/* 铁恋 — 现代简洁官网 */
:root {
  --blue: #3B63F5;
  --blue-soft: #E8EEFE;
  --ink: #111118;
  --text: #52525B;
  --mute: #A1A1AA;
  --line: #E4E4E7;
  --bg: #FFFFFF;
  --bg-soft: #F7F8FC;
  --radius: 16px;
  --font: "Sora", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
strong { font-weight: 600; color: var(--ink); }

.wrap { width: min(1100px, 90%); margin: 0 auto; }

/* —— 按钮 —— */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  height: 48px; padding: 0 24px;
  border-radius: 10px; border: 1px solid transparent;
  font: 500 15px/1 var(--font);
  transition: background .2s, color .2s, border-color .2s, transform .15s;
  cursor: pointer; white-space: nowrap;
}
.btn:active { transform: scale(.98); }
.btn--sm { height: 38px; padding: 0 16px; font-size: 13px; }
.btn--primary { background: var(--blue); color: #fff; }
.btn--primary:hover { background: #2F52D9; }
.btn--ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn--ghost:hover { border-color: var(--ink); }
.btn--light { background: #fff; color: var(--blue); }
.btn--light:hover { background: var(--blue-soft); }
.btn--outline { background: transparent; color: #fff; border-color: rgba(255,255,255,.45); }
.btn--outline:hover { border-color: #fff; background: rgba(255,255,255,.08); }
button.btn {
  font-family: inherit;
  appearance: none;
  -webkit-appearance: none;
}

/* —— 导航 —— */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.86);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled { border-bottom-color: var(--line); }
.nav__inner {
  display: flex; align-items: center; gap: 28px; height: 64px;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 17px; color: var(--ink); letter-spacing: .02em;
}
.logo img { width: 36px; height: 36px; border-radius: 10px; }
.nav__links { display: flex; gap: 26px; margin-left: auto; }
.nav__links a { font-size: 14px; color: var(--text); transition: color .2s; }
.nav__links a:hover { color: var(--ink); }
.nav__menu {
  display: none; margin-left: auto; background: none; border: 0; padding: 8px; cursor: pointer;
}
.nav__menu span {
  display: block; width: 18px; height: 1.5px; background: var(--ink); margin: 5px 0;
}

/* —— Hero —— */
.hero {
  padding: 72px 0 88px;
  background:
    radial-gradient(1200px 500px at 85% -10%, rgba(59, 99, 245, .08), transparent 60%),
    linear-gradient(180deg, #FBFBFE 0%, #FFFFFF 70%);
}
.hero__grid {
  display: grid; grid-template-columns: 1.05fr .95fr;
  gap: 64px; align-items: center;
}
.eyebrow {
  font-size: 12px; font-weight: 600; letter-spacing: .18em;
  text-transform: uppercase; color: var(--blue); margin-bottom: 16px;
}
.hero .eyebrow {
  font-size: 26px;
}
.hero h1 {
  font-size: clamp(40px, 5.5vw, 56px);
  font-weight: 700; color: var(--ink);
  line-height: 1.18; letter-spacing: -.02em;
  margin-bottom: 18px;
}
.lede {
  font-size: 17px; color: var(--text); max-width: 38ch; margin-bottom: 28px;
}
.hero__cta { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 22px; }
.hero__meta { font-size: 13px; color: var(--mute); }

/* 真实 App 截图 */
.shot {
  display: block;
  height: auto;
  filter: drop-shadow(0 28px 50px rgba(17, 17, 24, .22));
}
.shot--hero { width: min(300px, 78%); margin: 0 auto; }
.shot--panel { width: min(280px, 70%); margin: 0 auto; }

.hero__device { display: flex; justify-content: center; align-items: center; }

/* 截图画廊 */
.showcase {
  padding: 88px 0 40px;
  background: var(--bg-soft);
  border-top: 1px solid var(--line);
}
.showcase__row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
  align-items: end;
}
.showcase__item {
  text-align: center;
  margin: 0;
}
.showcase__item img {
  width: min(240px, 100%);
  height: auto;
  object-fit: contain;
  margin: 0 auto 14px;
  filter: drop-shadow(0 18px 36px rgba(17, 17, 24, .18));
  transition: transform .3s ease;
}
.showcase__item:hover img { transform: translateY(-8px); }
.showcase__item figcaption {
  font-size: 13px;
  font-weight: 500;
  color: var(--mute);
  letter-spacing: .04em;
}

/* —— 通用 section —— */
.section { padding: 96px 0; }
.section--soft { background: var(--bg-soft); }
.section__head { max-width: 520px; margin: 0 auto 48px; text-align: center; }
.section__head h2,
.split__copy h2,
.cta h2 {
  font-size: clamp(28px, 3.6vw, 36px);
  font-weight: 700; color: var(--ink);
  line-height: 1.3; letter-spacing: -.02em; margin-bottom: 12px;
}
.section__head p { color: var(--text); font-size: 16px; }

