/* ============================================================
   AgriROS Community Website - Main Stylesheet
   农业机器人技术社区官网样式表
   ============================================================ */

/* ---- Root Variables ---- */
:root {
  --green-darkest:  #0d2b1a;
  --green-dark:     #1b4332;
  --green-mid:      #2d6a4f;
  --green-main:     #40916c;
  --green-light:    #52b788;
  --green-pale:     #74c69d;
  --green-soft:     #b7e4c7;
  --green-mist:     #d8f3dc;
  --green-bg:       #f0faf4;
  --yellow:         #f4a261;
  --orange:         #e76f51;
  --white:          #ffffff;
  --text-primary:   #1a2e1c;
  --text-secondary: #3a5c42;
  --text-muted:     #6b8f71;
  --border:         #c8e6d0;
  --shadow-sm:      0 2px 8px rgba(64,145,108,.12);
  --shadow-md:      0 8px 32px rgba(64,145,108,.18);
  --shadow-lg:      0 20px 60px rgba(64,145,108,.22);
  --radius-sm:      8px;
  --radius-md:      16px;
  --radius-lg:      24px;
  --transition:     all .3s cubic-bezier(.4,0,.2,1);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans CJK SC', sans-serif;
  color: var(--text-primary);
  background: var(--white);
  line-height: 1.6;
  overflow-x: hidden;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ============================================================
   TOP BAR
   ============================================================ */
.topbar {
  background: var(--green-darkest);
  padding: 8px 0;
  font-size: 13px;
  color: var(--green-soft);
}
.topbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.topbar-inner i { color: var(--green-pale); margin-right: 6px; }
.topbar-right { display: flex; gap: 20px; }
.topbar-right a {
  color: var(--green-soft);
  font-size: 13px;
  transition: var(--transition);
}
.topbar-right a:hover { color: var(--white); }

