/* ===== 设计变量 ===== */
:root {
  --bg: #0a0e14;
  --bg-alt: #0f141c;
  --surface: #131a24;
  --surface-2: #1a2430;
  --border: #26303d;
  --border-strong: #35414f;
  --text: #eef2f7;
  --text-muted: #9aa7b8;
  --text-dim: #6b7787;
  --accent: #f75835;
  --accent-2: #ff835f;
  --accent-soft: rgba(247, 88, 53, 0.12);
  --success: #22c55e;
  --radius: 14px;
  --radius-lg: 22px;
  --maxw: 1160px;
  --nav-h: 68px;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
}

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

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease,
    border-color 0.2s ease, color 0.2s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn--primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #1a1206;
  box-shadow: 0 8px 24px rgba(247, 88, 53, 0.28);
}
.btn--primary:hover { box-shadow: 0 12px 34px rgba(247, 88, 53, 0.42); transform: translateY(-2px); }
.btn--ghost { background: transparent; border-color: var(--border-strong); color: var(--text); }
.btn--ghost:hover { border-color: var(--accent); color: var(--accent-2); }
.btn--sm { padding: 9px 18px; font-size: 14px; }
.btn--block { width: 100%; padding: 15px; font-size: 16px; }

/* ===== 导航 ===== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  background: rgba(10, 14, 20, 0.72);
  backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
.nav.is-scrolled { border-bottom-color: var(--border); background: rgba(10, 14, 20, 0.9); }
.nav__inner { height: var(--nav-h); display: flex; align-items: center; justify-content: space-between; gap: 20px; }

.brand { display: flex; align-items: center; gap: 10px; }
.brand__logo { height: 26px; width: auto; display: block; }

.nav__links { display: flex; align-items: center; gap: 30px; }
.nav__links a { color: var(--text-muted); font-size: 15px; font-weight: 500; transition: color 0.2s ease; }
.nav__links a:hover { color: var(--text); }

.nav__actions { display: flex; align-items: center; gap: 14px; }

.lang-toggle {
  display: inline-flex; align-items: center; gap: 4px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 999px; padding: 6px 12px;
  color: var(--text-dim); font-size: 13px; font-weight: 600; cursor: pointer;
  transition: border-color 0.2s ease;
}
.lang-toggle:hover { border-color: var(--border-strong); }
.lang-toggle__opt.is-active { color: var(--accent); }
.lang-toggle__sep { color: var(--border-strong); }

.nav__burger { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 6px; }
.nav__burger span { width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: 0.25s; }
.nav__burger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__burger.is-open span:nth-child(2) { opacity: 0; }
.nav__burger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero ===== */
.hero { position: relative; padding: calc(var(--nav-h) + 72px) 0 40px; overflow: hidden; }
.hero__bg {
  position: absolute; inset: 0; z-index: 0; pointer-events: none;
  background:
    radial-gradient(60% 60% at 75% 10%, rgba(247, 88, 53, 0.18), transparent 60%),
    radial-gradient(50% 50% at 10% 20%, rgba(80, 130, 255, 0.10), transparent 60%);
}
.hero__bg::after {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.12;
  mask-image: radial-gradient(70% 60% at 50% 30%, #000, transparent 75%);
}
.hero__inner { position: relative; z-index: 1; max-width: 820px; }
.hero__eyebrow {
  display: inline-block; color: var(--accent-2);
  background: var(--accent-soft); border: 1px solid rgba(247, 88, 53, 0.25);
  padding: 6px 14px; border-radius: 999px; font-size: 13px; font-weight: 600;
  letter-spacing: 0.02em; margin-bottom: 22px;
}
.hero__title {
  font-size: clamp(38px, 6vw, 68px);
  line-height: 1.08; font-weight: 800; letter-spacing: -0.02em;
  background: linear-gradient(180deg, #fff, #c6d0dc);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  margin-bottom: 22px;
}
.hero__subtitle { font-size: clamp(16px, 2.2vw, 20px); color: var(--text-muted); max-width: 640px; margin-bottom: 34px; }
.hero__actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero__stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; max-width: 620px; }
.stat { border-left: 2px solid var(--border-strong); padding-left: 16px; }
.stat__num { display: block; font-size: 22px; font-weight: 800; color: var(--accent-2); }
.stat__label { font-size: 13px; color: var(--text-dim); }

