/* ============================================================
   main.css — 全局基础样式：变量、布局、导航栏、Hero、动画
   ============================================================ */

/* ----- 自定义字体 ----- */
@font-face {
  font-family: 'Carattere';
  src: url('../fonts/Harshita.woff2') format('woff2');
  font-weight: normal;
  font-style: normal;
  font-display: swap;
}

/* ----- Reset & Variables ----- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --blue:       #1a6ff4;
  --blue-light: #4d94ff;
  --blue-dark:  #0047cc;
  --text-dark:  #1a1a2e;
  --text-mid:   #444;
  --text-gray:  #888;
  --bg-page:    linear-gradient(160deg, #e9f4ff 0%, #f4f0ff 40%, #fff 100%);
}

html { scroll-behavior: smooth; }

body {
  font-family: 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
  color: var(--text-dark);
  background: var(--bg-page);
  overflow-x: hidden;
}

/* ----- Scrollbar ----- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #c0d4f5; border-radius: 3px; }

/* ----- Top gradient line ----- */
.top-line {
  position: fixed; top: 0; left: 0; right: 0; height: 3px; z-index: 1001;
  background: linear-gradient(90deg, var(--blue), #a855f7, #06b6d4, var(--blue));
  background-size: 200% 100%;
  animation: gradShift 4s linear infinite;
}
@keyframes gradShift { 0%{ background-position: 0% } 100%{ background-position: 200% } }

/* ----- Navbar ----- */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  display: flex; align-items: center;
  height: 62px; padding: 0 48px;
  background: rgba(255,255,255,0.75);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid rgba(200,220,255,0.35);
  box-shadow: 0 2px 24px rgba(0,0,0,0.06);
  transition: background 0.4s, box-shadow 0.4s;
}
nav.solid {
  background: rgba(255,255,255,0.96);
  box-shadow: 0 2px 32px rgba(0,0,0,0.12);
}
.nav-logo { font-size: 20px; font-weight: 800; color: var(--blue); letter-spacing: -0.5px; cursor: pointer; }
.nav-logo span { color: var(--blue); }
.nav-logo img { height: 36px; width: auto; display: block; }
.nav-date { margin-left: 18px; font-size: 13px; color: var(--text-gray); }
.nav-spacer { flex: 1; }
.btn-nav {
  margin-left: 14px; padding: 8px 22px;
  background: var(--blue); color: white;
  border: none; border-radius: 22px;
  font-size: 13px; font-weight: 700; cursor: pointer;
  transition: all 0.3s; letter-spacing: 0.5px;
  display: flex; flex-direction: column; align-items: center; line-height: 1.3;
}
.btn-nav-sub {
  display: block; font-size: 10px; font-weight: 400;
  letter-spacing: 1px; opacity: 0.85; text-transform: uppercase;
}
.btn-nav:hover {
  background: var(--blue-dark);
  transform: translateY(-1px);
  box-shadow: 0 5px 18px rgba(26,111,244,0.38);
}

.blue {
  color: var(--blue) !important;
  font-family: 'Carattere', cursive;
}

/* ----- Hero ----- */
#hero {
  position: relative; height: 100vh;
  overflow: hidden; display: flex;
}

/* Hero Slideshow */
.hero-slides { position: absolute; inset: 0; overflow: hidden; }
.hero-slide {
  position: absolute; inset: 0;
  opacity: 0;
  transition: opacity 1.5s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 0;
}
.hero-slide.active { opacity: 1; z-index: 1; }
.hero-slide-bg {
  position: absolute;
  top: 62px; left: 0; right: 0; bottom: 0;   /* 顶部留出导航栏高度 */
  background-size: cover; background-position: center top;
  will-change: transform;
}
.hero-gradient {
  position: absolute; inset: 0;
  background: linear-gradient(105deg, rgba(0,20,60,0.28) 0%, rgba(0,10,30,0.10) 55%, transparent 100%);
}

/* Floating particles */
.particles { position: absolute; inset: 0; pointer-events: none; overflow: hidden; }
.particle {
  position: absolute; border-radius: 50%;
  background: rgba(255,255,255,0.55);
  animation: floatUp linear infinite;
}
@keyframes floatUp {
  0%   { transform: translateY(100vh) scale(0); opacity: 0; }
  5%   { opacity: 0.8; }
  90%  { opacity: 0.3; }
  100% { transform: translateY(-80px) scale(1); opacity: 0; }
}

