/* ============================================================
   友接接 · 产品页样式 · 全深色薄荷绿主题
   Theme: 深墨绿 + 薄荷绿强调（与公司官网/下载页统一）
   Author: 麻辣小龙虾 🦞
   Date: 2026-06-16
   ============================================================ */

:root {
  --bg-0:   #0F1A18;   /* 最深 · hero / intro / im */
  --bg-1:   #152521;   /* 次深 · three / dl */
  --bg-2:   #1A2E25;   /* 卡片 */
  --bg-3:   #213330;   /* 卡片 hover */

  --mint-200: #B6DBC6;
  --mint-300: #8BC5A8;
  --mint-400: #76AF9E;   /* 主色 */
  --mint-500: #5A8B7C;
  --mint-600: #436858;

  --clay:   #E07A5F;

  --paper:    #FAFAF7;
  --ink:      #0F1A18;
  --ink-soft: #4A5852;
  --text:     #FAFAF7;
  --text-2:   rgba(250, 250, 247, 0.78);
  --text-3:   rgba(250, 250, 247, 0.58);
  --text-4:   rgba(250, 250, 247, 0.42);
  --line:     rgba(250, 250, 247, 0.12);
  --line-2:   rgba(250, 250, 247, 0.06);

  --serif-zh: "Noto Serif SC", "Source Han Serif SC", "STSong", serif;
  --sans-zh:  "Noto Sans SC", "Source Han Sans SC", "PingFang SC", system-ui, sans-serif;
  --serif-en: "Playfair Display", "Source Serif 4", Georgia, serif;
  --mono:     "IBM Plex Mono", "JetBrains Mono", ui-monospace, monospace;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { width: 100%; overflow-x: hidden; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--sans-zh);
  font-size: 16px; line-height: 1.65;
  color: var(--text);
  background: var(--bg-0);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font: inherit; cursor: pointer; border: 0; background: none; color: inherit; }
ul { list-style: none; }
::selection { background: var(--mint-400); color: var(--ink); }

/* ============================================================
   Nav
   ============================================================ */
nav.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(15, 26, 24, 0.78);
  backdrop-filter: saturate(160%) blur(16px);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  border-bottom: 1px solid var(--line-2);
}
nav.nav.scrolled { background: rgba(15, 26, 24, 0.95); }
nav.nav .inner {
  max-width: 1200px; margin: 0 auto; padding: 14px 6vw;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px;
}
nav.nav .brand {
  display: flex; align-items: center; gap: 0;
  flex-shrink: 0;
}
nav.nav .brand img {
  height: 32px; width: auto; display: block;
}
nav.nav .menu { display: flex; gap: 36px; font-size: 14px; flex: 1; justify-content: center; }
nav.nav .menu a {
  position: relative; padding: 4px 0;
  color: var(--text-2);
  transition: color 0.3s;
  white-space: nowrap;
}
nav.nav .menu a:hover { color: var(--text); }
nav.nav .menu a.back { color: var(--text-3); font-size: 13px; }
nav.nav .menu a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -2px;
  height: 1px; background: var(--mint-300);
  transform: scaleX(0); transform-origin: left;
  transition: transform 0.4s var(--ease);
}
nav.nav .menu a:hover::after { transform: scaleX(1); }
nav.nav .cta {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 14px; font-weight: 500;
  padding: 10px 20px; border-radius: 999px;
  background: var(--text); color: var(--ink);
  transition: background 0.3s var(--ease), color 0.3s var(--ease);
  white-space: nowrap; flex-shrink: 0;
}
nav.nav .cta:hover { background: var(--mint-300); color: var(--ink); }
nav.nav .cta svg { display: block; width: 16px; height: 16px; }

