/* 肃鸟投资集团官网 - 全局样式 v2 */

/* 字体 - 系统字体栈，不依赖外部CDN */

:root {
  --black: #1a1a1a;
  --dark: #2c2c2c;
  --gray: #777777;
  --light-gray: #f7f6f4;
  --white: #ffffff;
  --accent: #8b7355;
  --accent-light: #b8a68e;
  --border: #e8e6e2;
  --bg-warm: #faf9f7;
}

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

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
}

body {
  font-family: "Songti SC", "STSong", "SimSun", Georgia, "Noto Serif CJK SC", serif;
  color: var(--black);
  background: var(--white);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.25s;
}

::selection {
  background: var(--accent-light);
  color: var(--white);
}

/* ===== 导航 ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(250, 249, 247, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.3s;
}

.nav.scrolled {
  box-shadow: 0 1px 12px rgba(0,0,0,0.06);
}

.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 32px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 3px;
  color: var(--black);
}

.nav-logo img {
  height: 32px;
  width: auto;
}

.nav-links {
  display: flex;
  gap: 36px;
  list-style: none;
}

.nav-links a {
  font-size: 13px;
  letter-spacing: 2px;
  color: var(--gray);
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--accent);
  transition: width 0.3s;
}

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

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

/* 汉堡按钮 - 默认隐藏 */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--black);
  margin: 5px 0;
  transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== 主体 ===== */
.main {
  margin-top: 68px;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ===== 首页英雄区 ===== */
.hero {
  min-height: 88vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 100px 32px 80px;
  background: linear-gradient(180deg, var(--bg-warm) 0%, var(--white) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 480px;
  height: 480px;
  transform: translate(-50%, -50%);
  border: 1px solid var(--border);
  border-radius: 50%;
  opacity: 0.4;
}

.hero::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 320px;
  height: 320px;
  transform: translate(-50%, -50%);
  border: 1px solid var(--border);
  border-radius: 50%;
  opacity: 0.25;
}

.hero-inner {
  max-width: 560px;
  position: relative;
  z-index: 1;
  /* 不设animation，由子元素各自stagger淡入 */
}

.hero-logo {
  width: 140px;
  height: auto;
  margin-bottom: 36px;
  filter: drop-shadow(0 2px 8px rgba(0,0,0,0.06));
}

.hero h1 {
  font-size: 36px;
  font-weight: 700;
  letter-spacing: 8px;
  margin-bottom: 12px;
  color: var(--black);
}

.hero .tagline {
  font-size: 15px;
  color: var(--gray);
  letter-spacing: 4px;
  margin-bottom: 8px;
  font-weight: 400;
}

.hero .tagline-sub {
  font-size: 13px;
  color: var(--accent-light);
  letter-spacing: 2px;
  margin-bottom: 36px;
  font-weight: 400;
}

.hero .philosophy {
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 4px;
  padding: 14px 32px;
  border: 1px solid var(--accent-light);
  display: inline-block;
  position: relative;
  background: rgba(255,255,255,0.6);
  backdrop-filter: blur(4px);
  max-width: 100%;
  box-sizing: border-box;
}

.hero .philosophy::before,
.hero .philosophy::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border-color: var(--accent-light);
  border-style: solid;
}

.hero .philosophy::before {
  top: -1px;
  left: -1px;
  border-width: 1px 0 0 1px;
}

.hero .philosophy::after {
  bottom: -1px;
  right: -1px;
  border-width: 0 1px 1px 0;
}

/* ===== 区块 ===== */
.section {
  padding: 88px 0;
}

.section-title {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 4px;
  margin-bottom: 56px;
  text-align: center;
  color: var(--black);
  position: relative;
}

.section-title::after {
  content: "";
  display: block;
  width: 28px;
  height: 2px;
  background: var(--accent);
  margin: 18px auto 0;
}

/* ===== 服务卡片 ===== */
.service-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.service-item {
  background: var(--white);
  padding: 36px 32px;
  border: 1px solid var(--border);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.service-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--accent);
  transition: height 0.3s ease;
}

.service-item:hover {
  border-color: var(--accent-light);
  box-shadow: 0 4px 20px rgba(139, 115, 85, 0.08);
  transform: translateY(-2px);
}

.service-item:hover::before {
  height: 100%;
}

.service-name {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 1.5px;
  margin-bottom: 10px;
  color: var(--black);
}

.service-desc {
  font-size: 13px;
  color: var(--gray);
  line-height: 1.8;
}

/* 首页4项服务 - 大卡片 */
.section-overview .service-item {
  padding: 40px 36px;
}

/* 服务页7项 - 紧凑 */
.section-services .service-grid {
  grid-template-columns: repeat(3, 1fr);
}

