/* ========================================
   识流文化 — 静态官网样式
   Mobile-first 响应式设计
   ======================================== */

:root {
  --color-primary: #2d5a4a;
  --color-primary-light: #3d7a64;
  --color-primary-dark: #1e3d32;
  --color-accent: #c4a35a;
  --color-accent-light: #d4b872;
  --color-bg: #faf9f6;
  --color-bg-alt: #f0ede6;
  --color-text: #2c2c2c;
  --color-text-muted: #6b6b6b;
  --color-white: #ffffff;
  --color-border: rgba(45, 90, 74, 0.12);

  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, serif;
  --font-sans: "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.12);

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --header-height: 64px;
  --section-padding: 72px;
  --container-max: 1140px;
  --transition: 0.3s ease;
}

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

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-primary-light);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---- Header ---- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(250, 249, 246, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow-sm);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-primary-dark);
}

.logo:hover {
  color: var(--color-primary);
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-primary-dark);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.site-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: var(--color-white);
  padding: 24px 20px;
  flex-direction: column;
  gap: 4px;
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
}

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

.site-nav a {
  padding: 12px 16px;
  font-size: 0.95rem;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}

.site-nav a:hover {
  background: var(--color-bg-alt);
  color: var(--color-primary);
}

.nav-cta {
  background: var(--color-primary) !important;
  color: var(--color-white) !important;
  text-align: center;
  margin-top: 8px;
}

.nav-cta:hover {
  background: var(--color-primary-light) !important;
  color: var(--color-white) !important;
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  font-size: 0.95rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
}

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

.btn-primary:hover {
  background: var(--color-accent-light);
  border-color: var(--color-accent-light);
  color: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn-outline {
  background: transparent;
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.6);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--color-white);
  color: var(--color-white);
}

/* ---- Hero ---- */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  padding-top: var(--header-height);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: url('hero-bg.jpg') center / cover no-repeat;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(30, 61, 50, 0.88) 0%,
    rgba(45, 90, 74, 0.75) 50%,
    rgba(30, 61, 50, 0.85) 100%
  );
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 48px 20px 80px;
  max-width: 720px;
}

.hero-tag {
  display: inline-block;
  font-size: 0.8rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent-light);
  margin-bottom: 20px;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 6vw, 3.25rem);
  font-weight: 700;
  color: var(--color-white);
  line-height: 1.25;
  margin-bottom: 20px;
}

.hero-subtitle {
  font-size: clamp(0.95rem, 2.5vw, 1.125rem);
  color: rgba(255, 255, 255, 0.88);
  margin-bottom: 36px;
  max-width: 560px;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* ---- Sections ---- */
.section {
  padding: var(--section-padding) 0;
}

.section-header {
  margin-bottom: 48px;
}

.section-header--center {
  text-align: center;
}

.section-header--center .section-desc {
  max-width: 560px;
  margin: 16px auto 0;
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  font-weight: 600;
  margin-bottom: 12px;
}

.section-header h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  color: var(--color-primary-dark);
  line-height: 1.3;
}

.section-desc {
  color: var(--color-text-muted);
  font-size: 1rem;
}

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

.about-grid {
  display: grid;
  gap: 40px;
}

.about-text p {
  margin-bottom: 20px;
  color: var(--color-text-muted);
  font-size: 1.02rem;
}

.about-text strong {
  color: var(--color-primary-dark);
}

.about-stats {
  list-style: none;
  display: grid;
  gap: 16px;
  margin-top: 32px;
}

.about-stats li {
  padding: 16px 20px;
  background: var(--color-bg);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--color-accent);
}

.about-stats strong {
  display: block;
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: var(--color-primary-dark);
  margin-bottom: 4px;
}

.about-stats span {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.about-card {
  background: linear-gradient(145deg, var(--color-primary-dark), var(--color-primary));
  color: var(--color-white);
  padding: 36px 28px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.about-card blockquote {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.8;
  font-style: italic;
  margin-bottom: 20px;
}

.about-card cite {
  font-size: 0.875rem;
  color: var(--color-accent-light);
  font-style: normal;
}

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

.services-grid {
  display: grid;
  gap: 24px;
}

.service-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.service-image {
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

.service-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.service-card:hover .service-image img {
  transform: scale(1.05);
}

.service-body {
  padding: 28px 24px 32px;
}

.service-num {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

.service-body h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  color: var(--color-primary-dark);
  margin-bottom: 8px;
}

.service-tagline {
  font-size: 0.875rem;
  color: var(--color-primary);
  font-weight: 500;
  margin-bottom: 12px;
}

.service-desc {
  font-size: 0.925rem;
  color: var(--color-text-muted);
  line-height: 1.75;
}

/* ---- Advantages ---- */
.advantages {
  background: var(--color-white);
}

.advantages-grid {
  display: grid;
  gap: 24px;
}

.advantage-card {
  padding: 32px 28px;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.advantage-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-sm);
}

.advantage-icon {
  width: 48px;
  height: 48px;
  color: var(--color-primary);
  margin-bottom: 20px;
}

.advantage-icon svg {
  width: 100%;
  height: 100%;
}

.advantage-card h3 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
}

.advantage-card p {
  font-size: 0.925rem;
  color: var(--color-text-muted);
  line-height: 1.75;
}

/* ---- Contact ---- */
.contact {
  background: var(--color-bg-alt);
}

.contact-box {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 40px 28px;
  box-shadow: var(--shadow-md);
  display: grid;
  gap: 32px;
}

.contact-text h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  color: var(--color-primary-dark);
  margin: 8px 0 16px;
}

.contact-text p {
  color: var(--color-text-muted);
  font-size: 0.975rem;
}

.contact-info {
  display: grid;
  gap: 20px;
}

.contact-item {
  padding: 16px 20px;
  background: var(--color-bg);
  border-radius: var(--radius-md);
}

.contact-label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

.contact-item a {
  font-weight: 500;
  font-size: 1rem;
}

/* ---- Footer ---- */
.site-footer {
  background: var(--color-primary-dark);
  color: rgba(255, 255, 255, 0.7);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-white);
  font-family: var(--font-serif);
  font-size: 1rem;
}

.footer-copy {
  font-size: 0.85rem;
}

.footer-beian {
  font-size: 0.85rem;
}

.footer-beian a {
  color: rgba(255, 255, 255, 0.85);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-beian a:hover {
  color: var(--color-white);
}

/* ========================================
   Tablet (≥ 640px)
   ======================================== */
@media (min-width: 640px) {
  .hero-actions {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .about-stats {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .advantages-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .contact-box {
    padding: 48px 40px;
    grid-template-columns: 1.2fr 1fr;
    align-items: center;
  }
}

/* ========================================
   Desktop (≥ 960px)
   ======================================== */
@media (min-width: 960px) {
  :root {
    --section-padding: 96px;
  }

  .nav-toggle {
    display: none;
  }

  .site-nav {
    display: flex !important;
    position: static;
    flex-direction: row;
    align-items: center;
    gap: 8px;
    background: transparent;
    padding: 0;
    border: none;
    box-shadow: none;
  }

  .site-nav a {
    padding: 8px 16px;
  }

  .nav-cta {
    margin-top: 0;
    margin-left: 8px;
  }

  .about-grid {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 56px;
  }

  .service-card--featured {
    grid-column: span 2;
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .service-card--featured .service-image {
    aspect-ratio: auto;
    min-height: 280px;
  }
}

/* ========================================
   Large Desktop (≥ 1200px)
   ======================================== */
@media (min-width: 1200px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}