/* ============================================================
   Mountain Duck 中文官网 · 通用样式 common.css
   主题色：#0A3E87  深色现代风
   ============================================================ */

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

:root {
  --md-primary: #0A3E87;
  --md-primary-light: #1E5FBF;
  --md-primary-glow: rgba(30, 95, 191, 0.45);
  --md-accent: #4FB8FF;
  --md-accent-2: #00E0C7;
  --md-bg: #05080F;
  --md-bg-2: #0A1024;
  --md-bg-3: #11183A;
  --md-surface: rgba(255, 255, 255, 0.04);
  --md-surface-hover: rgba(255, 255, 255, 0.07);
  --md-border: rgba(255, 255, 255, 0.08);
  --md-border-strong: rgba(255, 255, 255, 0.16);
  --md-text: #E8ECF5;
  --md-text-soft: #B5BCD0;
  --md-text-muted: #7A819A;
  --md-shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  --md-radius: 14px;
  --md-radius-sm: 8px;
  --md-radius-lg: 22px;
  --md-font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei",
    "Helvetica Neue", "Hiragino Sans GB", "Source Han Sans CN", Arial, sans-serif;
  --md-font-mono: "SF Mono", Consolas, "Cascadia Code", Menlo, monospace;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--md-font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--md-text);
  background: var(--md-bg);
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(30, 95, 191, 0.35), transparent 60%),
    radial-gradient(ellipse 60% 40% at 90% 20%, rgba(79, 184, 255, 0.18), transparent 70%),
    radial-gradient(ellipse 50% 40% at 10% 60%, rgba(0, 224, 199, 0.10), transparent 70%);
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--md-accent);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover { color: var(--md-accent-2); }

/* 中英文混排：自动添加间距 */
:lang(zh) {
  word-spacing: 0.05em;
}

/* ---------- 容器 ---------- */
.md-container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 通用按钮 ---------- */
.md-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.25s ease;
  white-space: nowrap;
  line-height: 1;
}
.md-btn svg { width: 16px; height: 16px; flex: none; }

.md-btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--md-primary) 0%, var(--md-primary-light) 60%, var(--md-accent) 100%);
  box-shadow: 0 8px 24px var(--md-primary-glow), inset 0 1px 0 rgba(255,255,255,0.25);
}
.md-btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 32px var(--md-primary-glow), inset 0 1px 0 rgba(255,255,255,0.3);
  color: #fff;
}

.md-btn-ghost {
  color: var(--md-text);
  background: rgba(255,255,255,0.04);
  border-color: var(--md-border-strong);
}
.md-btn-ghost:hover {
  background: rgba(255,255,255,0.08);
  border-color: var(--md-accent);
  color: #fff;
}

.md-btn-sm { padding: 9px 16px; font-size: 13.5px; }

/* ---------- 通用区段 ---------- */
.md-section {
  padding: 100px 0;
  position: relative;
}
.md-section-title {
  font-size: clamp(28px, 3.4vw, 44px);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.25;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #fff 0%, #B5BCD0 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.md-section-sub {
  font-size: 17px;
  color: var(--md-text-soft);
  max-width: 760px;
  line-height: 1.8;
}
.md-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--md-accent);
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(79, 184, 255, 0.08);
  border: 1px solid rgba(79, 184, 255, 0.25);
  margin-bottom: 18px;
}

/* ============================================================
   Header / 导航
   ============================================================ */
.md-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  background: rgba(5, 8, 15, 0.72);
  border-bottom: 1px solid var(--md-border);
}
.md-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 24px;
}
.md-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--md-text);
}
.md-brand img { width: 38px; height: 38px; }
.md-brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.md-brand-name { font-size: 16px; font-weight: 700; letter-spacing: -0.01em; }
.md-brand-by { font-size: 11.5px; color: var(--md-text-muted); margin-top: 2px; }

.md-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  flex: 1;
  justify-content: center;
}
.md-nav a {
  position: relative;
  padding: 8px 14px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--md-text-soft);
  border-radius: 8px;
  transition: all 0.2s ease;
}
.md-nav a:hover { color: #fff; background: var(--md-surface-hover); }
.md-nav a.active { color: #fff; }
.md-nav a.active::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--md-accent);
}

