/* ============================================
   农田水利官网 · 设计系统
   品牌蓝 #007AFF / 瑞士极简 / 零外部依赖
   ============================================ */

:root {
  --color-primary: #007AFF;
  --color-primary-dark: #0062CC;
  --color-heading: #0C2340;
  --color-text: #374151;
  --color-muted: #6B7280;
  --color-bg: #FFFFFF;
  --color-bg-soft: #F7F9FA;
  --color-bg-tint: #EFF6FF;
  --color-border: #E5E7EB;
  --radius: 6px;
  --radius-lg: 8px;
  --shadow-nav: 0 1px 8px rgba(12, 35, 64, 0.08);
  --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-stack);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 通用组件 ---------- */

.btn {
  display: inline-block;
  padding: 10px 22px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 500;
  line-height: 1.5;
  text-decoration: none;
  cursor: pointer;
  will-change: transform;
  transition: background-color 0.18s ease, color 0.18s ease,
    box-shadow 0.18s ease;
}

.btn-primary {
  background: var(--color-primary);
  color: #FFFFFF;
}
.btn-primary:hover {
  background: var(--color-primary-dark);
  box-shadow: 0 8px 22px rgba(0, 98, 204, 0.28);
}
.btn-primary:active { box-shadow: none; }

.btn-ghost {
  background: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}
.btn-ghost:hover {
  background: var(--color-bg-tint);
}

.btn-lg { padding: 13px 30px; font-size: 16px; }

.link-plain {
  color: var(--color-primary);
  text-decoration: none;
  position: relative;
  font-size: 15px;
}
.link-plain::after {
  content: "";
  position: absolute;
  left: 0; bottom: -2px;
  width: 100%; height: 1px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.2s ease;
}
.link-plain:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ---------- 顶部导航 ---------- */

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}
.nav.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-nav);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 64px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-heading);
  text-decoration: none;
}
.nav-logo { width: 28px; height: 28px; border-radius: var(--radius); }

.nav-links {
  display: flex;
  gap: 28px;
  margin-left: auto;
}
.nav-links a {
  color: var(--color-text);
  text-decoration: none;
  font-size: 15px;
  transition: color 0.18s ease;
}
.nav-links a:hover { color: var(--color-primary); }

.btn-nav { padding: 7px 18px; font-size: 14px; }

/* ---------- 首屏 ---------- */

.hero {
  position: relative;
  padding: 152px 0 120px;
  background: linear-gradient(180deg, #FFFFFF 0%, #F7F9FA 100%);
  overflow: hidden;
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 64px;
}

.hero-copy { flex: 1 1 58%; }

.hero-slogan {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 2px;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
  border-radius: 999px;
  padding: 4px 14px;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 48px;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: 0.5px;
  color: var(--color-heading);
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 17px;
  max-width: 34em;
  color: var(--color-muted);
  margin-bottom: 36px;
}

/* 打字机行 */
.hero-type {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 14px;
  letter-spacing: 0.5px;
  min-height: 1.6em;
}
.type-caret {
  display: inline-block;
  width: 2px;
  height: 1.05em;
  margin-left: 3px;
  vertical-align: -0.18em;
  background: var(--color-primary);
  animation: caret-blink 0.9s steps(1) infinite;
}
@keyframes caret-blink { 50% { opacity: 0; } }

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.hero-meta { font-size: 13px; color: var(--color-muted); }

.hero-side { flex: 0 0 300px; display: flex; justify-content: center; perspective: 900px; }

.qr-card {
  background: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  text-align: center;
  transform-style: preserve-3d;
  will-change: transform;
  transition: box-shadow 0.25s ease, border-color 0.25s ease;
}
.qr-card:hover {
  border-color: #C7DCF9;
  box-shadow: 0 18px 44px rgba(0, 98, 204, 0.14);
}
.qr-icon {
  width: 56px; height: 56px;
  border-radius: 12px;
  margin: 0 auto 10px;
}
.qr-appname {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: 16px;
}
.qr-code {
  display: flex;
  justify-content: center;
}
.qr-code img { border: 0; }
.qr-tip {
  margin-top: 14px;
  font-size: 14px;
  color: var(--color-text);
  font-weight: 500;
}
.qr-download {
  display: block;
  width: 100%;
  margin-top: 16px;
  padding: 9px 18px;
  font-size: 14px;
  text-align: center;
}

/* 双层水波：每层 SVG 画满两个周期，横向位移一个周期后无缝循环。
   前层颜色与功能区底色一致并焊死在衔接处，永不裂开。 */
.wave {
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 110px;
  line-height: 0;
  pointer-events: none;
  overflow: hidden;
}
.wave-layer {
  position: absolute;
  left: 0; bottom: 0;
  width: 200%;
  height: 110px;
  will-change: transform;
}
.wave-layer svg {
  width: 100%;
  height: 110px;
  display: block;
  overflow: hidden;
}
.wave-layer-front svg { animation: wave-flow 18s linear infinite; }
.wave-layer-back svg  { animation: wave-flow 26s linear infinite reverse; }
@keyframes wave-flow {
  from { transform: translate3d(0, 0, 0); }
  to   { transform: translate3d(-50%, 0, 0); }
}

