@font-face {
  font-family: "Alimama ShuHei";
  src: url("./assets/fonts/AlimamaShuHeiTi-Bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Alimama DongFangDaKai";
  src: url("./assets/fonts/AlimamaDongFangDaKai-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

:root {
  --primary-soft: #50c0f0;
  --bg: #f4fbfe;
  --surface: #ffffff;
  --surface-strong: #e0f4fa;
  --line: rgba(32, 160, 224, 0.18);
  --text: #1f2d3d;
  --muted: #5b6b7a;
  --primary: #20a0e0;
  --primary-deep: #0050a0;
  --shadow: 0 18px 44px rgba(0, 80, 160, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  min-height: 100%;
  background: linear-gradient(180deg, #f4fbfe 0%, #ffffff 58%, #e0f4fa 100%);
}

body {
  margin: 0;
  display: flex;
  flex-direction: column;
  font-family: "Microsoft YaHei UI", "PingFang SC", "Hiragino Sans GB", "Segoe UI", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #f4fbfe 0%, #ffffff 58%, #e0f4fa 100%);
  min-height: 100vh;
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(36px, 5vh, 72px) 0;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.container {
  width: min(980px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  background: linear-gradient(135deg, var(--primary-deep) 0%, var(--primary) 58%, var(--primary-soft, #50c0f0) 100%);
  backdrop-filter: blur(8px);
}

.header-inner {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.brand-wordmark {
  display: inline-flex;
  align-items: center;
  font-family: "Alimama DongFangDaKai", "KaiTi", serif;
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: 0.03em;
  color: #ffffff;
  line-height: 1;
}

.back-link {
  color: #ffffff;
  font-size: 0.92rem;
  font-family: "Consolas", "SFMono-Regular", "Courier New", monospace;
}

.hero {
  padding: 0;
}

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

.hero-logo {
  width: min(200px, 48vw);
  margin: 0 0 28px;
  border-radius: 50%;
  box-shadow: var(--shadow);
  border: 1px solid rgba(80, 192, 240, 0.22);
}

.hero-kicker {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 0.86rem;
  letter-spacing: 0.22em;
  font-family: "Consolas", "SFMono-Regular", "Courier New", monospace;
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.15rem, 4.2vw, 3.45rem);
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--primary);
  font-family: "Alimama ShuHei", "Microsoft YaHei UI", "PingFang SC", "Hiragino Sans GB", sans-serif;
}

.hero-subtitle {
  max-width: 640px;
  margin: 20px auto 0;
  font-size: clamp(1rem, 2vw, 1.25rem);
  line-height: 1.9;
  color: var(--muted);
}

.hero-actions {
  display: flex;
  justify-content: center;
  margin-top: 36px;
}

.button {
  --width: 108px;
  --height: 38px;
  --tooltip-height: 35px;
  --tooltip-width: 90px;
  --gap-between-tooltip-to-button: 18px;
  --button-color: #0050a0;
  --tooltip-color: #ffffff;
  width: var(--width);
  height: var(--height);
  background: var(--button-color);
  position: relative;
  text-align: center;
  border-radius: 0.45em;
  font-family: Arial, sans-serif;
  transition: background 0.3s ease;
  box-shadow: 0 6px 18px rgba(0, 80, 160, 0.22);
}

.button::before {
  position: absolute;
  content: attr(data-tooltip);
  width: var(--tooltip-width);
  height: var(--tooltip-height);
  background-color: var(--tooltip-color);
  font-size: 0.9rem;
  color: #1f2d3d;
  border-radius: 0.25em;
  line-height: var(--tooltip-height);
  bottom: calc(var(--height) + var(--gap-between-tooltip-to-button) + 10px);
  left: calc(50% - var(--tooltip-width) / 2);
  box-shadow: 0 12px 30px rgba(17, 53, 110, 0.12);
}

.button::after {
  position: absolute;
  content: "";
  width: 0;
  height: 0;
  border: 10px solid transparent;
  border-top-color: var(--tooltip-color);
  left: calc(50% - 10px);
  bottom: calc(100% + var(--gap-between-tooltip-to-button) - 10px);
}

.button::after,
.button::before {
  opacity: 0;
  visibility: hidden;
  transition: all 0.5s ease;
}

.button-wrapper,
.button-text,
.icon {
  overflow: hidden;
  position: absolute;
  width: 100%;
  height: 100%;
  left: 0;
  color: #ffffff;
}