.md-header-actions { display: flex; align-items: center; gap: 10px; }

.md-burger {
  display: none;
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--md-surface);
  border: 1px solid var(--md-border);
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--md-text);
}
.md-burger svg { width: 22px; height: 22px; }

/* ============================================================
   移动端菜单 · 全新设计
   ============================================================ */
.md-mobile-panel {
  position: fixed;
  inset: 72px 0 0 0;
  z-index: 999;
  padding: 32px 24px 48px;
  overflow-y: auto;
  background:
    radial-gradient(ellipse 80% 40% at 50% 0%, rgba(30, 95, 191, 0.35), transparent 70%),
    radial-gradient(ellipse 70% 40% at 100% 100%, rgba(0, 224, 199, 0.14), transparent 70%),
    rgba(5, 8, 15, 0.92);
  backdrop-filter: saturate(180%) blur(24px);
  -webkit-backdrop-filter: saturate(180%) blur(24px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-12px);
  transition: opacity 0.28s ease, transform 0.28s ease, visibility 0.28s;
}
.md-mobile-panel.open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.md-mobile-panel::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(79,184,255,0.5), transparent);
}

.md-mobile-eyebrow {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--md-text-muted);
  margin: 4px 0 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.md-mobile-eyebrow::before {
  content: "";
  width: 22px; height: 2px;
  background: linear-gradient(90deg, var(--md-accent), var(--md-accent-2));
  border-radius: 2px;
}

.md-mobile-nav {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.md-mobile-nav a {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--md-text);
  border-radius: 14px;
  border: 1px solid var(--md-border);
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  overflow: hidden;
  opacity: 0;
  transform: translateX(-12px);
}
.md-mobile-panel.open .md-mobile-nav a {
  animation: md-mobile-slide 0.45s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}
.md-mobile-panel.open .md-mobile-nav a:nth-child(1) { animation-delay: 0.04s; }
.md-mobile-panel.open .md-mobile-nav a:nth-child(2) { animation-delay: 0.09s; }
.md-mobile-panel.open .md-mobile-nav a:nth-child(3) { animation-delay: 0.14s; }
.md-mobile-panel.open .md-mobile-nav a:nth-child(4) { animation-delay: 0.19s; }
.md-mobile-panel.open .md-mobile-nav a:nth-child(5) { animation-delay: 0.24s; }
.md-mobile-panel.open .md-mobile-nav a:nth-child(6) { animation-delay: 0.29s; }

@keyframes md-mobile-slide {
  to { opacity: 1; transform: translateX(0); }
}

.md-mobile-nav a::before {
  content: "";
  position: absolute;
  left: 0; top: 20%; bottom: 20%;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: linear-gradient(180deg, var(--md-accent), var(--md-accent-2));
  opacity: 0;
  transition: opacity 0.25s ease;
}
.md-mobile-nav a.active,
.md-mobile-nav a:hover {
  border-color: rgba(79,184,255,0.35);
  background: linear-gradient(180deg, rgba(79,184,255,0.08), rgba(79,184,255,0.02));
}
.md-mobile-nav a.active::before,
.md-mobile-nav a:hover::before { opacity: 1; }

.md-mobile-nav a .num {
  font-family: var(--md-font-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--md-text-muted);
  letter-spacing: 0.08em;
}
.md-mobile-nav a .label { display: inline-flex; align-items: center; gap: 14px; }
.md-mobile-nav a .arrow {
  width: 28px; height: 28px;
  border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--md-border);
  color: var(--md-text-soft);
  transition: all 0.25s ease;
}
.md-mobile-nav a .arrow svg { width: 12px; height: 12px; }
.md-mobile-nav a.active .arrow,
.md-mobile-nav a:hover .arrow {
  background: linear-gradient(135deg, var(--md-accent), var(--md-accent-2));
  border-color: transparent;
  color: #051022;
  transform: translateX(2px);
}

.md-mobile-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 28px;
  padding-top: 24px;
  border-top: 1px dashed var(--md-border);
}
.md-mobile-actions .md-btn { width: 100%; padding: 16px; font-size: 15.5px; }

