/* ==========================================================================
   IMM TELECOM // SWISS-RATIONALIST PURE MONOCHROME ARCHITECTURAL SYSTEM
   Strict Optical Stark White (#ffffff) & Carbon Black Ink (#000000)
   Zero Color Tint, Zero Grayscale Softness, Zero AI Bot Icons
   Razor-sharp 1px Structural Datum Lines, Monospace Telemetry Rulers
   ========================================================================== */

:root {
  /* Stark Day Mode (Default) */
  --color-paper: #ffffff;
  --color-ink: #000000;
  --border-datum: 1px solid #000000;
  --border-datum-dashed: 1px dashed #000000;
  --border-hairline-subtle: 1px solid rgba(0, 0, 0, 0.15);
  --font-sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

[data-theme="dark"] {
  /* Dense Carbon Inversion (Dark Mode) */
  --color-paper: #000000;
  --color-ink: #ffffff;
  --border-datum: 1px solid #ffffff;
  --border-datum-dashed: 1px dashed #ffffff;
  --border-hairline-subtle: 1px solid rgba(255, 255, 255, 0.2);
}

/* Base Reset & Strict Zero-Radius Principles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important; /* Strict cardless / non-rounded Swiss aesthetic */
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-paper);
  color: var(--color-ink);
  line-height: 1.5;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
}

/* Telemetry & Blueprint Header Bar */
.telemetry-top-strip {
  border-bottom: var(--border-datum);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 6px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--color-paper);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.telemetry-live-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--color-ink);
  margin-right: 6px;
}

/* Typography Hierarchy */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-ink);
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

p {
  color: var(--color-ink);
}

.mono {
  font-family: var(--font-mono);
}

.container {
  width: 100%;
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Datum Grid System */
.datum-grid {
  display: grid;
  border-left: var(--border-datum);
  border-top: var(--border-datum);
}

.datum-cell {
  border-right: var(--border-datum);
  border-bottom: var(--border-datum);
  padding: 32px;
  position: relative;
  background: var(--color-paper);
}

/* 0ms Instant Optical Inversion on Hover */
.invert-on-hover {
  transition: none !important;
  cursor: pointer;
}

.invert-on-hover:hover {
  background-color: var(--color-ink) !important;
  color: var(--color-paper) !important;
  transition: none !important;
}

.invert-on-hover:hover * {
  color: var(--color-paper) !important;
  border-color: var(--color-paper) !important;
  transition: none !important;
}

.invert-on-hover:hover .telemetry-live-dot {
  background: var(--color-paper) !important;
}

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 500;
  background: var(--color-paper);
  border-bottom: var(--border-datum);
  height: 68px;
  display: flex;
  align-items: center;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--color-ink);
}

.brand-stamp {
  border: var(--border-datum);
  padding: 2px 7px;
  font-size: 0.8rem;
  background: var(--color-ink);
  color: var(--color-paper);
}

.nav-links {
  display: flex;
  align-items: center;
  list-style: none;
  border-left: var(--border-datum);
}

.nav-item {
  border-right: var(--border-datum);
}

.nav-link {
  display: block;
  padding: 22px 18px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--color-ink);
  transition: none;
}

.nav-link:hover {
  background: var(--color-ink);
  color: var(--color-paper);
}

.nav-link.highlight {
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 4px;
}

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

/* Day/Night Mode Switch (Stark Swiss Architectural Toggle) */
.theme-toggle-btn {
  background: var(--color-paper);
  border: var(--border-datum);
  border-right: none;
  height: 44px;
  padding: 0 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-ink);
  transition: none;
}

.theme-toggle-btn:hover {
  background: var(--color-ink);
  color: var(--color-paper);
}

.theme-toggle-btn:hover .theme-glyph {
  border-color: var(--color-paper);
  background: var(--color-paper);
}

.theme-glyph {
  width: 10px;
  height: 10px;
  border: 1px solid var(--color-ink);
  display: inline-block;
}

[data-theme="dark"] .theme-glyph {
  background: #ffffff;
}

/* Architectural Buttons */
.btn-swiss {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 28px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  border: var(--border-datum);
  cursor: pointer;
  min-height: 48px;
  transition: none;
}

