/* ==========================================================================
   CyberGuard - Security Brief Design System
   Theme: Security Brief ｜ 安全档案极简风
   Colors:
     Background: #F8F9F7
     Main Headings: #18252A
     Brand Cyan: #087F8C
     Light Cyan Grey: #E8F1F2
     Muted Text: #617178
     Divider Line: #DEE5E5
     Content Box: #FFFFFF
   ========================================================================== */

:root {
  --bg-page: #F8F9F7;
  --bg-surface: #FFFFFF;
  --bg-alt: #F2F4F2;
  --bg-highlight: #E8F1F2;
  --text-main: #18252A;
  --text-muted: #617178;
  --brand-cyan: #087F8C;
  --brand-cyan-hover: #066670;
  --border-color: #DEE5E5;
  --border-dark: #B9C6C7;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", Consolas, "Liberation Mono", Menlo, Courier, monospace;
  --sidebar-width: 260px;
  --container-max: 1200px;
  --radius-sm: 3px;
  --radius-md: 6px;
  --shadow-subtle: 0 1px 3px rgba(24, 37, 42, 0.04);
  --shadow-card: 0 4px 12px rgba(24, 37, 42, 0.06);
}

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

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

body {
  background-color: var(--bg-page);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.65;
  letter-spacing: -0.01em;
  overflow-x: hidden;
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.15s ease, border-color 0.15s ease, background 0.15s ease;
}

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

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

ul, ol {
  list-style: none;
}

/* App Shell Layout */
.app-layout {
  display: flex;
  min-height: 100vh;
}

/* Sidebar - Security Brief Left Rail */
.brief-sidebar {
  width: var(--sidebar-width);
  background-color: var(--bg-surface);
  border-right: 1px solid var(--border-color);
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  display: flex;
  flex-direction: column;
  padding: 24px 20px;
  overflow-y: auto;
}

.brand-badge {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 24px;
}

.brand-badge img {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: #0d161a;
  padding: 2px;
}

.brand-meta {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--text-main);
  font-family: var(--font-mono);
}

.brand-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.security-stamp {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  background: var(--bg-highlight);
  color: var(--brand-cyan);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.security-stamp::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--brand-cyan);
  border-radius: 50%;
}

/* Nav Menu */
.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
}

.nav-section-title {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 12px 10px 6px;
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-main);
  border-left: 2px solid transparent;
}

.sidebar-nav a:hover {
  background-color: var(--bg-alt);
  color: var(--brand-cyan);
  border-left-color: var(--brand-cyan);
}

.sidebar-nav a .sec-code {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-muted);
}

.sidebar-footer {
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.system-status {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #087F8C;
  position: relative;
}

.status-dot.pulse::after {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  border: 1px solid #087F8C;
  border-radius: 50%;
  animation: pulse 2s infinite ease-out;
}

@keyframes pulse {
  0% { transform: scale(1); opacity: 0.8; }
  100% { transform: scale(2.2); opacity: 0; }
}

/* Mobile Header */
.mobile-header {
  display: none;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 16px;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.mobile-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.mobile-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.mobile-brand img {
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  background: #0d161a;
  padding: 2px;
}

.mobile-brand-text {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-main);
}

.menu-toggle {
  padding: 6px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 34px;
  height: 34px;
  justify-content: center;
  align-items: center;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text-main);
  transition: transform 0.2s, opacity 0.2s;
}

/* Mobile Nav Drawer */
.mobile-drawer {
  display: none;
  flex-direction: column;
  gap: 8px;
  padding: 16px 0 8px;
  border-top: 1px solid var(--border-color);
  margin-top: 12px;
}

.mobile-drawer.open {
  display: flex;
}

.mobile-drawer a {
  padding: 10px 12px;
  font-size: 0.9375rem;
  color: var(--text-main);
  border-radius: var(--radius-sm);
}

.mobile-drawer a:hover {
  background: var(--bg-highlight);
  color: var(--brand-cyan);
}

/* Main Content Area */
.main-wrapper {
  margin-left: var(--sidebar-width);
  flex: 1;
  max-width: calc(100vw - var(--sidebar-width));
  padding: 40px 48px 80px;
}

.content-container {
  max-width: 1060px;
  margin: 0 auto;
}

/* Section Header Structure */
.section-marker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.sec-badge {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--brand-cyan);
  background: var(--bg-highlight);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  letter-spacing: 0.06em;
}

.sec-line {
  flex: 1;
  height: 1px;
  background: var(--border-color);
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.section-intro {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 32px;
  max-width: 760px;
}

