@import url("../fonts/inter.css");

:root {
  /* Colors */
  --brand-primary: #000000;
  --brand-on-primary: #ffffff;
  --surface-base: #f9fafb;
  --surface-card: #ffffff;
  --surface-muted: #f4f4f5;
  --text-primary: #101112;
  --text-secondary: #71717a;
  --text-strong: #18181b;
  --border-subtle: rgba(0, 0, 0, 0.06);
  --border-default: #e4e4e7;
  --state-focus-ring: #a1a1aa;
  --state-error: #dc2626;
  --state-error-bg: #fff7f7;
  --neutral-50: #fafafa;
  --neutral-100: #f4f4f5;
  --neutral-200: #e4e4e7;
  --neutral-300: #d4d4d8;
  --neutral-400: #9f9fa9;
  --neutral-500: #71717a;
  --neutral-600: #52525c;
  --neutral-700: #3f3f46;
  --neutral-800: #27272a;
  --neutral-900: #18181b;

  /* Typography */
  --font-family-base: "Inter", "SF Pro Display", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-lineHeight-base: 1.6;
  --font-letterSpacing-base: -0.015em;
  --font-letterSpacing-heading: -0.02em;

  /* Radii */
  --radius-pill: 9999px;
  --radius-xs: 0.55rem;
  --radius-sm: 0.65rem;
  --radius-md: 0.85rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;
  --radius-card: 16px;

  /* Shadows */
  --shadow-card: 0 0 0 1px rgba(0,0,0,0.03), 0 2px 4px rgba(0,0,0,0.05), 0 12px 24px rgba(0,0,0,0.05);
  --shadow-floating: 0 20px 40px -15px rgba(0,0,0,0.08), 0 8px 16px -8px rgba(0,0,0,0.05);
  --shadow-button-primary: 0 20px 60px -30px rgba(0, 0, 0, 0.12);
  --shadow-hover-card: 0 20px 60px -10px rgba(0, 0, 0, 0.08);

  /* Layout */
  --container: min(80rem, calc(100% - 2.5rem)); /* 80rem = 1280px, 2.5rem = 40px for padding */
  --section-padding-y: clamp(4rem, 8vw, 6rem);

  /* Transitions */
  --transition-base: 220ms ease;
}

* {
  box-sizing: border-box;
}

html, body {
  overflow-y: scroll;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  font-family: var(--font-family-base);
  color: var(--text-primary);
  background: linear-gradient(180deg, var(--surface-base) 0%, var(--neutral-50) 100%);
  line-height: var(--font-lineHeight-base);
  letter-spacing: var(--font-letterSpacing-base);
}

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

a {
  color: inherit;
  text-decoration: none;
}

button,
a.button-link,
.nav-link {
  font: inherit;
  cursor: pointer;
  transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base), color var(--transition-base), border-color var(--transition-base);
}

button {
  border: 0;
  background: none;
}

button:focus-visible,
.button-link:focus-visible,
.nav-link:focus-visible,
.mobile-nav-link:focus-visible,
.faq-trigger:focus-visible,
.brand-mark:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px #fff, 0 0 0 4px var(--state-focus-ring);
}

.page-shell {
  position: relative;
}

.container {
  width: var(--container);
  margin: 0 auto;
  padding-left: 1.25rem; /* layout.container.paddingX */
  padding-right: 1.25rem; /* layout.container.paddingX */
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  padding: 1.5rem 0;
  transition: background-color var(--transition-base), box-shadow var(--transition-base), backdrop-filter var(--transition-base);
}

.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand-logo-img {
  height: 80px;
  width: auto;
  object-fit: contain;
}

.brand-copy {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.brand-name {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: var(--font-letterSpacing-heading);
  color: var(--text-strong);
}

.brand-subtitle {
  color: var(--text-secondary);
  font-size: 0.8rem;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-link {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
}

.nav-link:hover,
.nav-link.is-active {
  color: var(--text-strong);
  background: var(--surface-muted);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.button-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 24px;
  border-radius: var(--radius-pill);
  font-weight: 600; /* semibold */
  white-space: nowrap;
}

.button-link:hover {
  transform: translateY(-1px);
}

.button-link.primary {
  color: var(--brand-on-primary);
  background: var(--brand-primary);
  box-shadow: var(--shadow-button-primary);
}

