/* =============================================
   玖玖鸿粤照明官网 - 明亮科技风格
   主色：深蓝 + 金橙渐变，背景白/浅灰
============================================= */

/* ===== 全局变量 ===== */
:root {
  --primary:      #1a56db;      /* 主蓝 */
  --primary-light:#3b82f6;
  --accent:       #f59e0b;      /* 金橙强调色 */
  --accent2:      #10b981;      /* 绿色辅助 */
  --dark:         #0f172a;      /* 深色文字 */
  --dark2:        #1e3a5f;
  --body:         #374151;
  --muted:        #6b7280;
  --light:        #f8fafc;
  --white:        #ffffff;
  --border:       #e5e7eb;
  --card-bg:      #ffffff;
  --section-alt:  #f0f6ff;
  --gradient:     linear-gradient(135deg, #1a56db, #3b82f6);
  --gradient-warm:linear-gradient(135deg, #f59e0b, #ef4444);
  --gradient-hero:linear-gradient(160deg, #0f172a 0%, #1e3a5f 60%, #1a56db 100%);
  --shadow-sm:    0 2px 8px rgba(0,0,0,.08);
  --shadow:       0 8px 30px rgba(0,0,0,.12);
  --shadow-lg:    0 20px 60px rgba(0,0,0,.18);
  --radius:       12px;
  --radius-lg:    20px;
  --transition:   all .3s cubic-bezier(.4,0,.2,1);
}

/* ===== 重置 & 基础 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: -apple-system,'PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  background: var(--white);
  color: var(--body);
  line-height: 1.6;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }

/* ===== 工具类 ===== */
.text-accent { color: var(--accent); }
.container { max-width: 1180px; margin: 0 auto; padding: 0 40px; }
.section { padding: 100px 0; }

/* ===== 按钮 ===== */
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px;
  background: var(--gradient);
  color: #fff; font-weight: 600; font-size: 14px;
  border: none; border-radius: 50px; cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 15px rgba(26,86,219,.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(26,86,219,.45); }
.btn-primary.btn-block { width: 100%; justify-content: center; border-radius: var(--radius); }

.btn-ghost {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px;
  background: rgba(255,255,255,.15);
  color: #fff; font-weight: 600; font-size: 14px;
  border: 1.5px solid rgba(255,255,255,.5); border-radius: 50px; cursor: pointer;
  transition: var(--transition); backdrop-filter: blur(6px);
}
.btn-ghost:hover { background: rgba(255,255,255,.25); }

.btn-outline {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px;
  background: transparent;
  color: var(--primary); font-weight: 600; font-size: 14px;
  border: 2px solid var(--primary); border-radius: 50px; cursor: pointer;
  transition: var(--transition);
}
.btn-outline:hover { background: var(--primary); color: #fff; transform: translateY(-2px); }

.btn-lg { padding: 15px 36px; font-size: 15px; }

/* ===== 章节标题 ===== */
.sec-header { text-align: center; margin-bottom: 60px; }
.sec-tag {
  display: inline-block; padding: 6px 18px;
  background: rgba(26,86,219,.08); color: var(--primary);
  border-radius: 50px; font-size: 12px; font-weight: 600;
  letter-spacing: 2px; text-transform: uppercase; margin-bottom: 14px;
}
.sec-title {
  font-size: clamp(1.8rem,3.5vw,2.6rem); font-weight: 800;
  color: var(--dark); margin-bottom: 14px; line-height: 1.2;
}
.sec-desc { font-size: 16px; color: var(--muted); max-width: 520px; margin: 0 auto; }

/* ===== 导航 ===== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: transparent; transition: var(--transition);
}
.navbar.scrolled {
  background: rgba(255,255,255,.97);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(16px);
}
.nav-container {
  max-width: 1180px; margin: 0 auto; padding: 0 40px;
  height: 70px; display: flex; align-items: center; justify-content: space-between;
}
.logo-img { height: 44px; width: auto; object-fit: contain; }
.nav-links { display: flex; list-style: none; gap: 4px; }
.nav-link {
  display: block; padding: 8px 14px; border-radius: 8px;
  font-size: 14px; color: rgba(255,255,255,.85); transition: var(--transition);
}
.navbar.scrolled .nav-link { color: var(--body); }
.nav-link:hover, .nav-link.active { color: #fff !important; background: rgba(255,255,255,.2); }
.navbar.scrolled .nav-link:hover, .navbar.scrolled .nav-link.active {
  color: var(--primary) !important; background: rgba(26,86,219,.08);
}
.nav-cta { display: flex; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 4px; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: #fff; margin: 5px 0; border-radius: 2px; transition: var(--transition); }
.navbar.scrolled .nav-toggle span { background: var(--dark); }