/* Hero Section */
.hero-section {
  padding: 24px 0 60px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 56px;
}

.hero-brief-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 28px;
  padding: 8px 12px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
}

.hero-brief-meta span strong {
  color: var(--text-main);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.85fr;
  gap: 40px;
  align-items: center;
}

.hero-title {
  font-size: 2.75rem;
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-main);
  margin-bottom: 16px;
}

.hero-title span {
  color: var(--brand-cyan);
  display: inline-block;
}

.hero-sub {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 28px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-bottom: 32px;
}

.hero-tag {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-muted);
  background: var(--bg-alt);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  white-space: nowrap;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--brand-cyan);
  color: #FFFFFF;
  border: 1px solid var(--brand-cyan);
}

.btn-primary:hover {
  background-color: var(--brand-cyan-hover);
  border-color: var(--brand-cyan-hover);
  box-shadow: 0 2px 6px rgba(8, 127, 140, 0.25);
}

.btn-outline {
  background-color: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-dark);
}

.btn-outline:hover {
  background-color: var(--bg-alt);
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
}

.btn-disabled {
  background-color: var(--bg-alt);
  color: var(--text-muted);
  border: 1px dashed var(--border-dark);
  cursor: not-allowed;
}

/* Hero Right: Security Geometric Graphic */
.hero-graphic {
  position: relative;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  box-shadow: var(--shadow-subtle);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.shield-frame {
  width: 140px;
  height: 140px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.shield-frame img {
  width: 96px;
  height: 96px;
  object-fit: contain;
  border-radius: var(--radius-sm);
  background: #0d161a;
  padding: 6px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  position: relative;
  z-index: 2;
}

.shield-ring {
  position: absolute;
  inset: 0;
  border: 1px dashed var(--brand-cyan);
  border-radius: 50%;
  opacity: 0.6;
}

.shield-axis {
  position: absolute;
  width: 100%;
  height: 1px;
  background: var(--border-color);
}

.shield-axis.vertical {
  transform: rotate(90deg);
}

.graphic-meta {
  width: 100%;
  border-top: 1px solid var(--border-color);
  padding-top: 16px;
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-muted);
}

/* Section 01: Three Highlights */
.highlights-section {
  margin-bottom: 64px;
}

.highlights-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.highlight-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-top: 3px solid var(--brand-cyan);
  padding: 24px;
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.highlight-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.highlight-num {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--brand-cyan);
  margin-bottom: 8px;
}

.highlight-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 10px;
}

.highlight-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* Section 02: Pricing Plans */
.plans-section {
  margin-bottom: 64px;
}

.plans-notice {
  background: var(--bg-highlight);
  border-left: 3px solid var(--brand-cyan);
  padding: 12px 16px;
  font-size: 0.8125rem;
  color: var(--text-main);
  margin-bottom: 24px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.plans-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.plan-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  padding: 24px 20px;
  position: relative;
  transition: all 0.2s ease;
}

.plan-card:hover {
  border-color: var(--brand-cyan);
  box-shadow: var(--shadow-card);
}

.plan-card.popular {
  border-color: var(--brand-cyan);
  background: linear-gradient(180deg, #FFFFFF 0%, #FAFDFC 100%);
}

.plan-card-tag {
  position: absolute;
  top: -10px;
  right: 16px;
  background: var(--brand-cyan);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.plan-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 16px;
  margin-bottom: 16px;
}

.plan-name {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.plan-currency {
  font-size: 1rem;
  font-weight: 600;
  color: var(--brand-cyan);
}

.plan-price {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  font-family: var(--font-mono);
  line-height: 1;
}

.plan-cycle {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.plan-traffic-badge {
  display: inline-block;
  background: var(--bg-alt);
  color: var(--text-main);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.8125rem;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  margin-top: 10px;
  border: 1px solid var(--border-color);
}

.plan-specs {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  flex: 1;
}

.spec-line {
  display: flex;
  justify-content: space-between;
  border-bottom: 1px dashed var(--border-color);
  padding-bottom: 6px;
}

.spec-line .label {
  color: var(--text-muted);
}

.spec-line .value {
  color: var(--text-main);
  font-weight: 500;
  text-align: right;
}

.plan-purpose {
  font-size: 0.75rem;
  color: var(--text-muted);
  background: var(--bg-alt);
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
  line-height: 1.5;
}

.plan-action {
  margin-top: auto;
}

.plan-action .btn {
  width: 100%;
}

/* Section 03: Technical Explanation */
.tech-section {
  margin-bottom: 64px;
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 24px;
}

.tech-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 20px;
  border-radius: var(--radius-sm);
}

