/* ================================================
   IDEALSEE 响应式网站样式
   mobile-first | flex + grid | CSS 变量
   ================================================ */

/* ---------- CSS 变量 ---------- */
:root {
  --bg:         #0a0a0a;
  --bg-card:    #1a1a1a;
  --bg-alt:     #141414;
  --accent:     #d90000;
  --accent-dim: rgba(217, 0, 0, 0.15);
  --text:       #ffffff;
  --text-soft:  #cccccc;
  --text-mute: #888888;
  --border:     #2a2a2a;

  --container:  1200px;
  --header-h:  60px;

  /* clamp 字号：移动端小，PC 端大 */
  --fs-hero:   clamp(2rem,   6vw, 4.5rem);
  --fs-h2:     clamp(1.5rem, 4vw, 2.5rem);
  --fs-h3:     clamp(1.1rem, 2.5vw, 1.4rem);
  --fs-body:   clamp(0.95rem, 1.5vw, 1.0625rem);
  --fs-small:  clamp(0.8rem,  1.2vw, 0.9rem);

  --radius:     6px;
  --transition: 0.25s ease;
}

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

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

body {
  font-family: 'OPPOSans-R', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: var(--fs-body);
  overflow-x: hidden;
}

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

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

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
}

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1.25rem;
}

@media (min-width: 768px) {
  .container { padding: 0 2rem; }
}

/* PC 断行 */
.br-pc { display: none; }
@media (min-width: 768px) {
  .br-pc { display: inline; }
}

/* ---------- 导航栏 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  z-index: 1000;
  transition: background var(--transition), box-shadow var(--transition);
}

.site-header.scrolled {
  background: rgba(10, 10, 10, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo img {
  height: 28px;
  width: auto;
}

/* PC 导航 */
.main-nav {
  display: none;
  align-items: center;
  gap: 2rem;
}

@media (min-width: 1024px) {
  .main-nav {
    display: flex;
  }
}

.nav-link {
  font-size: 0.875rem;
  color: var(--text-soft);
  transition: color var(--transition);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition);
}

.nav-link:hover {
  color: var(--text);
}

.nav-link:hover::after {
  width: 100%;
}

/* 汉堡按钮 */
.menu-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  border: none;
  padding: 6px;
}

@media (min-width: 1024px) {
  .menu-toggle {
    display: none;
  }
}

.menu-toggle .bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}

.menu-toggle.active .bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.menu-toggle.active .bar:nth-child(2) {
  opacity: 0;
}
.menu-toggle.active .bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* 移动端菜单 */
.main-nav.open {
  display: flex;
  position: fixed;
  top: var(--header-h);
  left: 0;
  right: 0;
  bottom: 0;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
  background: rgba(10, 10, 10, 0.98);
  backdrop-filter: blur(20px);
}

.main-nav.open .nav-link {
  font-size: 1.6rem;
  color: var(--text);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  padding: calc(var(--header-h) + 2rem) 1.25rem 4rem;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('../image/Rectangle_61_2.webp');
  background-size: cover;
  background-position: center;
  filter: brightness(0.35);
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 860px;
}

.hero-tagline {
  font-size: var(--fs-small);
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.hero-tagline .sep {
  color: var(--text-mute);
}

.hero-title {
  font-size: clamp(1.5rem, 3.2vw, 2.6rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}

.br-title-cn {
  display: block;
  height: 0.45em;
}

.hero-sub {
  font-size: clamp(0.82rem, 1.2vw, 0.95rem);
  color: var(--text-soft);
  line-height: 1.85;
  margin-bottom: 2.5rem;
  max-width: 880px;
  margin-left: auto;
  margin-right: auto;
  line-break: strict;
}

.hero-sub p {
  margin-bottom: 0.75rem;
}

.hero-sub p:last-child {
  margin-bottom: 0;
}

.hero-sub em {
  font-style: normal;
  color: var(--accent);
  font-weight: 600;
}

.hero-btns {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius);
  font-size: 0.9375rem;
  font-weight: 500;
  border: 2px solid transparent;
  transition: all var(--transition);
  white-space: nowrap;
  cursor: pointer;
}

.btn-red {
  background: var(--accent);
  color: #fff;
}

.btn-red:hover {
  background: #b80000;
  box-shadow: 0 8px 24px rgba(217, 0, 0, 0.4);
  transform: translateY(-2px);
}

.btn-outline {
  border-color: var(--text-soft);
  color: var(--text);
}

.btn-outline:hover {
  background: var(--text);
  color: var(--bg);
  transform: translateY(-2px);
}

/* 滚动提示 */
.scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
}

.scroll-arrow {
  display: block;
  width: 24px;
  height: 38px;
  border: 2px solid rgba(255,255,255,0.4);
  border-radius: 12px;
  position: relative;
}

.scroll-arrow::before {
  content: '';
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  background: rgba(255,255,255,0.6);
  border-radius: 2px;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% { top: 8px; opacity: 1; }
  50% { top: 18px; opacity: 0.3; }
}