.btn-solid {
  background: var(--color-ink);
  color: var(--color-paper);
}

.btn-solid:hover {
  background: var(--color-paper);
  color: var(--color-ink);
}

.btn-outline {
  background: var(--color-paper);
  color: var(--color-ink);
}

.btn-outline:hover {
  background: var(--color-ink);
  color: var(--color-paper);
}

.btn-block {
  width: 100%;
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  background: transparent;
  border: var(--border-datum);
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
  color: var(--color-ink);
}

/* ==========================================================================
   Hero Section: Rigid Typographic Blueprint
   ========================================================================== */
.hero-section {
  border-bottom: var(--border-datum);
  padding: 80px 0 0 0;
  position: relative;
}

.hero-meta-strip {
  display: flex;
  justify-content: space-between;
  border-bottom: var(--border-datum);
  padding-bottom: 12px;
  margin-bottom: 32px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.hero-title {
  font-size: clamp(1rem, 3.8vw, 3.4rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 28px;
  max-width: 100%;
  white-space: nowrap; /* 强制单行不折行 */
}

.hero-intro {
  font-size: 1.25rem;
  line-height: 1.55;
  max-width: 860px;
  margin-bottom: 40px;
  border-left: 3px solid var(--color-ink);
  padding-left: 20px;
  font-weight: 500;
}

.hero-cta-bar {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

/* Monospace Telemetry Rulers / Stats Table */
.hero-telemetry-table {
  width: 100%;
  border-collapse: collapse;
  border-top: var(--border-datum);
  margin-top: 40px;
}

.hero-telemetry-table th,
.hero-telemetry-table td {
  border-right: var(--border-datum);
  border-top: var(--border-datum);
  padding: 20px 24px;
  text-align: left;
}

.hero-telemetry-table th:first-child,
.hero-telemetry-table td:first-child {
  border-left: var(--border-datum);
}

.telemetry-key {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.telemetry-val {
  font-family: var(--font-mono);
  font-size: 1.85rem;
  font-weight: 900;
  letter-spacing: -0.02em;
}

/* ==========================================================================
   Section Headers: Rationalist Index Stamp
   ========================================================================== */
.section-blueprint {
  border-bottom: var(--border-datum);
  padding: 80px 0;
}

.blueprint-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  border-bottom: var(--border-datum);
  padding-bottom: 16px;
  margin-bottom: 40px;
}

.blueprint-index {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.blueprint-title {
  font-size: clamp(1.8rem, 3.2vw, 2.6rem);
  letter-spacing: -0.03em;
}

.blueprint-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-align: right;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ==========================================================================
   Advantage Matrix (3 Core Architecture Modules)
   ========================================================================== */
.architecture-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-left: var(--border-datum);
  border-top: var(--border-datum);
}

.architecture-col {
  border-right: var(--border-datum);
  border-bottom: var(--border-datum);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
}

.col-spec-code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  margin-bottom: 24px;
  display: flex;
  justify-content: space-between;
  border-bottom: var(--border-datum);
  padding-bottom: 8px;
}

.col-heading {
  font-size: 1.45rem;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.col-desc {
  font-size: 0.96rem;
  line-height: 1.6;
  margin-bottom: 32px;
  flex-grow: 1;
}

.spec-list {
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  border-top: var(--border-datum-dashed);
  padding-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.spec-list li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.spec-mark {
  font-weight: 900;
}

/* ==========================================================================
   Matrix Sections: Streaming & AI Unblock Matrices
   ========================================================================== */
.matrix-dual-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-left: var(--border-datum);
  border-top: var(--border-datum);
}

.matrix-pane {
  border-right: var(--border-datum);
  border-bottom: var(--border-datum);
  padding: 40px;
}

.matrix-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  border: var(--border-datum);
  display: inline-block;
  padding: 3px 8px;
  margin-bottom: 16px;
  font-weight: 800;
  text-transform: uppercase;
}

.matrix-pane-title {
  font-size: 1.65rem;
  margin-bottom: 12px;
}

.matrix-pane-desc {
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 32px;
}

.telemetry-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

.telemetry-table th {
  border-bottom: var(--border-datum);
  border-top: var(--border-datum);
  padding: 10px 12px;
  text-align: left;
  font-weight: 900;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  background: var(--color-paper);
}