.section-services .service-item {
  padding: 30px 28px;
}

.section-services .service-name {
  font-size: 14px;
}

/* 7项时前6项3列，第7项跨3列居中 */
.section-services .service-item:last-child:nth-child(3n+1) {
  grid-column: 2;
}

/* ===== 关于页 ===== */
.about-content {
  max-width: 680px;
  margin: 0 auto;
}

.about-block {
  margin-bottom: 56px;
  position: relative;
  padding-left: 20px;
  border-left: 2px solid var(--border);
  transition: border-color 0.3s;
}

.about-block:hover {
  border-left-color: var(--accent);
}

.about-block:last-child {
  border-left-color: var(--accent-light);
}

.about-block h3 {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 3px;
  margin-bottom: 14px;
  color: var(--black);
}

.about-block p {
  font-size: 14px;
  line-height: 2;
  color: var(--dark);
}

.about-block .reg-info {
  font-size: 12px;
  color: var(--gray);
  margin-top: 10px;
  letter-spacing: 1px;
  font-family: "SF Mono", "Menlo", monospace;
}

/* 免责声明弱化 */
.about-block.disclaimer {
  border-left-color: #ddd;
  opacity: 0.75;
  font-size: 13px;
}

.about-block.disclaimer p {
  font-size: 12.5px;
  line-height: 1.9;
  color: var(--gray);
}

/* ===== 查看更多链接 ===== */
.view-more {
  text-align: center;
  margin-top: 40px;
}

.view-more a {
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 2px;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: border-color 0.3s;
}

.view-more a:hover {
  border-bottom-color: var(--accent);
}

/* ===== 服务页底部免责 ===== */
.service-disclaimer {
  text-align: center;
  margin-top: 56px;
  padding: 24px;
  font-size: 12px;
  color: #aaa;
  line-height: 1.9;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  border-top: 1px solid var(--border);
}

.partner-invite {
  margin-top: 48px;
  padding: 28px 32px;
  background: var(--bg-warm);
  border: 1px solid var(--border);
  border-radius: 4px;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

.partner-invite h3 {
  font-size: 16px;
  color: var(--accent);
  margin-bottom: 12px;
  font-weight: 600;
}

.partner-invite p {
  font-size: 14px;
  color: var(--dark);
  line-height: 1.9;
}

.partner-invite a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-light);
}

.partner-invite a:hover {
  color: var(--black);
  border-bottom-color: var(--black);
}

/* ===== 页脚 ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  text-align: center;
  background: var(--bg-warm);
}

.footer p {
  font-size: 11.5px;
  color: #aaa;
  letter-spacing: 0.8px;
  line-height: 2.2;
  overflow-wrap: break-word;
  word-break: break-word;
}

.footer .complaint {
  color: var(--accent-light);
}

.footer .complaint a {
  color: var(--accent);
  border-bottom: 1px solid var(--accent-light);
  padding-bottom: 1px;
  transition: border-color 0.2s;
}

.footer .complaint a:hover {
  border-bottom-color: var(--accent);
}

/* ===== 淡入动画 ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-inner .hero-logo {
  animation: fadeInUp 0.8s ease-out 0.1s both;
}

.hero-inner h1 {
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-inner .tagline {
  animation: fadeInUp 0.8s ease-out 0.3s both;
}

.hero-inner .tagline-sub {
  animation: fadeInUp 0.8s ease-out 0.35s both;
}

.hero-inner .philosophy {
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .hero {
    min-height: 80vh;
    padding: 80px 24px 60px;
  }

  .hero::before {
    width: 300px;
    height: 300px;
  }

  .hero::after {
    width: 200px;
    height: 200px;
  }

  .hero h1 {
    font-size: 28px;
    letter-spacing: 6px;
  }

  .hero .philosophy {
    font-size: 11px;
    letter-spacing: 2px;
    padding: 10px 20px;
  }

  .service-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .section-services .service-grid {
    grid-template-columns: 1fr;
  }

  .section-services .service-item:last-child:nth-child(3n+1) {
    grid-column: auto;
  }

  .section {
    padding: 56px 0;
  }

  .section-title {
    font-size: 18px;
    letter-spacing: 3px;
    margin-bottom: 36px;
  }

  .section-subtitle {
    margin-top: -16px;
    margin-bottom: 40px;
  }

  .nav-links {
    gap: 24px;
  }

  .nav-links a {
    font-size: 12px;
    letter-spacing: 1.5px;
  }

  .container {
    padding: 0 20px;
  }
}

@media (max-width: 480px) {
  .nav-inner {
    padding: 0 16px;
    height: 56px;
  }

  .main {
    margin-top: 56px;
  }

  .nav-logo {
    font-size: 15px;
    gap: 6px;
    letter-spacing: 2px;
  }

  .nav-logo img {
    height: 26px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: rgba(250, 249, 247, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    gap: 0;
    padding: 12px 24px;
    border-bottom: 1px solid var(--border);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links li {
    padding: 10px 0;
  }