/* ---------- Section 通用 ---------- */
.section {
  padding: 4rem 0;
}

@media (min-width: 1024px) {
  .section {
    padding: 6rem 0;
  }
}

.section-dark {
  background: var(--bg-alt);
}

.section-black {
  background: var(--bg);
}

.section-tag {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-size: clamp(1.25rem, 2.1vw, 1.45rem);
  font-weight: 600;
  padding: 0.6rem 1.5rem;
  border-radius: 3px;
  margin-bottom: 1.5rem;
  letter-spacing: 0.08em;
}

.section-title {
  font-size: var(--fs-h2);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

.section-lead {
  font-size: clamp(1rem, 1.8vw, 1.15rem);
  color: var(--text-soft);
  line-height: 1.7;
  max-width: 700px;
  margin-bottom: 3rem;
}

/* ---------- 两栏布局 ---------- */
.two-col {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}

@media (min-width: 768px) {
  .two-col {
    grid-template-columns: 1fr 1fr;
    gap: 3.5rem;
  }

  .two-col--img-left {
    grid-template-columns: 1fr 2.2fr;
  }
  .two-col--img-right {
    grid-template-columns: 1fr 1.45fr;
  }

  .two-col--img-left .two-col__media {
    justify-self: center;
  }
  .two-col--img-right .two-col__media {
    order: 2;
  }
  .two-col--img-right .two-col__text {
    order: 1;
  }
}

.two-col__media img {
  width: 100%;
  max-width: 300px;
  border-radius: var(--radius);
  background: var(--bg-card);
}

.two-col--img-left .two-col__media img {
  max-width: 280px;
}

.two-col--img-left .two-col__media,
.two-col--img-right .two-col__media {
  background: #ffffff;
  padding: 1rem;
  border-radius: var(--radius);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
}

.two-col--img-right .two-col__media {
  padding: 1.25rem;
}

.two-col--img-left .two-col__media img {
  background: #ffffff;
  display: block;
  max-width: 260px;
  margin: 0 auto;
}

.two-col--img-right .two-col__media img {
  background: #ffffff;
  display: block;
  width: 100%;
  max-width: 520px;
  margin: 0 auto;
}

.two-col__text p {
  color: var(--text-soft);
  font-size: clamp(0.88rem, 1.2vw, 0.98rem);
  line-height: 1.75;
  margin-bottom: 0.85rem;
}

/* ---------- 数据卡片 ---------- */
.stats-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-top: 2rem;
}

@media (min-width: 640px) {
  .stats-row {
    grid-template-columns: repeat(4, 1fr);
  }
}

.stat-card {
  background: var(--bg-card);
  padding: 0.9rem 0.75rem;
  border-radius: var(--radius);
  border-left: 3px solid var(--accent);
}

.stat-card__val {
  font-size: clamp(1rem, 1.7vw, 1.2rem);
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.3rem;
}

.stat-card__key {
  font-size: var(--fs-small);
  color: var(--text-mute);
}

/* ---------- 技术卡片 ---------- */
.tech-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

@media (min-width: 640px) {
  .tech-cards {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .tech-cards {
    grid-template-columns: repeat(3, 1fr);
  }
}

.tech-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}

.tech-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.5);
}

.tech-card__img {
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
}

.tech-card__img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.tech-card:hover .tech-card__img img {
  transform: scale(1.06);
}

.tech-card__badge {
  background: var(--accent);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.25rem 0.6rem;
  border-radius: 2px;
  align-self: flex-start;
  margin: 1.25rem 1.25rem 0;
}

.tech-card__body {
  padding: 0.75rem 1.25rem 1.5rem;
  flex: 1;
}

.tech-card__body h3 {
  font-size: var(--fs-h3);
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.tech-card__body p {
  font-size: var(--fs-small);
  color: var(--text-soft);
  line-height: 1.75;
}

/* ---- FSD 专利关联链接 ---- */
.patent-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1.5rem;
  padding: 0.75rem 1.25rem;
  background: rgba(217, 0, 27, 0.1);
  border: 1px solid rgba(217, 0, 27, 0.3);
  border-radius: var(--radius);
  color: var(--accent);
  font-size: var(--fs-small);
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s, border-color 0.2s, transform 0.2s;
  cursor: pointer;
}

.patent-link:hover {
  background: rgba(217, 0, 27, 0.18);
  border-color: var(--accent);
  transform: translateX(4px);
}

.patent-link__icon {
  font-size: 1rem;
  animation: spin 4s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* ---------- 专利亮点 ---------- */
.patent-box {
  background: var(--accent-dim);
  border: 1px solid rgba(217, 0, 0, 0.25);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.75rem 2rem;
}

.patent-box__content {
  flex: 1;
}

.patent-box__title {
  font-weight: 700;
  font-size: clamp(1.15rem, 1.8vw, 1.35rem);
  margin-bottom: 0.85rem;
  color: var(--text);
  letter-spacing: 0.02em;
}

.patent-box__content p {
  font-size: clamp(0.95rem, 1.4vw, 1.05rem);
  color: var(--text-soft);
  line-height: 1.85;
  max-width: 780px;
}