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(27,67,50,.97);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(82,183,136,.2);
  transition: var(--transition);
}
.navbar.scrolled {
  background: rgba(13,43,26,.98);
  box-shadow: 0 4px 20px rgba(0,0,0,.3);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--green-light), var(--green-main));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(82,183,136,.4);
  flex-shrink: 0;
  padding: 2px;
}
.logo-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
.logo-text {
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  letter-spacing: .5px;
}
.logo-text em {
  font-style: normal;
  color: var(--green-pale);
}
.nav-links {
  display: flex;
  gap: 4px;
  flex: 1;
}
.nav-links a {
  padding: 6px 14px;
  color: rgba(255,255,255,.85);
  font-size: 15px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--green-pale);
  border-radius: 1px;
  transition: var(--transition);
}
.nav-links a:hover { color: var(--white); background: rgba(82,183,136,.15); }
.nav-links a:hover::after { width: 60%; }
.nav-links a.nav-active {
  color: var(--white);
  background: rgba(82,183,136,.22);
  font-weight: 600;
}
.nav-links a.nav-active::after {
  width: 60%;
  background: var(--white);
}
.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.btn-search {
  background: none;
  border: none;
  color: rgba(255,255,255,.7);
  font-size: 16px;
  cursor: pointer;
  padding: 8px;
  border-radius: 8px;
  transition: var(--transition);
}
.btn-search:hover { color: white; background: rgba(82,183,136,.2); }
.btn-primary {
  background: linear-gradient(135deg, var(--green-light), var(--green-main));
  color: white;
  padding: 9px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  transition: var(--transition);
  box-shadow: 0 2px 10px rgba(82,183,136,.4);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(82,183,136,.5);
}
.hamburger {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 20px;
  cursor: pointer;
  padding: 8px;
  margin-left: auto;
}
.mobile-menu {
  display: none;
  flex-direction: column;
  background: var(--green-darkest);
  padding: 12px 24px 20px;
  border-top: 1px solid rgba(82,183,136,.2);
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
  color: rgba(255,255,255,.85);
  padding: 10px 0;
  font-size: 15px;
  border-bottom: 1px solid rgba(82,183,136,.1);
  transition: var(--transition);
}
.mobile-menu a:hover { color: var(--green-pale); padding-left: 8px; }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 620px;
  background: linear-gradient(135deg, var(--green-darkest) 0%, var(--green-dark) 40%, var(--green-mid) 100%);
  display: flex;
  align-items: center;
  overflow: hidden;
  padding: 80px 24px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
}
.hero-particles {
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(82,183,136,.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(64,145,108,.2) 0%, transparent 50%),
    radial-gradient(circle at 60% 20%, rgba(116,198,157,.1) 0%, transparent 40%);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 560px;
  margin-left: max(24px, calc((100vw - 1200px)/2));
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(82,183,136,.2);
  border: 1px solid rgba(82,183,136,.4);
  color: var(--green-soft);
  padding: 6px 16px;
  border-radius: 100px;
  font-size: 13px;
  margin-bottom: 24px;
  backdrop-filter: blur(4px);
}
.hero-title {
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 800;
  color: white;
  line-height: 1.2;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}
.hero-title .highlight {
  color: var(--green-pale);
  background: linear-gradient(90deg, var(--green-pale), var(--green-soft));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  color: rgba(255,255,255,.75);
  font-size: 16px;
  line-height: 1.75;
  margin-bottom: 28px;
  max-width: 500px;
}
.hero-features {
  display: flex;
  gap: 20px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}
.hf-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--green-soft);
  font-size: 14px;
}
.hf-item i { color: var(--green-pale); font-size: 15px; }
.hero-btns {
  display: flex;
  gap: 14px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}
.btn-hero-primary {
  background: linear-gradient(135deg, var(--green-light), var(--green-main));
  color: white;
  padding: 14px 28px;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition);
  box-shadow: 0 4px 16px rgba(82,183,136,.4);
}
.btn-hero-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(82,183,136,.5);
}
.btn-hero-github {
  background: rgba(255,255,255,.08);
  color: white;
  padding: 14px 22px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1.5px solid rgba(255,255,255,.35);
  transition: var(--transition);
  backdrop-filter: blur(4px);
}
.btn-hero-github:hover {
  background: rgba(64,145,108,.3);
  border-color: var(--green-pale);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(64,145,108,.4);
}
.btn-hero-gitee {
  background: rgba(255,255,255,.08);
  color: white;
  padding: 14px 22px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1.5px solid rgba(255,255,255,.35);
  transition: var(--transition);
  backdrop-filter: blur(4px);
}
.btn-hero-gitee:hover {
  background: rgba(64,145,108,.3);
  border-color: var(--green-pale);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(64,145,108,.4);
}
.hero-version {
  display: flex;
  align-items: center;
  gap: 12px;
  color: rgba(255,255,255,.55);
  font-size: 13px;
}
.hero-version .divider { opacity: .4; }
.hero-illustration {
  position: absolute;
  right: max(24px, calc((100vw - 1200px)/2));
  top: 50%;
  transform: translateY(-50%);
  width: 360px;
  height: 360px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-circle {
  position: absolute;
  border-radius: 50%;
  border: 1.5px solid rgba(82,183,136,.2);
}
.c1 { width: 320px; height: 320px; animation: spin1 20s linear infinite; }
.c2 { width: 240px; height: 240px; border-color: rgba(82,183,136,.3); animation: spin2 15s linear infinite; }
.c3 { width: 160px; height: 160px; border-color: rgba(82,183,136,.4); animation: spin1 10s linear infinite; }
@keyframes spin1 { to { transform: rotate(360deg); } }
@keyframes spin2 { to { transform: rotate(-360deg); } }
.robot-card {
  background: rgba(13,43,26,.9);
  border: 1px solid rgba(82,183,136,.4);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  width: 260px;
  position: relative;
  z-index: 1;
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow-lg);
}
.robot-screen { font-family: 'Courier New', monospace; font-size: 14px; }
.screen-line { margin-bottom: 6px; color: rgba(255,255,255,.7); }
.s-green { color: #4ade80; }
.s-yellow { color: #fbbf24; }
.s-cyan { color: #22d3ee; }
.screen-cursor {
  color: #4ade80;
  animation: blink 1s step-end infinite;
  margin-top: 8px;
}
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0} }