/* ===== Hero ===== */
.hero {
  min-height: 100vh; position: relative;
  display: flex; align-items: center; justify-content: center;
  padding: 100px 40px 80px; overflow: hidden;
}
.hero-bg-img {
  position: absolute; inset: 0;
  background-size: cover; background-position: center;
  filter: brightness(.45);
}
.hero-overlay {
  position: absolute; inset: 0;
  background: var(--gradient-hero);
  opacity: .75;
}
.hero-content {
  position: relative; z-index: 2;
  text-align: center; max-width: 820px; margin: 0 auto;
}
.hero-logo-wrap { margin-bottom: 28px; display: flex; justify-content: center; }
.hero-logo { height: 80px; width: auto; filter: brightness(0) invert(1); }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 20px; margin-bottom: 28px;
  background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.3);
  border-radius: 50px; font-size: 13px; color: rgba(255,255,255,.9);
  letter-spacing: 1px; backdrop-filter: blur(8px);
}
.badge-pulse {
  width: 8px; height: 8px; background: var(--accent);
  border-radius: 50%; animation: pulse 2s infinite;
  box-shadow: 0 0 0 0 rgba(245,158,11,.5);
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(245,158,11,.5); }
  70%  { box-shadow: 0 0 0 8px rgba(245,158,11,0); }
  100% { box-shadow: 0 0 0 0 rgba(245,158,11,0); }
}
.hero-title {
  font-size: clamp(2.8rem, 6vw, 5rem); font-weight: 800;
  color: #fff; line-height: 1.1; margin-bottom: 22px; letter-spacing: -1px;
}
.hero-desc { font-size: 17px; color: rgba(255,255,255,.8); margin-bottom: 40px; line-height: 1.8; }
.hero-desc b { color: var(--accent); font-weight: 700; }
.hero-btns { display: flex; gap: 14px; justify-content: center; margin-bottom: 60px; flex-wrap: wrap; }
.hero-stats {
  display: flex; align-items: center; justify-content: center;
  gap: 0; flex-wrap: wrap;
  background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.2);
  border-radius: var(--radius-lg); padding: 28px 40px; backdrop-filter: blur(12px);
}
.stat-item { padding: 0 36px; text-align: center; }
.stat-num { font-size: 2.6rem; font-weight: 800; color: var(--accent); line-height: 1; margin-bottom: 4px; }
.stat-lbl { font-size: 13px; color: rgba(255,255,255,.7); letter-spacing: .5px; }
.stat-sep { width: 1px; height: 48px; background: rgba(255,255,255,.2); }
.hero-scroll-hint {
  position: absolute; bottom: 36px; left: 50%; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  color: rgba(255,255,255,.5); font-size: 12px; z-index: 2;
}
.scroll-mouse {
  width: 24px; height: 38px; border: 1.5px solid rgba(255,255,255,.4);
  border-radius: 12px; display: flex; justify-content: center; padding: 6px;
}
.scroll-wheel { width: 3px; height: 6px; background: rgba(255,255,255,.6); border-radius: 2px; animation: scrollAnim 2s infinite; }
@keyframes scrollAnim { 0%{transform:translateY(0);opacity:1} 100%{transform:translateY(12px);opacity:0} }

