/* ===========================
   全局基础
   =========================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --black: #111110;
  --white: #ffffff;
  --gray-50: #fafaf9;
  --gray-100: #f5f5f4;
  --gray-200: #e7e5e4;
  --gray-400: #a8a29e;
  --gray-600: #78716c;
  --gray-800: #292524;
  --accent: #1a1a2e;
  --accent-2: #16213e;
  --accent-light: #e8e8f0;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 32px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,.08);
  --shadow-lg: 0 16px 48px rgba(0,0,0,.12);
  --font: 'PingFang SC', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition: .3s cubic-bezier(.4,0,.2,1);
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font);
  color: var(--black);
  background: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
}

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

.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* ===========================
   导航栏
   =========================== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--gray-200);
  transition: var(--transition);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -.01em;
  color: var(--black);
}

.logo-icon {
  color: var(--accent);
  font-size: 1rem;
}

.nav {
  display: flex;
  gap: 2.5rem;
}

.nav-link {
  font-size: .9rem;
  color: var(--gray-600);
  letter-spacing: .02em;
  position: relative;
  transition: color var(--transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 1.5px;
  background: var(--black);
  transition: width var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--black);
}

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

.menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.menu-btn span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--black);
  transition: var(--transition);
}

/* 移动端菜单 */
.mobile-menu {
  display: none;
  position: fixed;
  top: 68px; left: 0; right: 0;
  z-index: 99;
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  padding: 1rem 2rem;
  flex-direction: column;
  gap: .5rem;
  box-shadow: var(--shadow-md);
}

.mobile-menu.open { display: flex; }

.mobile-link {
  padding: .75rem 0;
  font-size: .95rem;
  color: var(--gray-600);
  border-bottom: 1px solid var(--gray-100);
  transition: color var(--transition);
}

.mobile-link.active, .mobile-link:hover {
  color: var(--black);
}

/* ===========================
   按钮
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .75rem 2rem;
  border-radius: 99px;
  font-size: .9rem;
  font-weight: 500;
  letter-spacing: .02em;
  transition: all var(--transition);
  cursor: pointer;
  border: 1.5px solid transparent;
}

.btn-primary {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
}

.btn-primary:hover {
  background: var(--gray-800);
  border-color: var(--gray-800);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--black);
  border-color: var(--black);
}

.btn-outline:hover {
  background: var(--black);
  color: var(--white);
  transform: translateY(-1px);
}

.btn-white {
  background: var(--white);
  color: var(--black);
  border-color: var(--white);
}

.btn-white:hover {
  background: var(--gray-100);
  transform: translateY(-1px);
}

/* ===========================
   公共标题样式
   =========================== */
.section-tag {
  font-size: .78rem;
  letter-spacing: .15em;
  text-transform: uppercase;
  color: var(--gray-400);
  font-weight: 500;
  margin-bottom: .75rem;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -.03em;
  line-height: 1.2;
  color: var(--black);
  margin-bottom: 1rem;
}

.section-desc {
  font-size: 1rem;
  color: var(--gray-600);
  max-width: 540px;
  line-height: 1.8;
}

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-header .section-desc {
  margin: 0 auto;
}

/* ===========================
   首页 Hero
   =========================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: var(--gray-50);
  padding-top: 68px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 60% 30%, rgba(26,26,46,.04) 0%, transparent 70%),
    radial-gradient(ellipse 60% 80% at 10% 70%, rgba(26,26,46,.03) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding-top: 5rem;
  padding-bottom: 8rem;
}

.hero-tag {
  font-size: .78rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--gray-400);
  font-weight: 500;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  font-weight: 800;
  letter-spacing: -.04em;
  line-height: 1.05;
  color: var(--black);
  margin-bottom: 1.5rem;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--gray-600);
  max-width: 480px;
  line-height: 1.8;
  margin-bottom: 2.5rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero-scroll {
  position: absolute;
  bottom: 2.5rem;
  left: 2rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.hero-scroll span {
  font-size: .75rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--gray-400);
  writing-mode: vertical-rl;
}

.scroll-line {
  width: 1px;
  height: 60px;
  background: linear-gradient(to bottom, var(--gray-400) 50%, transparent);
  animation: scrollDown 2s ease-in-out infinite;
}