@media (max-width: 720px) {
  nav.nav .inner { padding: 12px 5vw; gap: 12px; }
  nav.nav .brand img { height: 28px; }
  nav.nav .menu { gap: 16px; }
  nav.nav .menu a { font-size: 13px; }
  nav.nav .cta { padding: 9px 18px; font-size: 13px; }
}
@media (max-width: 540px) {
  /* 返回链接居中，logo 留左，CTA 留右 */
  nav.nav .inner { position: relative; justify-content: space-between; gap: 12px; }
  nav.nav .menu { position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); justify-content: center; }
  nav.nav .cta { padding: 9px 18px; }
}
@media (max-width: 380px) {
  nav.nav .inner { padding: 10px 4vw; gap: 8px; }
  nav.nav .brand img { height: 26px; }
  nav.nav .cta { padding: 8px 14px; font-size: 12px; gap: 5px; }
  nav.nav .cta svg { width: 14px; height: 14px; }
}

/* ============================================================
   Wrap
   ============================================================ */
.wrap { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 6vw; }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  padding: 16vh 0 12vh;
  position: relative;
  background:
    radial-gradient(ellipse 70% 60% at 80% 20%, rgba(118, 175, 158, 0.22), transparent 60%),
    radial-gradient(ellipse 50% 50% at 10% 80%, rgba(224, 122, 95, 0.08), transparent 60%),
    var(--bg-0);
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(250, 250, 247, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(250, 250, 247, 0.04) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, #000, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, #000, transparent 80%);
  pointer-events: none;
}
.hero .wrap { position: relative; z-index: 1; }

.hero .kicker {
  font-family: var(--mono); font-size: 12px;
  letter-spacing: 0.28em; text-transform: uppercase;
  color: var(--mint-300);
  display: flex; align-items: center; gap: 12px;
  margin-bottom: 32px;
}
.hero .kicker .pill {
  display: inline-block; padding: 4px 12px;
  border: 1px solid var(--mint-400); border-radius: 999px;
  color: var(--mint-300);
}

.hero h1 {
  font-family: var(--serif-zh); font-weight: 700;
  font-size: clamp(44px, 7vw, 100px);
  line-height: 1.02; letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 36px;
  max-width: 900px;
}
.hero h1 .en {
  font-family: var(--serif-en); font-style: italic; font-weight: 500;
  color: var(--mint-300);
}
.hero h1 .accent { position: relative; display: inline-block; }
.hero h1 .accent::after {
  content: ""; position: absolute; left: -0.04em; right: -0.04em; bottom: 0.06em;
  height: 0.32em; background: var(--mint-400); opacity: 0.6;
  z-index: -1; border-radius: 2px;
}

.hero .sub {
  font-family: var(--serif-zh); font-weight: 400;
  font-size: clamp(17px, 1.5vw, 20px); line-height: 1.75;
  max-width: 580px; color: var(--text-2);
  margin-bottom: 48px;
}
.hero .sub em {
  font-style: normal; color: var(--mint-300); font-weight: 500;
}

.hero .ctas { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 26px; border-radius: 999px;
  font-size: 15px; font-weight: 500;
  transition: all 0.3s var(--ease);
}
.btn-primary { background: var(--mint-400); color: var(--ink); }
.btn-primary:hover { background: var(--mint-300); transform: translateY(-2px); box-shadow: 0 12px 24px rgba(118, 175, 158, 0.32); }
.btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: var(--text); }
.btn .arr { transition: transform 0.3s var(--ease); }
.btn:hover .arr { transform: translateX(3px); }

@media (max-width: 720px) {
  .hero { padding: 10vh 0 8vh; }
  .hero h1 { font-size: clamp(36px, 11vw, 64px); }
}

/* ============================================================
   Section 通用
   ============================================================ */
.sec { padding: 12vh 0; position: relative; }
.sec-label {
  font-family: var(--mono); font-size: 11px;
  letter-spacing: 0.28em; text-transform: uppercase;
  color: var(--mint-300);
  display: flex; align-items: center; gap: 12px;
  margin-bottom: 24px;
}
.sec-label::after { content: ""; width: 32px; height: 1px; background: currentColor; opacity: 0.5; }

