/* ==============================
   翼护——校园低空智慧医疗应急响应平台
   样式文件
   ============================== */

/* ---------- 基础重置 ---------- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #4A9EFF;       /* 天蓝色主色 */
  --primary-light: #7CB9FF;
  --primary-dark: #2D7FE0;
  --primary-bg: #E8F4FD;    /* 浅天蓝背景 */
  --primary-bg-alt: #F0F8FF;
  --text: #2C3E50;
  --text-light: #6B7C93;
  --text-white: #FFFFFF;
  --bg: #FFFFFF;
  --bg-alt: #F5FAFF;
  --card-shadow: 0 8px 32px rgba(74, 158, 255, 0.12);
  --card-hover-shadow: 0 16px 48px rgba(74, 158, 255, 0.2);
  --radius: 16px;
  --radius-sm: 10px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1100px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* ---------- 导航栏 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(74,158,255,0.1);
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(255,255,255,0.97);
  box-shadow: 0 2px 20px rgba(74,158,255,0.1);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary-dark);
  letter-spacing: 1px;
}

.nav-links {
  display: flex;
  gap: 4px;
}

.nav-links a {
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--text-light);
  transition: var(--transition);
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: rgba(74,158,255,0.08);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
  padding: 4px 8px;
}

/* ---------- HERO 区域 ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-bg) 0%, var(--bg) 50%, var(--primary-bg-alt) 100%);
  overflow: hidden;
  padding: 80px 24px 60px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 600px 400px at 20% 50%, rgba(74,158,255,0.08) 0%, transparent 70%),
    radial-gradient(ellipse 500px 500px at 80% 30%, rgba(74,158,255,0.06) 0%, transparent 70%),
    radial-gradient(ellipse 400px 400px at 50% 80%, rgba(74,158,255,0.05) 0%, transparent 70%);
  pointer-events: none;
}

/* 纯 CSS 无人机 */
.drone {
  position: absolute;
  width: 120px;
  height: 120px;
  top: 15%;
  right: 12%;
  transition: transform 0.1s ease-out;
  z-index: 1;
}

.drone-body {
  position: relative;
  width: 100%;
  height: 100%;
}

/* 机身（十字形） */
.drone-body::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 30px;
  height: 30px;
  background: var(--primary);
  border-radius: 8px;
  z-index: 2;
}

/* 机臂 */
.drone-body::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 90px;
  height: 4px;
  background: var(--primary-light);
  border-radius: 2px;
}

/* 垂直机臂 */
.drone-rotor {
  position: absolute;
  width: 4px;
  height: 90px;
  background: var(--primary-light);
  border-radius: 2px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.rotor-1 { transform: translate(-50%, -50%) rotate(0deg); }
.rotor-2 { transform: translate(-50%, -50%) rotate(90deg); }

/* 螺旋桨 */
.rotor-1::before,
.rotor-2::before,
.rotor-3::before,
.rotor-4::before {
  content: '';
  position: absolute;
  width: 36px;
  height: 8px;
  background: rgba(74,158,255,0.35);
  border-radius: 4px;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  animation: spin 0.6s linear infinite;
}

.rotor-1::after,
.rotor-2::after,
.rotor-3::after,
.rotor-4::after {
  content: '';
  position: absolute;
  width: 36px;
  height: 8px;
  background: rgba(74,158,255,0.25);
  border-radius: 4px;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  animation: spin 0.6s linear infinite reverse;
}

.rotor-3 {
  position: absolute;
  width: 8px;
  height: 36px;
  background: rgba(74,158,255,0.35);
  border-radius: 4px;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  animation: spin 0.6s linear infinite;
}

.rotor-4 {
  position: absolute;
  width: 8px;
  height: 36px;
  background: rgba(74,158,255,0.25);
  border-radius: 4px;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  animation: spin 0.6s linear infinite reverse;
}

@keyframes spin {
  from { transform: translateX(-50%) rotate(0deg); }
  to { transform: translateX(-50%) rotate(360deg); }
}

