/* WSnail 首页 · 极简一屏（home-v2） */
:root {
  --ink: #1a2b2e;
  --ink-soft: #2c3f43;
  --muted: rgba(26, 43, 46, 0.58);
  --line: rgba(26, 43, 46, 0.12);
  --paper: #f7f5f1;
  --paper-deep: #efece6;
  --sea: #0a3138;
  --sea-hover: #134850;
  --max: 920px;
  --nav-h: 56px;
  --font-display: "Fraunces", "Noto Serif SC", "Songti SC", serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  color: var(--ink);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.55;
  background:
    radial-gradient(900px 420px at 50% -8%, rgba(10, 49, 56, 0.06), transparent 60%),
    radial-gradient(700px 360px at 100% 100%, rgba(26, 43, 46, 0.04), transparent 55%),
    linear-gradient(180deg, #faf8f5 0%, var(--paper) 42%, var(--paper-deep) 100%);
}

a {
  color: inherit;
  text-underline-offset: 0.18em;
}

.skip {
  position: absolute;
  left: -999px;
  top: 0;
}
.skip:focus {
  left: 12px;
  top: 12px;
  z-index: 100;
  background: #fff;
  padding: 8px 12px;
}

.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;
}

/* —— 顶栏 —— */
.nav {
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 clamp(18px, 4vw, 40px);
  background: rgba(247, 245, 241, 0.78);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.nav__brand {
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-decoration: none;
  color: var(--ink);
  white-space: nowrap;
}

.nav__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 4px 18px;
  font-size: 0.84rem;
  color: var(--muted);
}
.nav__links a {
  text-decoration: none;
  padding: 4px 0;
  transition: color 0.18s ease;
}
.nav__links a:hover,
.nav__links a:focus-visible {
  color: var(--ink);
}

/* —— 主舞台：一屏居中 —— */
.stage {
  flex: 1;
  display: grid;
  align-items: center;
  padding: clamp(24px, 6vh, 56px) 0 clamp(16px, 4vh, 36px);
}

.hero {
  width: min(100% - 36px, var(--max));
  margin: 0 auto;
  text-align: center;
}

.hero__title {
  margin: 0 0 clamp(22px, 4.5vh, 36px);
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 5.2vw, 3.15rem);
  font-weight: 650;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--ink);
  animation: rise 0.8s ease both;
}

/* 服务行 / 产品行：圆点分隔 */
.services,
.products {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 8px 0;
  font-size: clamp(0.86rem, 1.7vw, 0.98rem);
  color: var(--ink-soft);
}

.services li,
.products li {
  display: inline-flex;
  align-items: center;
}

.services li:not(:last-child)::after,
.products li:not(:last-child)::after {
  content: "·";
  margin: 0 0.65em;
  color: var(--muted);
  pointer-events: none;
}

.services a,
.products a {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}
.services a:hover,
.services a:focus-visible,
.products a:hover,
.products a:focus-visible {
  color: var(--sea);
  border-bottom-color: rgba(10, 49, 56, 0.35);
}

.services {
  margin-bottom: clamp(28px, 5vh, 44px);
  animation: rise 0.8s ease 0.08s both;
}

/* —— po 轻报告表单（产品本体） —— */
.po-form {
  display: flex;
  justify-content: center;
  align-items: stretch;
  gap: 10px;
  width: min(100%, 540px);
  margin: 0 auto;
  animation: rise 0.8s ease 0.16s both;
}

.po-form input {
  flex: 1;
  min-width: 0;
  min-height: 48px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.72);
  font: inherit;
  font-size: 0.95rem;
  color: var(--ink);
  outline: none;
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}
.po-form input::placeholder {
  color: rgba(26, 43, 46, 0.4);
}
.po-form input:focus {
  border-color: rgba(10, 49, 56, 0.45);
  box-shadow: 0 0 0 3px rgba(10, 49, 56, 0.08);
}

.po-form button {
  flex-shrink: 0;
  min-height: 48px;
  padding: 0 18px;
  border: 0;
  border-radius: 10px;
  background: var(--sea);
  color: #f7f5f1;
  font: inherit;
  font-size: 0.92rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background 0.18s ease, transform 0.18s ease;
}
.po-form button:hover {
  background: var(--sea-hover);
  transform: translateY(-1px);
}
.po-form button:active {
  transform: none;
}

.po-hint {
  margin: 14px 0 0;
  font-size: 0.8rem;
  color: var(--muted);
  animation: rise 0.8s ease 0.22s both;
}
.po-hint a {
  margin-left: 0.35em;
  color: var(--ink-soft);
  text-decoration: underline;
  text-decoration-thickness: 1px;
}
.po-hint a:hover {
  color: var(--sea);
}

.products {
  margin-top: clamp(36px, 7vh, 64px);
  font-size: clamp(0.8rem, 1.5vw, 0.9rem);
  color: var(--muted);
  animation: rise 0.8s ease 0.28s both;
}
.products a {
  color: var(--muted);
}
.products a:hover,
.products a:focus-visible {
  color: var(--sea);
}

.easter {
  margin: clamp(18px, 3.5vh, 28px) 0 0;
  font-size: 0.78rem;
  color: var(--muted);
  animation: rise 0.8s ease 0.34s both;
}
.easter a {
  color: var(--ink-soft);
  text-decoration: underline;
  text-decoration-thickness: 1px;
}
.easter a:hover {
  color: var(--sea);
}

/* —— 页脚 —— */
.footer {
  padding: 18px clamp(18px, 4vw, 40px) 24px;
  border-top: 1px solid var(--line);
  text-align: center;
}
.footer__about {
  margin: 0 0 8px;
  font-size: 0.78rem;
  color: var(--muted);
}
.footer__meta {
  margin: 0;
  font-size: 0.78rem;
  color: var(--muted);
}
.footer__meta a {
  color: var(--muted);
  text-decoration: none;
}
.footer__meta a:hover {
  color: var(--sea);
}
.footer__meta .sep {
  margin: 0 0.55em;
  opacity: 0.55;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 640px) {
  .nav {
    align-items: flex-start;
    height: auto;
    padding-top: 14px;
    padding-bottom: 12px;
  }
  .nav__links {
    gap: 2px 14px;
    font-size: 0.8rem;
  }

  .po-form {
    flex-direction: column;
    width: 100%;
  }
  .po-form button {
    width: 100%;
  }

  .services,
  .products {
    row-gap: 10px;
  }
  .services li:not(:last-child)::after,
  .products li:not(:last-child)::after {
    margin: 0 0.5em;
  }

  .po-hint {
    max-width: 22em;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.65;
  }
}

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