  .nav-links a {
    font-size: 14px;
    letter-spacing: 2px;
  }

  .hero {
    min-height: 70vh;
    padding: 70px 16px 50px;
  }

  .hero::before {
    width: 220px;
    height: 220px;
  }

  .hero::after {
    width: 150px;
    height: 150px;
  }

  .hero h1 {
    font-size: 22px;
    letter-spacing: 4px;
  }

  .hero .tagline {
    font-size: 13px;
    letter-spacing: 2px;
  }

  .hero .tagline-sub {
    font-size: 11px;
    letter-spacing: 1px;
    margin-bottom: 24px;
  }

  .hero .philosophy {
    font-size: 10px;
    letter-spacing: 1px;
    padding: 8px 14px;
  }

  .section-subtitle {
    margin-top: -8px;
    margin-bottom: 32px;
    font-size: 11px;
    letter-spacing: 2px;
  }

  .footer {
    padding: 28px 0;
  }

  .footer p {
    font-size: 10.5px;
    letter-spacing: 0.4px;
    line-height: 2;
  }
}

/* ===== 研究洞察页 ===== */
.section-subtitle {
  text-align: center;
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 3px;
  margin-top: -40px;
  margin-bottom: 56px;
}

.insight-list {
  max-width: 720px;
  margin: 0 auto;
}

.insight-item {
  padding: 36px 0;
  border-bottom: 1px solid var(--border);
  transition: padding-left 0.3s;
}

.insight-item:hover {
  padding-left: 12px;
}

.insight-item:last-child {
  border-bottom: none;
}

.insight-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 12px;
}

.insight-tag {
  font-size: 11px;
  letter-spacing: 1.5px;
  color: var(--accent);
  border: 1px solid var(--accent-light);
  padding: 3px 10px;
  font-weight: 500;
}

.insight-date {
  font-size: 12px;
  color: var(--gray);
  letter-spacing: 1px;
}

.insight-title {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 1px;
  margin-bottom: 12px;
  color: var(--black);
  line-height: 1.6;
}

.insight-summary {
  font-size: 13.5px;
  color: var(--dark);
  line-height: 2;
}

.insight-footer {
  margin-top: 16px;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.insight-tag-sub {
  font-size: 11px;
  color: var(--accent-light);
  letter-spacing: 1px;
}

.insight-disclaimer {
  font-size: 11px;
  color: #bbb;
  letter-spacing: 0.5px;
}

@media (max-width: 768px) {
  .insight-title {
    font-size: 15px;
  }

  .insight-summary {
    font-size: 13px;
  }

  .insight-footer {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

/* ===== 创意视觉页 ===== */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.gallery-item {
  overflow: hidden;
  border: 1px solid var(--border);
  cursor: pointer;
  position: relative;
  aspect-ratio: 1 / 1;
  background: var(--bg-warm);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease, opacity 0.3s;
  opacity: 0;
}

.gallery-item img.loaded {
  opacity: 1;
}

.gallery-item:hover img {
  transform: scale(1.05);
}

.gallery-disclaimer {
  text-align: center;
  margin-top: 48px;
  font-size: 12px;
  color: var(--gray);
  letter-spacing: 0.5px;
}

/* 灯箱 */
.lightbox {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.92);
  align-items: center;
  justify-content: center;
  padding: 40px;
}

.lightbox.active {
  display: flex;
}

.lightbox img {
  max-width: 90vw;
  max-height: 85vh;
  object-fit: contain;
  border: 1px solid rgba(255,255,255,0.1);
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 28px;
  background: none;
  border: none;
  color: #fff;
  font-size: 36px;
  cursor: pointer;
  opacity: 0.7;
  transition: opacity 0.2s;
  z-index: 1001;
}

.lightbox-close:hover {
  opacity: 1;
}

.lightbox-prev,
.lightbox-next {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: #fff;
  font-size: 32px;
  cursor: pointer;
  opacity: 0.5;
  transition: opacity 0.2s;
  padding: 20px;
  z-index: 1001;
}

.lightbox-prev { left: 8px; }
.lightbox-next { right: 8px; }

.lightbox-prev:hover,
.lightbox-next:hover {
  opacity: 1;
}

@media (max-width: 768px) {
  .gallery-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
  }
}

@media (max-width: 480px) {
  .gallery-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 6px;
  }

  .section-services .service-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .section-services .service-item:last-child:nth-child(3n+1) {
    grid-column: auto;
  }

  .lightbox {
    padding: 20px;
  }

  .lightbox-prev,
  .lightbox-next {
    font-size: 24px;
    padding: 12px;
  }
}