/* ===== 关于我们 ===== */
.about { background: var(--white); }
.about-grid { display: grid; grid-template-columns: 1fr 1.3fr; gap: 64px; align-items: center; }
.about-img-col { position: relative; }
.about-img-wrap {
  background: linear-gradient(135deg, #dbeafe 0%, #eff6ff 100%);
  border-radius: var(--radius-lg);
  padding: 48px; display: flex; align-items: center; justify-content: center;
  min-height: 320px; position: relative;
  box-shadow: var(--shadow);
}
.about-logo-disp { max-width: 280px; height: auto; }
.float-card {
  position: absolute;
  background: var(--white); border-radius: var(--radius);
  padding: 14px 18px; box-shadow: var(--shadow);
  display: flex; align-items: center; gap: 12px;
  transition: var(--transition);
}
.float-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.about-badge-1 { bottom: -16px; left: -20px; }
.about-badge-2 { top: -16px; right: -20px; }
.fc-icon { font-size: 24px; }
.fc-num { font-size: 1.4rem; font-weight: 800; color: var(--primary); line-height: 1; }
.fc-lbl { font-size: 12px; color: var(--muted); }
.about-lead { font-size: 17px; color: var(--dark); margin-bottom: 16px; line-height: 1.8; }
.about-lead strong { color: var(--primary); }
.about-text { font-size: 15px; color: var(--body); line-height: 1.8; margin-bottom: 32px; }
.features-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.feat-item {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 16px; background: var(--light);
  border: 1px solid var(--border); border-radius: var(--radius);
  transition: var(--transition);
}
.feat-item:hover { border-color: var(--primary); background: #eff6ff; transform: translateY(-2px); }
.feat-ico {
  width: 38px; height: 38px; min-width: 38px;
  background: rgba(26,86,219,.1); border-radius: 10px;
  display: flex; align-items: center; justify-content: center; color: var(--primary);
}
.feat-ico svg { width: 18px; height: 18px; }
.feat-item > div:last-child { display: flex; flex-direction: column; gap: 3px; }
.feat-item strong { font-size: 14px; color: var(--dark); }
.feat-item span { font-size: 12px; color: var(--muted); line-height: 1.5; }

/* ===== 产品服务 ===== */
.products { background: var(--section-alt); }
.tab-bar {
  display: flex; gap: 6px; justify-content: center; margin-bottom: 48px;
  background: var(--white); border: 1px solid var(--border);
  border-radius: 50px; padding: 6px; width: fit-content; margin: 0 auto 48px;
  box-shadow: var(--shadow-sm);
}
.tab-btn {
  padding: 10px 28px; background: transparent;
  color: var(--muted); border: none; border-radius: 50px;
  font-size: 14px; font-weight: 500; cursor: pointer; transition: var(--transition);
}
.tab-btn.active { background: var(--gradient); color: #fff; font-weight: 600; box-shadow: 0 4px 12px rgba(26,86,219,.3); }
.tab-btn:hover:not(.active) { color: var(--primary); background: rgba(26,86,219,.06); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

.prod-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 18px; }
/* 最后一行只有1个卡片时居中 */
.prod-grid > .prod-card:nth-last-child(1):nth-child(4n+1) {
  grid-column: 2 / 4;
  max-width: calc(50% - 9px);
  justify-self: center;
}
.prod-grid > .prod-card:nth-last-child(1):nth-child(4n+1) .prod-icon {
  height: 180px;
}
.prod-card {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 18px;
  transition: var(--transition); position: relative; overflow: hidden;
}
.prod-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.prod-featured { border: 2px solid var(--accent); }
.feat-ribbon {
  position: absolute; top: 18px; right: 18px;
  padding: 4px 12px; background: var(--gradient-warm);
  border-radius: 20px; font-size: 11px; font-weight: 700; color: #fff;
}
.prod-icon {
  width: 100%; height: 150px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 12px; overflow: hidden;
  background: var(--gray-50);
}
.prod-icon img {
  width: 100%; height: 100%; object-fit: cover;
  object-position: center 10%;
  transition: transform 0.4s ease;
}
.prod-card:hover .prod-icon img { transform: scale(1.05); }
.prod-icon svg { width: 34px; height: 34px; }
.prod-icon img.show-full { object-fit: contain; padding: 4px; }
.ic-blue   { background: rgba(26,86,219,.06);  color: var(--primary); }
.ic-purple { background: rgba(139,92,246,.06); color: #7c3aed; }
.ic-orange { background: rgba(245,158,11,.06); color: #d97706; }
.ic-teal   { background: rgba(20,184,166,.06); color: #0d9488; }
.ic-green  { background: rgba(16,185,129,.06); color: #059669; }
.ic-pink   { background: rgba(236,72,153,.06); color: #db2777; }
.prod-card h3 { font-size: 15px; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
.prod-card p  { font-size: 12px; color: var(--muted); line-height: 1.6; margin-bottom: 12px; }
.prod-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.prod-tags span {
  padding: 3px 10px; border-radius: 20px; font-size: 11px; font-weight: 500;
  background: rgba(26,86,219,.08); color: var(--primary);
  border: 1px solid rgba(26,86,219,.15);
}

