/* ========================================
   WPS Office - Paper Studio Theme
   Clean editorial design with teal + orange
======================================== */

:root {
  --bg: #faf9f7;
  --bg-alt: #f5f3ef;
  --bg-dark: #1a1a1a;
  --fg: #1a1a1a;
  --fg-muted: #5a5a5a;
  --fg-light: #8a8a8a;
  --accent: #0d7377;
  --accent-light: #14a3a8;
  --highlight: #f97316;
  --highlight-light: #fb923c;
  --card: #ffffff;
  --border: #e5e3df;
  --shadow: rgba(0,0,0,0.06);
  --radius: 12px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  font-size: 16px;
}

/* Typography */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.3; color: var(--fg); }
h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.5rem); }
p { color: var(--fg-muted); }

a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--highlight); }

/* Container */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* Navigation */
.navbar {
  position: sticky;
  top: 0;
  background: rgba(250,249,247,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--fg);
}

.logo svg { width: 32px; height: 32px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  display: block;
  padding: 8px 16px;
  color: var(--fg-muted);
  font-weight: 500;
  border-radius: 8px;
  transition: all 0.2s;
}

.nav-links a:hover {
  background: var(--bg-alt);
  color: var(--fg);
}

.nav-links a.active {
  background: var(--accent);
  color: #fff;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(13,115,119,0.25);
}

.btn-highlight {
  background: var(--highlight);
  color: #fff;
}

.btn-highlight:hover {
  background: var(--highlight-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(249,115,22,0.25);
}

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 2px solid var(--accent);
}

.btn-outline:hover {
  background: var(--accent);
  color: #fff;
}

.btn-lg {
  padding: 16px 32px;
  font-size: 17px;
}

.btn svg { width: 18px; height: 18px; }

/* Hero Section */
.hero {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--bg) 0%, var(--bg-alt) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(13,115,119,0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content { position: relative; z-index: 1; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(13,115,119,0.1);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 20px;
}

.hero-badge svg { width: 14px; height: 14px; }

.hero-title { margin-bottom: 20px; }

.hero-title span {
  background: linear-gradient(135deg, var(--accent) 0%, var(--highlight) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 18px;
  margin-bottom: 32px;
  max-width: 520px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 40px;
}

.hero-stats {
  display: flex;
  gap: 40px;
}

.stat-item { text-align: left; }

.stat-num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-label {
  font-size: 14px;
  color: var(--fg-muted);
}

.hero-visual {
  position: relative;
}

.hero-card {
  background: var(--card);
  border-radius: 20px;
  box-shadow: 0 20px 60px var(--shadow);
  padding: 40px;
  position: relative;
}

.hero-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
  border-radius: 20px 20px 0 0;
}

.doc-preview {
  background: var(--bg-alt);
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 20px;
}

.doc-bar {
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  margin-bottom: 12px;
}

.doc-bar.short { width: 60%; }
.doc-bar.medium { width: 80%; }
.doc-bar.long { width: 100%; }

.doc-bar.accent { background: var(--accent); opacity: 0.3; }
.doc-bar.highlight { background: var(--highlight); opacity: 0.3; }

.hero-card-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--fg-muted);
}

.hero-card-label svg { width: 16px; height: 16px; color: var(--accent); }

/* Sections */
.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-dark {
  background: var(--bg-dark);
  color: #fff;
}

.section-dark h2, .section-dark h3 { color: #fff; }
.section-dark p { color: rgba(255,255,255,0.7); }

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 60px;
}

.section-label {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 12px;
}

.section-title { margin-bottom: 16px; }

.section-desc { font-size: 17px; }

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 32px;
  border: 1px solid var(--border);
  transition: all 0.3s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px var(--shadow);
  border-color: var(--accent);
}

.feature-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.feature-icon svg { width: 24px; height: 24px; color: #fff; }

.feature-name { margin-bottom: 8px; }

.feature-desc { font-size: 15px; }

/* Platform Grid */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.platform-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  border: 1px solid var(--border);
  transition: all 0.3s;
}

.platform-card:hover {
  border-color: var(--accent);
  box-shadow: 0 8px 30px var(--shadow);
}