.button-link.primary:hover {
  background: var(--neutral-800);
}

.button-link.secondary {
  color: var(--text-strong);
  background: var(--neutral-100);
  border: 1px solid var(--border-default);
}

.button-link.secondary:hover {
  background: var(--neutral-200);
}

.button-link.ghost {
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid transparent;
}

.button-link.ghost:hover {
  background: var(--neutral-50);
  color: var(--text-primary);
}

.button-link.small {
  min-height: 40px;
  padding: 0 18px;
  font-size: 0.9rem;
}

.mobile-nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  color: var(--text-primary);
  background: var(--surface-muted);
}

.mobile-panel {
  display: none;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-pill);
  background: var(--surface-card);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
}

.eyebrow i {
  color: var(--text-secondary);
}

.section {
  padding: var(--section-padding-y) 0;
}

.section-heading {
  max-width: var(--container-narrow, 48rem); /* Use 48rem for narrow content */
  margin-bottom: 2.5rem;
}

.section-heading.centered {
  text-align: center;
  margin-left: auto;
  margin-right: auto;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 0.8rem;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
}

.section-kicker i {
  color: var(--text-secondary);
}

.section-heading h2 {
  margin: 0 0 0.8rem;
  font-size: clamp(2.25rem, 5vw, 3.75rem); /* font.size.display */
  line-height: 1.1;
  letter-spacing: var(--font-letterSpacing-heading);
  font-weight: 800; /* extrabold */
}

.section-heading p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
}

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

.grid-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  position: relative;
  padding: 32px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-card);
  background: var(--surface-card);
  box-shadow: var(--shadow-card);
}

.card.soft {
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 0 0 1px rgba(0, 0, 0, 0.06);
}

.card h3,
.card h4 {
  margin: 0 0 12px;
  font-size: 1.25rem; /* font.size.600 */
  letter-spacing: var(--font-letterSpacing-heading);
  font-weight: 700; /* bold */
  color: var(--text-strong);
}

.card p {
  margin: 0;
  color: var(--text-secondary);
  line-height: 1.6;
}

.icon-tile {
  width: 56px;
  height: 56px;
  display: grid;
  place-items: center;
  margin-bottom: 20px;
  border-radius: var(--radius-md);
  color: var(--brand-primary);
  background: var(--surface-muted);
}

.pill-list,
.list-reset {
  list-style: none;
  padding: 0;
  margin: 0;
}

.pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.pill-list li {
  padding: 8px 12px;
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  background: var(--surface-muted);
  font-size: 0.9rem;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px;
}

.metric-item {
  padding: 24px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--surface-card);
  box-shadow: var(--shadow-card);
}

.metric-value {
  margin: 0 0 10px;
  color: var(--text-strong);
  font-size: clamp(2.25rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: var(--font-letterSpacing-heading);
}

.metric-label {
  margin: 0;
  color: var(--text-secondary);
  line-height: 1.6;
}

.quote-box {
  padding: 28px;
  border-left: 4px solid var(--brand-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--surface-card);
  box-shadow: var(--shadow-card);
  color: var(--text-secondary);
  line-height: 1.7;
}

.quote-box strong {
  color: var(--text-primary);
}

.page-banner {
  padding: 5rem 0 3rem; /* layout.hero.paddingTop, slightly less bottom */
}

.page-banner-card {
  position: relative;
  padding: 3rem; /* Adjusted for new style */
  overflow: hidden;
  border-radius: var(--radius-xl);
  color: var(--brand-on-primary);
  background: linear-gradient(180deg, var(--neutral-900) 0%, var(--brand-primary) 100%); /* Darker background */
  box-shadow: 0 28px 56px rgba(0, 0, 0, 0.2);
}

.page-banner-card::before,
.page-banner-card::after {
  content: "";
  position: absolute;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
}

.page-banner-card::before {
  width: 320px;
  height: 320px;
  top: -100px;
  right: -60px;
}

.page-banner-card::after {
  width: 200px;
  height: 200px;
  bottom: -80px;
  left: -30px;
}

.page-banner-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr); /* Adjusted ratio */
  gap: 36px;
  align-items: center;
}

