/* ===== Variables ===== */
:root {
  --color-bg: #000000;
  --color-bg-elevated: #0A0A0A;
  --color-text: #EFEFEF;
  --color-text-muted: #A0A0A0;
  --color-text-dim: #E8E8E8A6;
  --color-accent: #E0C787;
  --color-accent-hover: #C4AD6E;
  --color-border: #333333;
  --font-logo: "YouSheBiaoTiHei", "YouSheBiaoTiHei-Regular", "Poppins", sans-serif;
  --font-display: "Poppins", "Montserrat", -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Poppins", -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --max-width: 1200px;
  --section-padding: 120px;
}

/* ===== Reset ===== */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.65;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

h1, h2, h3, h4, h5, h6, p {
  margin: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ===== Utilities ===== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 30px;
}

.hide-mobile {
  display: inline;
}

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 22px 0;
  transition: background-color 0.3s ease, padding 0.3s ease;
}

.site-header.scrolled {
  background-color: rgba(0, 0, 0, 0.92);
  backdrop-filter: blur(10px);
  padding: 14px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

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

.logo {
  font-family: var(--font-logo);
  font-size: 28px;
  font-weight: normal;
  letter-spacing: 2px;
  color: var(--color-text);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 36px;
}

.main-nav a {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text);
  opacity: 0.85;
  transition: opacity 0.2s ease;
}

.main-nav a:hover {
  opacity: 1;
}

.nav-cta {
  padding: 10px 20px;
  border: 1px solid var(--color-accent);
  color: var(--color-accent) !important;
  transition: background-color 0.2s ease, color 0.2s ease !important;
}

.nav-cta:hover {
  background-color: var(--color-accent);
  color: #000 !important;
}

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

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 32px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  border: none;
  cursor: pointer;
  transition: all 0.25s ease;
}

.btn-primary {
  background-color: var(--color-accent);
  color: #000;
}

.btn-primary:hover {
  background-color: var(--color-accent-hover);
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-text);
  border: 1px solid rgba(255, 255, 255, 0.25);
}

.btn-ghost:hover {
  border-color: var(--color-text);
  background-color: rgba(255, 255, 255, 0.05);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-text);
  border: 1px solid rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn-full {
  width: 100%;
}

/* ===== Section Common ===== */
section {
  padding: var(--section-padding) 0;
}

.section-label {
  display: block;
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 4px;
  color: var(--color-accent);
  margin-bottom: 24px;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 70px;
}

.section-title {
  font-family: var(--font-display);
  font-size: 52px;
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.5px;
  color: var(--color-text);
  margin-bottom: 22px;
}

.section-desc {
  font-size: 18px;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-top: 100px;
  padding-bottom: 100px;
  overflow: hidden;
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1100px;
}

.hero-banner {
  width: 100%;
  aspect-ratio: 2480 / 1061;
  margin-bottom: 50px;
  background-image: url('hero-banner.png');
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

.hero-cta {
  display: flex;
  justify-content: center;
  gap: 20px;
}

/* ===== Services ===== */
.services {
  background-color: var(--color-bg);
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.service-card {
  background-color: var(--color-bg);
  overflow: hidden;
  transition: transform 0.3s ease;
}

.service-card:hover {
  transform: translateY(-6px);
}

.service-image {
  height: 220px;
  background-size: cover;
  background-position: center;
  opacity: 0.85;
  filter: grayscale(30%);
  transition: opacity 0.3s ease, filter 0.3s ease;
}

.service-card:hover .service-image {
  opacity: 1;
  filter: grayscale(0%);
}

.service-card:hover .service-image {
  opacity: 1;
  filter: grayscale(0%);
}

.service-body {
  padding: 32px 28px;
}

.service-body h3 {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 14px;
  color: var(--color-text);
}

.service-body p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 22px;
}

.link-arrow {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  position: relative;
  padding-bottom: 3px;
}

.link-arrow::after {
  content: "→";
  margin-left: 6px;
  transition: transform 0.2s ease;
  display: inline-block;
}

.link-arrow:hover::after {
  transform: translateX(4px);
}

/* ===== Framework ===== */
.framework {
  background-color: var(--color-bg);
}

.framework-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.step {
  padding: 40px 30px;
  border: 1px solid var(--color-border);
  background-color: var(--color-bg);
  transition: border-color 0.3s ease;
}

.step:hover {
  border-color: var(--color-accent);
}

.step-number {
  display: block;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: 2px;
  margin-bottom: 18px;
}