/* 无人机悬停动画 */
.drone-body {
  animation: hover 3s ease-in-out infinite;
}

@keyframes hover {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-15px); }
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
}

.hero-title {
  font-size: clamp(3.5rem, 10vw, 6rem);
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  letter-spacing: 8px;
  margin-bottom: 8px;
  animation: fadeUp 1s ease-out;
}

.hero-sub {
  font-size: clamp(1.2rem, 3vw, 1.8rem);
  color: var(--primary);
  font-weight: 600;
  letter-spacing: 6px;
  margin-bottom: 20px;
  animation: fadeUp 1s ease-out 0.2s both;
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 48px;
  animation: fadeUp 1s ease-out 0.4s both;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
  animation: fadeUp 1s ease-out 0.6s both;
}

.hero-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero-stat-num {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--primary-dark);
  line-height: 1;
}

.hero-stat span:not(.hero-stat-label) {
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--primary);
}

.hero-stat-label {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-top: 4px;
}

.scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-light);
  font-size: 0.85rem;
  animation: bounce 2s infinite;
  opacity: 0.6;
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- 通用区块 ---------- */
.section {
  padding: 100px 24px;
}

.section-alt {
  background: var(--bg-alt);
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 800;
  text-align: center;
  color: var(--text);
  margin-bottom: 16px;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  border-radius: 2px;
  margin: 16px auto 0;
}

.section-desc {
  text-align: center;
  color: var(--text-light);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto 60px;
  line-height: 1.8;
}

/* ---------- 项目简介卡片 ---------- */
.intro-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.intro-card {
  background: var(--bg);
  padding: 36px 28px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  transition: var(--transition);
  text-align: center;
  border: 1px solid rgba(74,158,255,0.06);
}

.intro-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--card-hover-shadow);
}

.intro-icon {
  font-size: 2.4rem;
  margin-bottom: 16px;
}

.intro-card h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
  color: var(--text);
}

.intro-card p {
  font-size: 0.92rem;
  color: var(--text-light);
  line-height: 1.7;
}

/* ---------- 案例卡片 ---------- */
.case-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 28px;
  margin-bottom: 60px;
}

.case-card {
  background: var(--bg);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border-left: 4px solid #E74C3C;
  transition: var(--transition);
}

.case-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}

.case-tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.case-tag-red {
  background: #FEE2E2;
  color: #DC2626;
}

.case-card h3 {
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.case-year {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 12px;
}

.case-card p {
  font-size: 0.92rem;
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 16px;
}

.case-lesson {
  background: #FFF7ED;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text);
  line-height: 1.6;
}

.case-lesson span {
  font-weight: 700;
  color: #DC2626;
  margin-right: 6px;
}

/* 痛点数据 */
.pain-data {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.pain-data-item {
  text-align: center;
  background: var(--bg);
  padding: 28px 20px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border: 1px solid rgba(74,158,255,0.06);
  transition: var(--transition);
}

.pain-data-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}

.pain-num {
  display: block;
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--primary-dark);
  margin-bottom: 6px;
}

.pain-label {
  font-size: 0.9rem;
  color: var(--text-light);
}

/* ---------- 架构图 ---------- */
.arch {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-template-rows: auto auto auto;
  gap: 20px;
  max-width: 800px;
  margin: 0 auto 60px;
  padding: 40px 20px;
}

.arch-node {
  background: var(--bg);
  padding: 24px 20px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  text-align: center;
  border: 1px solid rgba(74,158,255,0.08);
  transition: var(--transition);
  position: relative;
  z-index: 2;
}

.arch-node:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
  border-color: var(--primary-light);
}

.arch-node-center {
  grid-column: 2;
  grid-row: 2;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: white;
  border-color: transparent;
}

.arch-node-center h4 { color: white; }
.arch-node-center p { color: rgba(255,255,255,0.85); }