.feats {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.feat {
  padding: 28px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  transition: border-color .2s, box-shadow .2s;
}
.feat:hover {
  border-color: #C7D2FE;
  box-shadow: 0 12px 32px -20px rgba(59, 99, 245, .35);
}
.feat h3 {
  font-size: 17px; color: var(--ink); margin-bottom: 8px;
}
.feat p { font-size: 14px; color: var(--text); }

/* —— 分栏 —— */
.split {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 64px; align-items: center;
}
.split--rev .split__copy { order: 2; }
.split--rev .split__panel { order: 1; }
.split__copy p { margin: 0 0 22px; max-width: 42ch; font-size: 16px; }
.ticks { display: grid; gap: 10px; }
.ticks li {
  position: relative; padding-left: 18px;
  font-size: 14.5px; color: var(--ink); font-weight: 500;
}
.ticks li::before {
  content: ""; position: absolute; left: 0; top: 10px;
  width: 8px; height: 8px; border-radius: 50%; background: var(--blue);
}

.split__panel { display: grid; place-items: center; }

/* —— CTA —— */
.cta {
  background: var(--blue);
  color: rgba(255,255,255,.88);
  padding: 88px 0;
  text-align: center;
}
.cta__inner { max-width: 560px; }
.cta__logo {
  width: 56px; height: 56px; border-radius: 14px;
  margin: 0 auto 20px;
  box-shadow: 0 10px 28px -12px rgba(0,0,0,.35);
}
.cta h2 { color: #fff; margin-bottom: 10px; }
.cta p { margin-bottom: 28px; font-size: 16px; }
.cta__btns { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px; }
.cta__tip { margin-top: 22px; margin-bottom: 0; font-size: 13px; opacity: .65; }

.toast {
  position: fixed;
  left: 50%;
  bottom: 40px;
  transform: translateX(-50%) translateY(12px);
  z-index: 1000;
  padding: 12px 22px;
  border-radius: 10px;
  background: rgba(15, 17, 26, .92);
  color: #fff;
  font-size: 14px;
  letter-spacing: .02em;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease, transform .2s ease;
}
.toast.is-show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* —— Footer —— */
.footer {
  background: #0F111A;
  color: rgba(255,255,255,.55);
  padding-top: 40px;
}
.footer__inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: 20px; flex-wrap: wrap; padding-bottom: 28px;
}
.footer__brand { display: flex; align-items: center; gap: 12px; }
.footer__brand img { border-radius: 8px; }
.footer__brand strong { display: block; color: #fff; font-size: 14px; }
.footer__brand span { font-size: 12px; }
.footer__links { display: flex; gap: 22px; }
.footer__links a { font-size: 13px; transition: color .2s; }
.footer__links a:hover { color: #fff; }
.footer__copy {
  border-top: 1px solid rgba(255,255,255,.08);
  padding: 16px 0; text-align: center; font-size: 12px;
  display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 20px;
}
.footer__copy a { color: rgba(255,255,255,.55); transition: color .2s; }
.footer__copy a:hover { color: #fff; }

/* —— 动效 —— */
.reveal {
  opacity: 0; transform: translateY(16px);
  transition: opacity .6s ease, transform .6s ease;
}
.reveal.is-in { opacity: 1; transform: none; }

/* —— 响应式 —— */
@media (max-width: 900px) {
  .hero__grid, .split, .feats { grid-template-columns: 1fr; }
  .split--rev .split__copy, .split--rev .split__panel { order: initial; }
  .hero { padding: 48px 0 64px; }
  .hero__grid { gap: 0; }
  .hero__copy { text-align: center; }
  .hero__copy .lede { margin-left: auto; margin-right: auto; }
  .hero__cta { justify-content: center; }
  .hero__device { display: none; }
  .showcase__row { grid-template-columns: repeat(2, 1fr); gap: 20px; align-items: start; }
  .showcase__item img { width: min(160px, 100%); }
  .section { padding: 72px 0; }
}
@media (max-width: 640px) {
  .nav__links, .nav__inner > .btn { display: none; }
  .nav__menu { display: block; }
  .nav__links.open {
    display: flex; flex-direction: column; gap: 0;
    position: absolute; left: 0; right: 0; top: 64px;
    background: #fff; border-bottom: 1px solid var(--line);
  }
  .nav__links.open a { padding: 14px 5%; }
  .feats { grid-template-columns: 1fr; }
  .showcase__item img { width: min(140px, 100%); }
}