/* ============================================================
 * base.css — 全局基础样式（Cohere 体系：白底画布 / 扁平无重投影 / 细边框 / 大留白）
 * ============================================================ */

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

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: 1.5;
  letter-spacing: 0;
  color: var(--color-ink);
  background: var(--color-canvas);
  -webkit-font-smoothing: antialiased;
}

img, svg, video { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, textarea, select { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
h1, h2, h3, h4 { font-weight: 400; }

:focus-visible {
  outline: 2px solid var(--color-focus-blue);
  outline-offset: 2px;
  border-radius: var(--radius-xs);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- 版心 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-xl);
}
.container--narrow { max-width: var(--container-narrow); }

/* ---------- 分区 ---------- */
.section { padding-block: var(--space-section); }
.section--tight { padding-block: calc(var(--space-section) * 0.7); }
.section--stone { background: var(--color-soft-stone); }
.section--pale-blue { background: var(--color-pale-blue); }
.section--pale-green { background: var(--color-pale-green); }
.section--dark { background: var(--color-deep-green); color: var(--color-cta-on); }
.section--navy { background: var(--color-dark-navy); color: var(--color-cta-on); }

/* 大写 mono 眉标 */
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-mono-label);
  font-weight: 400;
  line-height: 1.4;
  letter-spacing: 0.28px;
  text-transform: uppercase;
  color: var(--color-slate);
  margin-bottom: var(--space-lg);
}
.section--dark .eyebrow, .section--navy .eyebrow { color: rgba(255, 255, 255, 0.62); }

/* 标题层级 */
.h-hero {
  font-family: var(--font-display);
  font-size: var(--fs-hero);
  line-height: var(--lh-hero);
  letter-spacing: var(--ls-hero);
  font-weight: 400;
}
.h-display {
  font-family: var(--font-display);
  font-size: var(--fs-section-display);
  line-height: 1.0;
  letter-spacing: -0.02em;
  font-weight: 400;
}
.h-section {
  font-size: var(--fs-section-heading);
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 400;
  font-family: var(--font-display);
}
.h-card {
  font-size: var(--fs-card-heading);
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 400;
}
.h-feature {
  font-size: var(--fs-feature-heading);
  line-height: 1.3;
  font-weight: 400;
}
.lead {
  font-size: var(--fs-body-lg);
  line-height: 1.4;
  color: var(--color-body-muted);
  max-width: 68ch;
}
.muted { color: var(--color-muted); }

/* 节头（眉标 + 标题 + 说明 + 可选链接） */
.section-head { margin-bottom: var(--space-xxl); }
.section-head .lead { margin-top: var(--space-lg); }
.section-head--split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: var(--space-xl);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  min-height: 44px;
  font-size: var(--fs-button);
  font-weight: 500;
  line-height: 1.71;
  border-radius: var(--radius-pill);
  padding: 12px 24px;
  transition: background-color .18s ease, color .18s ease, border-color .18s ease;
  white-space: nowrap;
}
.btn--primary { background: var(--color-cta); color: var(--color-cta-on); }
.btn--primary:hover { background: #000000; }
.btn--light { background: var(--color-canvas); color: var(--color-cta); }
.btn--light:hover { background: var(--color-soft-stone); }
.btn--outline {
  background: transparent;
  color: var(--color-cta);
  border: 1px solid var(--color-cta);
  border-radius: var(--radius-xl);
  padding: 6px 16px;
  min-height: 40px;
  font-weight: 400;
}
.btn--outline:hover { background: rgba(23, 23, 28, .06); }

/* 次级动作：下划线文字链接 */
.link-underline {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: var(--fs-body);
  color: var(--color-ink);
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 1px;
}
.link-underline:hover { color: var(--color-primary); }
.link-underline .arrow { transition: transform .18s ease; }
.link-underline:hover .arrow { transform: translateX(4px); }

/* 品牌蓝文字链接 */
.link-brand { color: var(--color-primary); }
.link-brand:hover { color: var(--color-primary-active); text-decoration: underline; text-underline-offset: 4px; }