.arch-node-l { grid-column: 1; grid-row: 2; }
.arch-node-r { grid-column: 3; grid-row: 2; }
.arch-node-bl { grid-column: 1; grid-row: 3; }
.arch-node-br { grid-column: 3; grid-row: 3; }

.arch-icon {
  font-size: 2rem;
  margin-bottom: 10px;
}

.arch-node h4 {
  font-size: 1rem;
  margin-bottom: 6px;
}

.arch-node p {
  font-size: 0.82rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* 连接线（纯 CSS） */
.arch-connector {
  position: absolute;
  background: rgba(74,158,255,0.15);
  z-index: 1;
}

.arch-connector-l {
  top: 50%;
  left: calc(33.33% + 20px);
  width: calc(16.67% - 40px);
  height: 2px;
  transform: translateY(-50%);
}

.arch-connector-r {
  top: 50%;
  right: calc(33.33% + 20px);
  width: calc(16.67% - 40px);
  height: 2px;
  transform: translateY(-50%);
}

.arch-connector-bl {
  top: calc(50% + 60px);
  left: calc(33.33% + 20px);
  width: 2px;
  height: 60px;
}

.arch-connector-br {
  top: calc(50% + 60px);
  right: calc(33.33% + 20px);
  width: 2px;
  height: 60px;
}

/* ---------- 三步操作 ---------- */
.steps-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.step {
  flex: 1;
  min-width: 180px;
  max-width: 260px;
  text-align: center;
  background: var(--bg);
  padding: 32px 20px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border: 1px solid rgba(74,158,255,0.06);
  transition: var(--transition);
}

.step:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}

.step-num {
  width: 44px;
  height: 44px;
  line-height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: white;
  font-weight: 700;
  font-size: 1.2rem;
  margin: 0 auto 12px;
}

.step h4 {
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.step p {
  font-size: 0.85rem;
  color: var(--text-light);
}

.step-arrow {
  font-size: 1.8rem;
  color: var(--primary-light);
  font-weight: 300;
  flex-shrink: 0;
}

/* ---------- 核心亮点 ---------- */
.highlight-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 60px;
}

.highlight-item {
  display: flex;
  gap: 24px;
  background: var(--bg);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border: 1px solid rgba(74,158,255,0.06);
  transition: var(--transition);
  align-items: flex-start;
}

.highlight-item:hover {
  transform: translateX(8px);
  box-shadow: var(--card-hover-shadow);
}

.highlight-num {
  font-size: 2.8rem;
  font-weight: 900;
  color: rgba(74,158,255,0.15);
  line-height: 1;
  flex-shrink: 0;
  min-width: 60px;
}

.highlight-content h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
  color: var(--text);
}

.highlight-content p {
  font-size: 0.92rem;
  color: var(--text-light);
  line-height: 1.8;
}

/* 特色网格 */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.feature-card {
  text-align: center;
  padding: 32px 24px;
  background: var(--bg);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border: 1px solid rgba(74,158,255,0.06);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--card-hover-shadow);
}

.feature-icon {
  font-size: 2.4rem;
  display: block;
  margin-bottom: 12px;
}

.feature-card h4 {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.88rem;
  color: var(--text-light);
}

/* ---------- 场景流程 ---------- */
.flow-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  padding: 40px 20px;
  background: var(--bg);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border: 1px solid rgba(74,158,255,0.06);
}

.flow-item {
  text-align: center;
  padding: 20px 16px;
  min-width: 120px;
  flex: 1;
  max-width: 160px;
  transition: var(--transition);
  border-radius: var(--radius-sm);
}

.flow-item:hover {
  background: var(--primary-bg);
  transform: scale(1.05);
}

.flow-icon {
  font-size: 2rem;
  margin-bottom: 8px;
}

.flow-label {
  font-size: 0.82rem;
  color: var(--text-light);
  line-height: 1.5;
}

.flow-arrow {
  font-size: 1.6rem;
  color: var(--primary-light);
  font-weight: 300;
  flex-shrink: 0;
}