.button-text,
.icon {
  display: flex;
  align-items: center;
  justify-content: center;
  transition: top 0.5s ease;
}

.button-text {
  top: 0;
  font-size: 0.98rem;
  font-weight: 600;
}

.icon {
  top: 100%;
}

.icon svg {
  width: 24px;
  height: 24px;
}

.button:hover {
  background: var(--button-color);
}

.button:hover .button-text {
  top: -100%;
}

.button:hover .icon {
  top: 0;
}

.button:hover::before,
.button:hover::after {
  opacity: 1;
  visibility: visible;
}

.button:hover::after {
  bottom: calc(var(--height) + var(--gap-between-tooltip-to-button) - 20px);
}

.button:hover::before {
  bottom: calc(var(--height) + var(--gap-between-tooltip-to-button));
}

.legal-entry {
  padding: clamp(28px, 4vh, 48px) 0 0;
}

.legal-entry-inner {
  display: flex;
  gap: 26px;
  justify-content: center;
  font-size: 0.98rem;
}

.legal-entry-inner a {
  color: var(--muted);
  transition: color 180ms ease;
}

.legal-entry-inner a:hover {
  color: var(--primary);
}

.site-footer {
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  background: linear-gradient(135deg, var(--primary-deep) 0%, var(--primary) 58%, var(--primary-soft, #50c0f0) 100%);
}

.footer-inner {
  padding: 24px 0 34px;
  text-align: center;
  color: #ffffff;
  line-height: 1.9;
  font-size: 0.9rem;
}

.footer-inner p {
  margin: 0;
}

.subpage-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.subpage-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(36px, 5vh, 72px) 0;
}

.doc-card {
  max-width: 760px;
  margin: 0 auto;
  padding: 12px 0 0;
  border-radius: 0;
  background: transparent;
  border: 1px solid var(--line);
  border-width: 1px 0 0;
  box-shadow: none;
}

.doc-tag {
  display: inline-flex;
  padding: 0;
  border-radius: 0;
  background: transparent;
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  font-family: "Consolas", "SFMono-Regular", "Courier New", monospace;
}

.doc-card h1 {
  margin: 16px 0 18px;
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 700;
}

.doc-card h2 {
  margin: 30px 0 10px;
  font-size: 1.18rem;
}

.doc-card p {
  margin: 0;
  line-height: 1.95;
  color: var(--muted);
}

@media (max-width: 860px) {
  .header-inner {
    min-height: 70px;
  }

  .brand {
    font-size: 1.35rem;
  }

  .brand-wordmark {
    font-size: 1.48rem;
  }

  .hero {
    padding: 0;
  }

  .doc-card {
    padding-top: 10px;
  }
}

/* ===== 下载按钮组 ===== */

.download-group {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 20px 10px 14px;
  border-radius: 12px;
  background: #ffffff;
  border: 1px solid var(--line);
  box-shadow: 0 2px 8px rgba(0, 80, 160, 0.06);
  text-decoration: none;
  color: var(--text);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  cursor: pointer;
}

.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 80, 160, 0.14);
  border-color: var(--primary);
}

.download-btn.is-disabled {
  opacity: 0.5;
  cursor: default;
  pointer-events: none;
}

.download-btn-icon {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  color: var(--primary);
}

.is-disabled .download-btn-icon {
  color: var(--muted);
}

.download-btn-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.download-btn-platform {
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.download-btn-label {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--muted);
}

@media (max-width: 560px) {
  .container {
    width: min(100% - 24px, 980px);
  }

  .header-inner {
    justify-content: flex-start;
  }

  .button {
    width: 100%;
  }

  .legal-entry-inner {
    gap: 20px;
  }

  .download-group {
    flex-direction: column;
    align-items: center;
    gap: 10px;
  }

  .download-btn {
    width: 220px;
    justify-content: center;
  }

  main {
    padding: clamp(28px, 4vh, 48px) 0;
  }

  .hero-logo {
    width: min(120px, 38vw);
    margin-bottom: 20px;
  }

  .hero h1 {
    font-size: 1.9rem;
  }

  .hero-subtitle {
    font-size: 0.95rem;
    margin-top: 14px;
  }

  .hero-actions {
    margin-top: 28px;
  }

  .subpage-main {
    padding: clamp(28px, 4vh, 48px) 0;
  }

  .doc-card h1 {
    font-size: 1.6rem;
  }
}