.telemetry-row {
  border-bottom: var(--border-datum);
  cursor: pointer;
}

.telemetry-row td {
  padding: 13px 12px;
}

.status-ok {
  font-weight: 800;
}

/* ==========================================================================
   Pricing Section (Real Market Benchmarks)
   ========================================================================== */
.pricing-matrix {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-left: var(--border-datum);
  border-top: var(--border-datum);
}

.pricing-slot {
  border-right: var(--border-datum);
  border-bottom: var(--border-datum);
  padding: 48px 36px;
  display: flex;
  flex-direction: column;
  position: relative;
}

.pricing-slot.recommended {
  outline: 3px solid var(--color-ink);
  outline-offset: -3px;
  z-index: 2;
}

.slot-stamp {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  display: flex;
  justify-content: space-between;
  border-bottom: var(--border-datum);
  padding-bottom: 8px;
  margin-bottom: 24px;
}

.slot-name {
  font-size: 1.6rem;
  margin-bottom: 8px;
}

.slot-summary {
  font-size: 0.88rem;
  line-height: 1.5;
  margin-bottom: 28px;
  min-height: 42px;
}

.slot-price-row {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: var(--border-datum);
  font-family: var(--font-mono);
}

.currency-sym {
  font-size: 1.4rem;
  font-weight: 800;
}

.price-num {
  font-size: 3.2rem;
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.04em;
}

.price-cycle {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
}

.slot-specs {
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 40px;
  flex-grow: 1;
}

.slot-specs li {
  display: flex;
  justify-content: space-between;
  border-bottom: var(--border-datum-dashed);
  padding-bottom: 6px;
}

.spec-label {
  color: inherit;
}

.spec-val {
  font-weight: 900;
}

/* ==========================================================================
   Testimonials (Engineering & Global Enterprise Reviews)
   ========================================================================== */
.review-datum-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-left: var(--border-datum);
  border-top: var(--border-datum);
}

.review-cell {
  border-right: var(--border-datum);
  border-bottom: var(--border-datum);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-id {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  margin-bottom: 18px;
  border-bottom: var(--border-datum);
  padding-bottom: 6px;
  display: flex;
  justify-content: space-between;
}

.review-text {
  font-size: 0.98rem;
  line-height: 1.65;
  margin-bottom: 28px;
  flex-grow: 1;
}

.reviewer-meta {
  font-family: var(--font-mono);
  border-top: var(--border-datum);
  padding-top: 14px;
}

.reviewer-name {
  font-weight: 900;
  font-size: 0.9rem;
  text-transform: uppercase;
  margin-bottom: 2px;
}

.reviewer-role {
  font-size: 0.75rem;
  letter-spacing: 0.04em;
}

/* ==========================================================================
   FAQ Section (Sharp Monospace Accordion)
   ========================================================================== */
.faq-blueprint-wrap {
  border-left: var(--border-datum);
  border-top: var(--border-datum);
}

.faq-row {
  border-right: var(--border-datum);
  border-bottom: var(--border-datum);
}

.faq-trigger {
  width: 100%;
  background: var(--color-paper);
  border: none;
  padding: 24px 28px;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--color-ink);
  cursor: pointer;
  transition: none;
}

.faq-trigger:hover {
  background: var(--color-ink);
  color: var(--color-paper);
}

.faq-trigger:hover .faq-indicator {
  color: var(--color-paper);
}

.faq-indicator {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 900;
  margin-left: 16px;
}

.faq-body {
  max-height: 0;
  overflow: hidden;
  padding: 0 28px;
  background: var(--color-paper);
  border-top: none;
  transition: max-height 0.25s ease-out, padding 0.25s ease-out;
}

.faq-row.active .faq-body {
  max-height: 400px;
  padding: 20px 28px 28px 28px;
  border-top: var(--border-datum-dashed);
}

.faq-body p {
  font-size: 0.96rem;
  line-height: 1.7;
}

/* ==========================================================================
   CTA Full-Width Banner
   ========================================================================== */
.cta-blueprint-bar {
  border-bottom: var(--border-datum);
  padding: 72px 0;
  background: var(--color-paper);
}