/* ---------- 数据统计 ---------- */
.data-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.data-card {
  text-align: center;
  background: var(--bg);
  padding: 36px 20px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border: 1px solid rgba(74,158,255,0.06);
  transition: var(--transition);
}

.data-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--card-hover-shadow);
}

.data-num {
  display: inline;
  font-size: 3rem;
  font-weight: 900;
  color: var(--primary-dark);
  line-height: 1;
}

.data-unit {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--primary);
  margin-left: 2px;
}

.data-label {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-top: 8px;
}

/* ---------- 时间线 ---------- */
.timeline {
  position: relative;
  max-width: 700px;
  margin: 0 auto;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 16px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--primary-light), var(--primary-bg));
}

.timeline-item {
  position: relative;
  padding-bottom: 40px;
  transition: var(--transition);
}

.timeline-item:last-child { padding-bottom: 0; }

.timeline-dot {
  position: absolute;
  left: -24px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--primary);
  border: 3px solid var(--primary-bg);
  box-shadow: 0 0 0 2px var(--primary-light);
}

.timeline-content {
  background: var(--bg);
  padding: 24px;
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  border: 1px solid rgba(74,158,255,0.06);
  transition: var(--transition);
}

.timeline-content:hover {
  transform: translateX(6px);
  box-shadow: var(--card-hover-shadow);
}

.timeline-month {
  display: inline-block;
  padding: 2px 12px;
  background: var(--primary-bg);
  color: var(--primary-dark);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.timeline-content h4 {
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.timeline-content p {
  font-size: 0.88rem;
  color: var(--text-light);
}

/* ---------- 页脚 ---------- */
.footer {
  background: var(--text);
  color: rgba(255,255,255,0.7);
  padding: 48px 24px 32px;
  text-align: center;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-brand {
  margin-bottom: 16px;
}

.footer-logo {
  font-size: 1.4rem;
  font-weight: 700;
  color: white;
  letter-spacing: 2px;
}

.footer-brand p {
  font-size: 0.9rem;
  margin-top: 4px;
  opacity: 0.6;
}

.footer-motto {
  font-size: 1rem;
  color: var(--primary-light);
  margin-bottom: 16px;
  letter-spacing: 2px;
}

.footer-copy {
  font-size: 0.85rem;
  opacity: 0.6;
  line-height: 2;
}

/* ---------- 滚动动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(255,255,255,0.98);
    backdrop-filter: blur(20px);
    padding: 16px;
    border-bottom: 1px solid rgba(74,158,255,0.1);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

  .arch {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto;
    gap: 16px;
  }

  .arch-node-center { grid-column: 1 / -1; grid-row: auto; }
  .arch-node-l { grid-column: 1; grid-row: auto; }
  .arch-node-r { grid-column: 2; grid-row: auto; }
  .arch-node-bl { grid-column: 1; grid-row: auto; }
  .arch-node-br { grid-column: 2; grid-row: auto; }

  .arch-connector { display: none; }

  .steps-row {
    flex-direction: column;
  }

  .step-arrow {
    transform: rotate(90deg);
  }

  .flow-container {
    flex-direction: column;
    gap: 12px;
  }

  .flow-arrow {
    transform: rotate(90deg);
  }

  .highlight-item {
    flex-direction: column;
    gap: 12px;
  }

  .hero-stats {
    gap: 24px;
  }

  .drone {
    width: 80px;
    height: 80px;
    top: 8%;
    right: 5%;
    opacity: 0.5;
  }
}

@media (max-width: 480px) {
  .section {
    padding: 60px 16px;
  }

  .case-cards {
    grid-template-columns: 1fr;
  }

  .pain-data {
    grid-template-columns: 1fr 1fr;
  }

  .data-grid {
    grid-template-columns: 1fr 1fr;
  }

  .intro-cards {
    grid-template-columns: 1fr;
  }
}