/* Hero content */
.hero-content {
  position: relative; z-index: 10;
  display: flex; 
  flex-direction: column;
  justify-content: flex-start; 
  align-items: center;
  text-align: center;
  width: 100%; max-width: 780px;
  margin: 0 auto;
  padding: calc(62px + 12vh) 24px 0;  /* 导航栏高度 + 上方留白 */
}
.hero-eyebrow {
  font-size: 18px; color: rgba(255,255,255,0.82); letter-spacing: 2px;
  opacity: 0; transform: translateY(22px);
  animation: fadeUp 0.8s ease 0.4s forwards;
}
/* 渐变文字（用于 Discover 等需要渐变色的标题词） */
.gradient-text {
  font-family: 'Carattere', cursive;
  background: #ffffff;
  background-clip: text;
}

.hero-title-en {
  font-size: clamp(48px, 6.5vw, 80px);
  font-weight: 900; color: white; line-height: 1.05;
  text-shadow: 0 3px 24px rgba(0,0,0,0.25);
  margin-top: 14px;
  opacity: 0; transform: translateY(32px);
  animation: fadeUp 0.9s ease 0.6s forwards;
}
.hero-title-en img { height: clamp(72px, 10vw, 280px); width: auto; display: block; }
.hero-title-cn {
  font-size: clamp(42px, 6vw, 72px);
  font-weight: 800; color: white;
  margin-top: 6px;
  text-shadow: 0 3px 24px rgba(0,0,0,0.25);
  opacity: 0; transform: translateY(32px);
  animation: fadeUp 0.9s ease 0.8s forwards;
}
.hero-sub {
  font-size: 22px; color: rgba(255,255,255,0.88);
  margin-top: 16px; letter-spacing: 1px;
  opacity: 0; transform: translateY(22px);
  animation: fadeUp 0.8s ease 1.0s forwards;
}
.hero-cta {
  margin-top: 36px; display: inline-flex; align-items: center; gap: 10px;
  padding: 13px 34px;
  background: linear-gradient(180deg, #E9D9FF 0%, #DBC1FD 32.25%, #E2DEFD 69.47%, #B7FFEE 100%);
  border: 2px solid rgba(255,255,255,0.6);
  border-radius: 32px; color: #2B29FF;
  font-size: 20px; font-weight: 700;
  cursor: pointer; backdrop-filter: blur(12px);
  transition: all 0.35s; width: fit-content;
  opacity: 0; transform: translateY(22px);
  animation: fadeUp 0.8s ease 1.2s forwards;
}
.hero-cta:hover {
  background: rgba(255,255,255,0.30);
  border-color: white;
  transform: translateY(-3px);
  box-shadow: 0 10px 36px rgba(0,0,0,0.22);
}
.hero-cta svg { width: 18px; height: 18px; transition: transform 0.3s; }
.hero-cta:hover svg { transform: rotate(45deg); }

/* Hero dots */
.hero-dots {
  position: absolute; bottom: 36px; left: 50%;
  transform: translateX(-50%);
  display: flex; gap: 8px; z-index: 10;
}
.hero-dot {
  height: 8px; border-radius: 4px;
  background: rgba(255,255,255,0.45); cursor: pointer;
  transition: all 0.35s; width: 8px;
}
.hero-dot.active { width: 26px; background: white; }

/* Scroll indicator */
.scroll-indicator {
  position: absolute; bottom: 36px; right: 60px;
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  color: rgba(255,255,255,0.7); font-size: 11px; letter-spacing: 2px;
  animation: bounce 2.2s ease infinite;
}
.scroll-indicator svg { width: 20px; height: 20px; }

/* ----- Keyframes ----- */
@keyframes fadeUp { to { opacity: 1; transform: translateY(0); } }
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(8px); }
}

/* ----- Scroll Reveal ----- */
.reveal {
  opacity: 0; transform: translateY(44px);
  transition: opacity 0.75s cubic-bezier(0.22,1,0.36,1),
              transform 0.75s cubic-bezier(0.22,1,0.36,1);
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-left  { opacity: 0; transform: translateX(-44px); transition: opacity 0.75s cubic-bezier(0.22,1,0.36,1), transform 0.75s cubic-bezier(0.22,1,0.36,1); }
.reveal-right { opacity: 0; transform: translateX(44px);  transition: opacity 0.75s cubic-bezier(0.22,1,0.36,1), transform 0.75s cubic-bezier(0.22,1,0.36,1); }
.reveal-left.visible, .reveal-right.visible { opacity: 1; transform: translateX(0); }
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }
.delay-5 { transition-delay: 0.5s; }

/* ----- Section Inner（限宽容器，PC 端不全屏铺满） ----- */
.section-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 60px;
  width: 100%;
}

/* ----- Section Common ----- */
.section-header { text-align: center; }
.section-title-en {
  font-size: clamp(28px, 3.5vw, 44px);
  font-weight: 900; color: var(--blue); letter-spacing: -1px;
}
.section-title-en img { height: clamp(44px, 5.5vw, 80px); width: auto; display: inline-block; }
.section-subtitle {
  font-size: 17px; color: var(--text-gray);
  margin-top: 10px; letter-spacing: 0.5px;
}