.cta-blueprint-inner {
  border: var(--border-datum);
  padding: 56px 48px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.cta-blueprint-title {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  margin-bottom: 12px;
}

.cta-blueprint-desc {
  font-size: 1.1rem;
  max-width: 650px;
}

/* ==========================================================================
   Site Footer (Strictly 4 Links)
   ========================================================================== */
.site-footer {
  border-top: var(--border-datum);
  padding: 48px 0;
  background: var(--color-paper);
}

.footer-nav-bar {
  display: flex;
  justify-content: center;
  gap: 40px;
  list-style: none;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-nav-link {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--color-ink);
  padding: 4px 6px;
  border-bottom: 2px solid transparent;
}

.footer-nav-link:hover {
  background: var(--color-ink);
  color: var(--color-paper);
}

.footer-meta-blueprint {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-align: center;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-ink);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

/* ==========================================================================
   Subpages Style (About, Terms, Privacy, Sitemap, News)
   ========================================================================== */
.subpage-container {
  padding: 60px 0 100px 0;
}

.blueprint-doc-box {
  border: var(--border-datum);
  background: var(--color-paper);
}

.blueprint-doc-header {
  border-bottom: var(--border-datum);
  padding: 32px 40px;
  background: var(--color-paper);
}

.blueprint-doc-body {
  padding: 48px 40px;
}

.blueprint-doc-body h2 {
  font-size: 1.5rem;
  margin: 36px 0 16px 0;
  padding-bottom: 10px;
  border-bottom: var(--border-datum);
}

.blueprint-doc-body h2:first-of-type {
  margin-top: 0;
}

.blueprint-doc-body h3 {
  font-size: 1.15rem;
  margin: 24px 0 12px 0;
}

.blueprint-doc-body p {
  font-size: 1rem;
  line-height: 1.75;
  margin-bottom: 18px;
}

.blueprint-doc-body ul {
  padding-left: 20px;
  margin-bottom: 24px;
}

.blueprint-doc-body li {
  font-size: 0.98rem;
  line-height: 1.7;
  margin-bottom: 10px;
}

.blueprint-callout {
  border: var(--border-datum);
  padding: 20px 24px;
  margin: 28px 0;
  background: var(--color-paper);
  border-left: 6px solid var(--color-ink);
  font-family: var(--font-mono);
  font-size: 0.92rem;
}

.news-article-card {
  border-bottom: var(--border-datum);
  padding: 36px 0;
}

.news-article-card:last-child {
  border-bottom: none;
}

.news-meta-row {
  display: flex;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.news-title {
  font-size: 1.6rem;
  margin-bottom: 12px;
}

.news-excerpt {
  font-size: 1.02rem;
  line-height: 1.65;
  margin-bottom: 20px;
}

/* ==========================================================================
   Responsive Adaptations (@media)
   ========================================================================== */
@media (max-width: 1080px) {
  .architecture-grid,
  .pricing-matrix,
  .review-datum-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
  }

  .nav-links.active {
    display: flex;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-paper);
    border-bottom: var(--border-datum);
    border-left: none;
    z-index: 1000;
  }

  .nav-item {
    border-right: none;
    border-bottom: var(--border-datum);
    width: 100%;
  }

  .nav-link {
    padding: 16px 24px;
  }

  .mobile-nav-toggle {
    display: block;
  }

  .architecture-grid,
  .matrix-dual-grid,
  .pricing-matrix,
  .review-datum-grid {
    grid-template-columns: 1fr;
  }

  .hero-telemetry-table {
    display: block;
  }

  .hero-telemetry-table tr {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .cta-blueprint-inner {
    padding: 32px 24px;
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-nav-bar {
    flex-direction: column;
    align-items: center;
    gap: 16px;
  }
}

@media (max-width: 540px) {
  .hero-telemetry-table tr {
    grid-template-columns: 1fr;
  }

  .hero-title {
    font-size: clamp(0.76rem, 4.2vw, 1.35rem);
    white-space: nowrap;
  }

  .blueprint-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .blueprint-doc-body,
  .blueprint-doc-header {
    padding: 24px 18px;
  }
}