.md-mobile-contact {
  margin-top: 28px;
  padding: 18px 20px;
  border-radius: 14px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--md-border);
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 13.5px;
  color: var(--md-text-soft);
}
.md-mobile-contact .row {
  display: flex;
  align-items: center;
  gap: 10px;
}
.md-mobile-contact .row svg {
  width: 15px; height: 15px;
  color: var(--md-accent);
  flex: none;
}
.md-mobile-contact a { color: var(--md-text); }
.md-mobile-contact .tag {
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--md-text-muted);
}

@media (max-width: 960px) {
  .md-nav, .md-header-actions .md-btn { display: none; }
  .md-burger { display: inline-flex; }
}

/* ============================================================
   Footer
   ============================================================ */
.md-footer {
  position: relative;
  margin-top: 80px;
  padding: 80px 0 32px;
  background:
    radial-gradient(ellipse at top, rgba(30,95,191,0.18), transparent 60%),
    linear-gradient(180deg, transparent, rgba(0,0,0,0.5));
  border-top: 1px solid var(--md-border);
}
.md-footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 56px;
  align-items: start;
}
.md-footer-brand { display: flex; flex-direction: column; gap: 18px; max-width: 420px; }
.md-footer-brand-row { display: flex; align-items: center; gap: 14px; }
.md-footer-brand-row img { width: 44px; height: 44px; }
.md-footer-brand-row .name { font-size: 18px; font-weight: 700; }
.md-footer-brand-row .by { font-size: 12px; color: var(--md-text-muted); margin-top: 2px; }
.md-footer-desc { font-size: 14px; color: var(--md-text-soft); line-height: 1.8; }

.md-footer-card {
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  border: 1px solid var(--md-border);
  border-radius: var(--md-radius);
  padding: 22px;
}
.md-footer-card h4 {
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--md-accent);
  margin-bottom: 14px;
  font-weight: 600;
}
.md-footer-contact { display: flex; flex-direction: column; gap: 10px; font-size: 14.5px; color: var(--md-text-soft); }
.md-footer-contact a { color: var(--md-text); }
.md-footer-contact a:hover { color: var(--md-accent); }
.md-footer-contact .row { display: flex; align-items: center; gap: 10px; }
.md-footer-contact svg { width: 16px; height: 16px; color: var(--md-accent); flex: none; }

.md-footer-notice {
  font-size: 13.5px;
  color: var(--md-text-soft);
  line-height: 1.85;
}
.md-footer-notice strong { color: #fff; font-weight: 600; }
.md-footer-notice .en { display: block; margin-top: 10px; color: var(--md-text-muted); font-size: 12.5px; line-height: 1.7; }

.md-footer-bottom {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--md-border);
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--md-text-muted);
}
.md-footer-bottom .badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: rgba(0, 224, 199, 0.08);
  border: 1px solid rgba(0, 224, 199, 0.25);
  color: var(--md-accent-2);
  border-radius: 999px;
  font-size: 12px;
  font-weight: 500;
}
.md-footer-bottom .badge svg {
  width: 14px;
  height: 14px;
  flex: none;
}

@media (max-width: 880px) {
  .md-footer-grid { grid-template-columns: 1fr; gap: 28px; }
}