/* 服务流程 */
.flow-steps {
  display: flex; align-items: stretch; gap: 4px; flex-wrap: wrap;
  background: var(--white); border-radius: var(--radius-lg);
  box-shadow: var(--shadow); overflow: hidden;
}
.flow-step {
  flex: 1; min-width: 170px; padding: 32px 20px;
  text-align: center; border-right: 1px solid var(--border);
  transition: var(--transition);
}
.flow-step:last-child { border-right: none; }
.flow-step:hover { background: #eff6ff; }
.flow-arr { display: flex; align-items: center; color: var(--primary); font-size: 18px; opacity: .4; padding: 0; }
.step-num { font-size: 2.4rem; font-weight: 800; color: var(--primary); opacity: .25; line-height: 1; margin-bottom: 14px; }
.flow-step h3 { font-size: 16px; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
.flow-step p  { font-size: 13px; color: var(--muted); line-height: 1.6; }

/* 技术优势 */
.tech-grid { display: grid; grid-template-columns: repeat(2,1fr); gap: 20px; }
.tech-card {
  padding: 32px; background: var(--white);
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  border-top: 4px solid var(--primary); transition: var(--transition);
}
.tech-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.tech-tag {
  display: inline-block; padding: 4px 12px; margin-bottom: 14px;
  background: rgba(26,86,219,.08); color: var(--primary);
  border-radius: 20px; font-size: 11px; font-weight: 700; letter-spacing: 1px;
}
.tech-card h3 { font-size: 20px; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.tech-card p  { font-size: 14px; color: var(--muted); line-height: 1.7; margin-bottom: 14px; }
.tech-card ul { padding-left: 16px; }
.tech-card ul li { font-size: 13px; color: var(--body); margin-bottom: 4px; }

/* ===== 工程案例 ===== */
.cases { background: var(--white); }
.cases-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; }
.case-card {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden; transition: var(--transition);
}
.case-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.case-wide { grid-column: span 3; display: grid; grid-template-columns: 1fr 1.5fr; }
.case-img-wrap { position: relative; overflow: hidden; }
.case-img-wrap img { width: 100%; height: 200px; object-fit: cover; transition: transform .5s ease; }
.case-wide .case-img-wrap img { height: 100%; min-height: 220px; }
.case-card:hover .case-img-wrap img { transform: scale(1.05); }
.case-badge {
  position: absolute; bottom: 12px; right: 12px;
  padding: 4px 12px; background: var(--accent);
  color: #fff; font-size: 12px; font-weight: 700;
  border-radius: 20px; box-shadow: 0 2px 8px rgba(0,0,0,.2);
}
.case-body { padding: 22px; }
.case-cat {
  display: inline-block; padding: 3px 10px; margin-bottom: 10px;
  background: rgba(26,86,219,.08); color: var(--primary);
  border-radius: 20px; font-size: 11px; font-weight: 600;
}
.case-body h3 { font-size: 16px; font-weight: 700; color: var(--dark); margin-bottom: 8px; line-height: 1.4; }
.case-body p  { font-size: 13px; color: var(--muted); line-height: 1.6; margin-bottom: 14px; }
.case-meta { display: flex; gap: 16px; flex-wrap: wrap; }
.case-meta span { font-size: 12px; color: var(--muted); }
.cases-more { text-align: center; margin-top: 48px; }

