/* =========================================================
   KARDS 手游 · 官网下载单页样式
   风格:二战军事 / 简洁大气 / 移动端自适应
   ========================================================= */

:root {
  /* 配色:深橄榄黑 + 黄铜金,呼应二战军事元素 */
  --c-bg: #12150f;
  --c-bg-2: #1a1e14;
  --c-panel: #20251a;
  --c-line: rgba(201, 162, 39, 0.18);
  --c-brass: #c9a227;
  --c-brass-light: #e6c655;
  --c-text: #e9e5d8;
  --c-muted: #9aa08c;
  --c-danger: #b3543a;
  --radius: 12px;
  --shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
  --header-h: 64px;
  --font: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); }

body {
  font-family: var(--font);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

.container { width: min(1120px, 92%); margin: 0 auto; }

/* ============ 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 1px;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  border: 1px solid transparent;
}
.btn-lg { padding: 15px 36px; font-size: 16px; }
.btn-primary {
  background: linear-gradient(160deg, var(--c-brass-light), var(--c-brass));
  color: #1c1a10;
  box-shadow: 0 6px 18px rgba(201, 162, 39, 0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 26px rgba(201, 162, 39, 0.5); }
.btn-ghost { border-color: rgba(233, 229, 216, 0.35); color: var(--c-text); background: rgba(255, 255, 255, 0.04); }
.btn-ghost:hover { border-color: var(--c-brass); color: var(--c-brass-light); }

/* ============ 顶部导航 ============ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(18, 21, 15, 0.82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
.site-header.is-scrolled { border-bottom-color: var(--c-line); background: rgba(18, 21, 15, 0.95); }
.nav { display: flex; align-items: center; justify-content: space-between; height: var(--header-h); }
.nav-brand { display: flex; align-items: center; gap: 10px; }
.nav-logo { border-radius: 8px; }
.nav-title { font-size: 20px; font-weight: 800; letter-spacing: 2px; }
.nav-title em { font-style: normal; font-size: 13px; color: var(--c-brass); margin-left: 4px; letter-spacing: 4px; }

.nav-menu { display: flex; align-items: center; gap: 34px; }
.nav-menu a { font-size: 15px; color: var(--c-muted); transition: color 0.2s ease; }
.nav-menu a:hover { color: var(--c-brass-light); }
.nav-cta {
  padding: 8px 20px;
  border: 1px solid var(--c-brass);
  border-radius: 5px;
  color: var(--c-brass-light) !important;
}
.nav-cta:hover { background: var(--c-brass); color: #1c1a10 !important; }

.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--c-text); transition: 0.3s ease; }
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============ Hero ============ */
.hero { position: relative; min-height: 100svh; display: flex; align-items: center; overflow: hidden; }
.hero-bg {
  position: absolute; inset: 0;
  background: url("../images/hero-bg.png") center 30% / cover no-repeat;
  transform: scale(1.05);
  animation: heroDrift 18s ease-in-out infinite alternate;
}
@keyframes heroDrift { from { transform: scale(1.05) translateY(0); } to { transform: scale(1.1) translateY(-12px); } }
.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(18, 21, 15, 0.55) 0%, rgba(18, 21, 15, 0.72) 55%, var(--c-bg) 100%);
}
.hero-content { position: relative; z-index: 1; padding: calc(var(--header-h) + 48px) 0 80px; }
.hero-kicker {
  display: inline-block;
  font-size: 12px; letter-spacing: 5px; color: var(--c-brass-light);
  border: 1px solid var(--c-line);
  padding: 6px 16px; border-radius: 99px;
  margin-bottom: 24px;
  background: rgba(18, 21, 15, 0.5);
}
.hero-title {
  font-size: clamp(52px, 10vw, 108px);
  font-weight: 900; line-height: 1.05; letter-spacing: 6px;
  text-shadow: 0 6px 30px rgba(0, 0, 0, 0.6);
}
.hero-title span {
  display: inline-block; margin-left: 10px;
  font-size: 0.32em; letter-spacing: 8px; vertical-align: middle;
  color: var(--c-brass-light);
  border: 2px solid var(--c-brass);
  padding: 4px 14px; border-radius: 4px;
}
.hero-slogan { margin-top: 20px; font-size: clamp(16px, 2.4vw, 21px); color: var(--c-brass-light); letter-spacing: 1px; }
.hero-desc { margin-top: 14px; max-width: 560px; color: rgba(233, 229, 216, 0.85); font-size: 15px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 34px; }

.hero-stats { display: flex; gap: 44px; margin-top: 52px; }
.hero-stats li { position: relative; padding-left: 14px; }
.hero-stats li::before { content: ""; position: absolute; left: 0; top: 8px; bottom: 8px; width: 3px; background: var(--c-brass); border-radius: 2px; }
.hero-stats strong { display: block; font-size: 30px; color: var(--c-brass-light); line-height: 1.2; }
.hero-stats span { font-size: 13px; color: var(--c-muted); }