/* ============================================================
   QUICK ENTRY
   ============================================================ */
.quick-entry {
  background: var(--white);
  padding: 60px 0;
  border-bottom: 1px solid var(--border);
}
.qe-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.qe-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  transition: var(--transition);
  background: var(--green-bg);
  cursor: pointer;
}
.qe-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--green-light);
}
.qe-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 22px;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}
.qe-info { flex: 1; }
.qe-info h4 { font-size: 15px; font-weight: 600; color: var(--text-primary); margin-bottom: 4px; }
.qe-info p { font-size: 12px; color: var(--text-muted); line-height: 1.5; }
.qe-arrow { color: var(--green-main); font-size: 14px; transition: var(--transition); }
.qe-card:hover .qe-arrow { transform: translateX(4px); }

/* ============================================================
   CONTRIBUTE
   ============================================================ */
.contribute {
  padding: 80px 0;
  background: var(--green-bg);
}
.contrib-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
.contrib-card {
  padding: 40px;
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
}
.contrib-card.personal {
  background: linear-gradient(135deg, var(--green-dark), var(--green-mid));
  color: white;
}
.contrib-card.enterprise {
  background: white;
  border: 2px solid var(--border);
}
.contrib-badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 100px;
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: 1px;
}
.personal .contrib-badge {
  background: rgba(255,255,255,.2);
  color: var(--green-soft);
}
.enterprise .contrib-badge {
  background: var(--green-mist);
  color: var(--green-mid);
}
.contrib-card h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 14px;
  line-height: 1.3;
}
.enterprise h2 { color: var(--text-primary); }
.contrib-card p {
  font-size: 15px;
  line-height: 1.75;
  margin-bottom: 20px;
  opacity: .9;
}
.enterprise p { color: var(--text-secondary); }
.contrib-list { margin-bottom: 28px; display: flex; flex-direction: column; gap: 10px; }
.contrib-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
}
.personal .contrib-list li { color: rgba(255,255,255,.9); }
.enterprise .contrib-list li { color: var(--text-secondary); }
.contrib-list i { color: var(--green-pale); font-size: 14px; }
.enterprise .contrib-list i { color: var(--green-main); }
.btn-green {
  display: inline-flex;
  align-items: center;
  padding: 12px 28px;
  background: var(--green-pale);
  color: var(--green-darkest);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-green:hover { background: white; transform: translateY(-2px); }
.btn-outline-green {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border: 2px solid var(--green-main);
  color: var(--green-main);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-outline-green:hover {
  background: var(--green-main);
  color: white;
  transform: translateY(-2px);
}

/* ============================================================
   STATS
   ============================================================ */
.stats {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--green-dark) 0%, var(--green-mid) 100%);
}
.stats-header {
  text-align: center;
  margin-bottom: 48px;
}
.stats-header h2 {
  font-size: 32px;
  font-weight: 700;
  color: white;
  margin-bottom: 12px;
}
.stats-header p { color: rgba(255,255,255,.7); font-size: 16px; }
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.stat-item {
  background: rgba(255,255,255,.1);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  text-align: center;
  position: relative;
  transition: var(--transition);
}
.stat-item:hover {
  background: rgba(255,255,255,.15);
  transform: translateY(-4px);
}
.stat-num {
  font-size: 44px;
  font-weight: 800;
  color: white;
  line-height: 1;
  margin-bottom: 8px;
  letter-spacing: -1px;
}
.stat-label {
  font-size: 14px;
  color: rgba(255,255,255,.7);
  font-weight: 500;
}
.stat-icon {
  position: absolute;
  top: 16px;
  right: 20px;
  font-size: 22px;
  color: rgba(255,255,255,.2);
}