.step h3 {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 12px;
}

.step p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ===== Content Center ===== */
.content-center {
  background-color: var(--color-bg);
}

.post-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.post-card {
  background-color: var(--color-bg);
  padding: 32px;
  border: 1px solid var(--color-border);
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.post-card:hover {
  border-color: rgba(224, 199, 135, 0.4);
  transform: translateY(-4px);
}

.post-link {
  display: block;
}

.post-link h3 {
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 14px;
  color: var(--color-text);
  transition: color 0.2s ease;
}

.post-card:hover .post-link h3 {
  color: var(--color-accent);
}

.post-link p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 20px;
}

.post-meta {
  font-size: 13px;
  color: var(--color-text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.load-more {
  text-align: center;
  margin-top: 60px;
}

/* ===== Live Stream ===== */
.livestream {
  background-color: var(--color-bg);
}

/* ===== About ===== */
.about {
  background-color: var(--color-bg);
}

.about-inner {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 80px;
  align-items: center;
}

.about-image {
  position: relative;
}

.about-image img {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 50%;
  border: 4px solid var(--color-text);
}

.about-text .section-title {
  text-align: left;
  margin-bottom: 28px;
}

.about-text p {
  font-size: 16px;
  color: var(--color-text-muted);
  margin-bottom: 18px;
  line-height: 1.8;
}

.about-text p strong {
  color: var(--color-text);
  font-weight: 600;
}

.about-social {
  display: flex;
  gap: 20px;
  margin-top: 32px;
}

.about-social a {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  transition: opacity 0.2s ease;
}

.about-social a:hover {
  opacity: 0.8;
}

/* ===== Contact ===== */
.contact {
  background-color: var(--color-bg);
  text-align: center;
}

.contact-inner {
  max-width: 700px;
  margin: 0 auto;
}

.contact-desc {
  font-size: 17px;
  color: var(--color-text-muted);
  margin-bottom: 40px;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 18px;
  text-align: left;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 16px 18px;
  font-family: var(--font-body);
  font-size: 15px;
  color: var(--color-text);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  outline: none;
  transition: border-color 0.2s ease;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: #666;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--color-accent);
}

.contact-form textarea {
  resize: vertical;
  min-height: 120px;
}

.contact-wechat {
  margin-top: 28px;
  font-size: 15px;
  color: var(--color-text-muted);
}

.contact-wechat strong {
  color: var(--color-accent);
  margin-left: 8px;
  font-weight: 600;
}

/* ===== Footer ===== */
.site-footer {
  background-color: var(--color-bg);
  padding: 80px 0 40px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-main {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 80px;
  margin-bottom: 60px;
}

.footer-brand .logo {
  margin-bottom: 18px;
  display: inline-block;
}

.footer-brand p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
  max-width: 360px;
}

.footer-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}

.footer-col h4 {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-text);
  margin-bottom: 20px;
}

.footer-col a {
  display: block;
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 12px;
  transition: color 0.2s ease;
}

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

.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: var(--color-text-dim);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .service-grid,
  .post-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .framework-steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .about-inner {
    grid-template-columns: 280px 1fr;
    gap: 50px;
  }
}

@media (max-width: 768px) {
  :root {
    --section-padding: 80px;
  }

  .container {
    padding: 0 22px;
  }

  .hide-mobile {
    display: none;
  }

  .hero {
    text-align: center;
  }

  .main-nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 75%;
    max-width: 320px;
    height: 100vh;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 28px;
    padding: 80px 36px;
    background-color: rgba(0, 0, 0, 0.98);
    backdrop-filter: blur(10px);
    transition: right 0.35s ease;
    border-left: 1px solid rgba(255, 255, 255, 0.06);
  }

  .main-nav.open {
    right: 0;
  }

  .main-nav a {
    font-size: 18px;
  }

  .nav-cta {
    margin-top: 10px;
  }

  .menu-toggle {
    display: flex;
    z-index: 1100;
  }

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

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

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

  .hero-cta {
    flex-direction: column;
    gap: 14px;
  }

  .section-title {
    font-size: 32px;
    letter-spacing: -0.3px;
  }

  .service-grid,
  .post-grid,
  .framework-steps {
    grid-template-columns: 1fr;
  }

  .about-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .about-image {
    max-width: 240px;
    margin: 0 auto;
  }

  .about-text .section-title {
    text-align: center;
  }

  .about-social {
    justify-content: center;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 50px;
  }

  .footer-brand p {
    max-width: 100%;
  }
}