20px; }
  .section { padding: 48px 0; }
  .hero { padding-top: 40px; padding-bottom: 48px; }
  .hero-text h1 { font-size: 2.2rem; }
  .features-grid { grid-template-columns: 1fr; }
  .showcase-grid { grid-template-columns: 1fr; }
  .nav-links { gap: 18px; }
  .trust-bar { gap: 18px; }
  .footer-inner { justify-content: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}