/* ---------- 核心功能 ---------- */

.features {
  background: var(--color-bg-tint);
  padding: 88px 0 96px;
}

.section-tag {
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 2px;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.section-title {
  font-size: 34px;
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: 56px;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
}
.feature {
  padding: 36px 48px 36px 0;
  border-bottom: 1px solid #DCE7F5;
  transition: transform 0.25s ease;
}
.feature:hover { transform: translateX(6px); }
.feature:nth-child(odd) {
  border-right: 1px solid #DCE7F5;
  padding-right: 48px;
}
.feature:nth-child(even) { padding-left: 48px; }
.feature:nth-child(3),
.feature:nth-child(4) { border-bottom: none; }

.feature-icon {
  width: 44px; height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  background: #FFFFFF;
  border: 1px solid var(--color-border);
  color: var(--color-primary);
  margin-bottom: 18px;
  transition: transform 0.25s ease, background-color 0.25s ease,
    border-color 0.25s ease, color 0.25s ease;
}
.feature-icon svg { width: 22px; height: 22px; }
.feature:hover .feature-icon {
  transform: rotate(-6deg) scale(1.08);
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #FFFFFF;
}
.feature h3 {
  font-size: 19px;
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: 10px;
  transition: color 0.2s ease;
}
.feature:hover h3 { color: var(--color-primary); }
.feature p {
  font-size: 15px;
  color: var(--color-muted);
  max-width: 30em;
}

/* ---------- 应用信息 ---------- */

.appinfo {
  padding: 88px 0;
  background: #FFFFFF;
}
.appinfo-inner {
  display: flex;
  align-items: center;
  gap: 32px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 40px 48px;
  background: var(--color-bg-soft);
}
.appinfo-icon {
  width: 72px; height: 72px;
  border-radius: 14px;
  flex-shrink: 0;
}
.appinfo-text h2 {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: 6px;
}
.appinfo-text p { color: var(--color-muted); font-size: 15px; }
.appinfo-actions {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 18px;
}

/* ---------- 页脚 ---------- */

.footer {
  background: #F2F5F8;
  border-top: 1px solid var(--color-border);
  padding: 56px 0 0;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.2fr 1.2fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
}
.footer-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: 12px;
}
.footer-text {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.9;
}
.footer-text a {
  color: var(--color-muted);
  text-decoration: none;
  transition: color 0.18s ease;
}
.footer-text a:hover { color: var(--color-primary); }

.footer-beian {
  border-top: 1px solid var(--color-border);
  padding-top: 20px;
  padding-bottom: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 28px;
  font-size: 13px;
  color: var(--color-muted);
}
.footer-beian a {
  color: var(--color-muted);
  text-decoration: none;
  transition: color 0.18s ease;
}
.footer-beian a:hover { color: var(--color-primary); }

/* ---------- 动效 ---------- */

.qr-float { animation: float-soft 6s ease-in-out infinite; }
@keyframes float-soft {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

/* GSAP 就绪前的初始隐藏由 html.sr 类控制（头部内联脚本添加），
   无 JS / 降级 / 库缺失时内容直接可见 */
html.sr .reveal-hero,
html.sr .reveal-fade,
html.sr .reveal-item {
  visibility: hidden;
}

/* ---------- 响应式 ---------- */

@media (max-width: 1024px) {
  .hero-inner { gap: 40px; }
  .hero-title { font-size: 40px; }
  .hero-side { flex-basis: 260px; }
  .feature { padding: 28px 32px 28px 0; }
  .feature:nth-child(odd) { padding-right: 32px; }
  .feature:nth-child(even) { padding-left: 32px; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-inner { justify-content: space-between; }

  .hero { padding: 112px 0 96px; }
  .hero-inner { flex-direction: column; align-items: flex-start; gap: 48px; }
  .hero-title { font-size: 34px; }
  .hero-side { flex-basis: auto; width: 100%; justify-content: flex-start; }

  .feature-grid { grid-template-columns: 1fr; }
  .feature,
  .feature:nth-child(odd),
  .feature:nth-child(even) {
    border-right: none;
    padding-left: 0;
    padding-right: 0;
  }
  .feature:nth-child(3) { border-bottom: 1px solid #DCE7F5; }

  .appinfo-inner {
    flex-direction: column;
    align-items: flex-start;
    padding: 32px 24px;
  }

  .footer-inner { grid-template-columns: 1fr 1fr; gap: 32px; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 29px; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .btn-lg { text-align: center; }
  .footer-inner { grid-template-columns: 1fr; }
  .section-title { font-size: 27px; }
}

/* ---------- 减弱动态 ---------- */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .qr-float, .type-caret, .wave-layer svg { animation: none; }
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}