/* ============================================================
   内页页头 page-hero · 各子页通用
   ============================================================ */
.page-hero {
  position: relative;
  padding: 80px 0 56px;
  overflow: hidden;
}
.page-hero::before {
  content: "";
  position: absolute;
  top: -200px; left: 50%;
  transform: translateX(-50%);
  width: 1000px; height: 700px;
  background: radial-gradient(ellipse at center, rgba(30,95,191,0.4), transparent 60%);
  filter: blur(40px);
  z-index: -1;
  pointer-events: none;
}
/* 同心信号波 + 浮动节点：呼应"云端连接 / 数据挂载"主题 */
.page-hero::after {
  content: "";
  position: absolute; inset: 0;
  background:
    /* 左下角发起的信号波 */
    radial-gradient(circle at 12% 88%, transparent 0,
      transparent 80px, rgba(79,184,255,0.10) 81px, rgba(79,184,255,0.10) 82px, transparent 83px,
      transparent 160px, rgba(79,184,255,0.08) 161px, rgba(79,184,255,0.08) 162px, transparent 163px,
      transparent 260px, rgba(79,184,255,0.06) 261px, rgba(79,184,255,0.06) 262px, transparent 263px,
      transparent 380px, rgba(79,184,255,0.04) 381px, rgba(79,184,255,0.04) 382px, transparent 100%),
    /* 右上角发起的信号波 */
    radial-gradient(circle at 88% 12%, transparent 0,
      transparent 100px, rgba(0,224,199,0.10) 101px, rgba(0,224,199,0.10) 102px, transparent 103px,
      transparent 200px, rgba(0,224,199,0.07) 201px, rgba(0,224,199,0.07) 202px, transparent 203px,
      transparent 320px, rgba(0,224,199,0.05) 321px, rgba(0,224,199,0.05) 322px, transparent 323px,
      transparent 460px, rgba(0,224,199,0.03) 461px, rgba(0,224,199,0.03) 462px, transparent 100%);
  mask-image: radial-gradient(ellipse 80% 100% at 50% 40%, #000 30%, transparent 85%);
  -webkit-mask-image: radial-gradient(ellipse 80% 100% at 50% 40%, #000 30%, transparent 85%);
  z-index: -2;
  pointer-events: none;
}
/* 漂浮节点光点 */
.page-hero .page-hero-inner::before,
.page-hero .page-hero-inner::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  z-index: -1;
}
.page-hero .page-hero-inner::before {
  top: -10px; right: 4%;
  width: 10px; height: 10px;
  background: var(--md-accent-2);
  box-shadow:
    0 0 16px var(--md-accent-2),
    -180px 60px 0 -3px var(--md-accent),
    -180px 60px 14px -1px rgba(79,184,255,0.6),
    260px 220px 0 -4px var(--md-accent-2),
    260px 220px 12px -1px rgba(0,224,199,0.55);
  animation: md-float 6s ease-in-out infinite;
}
.page-hero .page-hero-inner::after {
  bottom: -20px; left: 8%;
  width: 8px; height: 8px;
  background: var(--md-accent);
  box-shadow:
    0 0 14px var(--md-accent),
    220px 30px 0 -2px var(--md-accent-2),
    220px 30px 12px 0 rgba(0,224,199,0.5);
  animation: md-float 7.5s ease-in-out infinite 0.6s;
}
.page-hero-inner { position: relative; }
.page-kicker {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 22px;
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--md-text-soft);
}
.page-kicker .bar {
  width: 40px; height: 2px;
  background: linear-gradient(90deg, var(--md-accent), var(--md-accent-2));
  border-radius: 2px;
}
.page-kicker .num {
  color: var(--md-accent-2);
  font-family: var(--md-font-mono);
  font-size: 12px;
}
.page-kicker .sep { color: var(--md-text-muted); opacity: 0.6; }
.page-title {
  font-size: clamp(32px, 4.4vw, 54px);
  line-height: 1.12;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
}
.page-title .gradient {
  background: linear-gradient(120deg, #4FB8FF 0%, #00E0C7 50%, #FFFFFF 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.page-lead {
  font-size: 17px;
  color: var(--md-text-soft);
  line-height: 1.85;
  max-width: 760px;
}

@media (max-width: 640px) {
  .page-hero { padding: 48px 0 32px; }
  .page-lead { font-size: 15.5px; }
}

/* ============================================================
   全局响应式精修
   ============================================================ */
@media (max-width: 960px) {
  .md-section { padding: 72px 0; }
}
@media (max-width: 640px) {
  .md-container { padding: 0 18px; }
  .md-section { padding: 56px 0; }
  .md-section-sub { font-size: 15.5px; }
  .md-eyebrow { font-size: 11.5px; padding: 5px 12px; margin-bottom: 14px; }
  .md-btn { padding: 11px 18px; font-size: 14px; }
}
@media (max-width: 420px) {
  .md-container { padding: 0 14px; }
  .md-section { padding: 44px 0; }
}

/* ---------- 通用动画 ---------- */
@keyframes md-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}
@keyframes md-fade-up {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}