/* ---------- 细线几何图标 ---------- */
.icon-line {
  width: 40px;
  height: 40px;
  stroke: var(--color-ink);
  stroke-width: 1.2;
  fill: none;
}
.section--dark .icon-line, .section--navy .icon-line { stroke: #ffffff; }

/* ---------- 全局 Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-card-border);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-xl);
  height: 64px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.brand img { width: 26px; height: auto; }
.brand__name { font-size: 17px; letter-spacing: -0.01em; white-space: nowrap; }
.brand__name small { color: var(--color-muted); font-size: 12px; margin-left: 6px; letter-spacing: 0.02em; }

.main-nav { display: flex; align-items: center; gap: var(--space-xl); }
.main-nav a {
  font-size: var(--fs-button);
  line-height: 1.71;
  color: var(--color-ink);
  padding: 6px 2px;
  position: relative;
}
.main-nav a:hover { color: var(--color-primary); }
.main-nav a[aria-current="page"] { color: var(--color-cta); }
.main-nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px;
  background: var(--color-cta);
  border-radius: var(--radius-full);
}
.header-cta { display: flex; align-items: center; gap: var(--space-lg); flex-shrink: 0; }

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
}
.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--color-cta);
  position: relative;
  transition: transform .2s ease;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }
body.nav-open .nav-toggle span { background: transparent; }
body.nav-open .nav-toggle span::before { transform: translateY(6px) rotate(45deg); }
body.nav-open .nav-toggle span::after { transform: translateY(-6px) rotate(-45deg); }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  align-items: center;
  font-size: var(--fs-caption);
  color: var(--color-muted);
  padding-block: var(--space-lg);
}
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb .sep { color: var(--color-hairline); }
.breadcrumb [aria-current="page"] { color: var(--color-ink); }

/* ---------- 页头横幅（内页 Hero） ---------- */
.page-hero { padding-block: calc(var(--space-section) * 0.9) var(--space-section); }
.page-hero .lead { margin-top: var(--space-xl); }
.page-hero__media {
  margin-top: var(--space-xxl);
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 21 / 9;
  background: var(--color-soft-stone);
}
.page-hero__media img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- 媒体卡 ---------- */
.media-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-soft-stone);
}
.media-card img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- 行业色点 ---------- */
.dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  margin-right: 8px;
  vertical-align: middle;
  background: var(--color-slate);
}
.dot--smart-home { background: var(--industry-smart-home); }
.dot--industrial { background: var(--industry-industrial); }
.dot--ev-charging { background: var(--industry-ev-charging); }
.dot--smart-agri { background: var(--industry-smart-agri); }
.dot--medical { background: var(--industry-medical); }
.dot--smart-lighting { background: var(--industry-smart-lighting); }
.dot--two-wheeler { background: var(--industry-two-wheeler); }

/* ---------- 标签 chips ---------- */
.chip {
  display: inline-flex;
  align-items: center;
  font-size: var(--fs-caption);
  line-height: 1.4;
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-hairline);
  color: var(--color-body-muted);
  background: transparent;
  transition: border-color .18s ease, color .18s ease;
}
a.chip:hover { border-color: var(--color-ink); color: var(--color-ink); }
.chip--active { background: var(--color-cta); border-color: var(--color-cta); color: var(--color-cta-on); }
.chip--coral { color: var(--color-coral); border-color: var(--color-coral); }
.chip--coral.chip--active { background: var(--color-coral); border-color: var(--color-coral); color: var(--color-cta); }

/* ---------- 表单 ---------- */
.form-card {
  background: var(--color-canvas);
  border-radius: var(--radius-lg);
  padding: var(--space-xxl);
  border: 1px solid var(--color-card-border);
}
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
}
.form-field { display: flex; flex-direction: column; gap: var(--space-xs); }
.form-field--full { grid-column: 1 / -1; }
.form-field label { font-size: var(--fs-caption); color: var(--color-body-muted); }
.form-field label .req { color: var(--color-error); margin-left: 2px; }
.form-field input,
.form-field textarea,
.form-field select {
  width: 100%;
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-xs);
  padding: 12px 16px;
  font-size: var(--fs-body);
  background: var(--color-canvas);
  transition: border-color .18s ease, box-shadow .18s ease;
}
.form-field textarea { resize: vertical; min-height: 120px; }
.form-field input:focus,
.form-field textarea:focus,
.form-field select:focus {
  outline: none;
  border-color: var(--color-form-focus);
  box-shadow: 0 0 0 1px var(--color-form-focus);
}
.form-field .error-msg {
  font-size: var(--fs-micro);
  color: var(--color-error);
  min-height: 16px;
}
.form-field input[aria-invalid="true"],
.form-field textarea[aria-invalid="true"] { border-color: var(--color-error); }
.hp-field { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }

.form-note { font-size: var(--fs-micro); color: var(--color-muted); line-height: 1.5; }
.form-consent { display: flex; gap: var(--space-sm); align-items: flex-start; font-size: var(--fs-caption); color: var(--color-body-muted); }
.form-consent a { color: var(--color-primary, #1b69cd); text-decoration: underline; text-underline-offset: 2px; }
.form-consent a:hover { color: var(--color-primary-active, #15529e); }
.form-consent input[type="checkbox"] {
  width: 15px;
  height: 15px;
  min-height: 0;
  min-width: 0;
  flex: 0 0 auto;
  padding: 0;
  margin-top: 3px;
  border: 1px solid var(--color-hairline);
  border-radius: 3px;
  accent-color: var(--color-primary, #1b69cd);
  cursor: pointer;
}

.form-feedback {
  display: none;
  border-radius: var(--radius-sm);
  padding: var(--space-lg);
  font-size: var(--fs-body);
  margin-top: var(--space-lg);
}
.form-feedback--ok { display: block; background: var(--color-pale-green); color: var(--color-deep-green); }
.form-feedback--err { display: block; background: #fdecec; color: var(--color-error); }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-cta);
  color: var(--color-cta-on);
  padding-top: calc(var(--space-section) * 0.8);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: var(--space-xxl);
  padding-bottom: var(--space-section);
}
.footer-brand .brand__name { color: #fff; }
.footer-brand p {
  margin-top: var(--space-lg);
  font-size: var(--fs-caption);
  color: var(--color-muted);
  max-width: 30ch;
  line-height: 1.6;
}
.footer-col h3 {
  font-size: var(--fs-mono-label);
  font-family: var(--font-mono);
  letter-spacing: 0.28px;
  text-transform: uppercase;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: var(--space-lg);
}
.footer-col ul { display: grid; gap: var(--space-md); }
.footer-col a { font-size: var(--fs-caption); color: var(--color-muted); }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-block: var(--space-xl);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-lg) var(--space-xxl);
  justify-content: space-between;
  align-items: center;
  font-size: var(--fs-micro);
  color: var(--color-muted);
}
.footer-bottom a { color: var(--color-muted); }
.footer-bottom a:hover { color: #fff; }

/* ---------- 回到顶部 ---------- */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: var(--color-cta);
  color: #fff;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 90;
}
.back-top.show { display: flex; }

/* ---------- 响应式 ---------- */
@media (max-width: 1023px) {
  .footer-grid { grid-template-columns: 1fr 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 767px) {
  :root { --space-section: 56px; }
  .nav-toggle { display: inline-flex; }
  .header-cta .btn { display: none; }
  .main-nav {
    position: fixed;
    inset: 64px 0 auto 0;
    background: var(--color-canvas);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-lg) var(--space-xl) var(--space-xl);
    border-bottom: 1px solid var(--color-hairline);
    transform: translateY(-120%);
    visibility: hidden;
    transition: transform .25s ease, visibility .25s ease;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
  }
  body.nav-open .main-nav { transform: translateY(0); visibility: visible; }
  .main-nav a { padding: var(--space-md) 0; border-bottom: 1px solid var(--color-card-border); font-size: var(--fs-body); }
  .main-nav a[aria-current="page"]::after { display: none; }
  .form-grid { grid-template-columns: 1fr; }
  .section-head--split { grid-template-columns: 1fr; align-items: start; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: var(--space-xl); }
}

@media (max-width: 424px) {
  .footer-grid { grid-template-columns: 1fr; }
  .container { padding-inline: var(--space-lg); }
}