/* ========================================
   大连旭鼎环保科技有限公司 - 官网公共样式
   ======================================== */

/* --- CSS Variables --- */
:root {
  /* 背景色 */
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-card: #1c2128;
  --bg-elevated: #21262d;

  /* 品牌色 */
  --brand-yellow: #f5d020;
  --brand-yellow-dark: #e6c419;
  --brand-yellow-glow: #fff8d6;
  --accent-blue: #00d4ff;
  --accent-blue-dim: rgba(0, 212, 255, 0.15);

  /* 文字色 */
  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --text-muted: #6e7681;

  /* 边框 */
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(0, 212, 255, 0.3);

  /* 字体 */
  --font-heading: 'Noto Serif SC', 'Noto Sans SC', serif;
  --font-body: 'Noto Sans SC', sans-serif;
  --font-en: 'Space Grotesk', sans-serif;

  /* 间距 */
  --section-padding: 180px 0;
  --container-width: 1200px;

  /* 动效 */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-fast: 0.3s var(--ease-out);
  --transition-normal: 0.6s var(--ease-out);
}

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

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

ul, ol {
  list-style: none;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* --- Typography --- */
h1, h2, h3 {
  font-family: var(--font-heading);
  line-height: 1.25;
  color: var(--text-primary);
}

h4, h5, h6 {
  font-family: var(--font-body);
  line-height: 1.4;
  color: var(--text-primary);
}

h1 { font-size: clamp(3rem, 6vw, 4.8rem); font-weight: 700; letter-spacing: -0.01em; }
h2 { font-size: clamp(2.1rem, 3.8vw, 3rem); font-weight: 700; letter-spacing: -0.005em; }
h3 { font-size: clamp(1.4rem, 2.2vw, 1.7rem); font-weight: 600; }
h4 { font-size: 1.15rem; font-weight: 600; }

p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.8;
}

.en-text {
  font-family: var(--font-en);
}

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 40px;
}

.section {
  padding: var(--section-padding);
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 90px;
}

.section-header h2 {
  margin-bottom: 18px;
}

.section-header p {
  max-width: 600px;
  margin: 0 auto;
  font-size: 1.1rem;
}

.section-label {
  font-family: var(--font-en);
  font-size: 0.75rem;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--accent-blue);
  margin-bottom: 18px;
  display: block;
  font-weight: 500;
}

/* --- Buttons (苹果药丸形) --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 34px;
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  border-radius: 980px;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--brand-yellow);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background: var(--brand-yellow-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(245, 208, 32, 0.3);
}

.btn-outline {
  border: 1px solid var(--accent-blue);
  color: var(--accent-blue);
  background: transparent;
}

.btn-outline:hover {
  background: var(--accent-blue-dim);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 212, 255, 0.15);
}

.btn-ghost {
  color: var(--text-primary);
  padding: 12px 0;
}

.btn-ghost::after {
  content: '';
  position: absolute;
  bottom: 8px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--brand-yellow);
  transition: width var(--transition-fast);
}

.btn-ghost:hover::after {
  width: 100%;
}

/* --- Cards --- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 40px;
  transition: all var(--transition-fast);
}

.card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

/* --- Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 18px 0;
  background: rgba(245, 245, 247, 0.75);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: all var(--transition-fast);
}

.navbar.scrolled {
  padding: 12px 0;
  background: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: #1d1d1f;
  letter-spacing: 0.08em;
}

.nav-logo span {
  color: #c8901a;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 42px;
}

.nav-links a {
  font-size: 0.85rem;
  font-weight: 400;
  letter-spacing: 0.14em;
  color: #515154;
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: #c8901a;
  transition: width var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
  color: #1d1d1f;
}

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

.nav-cta {
  padding: 9px 22px !important;
  font-size: 0.88rem !important;
  border-color: rgba(29, 29, 31, 0.25) !important;
  color: #1d1d1f !important;
}

.nav-cta:hover {
  border-color: #1d1d1f !important;
  background: rgba(29, 29, 31, 0.05) !important;
  box-shadow: none !important;
}

/* Hamburger */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
}

.nav-hamburger span {
  width: 24px;
  height: 2px;
  background: #1d1d1f;
  transition: all var(--transition-fast);
}

/* --- Footer --- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 60px;
  margin-bottom: 40px;
}

.footer-brand p {
  margin-top: 16px;
  font-size: 0.9rem;
}

.footer-col h4 {
  font-size: 1rem;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.footer-col a {
  display: block;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 12px;
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- Light Sections --- */
.section-light {
  background: #ffffff;
  color: #1d1d1f;
}

.section-light h1,
.section-light h2,
.section-light h3,
.section-light h4 {
  color: #1d1d1f;
}

.section-light p {
  color: #6e6e73;
}

.section-light .section-label {
  color: #0090b3;
}

.section-light .glow-line {
  background: linear-gradient(90deg, var(--brand-yellow), #0090b3);
}

.section-gray {
  background: #f5f5f7;
  color: #1d1d1f;
}

.section-gray h1,
.section-gray h2,
.section-gray h3,
.section-gray h4 {
  color: #1d1d1f;
}

.section-gray p {
  color: #6e6e73;
}

.section-gray .section-label {
  color: #0090b3;
}

.section-gray .glow-line {
  background: linear-gradient(90deg, var(--brand-yellow), #0090b3);
}

/* Light cards */
.section-light .card,
.section-gray .card {
  background: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}

.section-light .card:hover,
.section-gray .card:hover {
  border-color: rgba(0, 144, 179, 0.3);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

/* --- Utilities --- */
.text-yellow { color: var(--brand-yellow); }
.text-blue { color: var(--accent-blue); }
.text-center { text-align: center; }

.glow-line {
  width: 40px;
  height: 2px;
  background: var(--brand-yellow);
  margin: 26px auto 0;
  border-radius: 1px;
  opacity: 0.7;
}

/* Scroll progress bar */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--brand-yellow), var(--accent-blue));
  z-index: 9999;
  transition: width 0.1s linear;
}

/* Oil shimmer effect */
.shimmer {
  position: relative;
  overflow: hidden;
}

.shimmer::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 60%;
  height: 100%;
  background: linear-gradient(
    120deg,
    transparent,
    rgba(245, 208, 32, 0.04),
    rgba(245, 208, 32, 0.07),
    rgba(245, 208, 32, 0.04),
    transparent
  );
  transition: none;
}

.shimmer:hover::after {
  animation: shimmerSlide 0.8s ease forwards;
}

@keyframes shimmerSlide {
  0% { left: -100%; }
  100% { left: 150%; }
}

/* --- Responsive --- */
@media (max-width: 768px) {
  :root {
    --section-padding: 80px 0;
  }

  .container {
    padding: 0 20px;
  }

  .nav-links {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.98);
    flex-direction: column;
    justify-content: center;
    gap: 30px;
  }

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

  .nav-links a {
    font-size: 1.3rem;
    color: #1d1d1f;
  }

  .nav-hamburger {
    display: flex;
    z-index: 1001;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 10px;
    text-align: center;
  }

  .section-header {
    margin-bottom: 50px;
  }
}