/* ============ 通用 Section ============ */
.section { padding: 96px 0; position: relative; }
.section-dark { background: var(--c-bg-2); }
.section-head { text-align: center; margin-bottom: 56px; }
.section-kicker { font-size: 12px; letter-spacing: 5px; color: var(--c-brass); margin-bottom: 10px; }
.section-title { font-size: clamp(28px, 4.5vw, 40px); font-weight: 800; letter-spacing: 4px; position: relative; display: inline-block; }
.section-title::after {
  content: "★"; display: block;
  font-size: 14px; color: var(--c-brass);
  letter-spacing: 8px; margin-top: 6px;
}
.section-sub { margin-top: 12px; color: var(--c-muted); font-size: 15px; }

/* 滚动渐入 */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* ============ 游戏简介 ============ */
.about-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.about-card {
  background: linear-gradient(180deg, var(--c-panel), rgba(32, 37, 26, 0.6));
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: transform 0.25s ease, border-color 0.25s ease;
}
.about-card:hover { transform: translateY(-6px); border-color: rgba(201, 162, 39, 0.45); }
.about-icon {
  width: 52px; height: 52px;
  display: flex; align-items: center; justify-content: center;
  font-size: 24px; color: var(--c-brass-light);
  border: 1px solid var(--c-line); border-radius: 10px;
  margin-bottom: 20px;
  background: rgba(201, 162, 39, 0.08);
}
.about-card h3 { font-size: 19px; margin-bottom: 14px; letter-spacing: 1px; }
.about-card p { font-size: 14px; color: var(--c-muted); margin-bottom: 12px; }
.about-card p:last-child { margin-bottom: 0; }
.about-card strong { color: var(--c-brass-light); font-weight: 600; }

/* ============ 场景轮播 ============ */
.carousel { position: relative; max-width: 1120px; margin: 0 auto; overflow: hidden; border-radius: var(--radius); box-shadow: var(--shadow); }
.carousel-track { display: flex; transition: transform 0.6s cubic-bezier(0.65, 0, 0.35, 1); }
.carousel-slide { position: relative; flex: 0 0 100%; aspect-ratio: 16 / 8.5; background: #000; }
.carousel-slide img { width: 100%; height: 100%; object-fit: cover; }
.carousel-slide figcaption {
  position: absolute; left: 0; right: 0; bottom: 0;
  padding: 40px 28px 20px;
  font-size: 15px; letter-spacing: 2px;
  background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.75));
  color: var(--c-text);
}
.carousel-btn {
  position: absolute; top: 50%; transform: translateY(-50%);
  width: 46px; height: 46px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 50%;
  background: rgba(18, 21, 15, 0.55);
  color: #fff; font-size: 26px; line-height: 1;
  cursor: pointer; z-index: 2;
  transition: background 0.2s ease, border-color 0.2s ease;
  backdrop-filter: blur(4px);
}
.carousel-btn:hover { background: rgba(201, 162, 39, 0.85); border-color: var(--c-brass); color: #1c1a10; }
.carousel-btn.prev { left: 18px; }
.carousel-btn.next { right: 18px; }
.carousel-dots { position: absolute; bottom: 16px; right: 24px; display: flex; gap: 8px; z-index: 2; }
.carousel-dots button {
  width: 10px; height: 10px; border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.6);
  background: transparent; cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease;
  padding: 0;
}
.carousel-dots button.is-active { background: var(--c-brass-light); border-color: var(--c-brass-light); transform: scale(1.25); }

/* ============ 玩法攻略 ============ */
.guide-tabs { display: flex; justify-content: center; gap: 12px; margin-bottom: 40px; flex-wrap: wrap; }
.guide-tab {
  padding: 11px 30px;
  font-size: 15px; letter-spacing: 2px;
  color: var(--c-muted);
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.25s ease;
}
.guide-tab:hover { color: var(--c-brass-light); border-color: rgba(201, 162, 39, 0.45); }
.guide-tab.is-active {
  background: linear-gradient(160deg, var(--c-brass-light), var(--c-brass));
  color: #1c1a10; font-weight: 700;
  border-color: transparent;
}
.guide-panel { animation: fadeUp 0.45s ease; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }

.guide-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
#panel-rules .guide-grid { grid-template-columns: repeat(3, 1fr); }
.guide-card {
  position: relative;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-left: 3px solid var(--c-brass);
  border-radius: var(--radius);
  padding: 30px 26px 26px;
}
.guide-no {
  position: absolute; top: 18px; right: 22px;
  font-size: 34px; font-weight: 900;
  color: rgba(201, 162, 39, 0.18);
  letter-spacing: 1px;
}
.guide-card h3 { font-size: 18px; margin-bottom: 12px; letter-spacing: 1px; }
.guide-card p { font-size: 14px; color: var(--c-muted); margin-bottom: 10px; }
.guide-card p:last-child { margin-bottom: 0; }
.guide-card strong { color: var(--c-brass-light); font-weight: 600; }
.guide-tip {
  padding: 12px 14px;
  background: rgba(201, 162, 39, 0.07);
  border-left: 2px solid var(--c-brass);
  border-radius: 4px;
  color: rgba(233, 229, 216, 0.85) !important;
  font-size: 13px !important;
}

/* ============ 下载板块 ============ */
.section-download {
  background:
    linear-gradient(180deg, rgba(18, 21, 15, 0.88), rgba(18, 21, 15, 0.94)),
    url("../images/hero-bg.png") center 70% / cover no-repeat fixed;
}
.download-panel {
  display: flex; align-items: center; justify-content: space-between; gap: 40px;
  background: rgba(26, 30, 20, 0.82);
  border: 1px solid var(--c-line);
  border-radius: 16px;
  padding: 48px 52px;
  backdrop-filter: blur(6px);
  box-shadow: var(--shadow);
}
.download-info h3 { font-size: clamp(22px, 3vw, 30px); letter-spacing: 2px; margin-bottom: 22px; }
.download-meta { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px 32px; margin-bottom: 30px; max-width: 460px; }
.download-meta li { display: flex; gap: 12px; font-size: 14px; align-items: baseline; }
.download-meta span { color: var(--c-muted); flex-shrink: 0; }
.download-meta strong { color: var(--c-text); font-weight: 600; }
.btn-download { width: fit-content; }
.download-note { margin-top: 14px; font-size: 13px; color: var(--c-muted); }

.download-qr { text-align: center; flex-shrink: 0; }
.qr-frame {
  padding: 14px;
  background: #fff;
  border-radius: 12px;
  border: 2px solid var(--c-brass);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}
.qr-frame img { width: 180px; height: 180px; }
.download-qr p { margin-top: 14px; font-size: 13px; color: var(--c-muted); line-height: 1.6; letter-spacing: 1px; }

/* ============ 页脚 ============ */
.site-footer { border-top: 1px solid var(--c-line); padding: 40px 0; background: var(--c-bg-2); }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 18px; text-align: center; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: 2px; }
.footer-brand img { border-radius: 8px; }
.footer-nav { display: flex; gap: 26px; flex-wrap: wrap; justify-content: center; }
.footer-nav a { font-size: 14px; color: var(--c-muted); }
.footer-nav a:hover { color: var(--c-brass-light); }
.footer-copy { font-size: 12px; color: rgba(154, 160, 140, 0.7); }

/* ============ 响应式:平板 ============ */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; }
  #panel-rules .guide-grid { grid-template-columns: 1fr; }
  .guide-grid { grid-template-columns: 1fr; }
  .download-panel { flex-direction: column; text-align: center; padding: 40px 28px; }
  .download-meta { margin-left: auto; margin-right: auto; text-align: left; }
  .btn-download { margin: 0 auto; }
}

/* ============ 响应式:手机 ============ */
@media (max-width: 640px) {
  .section { padding: 64px 0; }

  .nav-toggle { display: flex; }
  .nav-menu {
    position: fixed;
    top: var(--header-h); right: 0; left: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(18, 21, 15, 0.98);
    border-bottom: 1px solid var(--c-line);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
  }
  .nav-menu.is-open { max-height: 320px; }
  .nav-menu li { width: 100%; }
  .nav-menu a { display: block; padding: 16px 24px; font-size: 16px; }
  .nav-cta { border: 0; color: var(--c-brass-light) !important; }

  .hero-stats { gap: 26px; flex-wrap: wrap; }
  .hero-stats strong { font-size: 24px; }
  .hero-actions .btn { flex: 1 1 100%; }

  .carousel-slide { aspect-ratio: 4 / 3; }
  .carousel-btn { width: 38px; height: 38px; font-size: 20px; }
  .carousel-btn.prev { left: 10px; }
  .carousel-btn.next { right: 10px; }
  .carousel-slide figcaption { font-size: 13px; padding: 30px 16px 14px; }

  .guide-tabs { gap: 8px; }
  .guide-tab { padding: 9px 18px; font-size: 14px; flex: 1; text-align: center; }

  .section-download { background-attachment: scroll; }
}

/* 动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .hero-bg { animation: none; }
  html { scroll-behavior: auto; }
  .reveal { transition: none; opacity: 1; transform: none; }
}