.patent-box__content strong {
  color: var(--accent);
  font-weight: 700;
  font-size: clamp(1.05rem, 1.55vw, 1.2rem);
  margin: 0 0.1em;
}

/* ---------- 公司数字 ---------- */
.company-nums {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 3rem;
}

@media (min-width: 768px) {
  .company-nums {
    grid-template-columns: repeat(4, 1fr);
  }
}

.company-num {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 1.75rem 1rem;
  text-align: center;
  border-top: 3px solid var(--accent);
}

.company-num__val {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.4rem;
}

.company-num__key {
  font-size: clamp(0.9rem, 1.4vw, 1.05rem);
  color: var(--text-soft);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.company-desc p {
  color: var(--text-soft);
  line-height: 1.8;
  margin-bottom: 1rem;
  max-width: 860px;
}

/* ---------- 元宇宙 ---------- */
.meta-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}

@media (min-width: 640px) {
  .meta-stats {
    gap: 1.5rem;
  }
}

.meta-stat {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 1.25rem;
  text-align: center;
}

.meta-stat__val {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.3rem;
}

.meta-stat__key {
  font-size: var(--fs-small);
  color: var(--text-mute);
  margin-bottom: 0.75rem;
}

.meta-stat__future {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 500;
}

.meta-desc {
  color: var(--text-soft);
  line-height: 1.8;
  max-width: 720px;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: #000;
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr;
    gap: 3rem;
  }
}

.footer-brand {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.footer-en {
  color: var(--text-mute);
  font-size: var(--fs-small);
  letter-spacing: 0.08em;
}

.site-footer h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-soft);
}

.site-footer p {
  color: var(--text-mute);
  font-size: var(--fs-small);
  line-height: 2;
}

.site-footer a {
  color: var(--text-mute);
  transition: color var(--transition);
}

.site-footer a:hover {
  color: var(--accent);
}

.footer-icon {
  margin-right: 0.4rem;
}

.footer-copy {
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-mute);
  font-size: var(--fs-small);
}

/* ---------- 回到顶部 ---------- */
.back-to-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 44px;
  height: 44px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition), transform var(--transition), background var(--transition);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: #b80000;
  transform: translateY(-3px);
}

/* ---------- 淡入动画 ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* 延迟 */
.fade-in:nth-child(2) { transition-delay: 0.1s; }
.fade-in:nth-child(3) { transition-delay: 0.2s; }
.fade-in:nth-child(4) { transition-delay: 0.3s; }

/* ---------- 滚动条美化 ---------- */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: #444;
}

/* ---------- 选中文字颜色 ---------- */
::selection {
  background: var(--accent);
  color: #fff;
}

/* ---------- AR 眼镜光机模块 ---------- */
.ar-intro {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  align-items: center;
  margin-bottom: 3.5rem;
}
@media (min-width: 768px) {
  .ar-intro {
    grid-template-columns: 1fr 380px;
    gap: 3rem;
  }
}
.ar-intro__text .section-tag { margin-bottom: 1.5rem; }
.ar-intro__text .section-title { margin-bottom: 1rem; }
.ar-intro__text .section-lead { margin-bottom: 0; }
.ar-optic {
  display: block;
  width: 216px;
  max-width: 100%;
  background: #ffffff;
  padding: 0.5rem;
  border-radius: var(--radius);
  margin: 0;
  transform: translate(20px, 20px);
}
.ar-feature {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}
@media (min-width: 768px) {
  .ar-feature {
    grid-template-columns: 1.1fr 1fr;
    gap: 3rem;
  }
}
.ar-feature__media {
  background: #ffffff;
  padding: 1.5rem;
  border-radius: var(--radius);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}
.ar-feature__media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
}
.ar-feature__text p {
  margin-bottom: 1rem;
  line-height: 1.7;
  color: var(--text-soft);
}
.ar-feature__text p:last-of-type {
  margin-bottom: 1.5rem;
}

/* ---------- 车载投影：左文右图布局 ---------- */
.auto-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  align-items: start;
  margin-top: 2rem;
}
@media (min-width: 900px) {
  .auto-layout {
    grid-template-columns: 1fr 1.4fr;
    gap: 3rem;
    align-items: center;
  }
}
.auto-layout__text p {
  color: var(--text-soft);
  font-size: clamp(0.88rem, 1.2vw, 0.98rem);
  line-height: 1.85;
  margin-bottom: 0.875rem;
}
.auto-layout__text .stats-row {
  margin-top: 1.5rem;
}
.auto-layout__media .auto-cards {
  margin-top: 0;
}
/* ---------- 车载投影卡片（2×2 网格） ---------- */
.auto-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.875rem;
}
.auto-card {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.auto-card__img {
  background: #ffffff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
  aspect-ratio: 4 / 3;
}
.auto-card__img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.auto-card__label {
  background: var(--bg-card);
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 0.65rem 0.75rem;
  font-size: clamp(0.75rem, 1.1vw, 0.875rem);
  font-weight: 600;
  color: var(--text-soft);
  letter-spacing: 0.04em;
  text-align: center;
  border-top: 2px solid var(--accent);
}