/* ============================================================
   USE CASES
   ============================================================ */
.cases {
  padding: 80px 0;
  background: var(--green-bg);
}
.cases-header {
  text-align: center;
  margin-bottom: 40px;
}
.cases-header h2 { font-size: 32px; font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
.cases-header p { color: var(--text-muted); font-size: 16px; }
.cases-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 32px;
  flex-wrap: wrap;
  justify-content: center;
}
.tab-btn {
  padding: 9px 22px;
  border-radius: 100px;
  border: 1.5px solid var(--border);
  background: white;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}
.tab-btn:hover { border-color: var(--green-main); color: var(--green-main); }
.tab-btn.active {
  background: var(--green-main);
  border-color: var(--green-main);
  color: white;
}
.tab-panel { display: none; }
.tab-panel.active { display: block; }
.case-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.case-card {
  border-radius: var(--radius-md);
  overflow: hidden;
  background: white;
  border: 1px solid var(--border);
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}
.case-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}
.case-img {
  height: 160px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.grain-img  { background: linear-gradient(135deg, #1b4332, #52b788); }
.grain-img2 { background: linear-gradient(135deg, #2d6a4f, #74c69d); }
.grain-img3 { background: linear-gradient(135deg, #0d2b1a, #40916c); }
.fruit-img  { background: linear-gradient(135deg, #d62828, #f7941d); }
.fruit-img2 { background: linear-gradient(135deg, #e9c46a, #f4a261); }
.live-img   { background: linear-gradient(135deg, #6d4c41, #a1887f); }
.green-img  { background: linear-gradient(135deg, #1b4332, #b7e4c7); }
.aqua-img   { background: linear-gradient(135deg, #023e8a, #0096c7); }
.case-overlay {
  width: 64px;
  height: 64px;
  background: rgba(255,255,255,.25);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: white;
  backdrop-filter: blur(4px);
}
.case-body { padding: 20px; }
.case-body h4 { font-size: 15px; font-weight: 600; color: var(--text-primary); margin-bottom: 8px; }
.case-body p { font-size: 13px; color: var(--text-secondary); line-height: 1.65; margin-bottom: 14px; }
.case-link {
  font-size: 13px;
  color: var(--green-main);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}
.case-link:hover { gap: 10px; color: var(--green-dark); }

/* ============================================================
   TECH FEATURES
   ============================================================ */
.tech-features {
  padding: 80px 0;
  background: white;
}
.tf-header {
  text-align: center;
  margin-bottom: 48px;
}
.tf-header h2 { font-size: 32px; font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
.tf-header p { color: var(--text-muted); font-size: 16px; }
.tf-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.tf-card {
  padding: 32px 28px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--green-bg);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.tf-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--green-main), var(--green-pale));
  transform: scaleX(0);
  transform-origin: left;
  transition: var(--transition);
}
.tf-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--green-light);
}
.tf-card:hover::before { transform: scaleX(1); }
.tf-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--green-main), var(--green-dark));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: white;
  margin-bottom: 18px;
  box-shadow: var(--shadow-sm);
}
.tf-card h3 { font-size: 17px; font-weight: 600; color: var(--text-primary); margin-bottom: 10px; }
.tf-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* ============================================================
   TOOLS
   ============================================================ */
.tools-section {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--green-dark), var(--green-mid));
}
.tools-header {
  text-align: center;
  margin-bottom: 48px;
}
.tools-header h2 { font-size: 32px; font-weight: 700; color: white; margin-bottom: 12px; }
.tools-header p { color: rgba(255,255,255,.7); font-size: 16px; }
.tools-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.tool-item {
  background: rgba(255,255,255,.1);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: var(--radius-md);
  padding: 28px 22px;
  text-align: center;
  transition: var(--transition);
}
.tool-item:hover {
  background: rgba(255,255,255,.18);
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(0,0,0,.2);
}
.tool-icon {
  width: 56px;
  height: 56px;
  background: rgba(255,255,255,.15);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  color: var(--green-pale);
  margin: 0 auto 16px;
}
.tool-item h4 { font-size: 16px; font-weight: 600; color: white; margin-bottom: 8px; }
.tool-item p { font-size: 13px; color: rgba(255,255,255,.65); line-height: 1.6; margin-bottom: 18px; }
.tool-link {
  display: inline-flex;
  padding: 8px 18px;
  border: 1.5px solid rgba(255,255,255,.4);
  border-radius: var(--radius-sm);
  color: white;
  font-size: 13px;
  font-weight: 500;
  transition: var(--transition);
}
.tool-link:hover { background: var(--green-pale); border-color: var(--green-pale); color: var(--green-darkest); }