/* ===== 通用 section ===== */
.section { padding: 72px 0; }
.section--alt { background: var(--bg-alt); }
.section__head { text-align: center; max-width: 680px; margin: 0 auto 56px; }
.section__title { font-size: clamp(28px, 4vw, 42px); font-weight: 800; letter-spacing: -0.02em; margin-bottom: 14px; }
.section__lead { color: var(--text-muted); font-size: 17px; }

/* ===== 服务卡片 ===== */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 30px 26px;
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}
.card:hover { transform: translateY(-4px); border-color: var(--border-strong); background: var(--surface-2); }
.card__icon {
  width: 52px; height: 52px; display: grid; place-items: center;
  border-radius: 14px; background: var(--accent-soft);
  color: var(--accent-2); font-size: 22px; font-weight: 700; margin-bottom: 20px;
}
.card__title { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
.card__desc { color: var(--text-muted); font-size: 15px; }

/* ===== 关于 ===== */
.about { display: grid; grid-template-columns: 1.4fr 1fr; gap: 60px; align-items: center; }
.about__lead { font-size: 19px; color: var(--text); margin: 18px 0; font-weight: 500; }
.about__desc { color: var(--text-muted); font-size: 16px; margin-bottom: 26px; }
.about__quote {
  border-left: 3px solid var(--accent); padding: 6px 0 6px 20px;
  font-size: 17px; font-style: italic; color: var(--accent-2);
}
.about__aside { display: grid; place-items: center; }
.about__logo {
  width: 260px; height: 260px; border-radius: 28px;
  box-shadow: var(--shadow);
}

/* ===== 联系区（仿 Cloudflare 分栏） ===== */
.contact-section { background: var(--bg-alt); }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: start; }

.contact-value__eyebrow { color: var(--accent-2); font-size: 13px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 14px; }
.contact-value__title { font-size: clamp(28px, 4vw, 40px); font-weight: 800; letter-spacing: -0.02em; margin-bottom: 34px; }

.value-list { list-style: none; display: grid; gap: 24px; }
.value-item { display: flex; gap: 16px; }
.value-item__icon {
  flex: none; width: 34px; height: 34px; margin-top: 2px;
  display: grid; place-items: center; border-radius: 10px;
  background: var(--accent-soft); color: var(--accent-2); font-size: 15px;
}
.value-item h3 { font-size: 17px; font-weight: 700; margin-bottom: 4px; }
.value-item p { color: var(--text-muted); font-size: 15px; }

.contact-value__reach { margin-top: 40px; padding-top: 30px; border-top: 1px solid var(--border); }
.reach__label { color: var(--text-dim); font-size: 14px; margin-bottom: 8px; }
.reach__email { font-size: 22px; font-weight: 700; color: var(--accent-2); }
.reach__email:hover { text-decoration: underline; }
.reach__meta { color: var(--text-muted); font-size: 14px; margin-top: 8px; }

/* 表单卡片 */
.contact-form-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 34px; box-shadow: var(--shadow);
}
.contact-form__title { font-size: 24px; font-weight: 700; margin-bottom: 6px; }
.contact-form__sub { color: var(--text-muted); font-size: 15px; margin-bottom: 26px; }
.contact-form { display: grid; gap: 18px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field { display: grid; gap: 7px; }
.field label { font-size: 13px; font-weight: 600; color: var(--text-muted); }
.field input, .field select, .field textarea {
  width: 100%; padding: 12px 14px;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: 10px; color: var(--text); font-size: 15px; font-family: inherit;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.field textarea { resize: vertical; min-height: 96px; }
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.field input.is-invalid, .field textarea.is-invalid { border-color: #ef4444; box-shadow: 0 0 0 3px rgba(239,68,68,0.14); }
.form-hint { font-size: 12.5px; color: var(--text-dim); text-align: center; }