.tech-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.tech-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.tech-code {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  background: var(--bg-highlight);
  color: var(--brand-cyan);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

.tech-body {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}

.tech-alert-box {
  background: #FFFBF0;
  border: 1px solid #F6E2B3;
  border-left: 3px solid #D9822B;
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: #5C3E00;
  line-height: 1.6;
}

.tech-alert-box h4 {
  font-size: 0.9375rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: #3D2900;
}

/* Section 04: Three Steps */
.steps-section {
  margin-bottom: 64px;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.step-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 24px;
  border-radius: var(--radius-sm);
  position: relative;
}

.step-phase {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--brand-cyan);
  text-transform: uppercase;
  margin-bottom: 8px;
  display: block;
}

.step-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-main);
}

.step-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Section 05: Six Articles Showcase */
.articles-section {
  margin-bottom: 64px;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.article-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 22px;
  display: flex;
  flex-direction: column;
  transition: all 0.2s ease;
}

.article-card:hover {
  border-color: var(--brand-cyan);
  box-shadow: var(--shadow-card);
  transform: translateY(-2px);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.art-tag {
  background: var(--bg-highlight);
  color: var(--brand-cyan);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.article-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text-main);
  margin-bottom: 10px;
}

.article-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 16px;
  flex: 1;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
  font-size: 0.8125rem;
}

.read-link {
  font-weight: 600;
  color: var(--brand-cyan);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.read-link:hover {
  color: var(--brand-cyan-hover);
  text-decoration: underline;
}

/* Section 06: FAQ Section */
.faq-section {
  margin-bottom: 64px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.15s ease;
}

.faq-item:hover {
  border-color: var(--border-dark);
}

.faq-item.active {
  border-color: var(--brand-cyan);
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 18px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
}

.faq-icon {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  color: var(--brand-cyan);
  line-height: 1;
  transition: transform 0.2s ease;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  display: none;
  padding: 0 20px 20px;
  font-size: 0.90625rem;
  color: var(--text-muted);
  line-height: 1.7;
  border-top: 1px dashed var(--border-color);
  margin-top: 4px;
  padding-top: 14px;
}

.faq-item.active .faq-answer {
  display: block;
}

/* Section 07: About Us & Footer */
.brief-footer {
  border-top: 2px solid var(--border-color);
  padding-top: 48px;
  margin-top: 48px;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 36px;
  margin-bottom: 40px;
}

.footer-brand h4 {
  font-size: 1.125rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text-main);
  margin-bottom: 8px;
}

.footer-brand p {
  font-size: 0.84375rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-col h5 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-main);
  margin-bottom: 12px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col a {
  font-size: 0.84375rem;
  color: var(--text-muted);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* Modal Dialog for Unconfigured Safe State */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(24, 37, 42, 0.45);
  backdrop-filter: blur(2px);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.modal-overlay.open {
  display: flex;
}

.modal-dialog {
  background: var(--bg-surface);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  max-width: 480px;
  width: 100%;
  box-shadow: 0 12px 32px rgba(24, 37, 42, 0.15);
  padding: 24px;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 12px;
  margin-bottom: 16px;
}

.modal-title {
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.modal-close {
  font-size: 1.25rem;
  color: var(--text-muted);
  line-height: 1;
  padding: 4px;
}

.modal-body {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */

/* 1024px and below: Collapse left sidebar into top bar */
@media (max-width: 1024px) {
  .app-layout {
    flex-direction: column;
  }
  .brief-sidebar {
    display: none;
  }
  .mobile-header {
    display: block;
    width: 100%;
  }
  .main-wrapper {
    margin-left: 0;
    max-width: 100%;
    width: 100%;
    padding: 24px 20px 60px;
  }
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .plans-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .tech-grid {
    grid-template-columns: 1fr;
  }
  .highlights-row {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .steps-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .footer-top {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

/* 768px and below */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.15rem;
  }
  .hero-sub {
    font-size: 1.1rem;
  }
  .articles-grid {
    grid-template-columns: 1fr;
  }
  .plans-grid {
    grid-template-columns: 1fr;
  }
}

/* 390px / 375px small mobile devices */
@media (max-width: 420px) {
  .hero-title {
    font-size: 1.85rem;
  }
  .hero-brief-meta {
    flex-direction: column;
    gap: 6px;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .btn {
    width: 100%;
  }
  .section-title {
    font-size: 1.45rem;
  }
  .main-wrapper {
    padding: 16px 12px 48px;
  }
}

/* Accessibility: Support prefers-reduced-motion for Core Web Vitals & Crawlers */
@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;
  }
}