@keyframes scrollDown {
  0%, 100% { transform: scaleY(1); transform-origin: top; }
  50% { transform: scaleY(.5); transform-origin: top; }
}

/* ===========================
   作品展示
   =========================== */
.works {
  padding: 7rem 0;
  background: var(--white);
}

.works-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  max-width: 480px;
  margin: 0 auto;
}

.work-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--gray-100);
  transition: transform var(--transition), box-shadow var(--transition);
  cursor: pointer;
}

.work-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.work-img {
  position: relative;
  aspect-ratio: 4/3;
  overflow: hidden;
}

.work-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform .4s ease;
}

.work-card:hover .work-photo {
  transform: scale(1.04);
}

.work-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0);
  display: flex;
  align-items: flex-start;
  justify-content: flex-end;
  padding: 1rem;
  transition: background var(--transition);
}

.work-card:hover .work-overlay {
  background: rgba(0,0,0,.06);
}

.work-cat {
  background: rgba(255,255,255,.9);
  color: var(--black);
  font-size: .75rem;
  font-weight: 500;
  padding: .3rem .8rem;
  border-radius: 99px;
  letter-spacing: .03em;
}

.work-info {
  padding: 1.25rem 1.5rem;
}

.work-info h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: .4rem;
  letter-spacing: -.01em;
}

.work-info p {
  font-size: .85rem;
  color: var(--gray-600);
  line-height: 1.6;
}

/* ===========================
   回到顶部
   =========================== */
.back-top {
  position: fixed;
  right: 2rem;
  bottom: 2rem;
  z-index: 200;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--black);
  color: var(--white);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity .35s ease, transform .35s ease, background .2s ease;
}

.back-top.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-top:hover {
  background: var(--gray-800);
  transform: translateY(-3px);
}

.back-top:active {
  transform: translateY(0);
}

@media (max-width: 600px) {
  .back-top {
    right: 1.25rem;
    bottom: 1.25rem;
    width: 40px;
    height: 40px;
  }
}

/* ===========================
   页脚
   =========================== */
.footer {
  background: var(--gray-50);
  border-top: 1px solid var(--gray-200);
  padding: 2rem 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  text-align: center;
}

.footer .logo-icon { color: var(--gray-600); }
.footer .logo-text { color: var(--gray-800); }

.footer-copy {
  font-size: .8rem;
  color: var(--gray-600);
  letter-spacing: .02em;
}

.footer-beian {
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-wrap: wrap;
  justify-content: center;
}

.beian-link {
  font-size: .78rem;
  color: var(--gray-600);
  display: flex;
  align-items: center;
  gap: .3rem;
  transition: color var(--transition);
  letter-spacing: .02em;
}

.beian-link:hover { color: var(--black); }

/* 公安备案行内对齐 */
.beian-row {
  display: inline-flex;
  align-items: center;
  gap: 1px;
}

.beian-gov-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.beian-sep {
  color: var(--gray-300);
  font-size: .7rem;
}

.beian-icon {
  font-size: .7rem;
  color: var(--gray-400);
}

/* ===========================
   关于页 Hero
   =========================== */
.page-hero {
  padding: 9rem 0 5rem;
  background: var(--gray-50);
  border-bottom: 1px solid var(--gray-200);
}

.page-hero-title {
  font-size: clamp(2.2rem, 5vw, 4rem);
  font-weight: 800;
  letter-spacing: -.04em;
  line-height: 1.1;
  margin-bottom: .75rem;
}

.page-hero-sub {
  font-size: 1.05rem;
  color: var(--gray-600);
}

/* ===========================
   关于我们内容
   =========================== */
.about-section {
  padding: 7rem 0;
  background: var(--white);
}

.about-layout {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 6rem;
  align-items: center;
}

.about-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 420px;
}

.about-card-main {
  width: 260px;
  height: 320px;
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  box-shadow: var(--shadow-md);
}

.about-monogram {
  width: 80px; height: 80px;
  border-radius: 50%;
  background: var(--black);
  color: var(--white);
  font-size: 2.2rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  letter-spacing: -.02em;
}

.about-card-label {
  font-size: .85rem;
  color: var(--gray-600);
  font-weight: 500;
  letter-spacing: .03em;
}