/* ===== 自研产品 ===== */
.product-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: stretch;
}

.product-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}
.product-card:hover { transform: translateY(-3px); border-color: var(--border-strong); }

.product-card__head { display: flex; align-items: center; gap: 16px; }

.product-card__icon {
  flex: none;
  width: 56px; height: 56px;
  border-radius: 14px;
  object-fit: contain;
  background: #fff;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.28);
}

.product-card__meta { min-width: 0; }
.product-card__title-row {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
}

.product-badge {
  display: inline-block;
  padding: 2px 9px;
  border-radius: 999px;
  font-size: 11px; font-weight: 700;
  width: fit-content;
}
.product-badge--live {
  background: rgba(34, 197, 94, 0.12);
  color: var(--success);
  border: 1px solid rgba(34, 197, 94, 0.3);
}
.product-badge--dev {
  background: rgba(251, 191, 36, 0.1);
  color: #fbbf24;
  border: 1px solid rgba(251, 191, 36, 0.25);
}

.product-card__name { font-size: 20px; font-weight: 800; letter-spacing: -0.01em; }
.product-card__tagline { font-size: 13px; color: var(--text-dim); margin-top: 2px; }
.product-card__desc { color: var(--text-muted); font-size: 15px; line-height: 1.7; }

.product-features { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.product-features li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.55;
}
.product-features li::before {
  content: "";
  position: absolute; left: 0; top: 8px;
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent);
}

.product-card__foot {
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
}

.platform-pills { display: flex; flex-wrap: wrap; gap: 6px; }
.platform-pill {
  padding: 3px 10px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 12px; color: var(--text-dim);
}
.platform-pill--live {
  background: rgba(34, 197, 94, 0.08);
  border-color: rgba(34, 197, 94, 0.3);
  color: var(--success);
}

.product-card__more {
  font-size: 14px; font-weight: 600; color: var(--accent-2);
  white-space: nowrap;
}
.product-card__more:hover { text-decoration: underline; }
.product-card__more--muted { color: var(--text-dim); font-weight: 500; }

/* ===== 产品详情页（yuyan/ 复用） ===== */
.yuyan-hero { padding: calc(var(--nav-h) + 64px) 0 56px; }
.yuyan-hero__inner { max-width: 760px; position: relative; z-index: 1; }

.download-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.download-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 26px 18px;
  display: flex; flex-direction: column; gap: 12px;
  align-items: center; text-align: center;
}
.download-card--featured {
  border-color: rgba(34, 197, 94, 0.4);
  background: rgba(34, 197, 94, 0.04);
}
.download-card__name { font-size: 16px; font-weight: 700; }
.download-card__desc { color: var(--text-muted); font-size: 13px; line-height: 1.5; }
.download-card__qr {
  width: 148px; height: 148px; border-radius: 14px; overflow: hidden;
  background: #fff;
}
.download-card__qr img { width: 100%; height: 100%; object-fit: cover; }
.download-card__qr--pending {
  background: var(--bg);
  border: 1px dashed var(--border-strong);
}

.steps {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  position: relative;
}
.steps::before {
  content: "";
  position: absolute;
  top: 19px;
  left: 16.6%;
  right: 16.6%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-strong), transparent);
}
.steps li {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 12px;
  padding: 0 28px;
  position: relative;
}
.step-no {
  width: 38px; height: 38px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid rgba(247, 88, 53, 0.35);
  display: grid; place-items: center;
  font-size: 15px; font-weight: 800; color: var(--accent-2);
  position: relative; z-index: 1;
  box-shadow: 0 0 0 8px var(--bg-alt);
}
.steps li h3 { font-size: 18px; font-weight: 700; }
.steps li p { color: var(--text-muted); font-size: 14px; max-width: 240px; }