/* ============================================================
   NEWS
   ============================================================ */
.news-section {
  padding: 80px 0;
  background: var(--white);
}
.news-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 36px;
  flex-wrap: wrap;
  gap: 16px;
}
.news-header h2 { font-size: 32px; font-weight: 700; color: var(--text-primary); }
.news-tabs { display: flex; gap: 6px; flex-wrap: wrap; }
.news-tab {
  padding: 7px 18px;
  border-radius: 100px;
  border: 1.5px solid var(--border);
  background: none;
  color: var(--text-secondary);
  font-size: 13px;
  cursor: pointer;
  transition: var(--transition);
}
.news-tab:hover { border-color: var(--green-main); color: var(--green-main); }
.news-tab.active {
  background: var(--green-main);
  border-color: var(--green-main);
  color: white;
}
.news-grid {
  display: grid;
  grid-template-columns: 5fr 4fr;
  gap: 28px;
  margin-bottom: 32px;
}
.news-card.featured {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.news-card.featured:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.news-img {
  height: 220px;
  position: relative;
}
.featured-img {
  background: linear-gradient(135deg, var(--green-darkest), var(--green-mid));
  display: flex;
  align-items: flex-end;
  padding: 16px;
}
.news-tag {
  display: inline-block;
  padding: 5px 12px;
  border-radius: 100px;
  font-size: 12px;
  font-weight: 600;
}
.release-tag { background: rgba(82,183,136,.25); color: #1b4332; }
.blog-tag { background: rgba(244,162,97,.25); color: #7b3f00; }
.news-tag-green { background: rgba(64,145,108,.15); color: var(--green-mid); }
.news-body { padding: 20px; }
.news-date {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 10px;
}
.news-body h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  line-height: 1.4;
}
.news-body p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}
.news-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--green-main);
  font-weight: 600;
  transition: var(--transition);
}
.news-link:hover { gap: 10px; }
.news-side { display: flex; flex-direction: column; gap: 12px; }
.news-item {
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--green-bg);
  transition: var(--transition);
}
.news-item:hover {
  border-color: var(--green-light);
  transform: translateX(4px);
}
.news-tag2 {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 100px;
  font-size: 11px;
  font-weight: 600;
  margin-bottom: 6px;
}
.news-date2 { font-size: 12px; color: var(--text-muted); margin-bottom: 6px; }
.news-item h4 a {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.5;
  transition: var(--transition);
}
.news-item h4 a:hover { color: var(--green-main); }
.news-more { text-align: center; }
.news-loading { grid-column: 1 / -1; }