.page-banner-copy h1 {
  margin: 1rem 0 1.2rem;
  font-size: clamp(2.75rem, 5vw, 4rem); /* font.size.display */
  line-height: 1.05;
  letter-spacing: var(--font-letterSpacing-heading);
  font-weight: 800;
}

.page-banner-copy p {
  margin: 0;
  max-width: 680px;
  color: rgba(255, 255, 255, 0.7);
  font-size: 1.15rem;
  line-height: 1.7;
}

.page-banner-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 2rem;
}

.page-banner-aside {
  display: grid;
  gap: 16px;
}

.aside-panel {
  padding: 20px 22px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
}

.aside-panel h3 {
  margin: 0 0 8px;
  font-size: 1rem;
  color: var(--brand-on-primary);
}

.aside-panel p {
  margin: 0;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.6;
}

.cta-panel {
  padding: 3rem;
  border-radius: var(--radius-xl);
  background: linear-gradient(180deg, var(--neutral-900) 0%, var(--brand-primary) 100%);
  color: var(--brand-on-primary);
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.15);
}

.cta-panel h2 {
  margin: 0 0 1rem;
  font-size: clamp(2.25rem, 5vw, 3rem);
  line-height: 1.1;
  letter-spacing: var(--font-letterSpacing-heading);
  font-weight: 800;
}

.cta-panel p {
  margin: 0 0 1.5rem;
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.7;
}

.cta-panel .button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.site-footer {
  padding: 2rem 0 3rem;
}

.footer-card {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: 24px;
  padding: 2rem;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-card);
  background: var(--surface-card);
  box-shadow: var(--shadow-card);
}

.footer-brand p,
.footer-meta p {
  margin: 0;
  color: var(--text-secondary);
  line-height: 1.7;
}

.footer-brand .brand-mark .brand-logo {
  background: var(--neutral-800);
}

.footer-meta {
  display: grid;
  gap: 14px;
}

.footer-meta strong {
  color: var(--text-primary);
}

.footer-copyright {
  margin-top: 2rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 500ms ease, transform 500ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive adjustments for 亮色现代极简 */
@media (max-width: 1080px) {
  .desktop-nav,
  .header-actions .button-link.secondary {
    display: none;
  }

  .mobile-nav-toggle {
    display: inline-grid;
    place-items: center;
  }

  .mobile-panel {
    display: none;
    margin-top: 14px;
    padding: 18px;
    border-radius: var(--radius-lg);
    background: var(--surface-card);
    border: 1px solid var(--border-default);
    box-shadow: var(--shadow-card);
  }

  .mobile-panel.is-open {
    display: grid;
    gap: 12px;
  }

  .mobile-nav-link {
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    color: var(--text-strong);
    background: var(--surface-muted);
    font-weight: 600;
  }

  .page-banner-inner,
  .footer-card {
    grid-template-columns: 1fr;
  }

  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .metric-strip {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-banner-copy h1 {
    font-size: clamp(2.25rem, 6vw, 3.5rem);
  }

  .page-banner-copy p {
    font-size: 1rem;
  }

  .page-banner-aside {
    display: grid; /* Ensure aside panels stack on mobile */
    gap: 16px;
  }
}

@media (max-width: 768px) {
  :root {
    --container: min(100% - 24px, 100%);
  }

  .site-header {
    padding: 1rem 0;
  }

  .header-inner {
    padding: 12px 14px;
  }

  .brand-subtitle {
    display: none;
  }

  .section {
    padding: 4rem 0;
  }

  .section-heading h2 {
    font-size: clamp(2rem, 8vw, 2.5rem);
  }

  .section-heading p {
    font-size: 0.95rem;
  }

  .grid-2,
  .grid-3,
  .grid-4,
  .metric-strip {
    grid-template-columns: 1fr;
  }

  .card,
  .page-banner-card,
  .cta-panel,
  .footer-card {
    padding: 24px;
  }

  .page-banner-actions,
  .cta-panel .button-group {
    flex-direction: column;
  }

  .button-link {
    width: 100%;
  }

  .cta-panel {
    padding: 2rem;
  }
}

@media (max-width: 480px) {
  .brand-logo {
    width: 36px;
    height: 36px;
  }
  .brand-name {
    font-size: 1rem;
  }
  .button-link.primary {
    min-height: 44px;
  }
  .eyebrow {
    font-size: 0.8rem;
    padding: 6px 10px;
  }
}