.platform-board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.platform-tile {
  display: flex; align-items: center; gap: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 20px 18px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}
.platform-tile:hover { border-color: var(--border-strong); transform: translateY(-2px); }
.platform-tile h3 { font-size: 17px; font-weight: 700; margin-bottom: 4px; }
.platform-tile p { color: var(--text-muted); font-size: 14px; }

.platform-mark {
  flex: none;
  width: 40px; height: 40px;
  border-radius: 10px;
  object-fit: cover;
}
.platform-mark--more {
  display: grid; place-items: center;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 22px; font-weight: 500; line-height: 1;
}

.page-note { color: var(--text-dim); font-size: 13px; margin-top: 18px; text-align: center; }

.back-link { color: var(--text-dim); font-size: 14px; display: inline-flex; align-items: center; gap: 6px; }
.back-link:hover { color: var(--accent-2); }

@media (max-width: 900px) {
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .platform-board { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; gap: 28px; padding-left: 8px; }
  .steps::before {
    top: 0; bottom: 0; left: 18px; right: auto; width: 1px; height: auto;
    background: linear-gradient(180deg, transparent, var(--border-strong), transparent);
  }
  .steps li { align-items: flex-start; text-align: left; padding: 0 0 0 52px; }
  .steps li p { max-width: none; }
  .step-no { position: absolute; left: 0; top: 0; box-shadow: 0 0 0 8px var(--bg-alt); }
}
@media (max-width: 720px) {
  .product-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .platform-board { grid-template-columns: 1fr; }
  .download-grid { grid-template-columns: 1fr; }
}

/* ===== 页脚 ===== */
.footer { background: var(--bg); border-top: 1px solid var(--border); padding: 54px 0 28px; }
.footer__inner { display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap; padding-bottom: 30px; border-bottom: 1px solid var(--border); }
.footer__brand { display: flex; align-items: center; gap: 14px; }
.footer__logo { height: 30px; width: auto; opacity: 0.9; }
.footer__name { font-weight: 700; font-size: 16px; }
.footer__slogan { color: var(--text-dim); font-size: 14px; }
.footer__links { display: flex; gap: 26px; flex-wrap: wrap; align-items: center; }
.footer__links a { color: var(--text-muted); font-size: 14px; transition: color 0.2s ease; }
.footer__links a:hover { color: var(--accent-2); }
.footer__bottom { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; padding-top: 22px; color: var(--text-dim); font-size: 13px; }

/* ===== Toast ===== */
.toast {
  position: fixed; left: 50%; bottom: 34px; transform: translate(-50%, 20px);
  background: var(--surface-2); border: 1px solid var(--border-strong);
  color: var(--text); padding: 13px 22px; border-radius: 12px;
  font-size: 14px; box-shadow: var(--shadow);
  opacity: 0; pointer-events: none; transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 200; max-width: 90vw;
}
.toast.is-show { opacity: 1; transform: translate(-50%, 0); }
.toast.is-success { border-color: rgba(34, 197, 94, 0.5); }

/* ===== 滚动入场动画 ===== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
  .about { grid-template-columns: 1fr; gap: 36px; }
  .about__aside { order: -1; }
  .contact-grid { grid-template-columns: 1fr; gap: 40px; }
}

@media (max-width: 720px) {
  .nav__links {
    position: fixed; top: var(--nav-h); left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: 0;
    background: var(--bg-alt); border-bottom: 1px solid var(--border);
    padding: 8px 24px; transform: translateY(-120%);
    transition: transform 0.28s ease; visibility: hidden;
  }
  .nav__links.is-open { transform: translateY(0); visibility: visible; }
  .nav__links a { width: 100%; padding: 14px 0; border-bottom: 1px solid var(--border); }
  .nav__burger { display: flex; }
  .nav__actions .btn { display: none; }
  .hero__stats { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .cards { grid-template-columns: 1fr; }
  .field-row { grid-template-columns: 1fr; }
  .contact-form-card { padding: 26px 20px; }
  .section { padding: 70px 0; }
}