/* ============================================================
   Section · Intro
   ============================================================ */
.intro { background: var(--bg-0); }
.intro .lede {
  font-family: var(--serif-zh); font-weight: 400;
  font-size: clamp(20px, 1.9vw, 28px); line-height: 1.6;
  color: var(--text);
  max-width: 820px;
  letter-spacing: 0.005em;
}
.intro .lede em {
  font-style: normal; font-weight: 600; color: var(--mint-300);
}
.intro .lede .quote-mark {
  font-family: var(--serif-en); font-style: italic; font-size: 1.4em;
  color: var(--mint-300); line-height: 0; vertical-align: -0.18em;
  margin-right: 0.04em;
}
.intro .lede .quote-mark.end {
  margin-left: 0.04em; margin-right: 0;
}

/* ============================================================
   Section · 三个核心点
   ============================================================ */
.three { background: var(--bg-1); }
.three-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 20px; margin-top: 56px;
}
.three-card {
  background: rgba(250, 250, 247, 0.03);
  border: 1px solid var(--line-2);
  border-radius: 20px;
  padding: 36px 30px;
  transition: all 0.4s var(--ease);
  backdrop-filter: blur(8px);
}
.three-card:hover {
  transform: translateY(-3px);
  background: rgba(250, 250, 247, 0.05);
  border-color: rgba(118, 175, 158, 0.3);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.2);
}
.three-card .icon {
  width: 44px; height: 44px; border-radius: 12px;
  background: rgba(118, 175, 158, 0.15);
  display: flex; align-items: center; justify-content: center;
  color: var(--mint-300);
  margin-bottom: 22px;
}
.three-card .icon svg { width: 22px; height: 22px; }
.three-card .num {
  font-family: var(--mono); font-size: 11px;
  letter-spacing: 0.2em; color: var(--mint-300);
  margin-bottom: 12px;
}
.three-card h3 {
  font-family: var(--serif-zh); font-weight: 700;
  font-size: 22px; color: var(--text);
  margin-bottom: 12px;
  letter-spacing: 0.01em;
}
.three-card p {
  font-family: var(--sans-zh); font-size: 14.5px; line-height: 1.75;
  color: var(--text-2);
}
@media (max-width: 800px) {
  .three-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   Section · IM 对话预览
   ============================================================ */
.im { background: var(--bg-0); }
.im-stage {
  display: grid; grid-template-columns: 1fr 1.05fr;
  gap: 80px; align-items: center;
  margin-top: 56px;
}
.im-stage .text h2 {
  font-family: var(--serif-zh); font-weight: 700;
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1.1; letter-spacing: -0.01em;
  color: var(--text);
  margin-bottom: 24px;
}
.im-stage .text h2 em {
  font-family: var(--serif-en); font-style: italic; font-weight: 500;
  color: var(--mint-300);
}
.im-stage .text p {
  font-family: var(--sans-zh); font-size: 16px; line-height: 1.8;
  color: var(--text-2); margin-bottom: 28px;
  max-width: 440px;
}
.im-stage .text .tag {
  display: inline-block; padding: 6px 14px;
  background: rgba(118, 175, 158, 0.1);
  border: 1px solid rgba(118, 175, 158, 0.3);
  border-radius: 999px;
  font-family: var(--mono); font-size: 11px;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--mint-300); margin-right: 8px; margin-bottom: 8px;
}