.about-tag-float {
  position: absolute;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 99px;
  padding: .5rem 1.2rem;
  font-size: .8rem;
  font-weight: 500;
  color: var(--black);
  box-shadow: var(--shadow-sm);
  white-space: nowrap;
}

.about-tag-1 { top: 10%; right: 0; }
.about-tag-2 { bottom: 20%; right: 5%; }
.about-tag-3 { top: 42%; left: 0; }

.about-para {
  font-size: .95rem;
  color: var(--gray-600);
  line-height: 1.9;
  margin-bottom: 1.2rem;
}

.about-tags-row {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-top: 1.5rem;
}

.tag {
  background: var(--gray-100);
  color: var(--gray-800);
  font-size: .78rem;
  font-weight: 500;
  padding: .35rem .9rem;
  border-radius: 99px;
  letter-spacing: .02em;
}

/* ===========================
   价值理念
   =========================== */
.values {
  padding: 7rem 0;
  background: var(--gray-50);
}

.values-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.value-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  transition: transform var(--transition), box-shadow var(--transition);
}

.value-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.value-icon {
  font-size: 1.4rem;
  color: var(--black);
  margin-bottom: 1rem;
}

.value-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: .6rem;
  letter-spacing: -.01em;
}

.value-card p {
  font-size: .85rem;
  color: var(--gray-600);
  line-height: 1.8;
}

/* ===========================
   时间线
   =========================== */
.timeline-section {
  padding: 7rem 0;
  background: var(--white);
}

.timeline {
  max-width: 680px;
  margin: 0 auto;
  position: relative;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 5.5rem;
  top: 0; bottom: 0;
  width: 1px;
  background: var(--gray-200);
}

.tl-item {
  display: flex;
  gap: 2.5rem;
  align-items: flex-start;
  padding-bottom: 3rem;
  position: relative;
}

.tl-item:last-child { padding-bottom: 0; }

.tl-year {
  font-size: .85rem;
  font-weight: 600;
  color: var(--gray-400);
  width: 3.5rem;
  flex-shrink: 0;
  padding-top: .1rem;
  text-align: right;
}

.tl-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--gray-400);
  flex-shrink: 0;
  margin-top: .25rem;
  position: relative;
  z-index: 1;
}

.tl-dot-now {
  background: var(--black);
  box-shadow: 0 0 0 3px rgba(0,0,0,.12);
}

.tl-year-now { color: var(--black); }

.tl-body h4 {
  font-size: .95rem;
  font-weight: 600;
  margin-bottom: .5rem;
  letter-spacing: -.01em;
}

.tl-body p {
  font-size: .875rem;
  color: var(--gray-600);
  line-height: 1.8;
}

/* ===========================
   联系卡片
   =========================== */
.contact-about {
  padding: 7rem 0;
  background: var(--gray-50);
}

.contact-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  max-width: 760px;
  margin: 0 auto;
}

.contact-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition);
}

.contact-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.contact-card-icon {
  font-size: 1.6rem;
  margin-bottom: 1rem;
  color: var(--black);
}

.contact-card h4 {
  font-size: .9rem;
  font-weight: 600;
  margin-bottom: .5rem;
}

.contact-card p {
  font-size: .85rem;
  color: var(--gray-600);
}

/* ===========================
   响应式
   =========================== */
@media (max-width: 900px) {
  .nav { display: none; }
  .menu-btn { display: flex; }

  .works-grid { grid-template-columns: 1fr; max-width: 480px; margin: 0 auto; }
  .skills-layout { grid-template-columns: 1fr; gap: 3rem; }
  .about-layout { grid-template-columns: 1fr; gap: 3rem; }
  .about-visual { min-height: 320px; }
}

@media (max-width: 600px) {
  .container { padding: 0 1.25rem; }
  .hero-content { padding-top: 3rem; padding-bottom: 6rem; }
  .hero-title { font-size: 2.4rem; }
  .section-title { font-size: 1.7rem; }
  .works-grid { grid-template-columns: 1fr; max-width: 480px; margin: 0 auto; }
  .values-grid { grid-template-columns: 1fr; }
  .contact-cards { grid-template-columns: 1fr; }
  .timeline::before { left: 3.5rem; }
  .tl-year { width: 2.5rem; font-size: .75rem; }
  .hero-scroll { display: none; }
}