/* ============================================================
   PARTNERS
   ============================================================ */
.partners {
  padding: 72px 0;
  background: var(--green-bg);
}
.partners-header {
  text-align: center;
  margin-bottom: 48px;
}
.partners-header h2 { font-size: 28px; font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
.partners-header p { color: var(--text-muted); font-size: 15px; }
.partners-logos {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.partner-item { display: flex; align-items: center; justify-content: center; }
.partner-logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 28px 20px;
  background: white;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  width: 100%;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  text-align: center;
  transition: var(--transition);
  cursor: pointer;
}
.partner-logo i { font-size: 28px; color: var(--green-main); }
.partner-logo:hover {
  border-color: var(--green-main);
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--green-darkest);
  color: rgba(255,255,255,.75);
  padding-top: 64px;
}
.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,.1);
}
.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}
.footer-logo i { font-size: 24px; color: var(--green-pale); }
.footer-bee-img {
  width: 38px;
  height: 38px;
  object-fit: contain;
  display: block;
  flex-shrink: 0;
}
.footer-logo span {
  font-size: 20px;
  font-weight: 700;
  color: white;
}
.footer-logo em { font-style: normal; color: var(--green-pale); }
.footer-brand p { font-size: 13px; line-height: 1.75; margin-bottom: 20px; }
.footer-social { display: flex; gap: 12px; }
.footer-social a {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: rgba(255,255,255,.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,.7);
  font-size: 16px;
  transition: var(--transition);
}
.footer-social a:hover { background: var(--green-main); color: white; }
.footer-links-group h5 {
  font-size: 14px;
  font-weight: 600;
  color: white;
  margin-bottom: 16px;
  letter-spacing: .5px;
}
.footer-links-group ul { display: flex; flex-direction: column; gap: 10px; }
.footer-links-group a {
  font-size: 13px;
  color: rgba(255,255,255,.6);
  transition: var(--transition);
}
.footer-links-group a:hover { color: var(--green-pale); padding-left: 4px; }
.footer-bottom {
  padding: 20px 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.footer-friendly {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
}
.footer-friendly span { color: rgba(255,255,255,.5); }
.footer-friendly a {
  color: rgba(255,255,255,.6);
  transition: var(--transition);
}
.footer-friendly a:hover { color: var(--green-pale); }
.footer-legal {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  font-size: 12px;
  color: rgba(255,255,255,.4);
}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.back-top {
  position: fixed;
  bottom: 36px;
  right: 36px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--green-main);
  color: white;
  border: none;
  font-size: 18px;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  opacity: 0;
  pointer-events: none;
  z-index: 999;
}
.back-top.show { opacity: 1; pointer-events: all; }
.back-top:hover { background: var(--green-dark); transform: translateY(-4px); }

/* ============================================================
   CONTENT AREAS (内页通用)
   ============================================================ */
.main-content {
  min-height: 600px;
  padding: 60px 0;
}
.section-header {
  text-align: center;
  margin-bottom: 48px;
}
.section-header h1 { font-size: 40px; font-weight: 800; color: var(--text-primary); margin-bottom: 16px; }
.section-header h2 { font-size: 32px; font-weight: 700; color: var(--text-primary); margin-bottom: 16px; }
.section-header h3 { font-size: 24px; font-weight: 600; color: var(--text-primary); margin-bottom: 12px; }
.section-header p { font-size: 18px; color: var(--text-secondary); max-width: 700px; margin: 0 auto; }

/* ============================================================
   SCROLL ANIMATIONS
   ============================================================ */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity .6s ease, transform .6s ease;
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   UTILITY
   ============================================================ */
.text-center { text-align: center; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}
.btn-outline {
  background: transparent;
  border: 2px solid var(--green-main);
  color: var(--green-main);
}
.btn-outline:hover {
  background: var(--green-main);
  color: white;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1100px) {
  .hero-illustration { display: none; }
  .hero-content { max-width: 100%; margin-left: 0; }
  .qe-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-top { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 900px) {
  .contrib-grid,
  .stats-grid,
  .tf-grid,
  .news-grid { grid-template-columns: 1fr; }
  .case-cards { grid-template-columns: 1fr; }
  .tools-grid { grid-template-columns: repeat(2, 1fr); }
  .partners-logos { grid-template-columns: repeat(2, 1fr); }
  .nav-links, .nav-actions { display: none; }
  .hamburger { display: flex; }
  .footer-top { grid-template-columns: 1fr; gap: 24px; }
}
@media (max-width: 600px) {
  .qe-grid { grid-template-columns: 1fr; }
  .tools-grid { grid-template-columns: 1fr; }
  .partners-logos { grid-template-columns: 1fr 1fr; }
  .hero { padding: 60px 20px; }
  .hero-btns { flex-direction: column; }
  .hero-features { flex-direction: column; gap: 12px; }
  .news-header { flex-direction: column; align-items: flex-start; }
  .footer-bottom { flex-direction: column; }
  .back-top { bottom: 20px; right: 20px; }
  .section-header h1 { font-size: 32px; }
  .section-header h2 { font-size: 28px; }
  .container { padding: 0 16px; }
}