/* ===== 联系我们 ===== */
.contact { background: var(--section-alt); }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: start; }
.contact-logo-wrap { margin-bottom: 20px; }
.contact-logo { height: 56px; width: auto; }
.contact-info h3 { font-size: 18px; font-weight: 700; color: var(--dark); margin-bottom: 28px; padding-bottom: 16px; border-bottom: 1px solid var(--border); }
.info-list { display: flex; flex-direction: column; gap: 18px; margin-bottom: 32px; }
.info-item { display: flex; align-items: center; gap: 16px; }
.info-ico {
  width: 46px; height: 46px; min-width: 46px;
  background: rgba(26,86,219,.08); border: 1px solid rgba(26,86,219,.15);
  border-radius: 12px; display: flex; align-items: center; justify-content: center;
  font-size: 20px; transition: var(--transition);
}
.info-item:hover .info-ico { background: var(--gradient); box-shadow: 0 4px 12px rgba(26,86,219,.3); }
.info-lbl { font-size: 12px; color: var(--muted); margin-bottom: 2px; }
.info-val { font-size: 15px; color: var(--dark); font-weight: 500; }
.cov-title { font-size: 12px; color: var(--muted); margin-bottom: 10px; font-weight: 600; letter-spacing: 1px; text-transform: uppercase; }
.cov-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.cov-tags span {
  padding: 6px 14px; background: var(--white); border: 1px solid var(--border);
  border-radius: 20px; font-size: 13px; color: var(--body); transition: var(--transition);
}
.cov-tags span:hover { border-color: var(--primary); color: var(--primary); background: #eff6ff; }

.contact-form-wrap {
  background: var(--white); border-radius: var(--radius-lg);
  padding: 36px; box-shadow: var(--shadow);
  border: 1px solid var(--border);
}
.cform h3 { font-size: 20px; font-weight: 700; color: var(--dark); margin-bottom: 28px; }
.fg { margin-bottom: 18px; }
.fg label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 8px; font-weight: 500; }
.fg input, .fg select, .fg textarea {
  width: 100%; padding: 12px 16px;
  background: var(--light); border: 1.5px solid var(--border);
  border-radius: var(--radius); color: var(--dark); font-size: 14px; font-family: inherit;
  transition: var(--transition); outline: none;
}
.fg input:focus, .fg select:focus, .fg textarea:focus {
  border-color: var(--primary); background: #eff6ff;
  box-shadow: 0 0 0 3px rgba(26,86,219,.1);
}
.fg textarea { resize: vertical; min-height: 100px; }
.fg select option { background: #fff; color: var(--dark); }

/* ===== 页脚 ===== */
.footer { background: var(--dark); color: rgba(255,255,255,.7); }
.footer .container { padding-top: 60px; padding-bottom: 32px; }
.foot-main {
  display: grid; grid-template-columns: 1.5fr 1fr; gap: 60px;
  padding-bottom: 40px; border-bottom: 1px solid rgba(255,255,255,.1); margin-bottom: 28px;
}
.foot-logo { height: 44px; width: auto; filter: brightness(0) invert(1); margin-bottom: 16px; }
.foot-tag { font-size: 16px; color: var(--accent); font-weight: 600; margin-bottom: 10px; }
.foot-desc { font-size: 14px; line-height: 1.7; color: rgba(255,255,255,.5); }
.foot-cols { display: grid; grid-template-columns: repeat(3,1fr); gap: 32px; }
.foot-col h4 { font-size: 14px; font-weight: 700; color: #fff; margin-bottom: 16px; letter-spacing: .5px; }
.foot-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.foot-col li, .foot-col a { font-size: 13px; color: rgba(255,255,255,.5); transition: var(--transition); }
.foot-col a:hover { color: var(--accent); }
.foot-bottom { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 6px; }
.foot-bottom p { font-size: 13px; color: rgba(255,255,255,.35); }

/* ===== 滚动进度 ===== */
.scroll-progress {
  position: fixed; top: 70px; left: 0; height: 3px;
  background: var(--gradient); z-index: 999; width: 0%; transition: width .1s;
}