/* Phone — 内部仍用浅色模拟真实聊天界面 */
.phone {
  position: relative;
  width: 340px; max-width: 100%;
  margin: 0 auto;
  aspect-ratio: 9/19;
  background: #0A0F0E;
  border-radius: 44px;
  padding: 12px;
  box-shadow:
    0 30px 60px rgba(0, 0, 0, 0.5),
    0 0 0 1px rgba(250, 250, 247, 0.08) inset;
}
.phone::before {
  content: ""; position: absolute; left: 50%; top: 16px; transform: translateX(-50%);
  width: 92px; height: 22px; background: #050807;
  border-radius: 0 0 14px 14px; z-index: 2;
}
.phone-inner {
  position: relative; width: 100%; height: 100%;
  background: #F4F7F6;
  border-radius: 32px;
  overflow: hidden;
  display: flex; flex-direction: column;
}
.phone-status {
  height: 42px; flex-shrink: 0;
  display: flex; align-items: flex-end; justify-content: space-between;
  padding: 0 22px 6px; font-size: 12.5px; font-weight: 600;
  color: #0F1A18; background: #F4F7F6;
  font-feature-settings: "tnum" 1;
}
.phone-status .right { display: flex; gap: 5px; align-items: center; }
.phone-status svg { width: 13px; height: 13px; }
.phone-header {
  flex-shrink: 0; padding: 10px 14px;
  display: flex; align-items: center; gap: 10px;
  background: #F4F7F6;
  border-bottom: 1px solid rgba(15, 26, 24, 0.08);
}
.phone-header .avatar {
  width: 30px; height: 30px; border-radius: 50%;
  background: linear-gradient(135deg, #8BC5A8, #5A8B7C);
  display: flex; align-items: center; justify-content: center;
  color: #FAFAF7; font-size: 14px; font-weight: 700;
  font-family: var(--serif-en);
}
.phone-header .info { flex: 1; }
.phone-header .name { font-size: 13.5px; font-weight: 600; color: #0F1A18; }
.phone-header .status { font-size: 11px; color: #5A8B7C; }
.phone-header .more {
  color: #4A5852;
  display: flex; align-items: center; justify-content: center;
  width: 22px; height: 22px;
}
.phone-header .more svg { width: 18px; height: 18px; display: block; }

.phone-body {
  flex: 1; overflow-y: auto;
  padding: 14px 12px;
  display: flex; flex-direction: column; gap: 8px;
  scrollbar-width: none;
}
.phone-body::-webkit-scrollbar { display: none; }

.bubble {
  max-width: 78%;
  padding: 9px 13px;
  border-radius: 18px;
  font-size: 13px; line-height: 1.55;
  opacity: 0; transform: translateY(8px);
  animation: bubbleIn 0.5s var(--ease) forwards;
}
.bubble-agent {
  align-self: flex-start;
  background: #FAFAF7;
  color: #0F1A18;
  border-bottom-left-radius: 4px;
  box-shadow: 0 1px 0 rgba(15, 26, 24, 0.04);
}
.bubble-user {
  align-self: flex-end;
  background: #76AF9E;
  color: #FAFAF7;
  border-bottom-right-radius: 4px;
}
.bubble-system {
  align-self: center;
  background: rgba(118, 175, 158, 0.15);
  color: #436858;
  font-size: 11px; padding: 4px 10px;
  border-radius: 999px;
  font-family: var(--mono); letter-spacing: 0.06em;
}
.bubble-card {
  align-self: flex-start;
  background: #FAFAF7;
  color: #0F1A18;
  border-radius: 14px; border-bottom-left-radius: 4px;
  padding: 10px 12px;
  font-size: 12.5px; line-height: 1.5;
  border: 1px solid rgba(15, 26, 24, 0.08);
  width: 86%;
}
.bubble-card .title {
  font-weight: 600; color: #0F1A18; margin-bottom: 4px;
}
.bubble-card .meta {
  font-family: var(--mono); font-size: 10px; letter-spacing: 0.1em;
  color: #5A8B7C; text-transform: uppercase;
  margin-bottom: 4px;
}
.bubble-card .row {
  display: flex; gap: 10px; margin-top: 4px;
  font-size: 11px; color: #4A5852;
}

.bubble.delay-1 { animation-delay: 0.3s; }
.bubble.delay-2 { animation-delay: 0.7s; }
.bubble.delay-3 { animation-delay: 1.1s; }
.bubble.delay-4 { animation-delay: 1.5s; }
.bubble.delay-5 { animation-delay: 1.9s; }
.bubble.delay-6 { animation-delay: 2.3s; }
.bubble.delay-7 { animation-delay: 2.7s; }
.bubble.delay-8 { animation-delay: 3.1s; }
.bubble.delay-9 { animation-delay: 3.5s; }

@keyframes bubbleIn {
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 800px) {
  .im-stage { grid-template-columns: 1fr; gap: 56px; }
  .im-stage .text { order: 2; }
  .im-stage .phone-wrap { order: 1; }
  .phone { width: 290px; }
}