/* ===== 淡入动画 ===== */
.reveal {
  opacity: 0; transform: translateY(28px);
  transition: opacity .7s ease, transform .7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== Toast ===== */
.toast {
  position: fixed; bottom: 36px; right: 36px;
  padding: 14px 22px; background: var(--dark);
  border-radius: var(--radius); color: #fff; font-size: 14px;
  box-shadow: var(--shadow-lg); z-index: 9999;
  transform: translateY(20px); opacity: 0; transition: var(--transition);
  border-left: 4px solid var(--accent2);
}
.toast.show { transform: translateY(0); opacity: 1; }

/* ===== 移动端导航抽屉 ===== */
.nav-drawer {
  display: none; position: fixed;
  top: 70px; left: 0; right: 0;
  background: rgba(255,255,255,.98); backdrop-filter: blur(20px);
  box-shadow: var(--shadow); z-index: 999;
  padding: 16px; flex-direction: column; gap: 4px;
  border-top: 1px solid var(--border);
}
.nav-drawer.open { display: flex; }
.nav-drawer .nav-link { color: var(--body) !important; padding: 12px 16px; border-radius: 8px; }
.nav-drawer .nav-link:hover { background: #eff6ff; color: var(--primary) !important; }

/* ===== 响应式 ===== */
@media(max-width:1024px){
  .about-grid { grid-template-columns:1fr; }
  .about-img-col { display: none; }
  .prod-grid { grid-template-columns: repeat(2,1fr); }
  .prod-grid > .prod-card:nth-last-child(1):nth-child(4n+1) {
    grid-column: auto; max-width: none; justify-self: auto;
  }
  .prod-grid > .prod-card:nth-last-child(1):nth-child(4n+1) .prod-icon { height: 150px; }
  .cases-grid { grid-template-columns: repeat(2,1fr); }
  .case-wide { grid-column: span 2; }
  .tech-grid { grid-template-columns: 1fr; }
}

@media(max-width:768px){
  .nav-links, .nav-cta { display: none; }
  .nav-toggle { display: block; }
  .hero-stats { padding: 20px; gap: 16px; }
  .stat-item { padding: 0 16px; }
  .stat-sep { display: none; }
  .container { padding: 0 20px; }
  .section { padding: 60px 0; }
  .cases-grid { grid-template-columns: 1fr; }
  .case-wide { grid-column: span 1; display: block; }
  .contact-grid { grid-template-columns: 1fr; gap: 36px; }
  .foot-main { grid-template-columns: 1fr; gap: 40px; }
  .foot-cols { grid-template-columns: repeat(2,1fr); }
  .foot-bottom { flex-direction: column; }
  .flow-steps { flex-direction: column; }
  .flow-arr { display: none; }
  .flow-step { border-right: none; border-bottom: 1px solid var(--border); }
  .flow-step:last-child { border-bottom: none; }
  .hero-btns { flex-direction: column; align-items: center; }

  /* 产品系列 - 竖屏双列紧凑布局 */
  .prod-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }
  /* 覆盖桌面端的最后一行居中规则 */
  .prod-grid > .prod-card:nth-last-child(1):nth-child(4n+1) {
    grid-column: auto;
    max-width: none;
    justify-self: auto;
  }
  .prod-grid > .prod-card:nth-last-child(1):nth-child(4n+1) .prod-icon {
    height: 90px;
  }
  .prod-card {
    padding: 10px;
    border-radius: var(--radius);
  }
  .prod-icon {
    height: 90px;
    border-radius: 8px;
    margin-bottom: 8px;
  }
  .prod-card h3 { font-size: 13px; margin-bottom: 4px; }
  .prod-card p { font-size: 11px; line-height: 1.5; margin-bottom: 8px;
    display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
  .prod-tags { gap: 4px; }
  .prod-tags span { font-size: 10px; padding: 2px 8px; }
  .prod-featured { grid-column: auto; }
  .prod-featured .prod-icon { height: 90px; }
  .feat-ribbon { top: 10px; right: 10px; }
}

@media(max-width:480px){
  .features-grid { grid-template-columns: 1fr; }
  .tab-bar { flex-direction: column; border-radius: var(--radius); width: 100%; }
  .tab-btn { border-radius: 8px; text-align: center; }
  .hero-title { font-size: 2.4rem; }
}