/* ============================================================
   Section · Download
   ============================================================ */
.dl {
  background: var(--bg-1);
  color: var(--text);
  padding: 14vh 0;
  position: relative; overflow: hidden;
}
.dl::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(250, 250, 247, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(250, 250, 247, 0.04) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, #000, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, #000, transparent 80%);
}
.dl .wrap { position: relative; z-index: 1; }
.dl-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 80px; align-items: center;
}
.dl-grid .text .sec-label { color: var(--mint-300); }
.dl-grid .text .sec-label::after { background: var(--mint-300); }
.dl-grid .text h2 {
  font-family: var(--serif-zh); font-weight: 700;
  font-size: clamp(36px, 4.6vw, 64px);
  line-height: 1.1; letter-spacing: -0.01em;
  color: var(--text);
  margin-bottom: 24px;
}
.dl-grid .text h2 em {
  font-family: var(--serif-en); font-style: italic; font-weight: 500;
  color: var(--mint-300);
}
.dl-grid .text p {
  font-family: var(--serif-zh); font-size: 16px; line-height: 1.8;
  color: var(--text-2);
  margin-bottom: 36px;
  max-width: 480px;
}

.dl-buttons { display: flex; gap: 12px; flex-wrap: wrap; }
.dl-btn {
  display: inline-flex; align-items: center; gap: 12px;
  padding: 14px 22px;
  background: var(--text);
  color: var(--ink);
  border-radius: 12px;
  transition: all 0.3s var(--ease);
  min-width: 180px;
}
.dl-btn:hover { transform: translateY(-2px); box-shadow: 0 14px 28px rgba(0,0,0,0.3); }
.dl-btn .icon { width: 26px; height: 26px; display: flex; align-items: center; justify-content: center; }
.dl-btn .icon svg { width: 100%; height: 100%; }
.dl-btn .meta {
  font-family: var(--mono); font-size: 10px;
  letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--ink-soft); margin-bottom: 2px;
}
.dl-btn .label {
  font-family: var(--sans-zh); font-weight: 600; font-size: 15px;
  color: var(--ink);
}

.dl-qr {
  background: var(--text);
  border-radius: 20px;
  padding: 32px;
  text-align: center;
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.3);
  max-width: 280px; margin: 0 auto;
}
.dl-qr img {
  width: 180px; height: 180px;
  border-radius: 8px;
  margin: 0 auto 16px;
  display: block;
}
.dl-qr .qrl {
  font-family: var(--mono); font-size: 10px;
  letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--mint-500); margin-bottom: 4px;
}
.dl-qr .qrt {
  font-family: var(--serif-zh); font-size: 14px;
  color: var(--ink); font-weight: 500;
}

@media (max-width: 800px) {
  .dl-grid { grid-template-columns: 1fr; gap: 48px; }
}

/* ============================================================
   Footer
   ============================================================ */
footer.foot {
  background: #0A1311;
  color: var(--text-2);
  padding: 48px 0 32px;
  font-size: 13px;
}
footer.foot .row { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 24px; }
footer.foot .meta { font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase; }
footer.foot a { color: var(--text-2); transition: color 0.3s; }
footer.foot a:hover { color: var(--mint-300); }
footer.foot .links { display: flex; gap: 22px; flex-wrap: wrap; }
footer.foot .icp { font-family: var(--mono); font-size: 11px; letter-spacing: 0.06em; opacity: 0.7; }
footer.foot .copy { margin-top: 24px; padding-top: 20px; border-top: 1px solid var(--line-2); font-size: 12px; color: var(--text-3); font-family: var(--mono); letter-spacing: 0.04em; }

/* ============================================================
   Reveal
   ============================================================ */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.9s var(--ease), transform 0.9s var(--ease); }
.reveal.in { opacity: 1; transform: translateY(0); }
.reveal[data-delay="1"] { transition-delay: 0.1s; }
.reveal[data-delay="2"] { transition-delay: 0.2s; }
.reveal[data-delay="3"] { transition-delay: 0.3s; }
.reveal[data-delay="4"] { transition-delay: 0.4s; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  .reveal { opacity: 1; transform: none; }
}