.platform-card.featured {
  border: 2px solid var(--accent);
  background: linear-gradient(135deg, rgba(13,115,119,0.05) 0%, transparent 100%);
}

.platform-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.platform-icon svg { width: 40px; height: 40px; }

.platform-name {
  font-weight: 600;
  margin-bottom: 4px;
}

.platform-version {
  font-size: 13px;
  color: var(--fg-light);
  margin-bottom: 16px;
}

/* Deep Features */
.deep-section {
  padding: 60px 0;
  border-bottom: 1px solid var(--border);
}

.deep-section:last-child { border-bottom: none; }

.deep-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.deep-row.reverse { direction: rtl; }
.deep-row.reverse > * { direction: ltr; }

.deep-content { max-width: 480px; }

.deep-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--highlight);
  margin-bottom: 12px;
}

.deep-badge svg { width: 14px; height: 14px; }

.deep-title { margin-bottom: 16px; }

.deep-desc { margin-bottom: 24px; }

.deep-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.deep-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 15px;
  color: var(--fg-muted);
}

.deep-list svg {
  width: 20px;
  height: 20px;
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 2px;
}

.deep-visual {
  background: var(--card);
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 8px 30px var(--shadow);
}

/* Reviews */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid var(--border);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.review-avatar {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--accent), var(--highlight));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 600;
  font-size: 16px;
}

.review-info h4 { font-size: 15px; margin-bottom: 2px; }
.review-info span { font-size: 13px; color: var(--fg-light); }

.review-stars {
  display: flex;
  gap: 2px;
  margin-bottom: 12px;
}

.review-stars svg { width: 16px; height: 16px; color: #fbbf24; }

.review-text {
  font-size: 15px;
  color: var(--fg-muted);
  line-height: 1.6;
}

/* Comparison Table */
.comparison-wrap {
  overflow-x: auto;
  margin: 40px 0;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 20px var(--shadow);
}

.comparison-table th,
.comparison-table td {
  padding: 16px 20px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.comparison-table th {
  background: var(--bg-alt);
  font-weight: 600;
  font-size: 14px;
  color: var(--fg);
}

.comparison-table td { font-size: 15px; }

.comparison-table tr:last-child td { border-bottom: none; }

.comparison-table .highlight {
  background: rgba(13,115,119,0.05);
  font-weight: 600;
}

.comparison-table .check { color: var(--accent); }
.comparison-table .cross { color: #dc2626; }

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--card);
  border-radius: var(--radius);
  margin-bottom: 12px;
  border: 1px solid var(--border);
  overflow: hidden;
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 600;
  transition: background 0.2s;
}

.faq-question:hover { background: var(--bg-alt); }

.faq-question svg {
  width: 20px;
  height: 20px;
  color: var(--fg-light);
  transition: transform 0.3s;
}

.faq-item.open .faq-question svg { transform: rotate(180deg); }

.faq-answer {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s;
}

.faq-item.open .faq-answer {
  padding: 0 24px 20px;
  max-height: 500px;
}

.faq-answer p { font-size: 15px; line-height: 1.7; }

/* CTA Banner */
.cta-banner {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
  border-radius: 20px;
  padding: 60px;
  text-align: center;
  color: #fff;
}

.cta-banner h2 { color: #fff; margin-bottom: 12px; }

.cta-banner p {
  color: rgba(255,255,255,0.9);
  font-size: 17px;
  margin-bottom: 28px;
}

.cta-banner .btn-highlight {
  background: #fff;
  color: var(--accent);
}

.cta-banner .btn-highlight:hover {
  background: var(--bg-alt);
  transform: translateY(-2px);
}

/* Download Page */
.download-hero {
  padding: 60px 0;
  background: linear-gradient(135deg, var(--bg) 0%, var(--bg-alt) 100%);
}

.download-main {
  background: var(--card);
  border-radius: 20px;
  padding: 48px;
  text-align: center;
  box-shadow: 0 20px 60px var(--shadow);
  max-width: 600px;
  margin: 0 auto 40px;
  position: relative;
}

.download-main::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
  border-radius: 20px 20px 0 0;
}

.download-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.download-icon svg { width: 40px; height: 40px; color: #fff; }

.download-title { margin-bottom: 8px; }

.download-version {
  font-size: 14px;
  color: var(--fg-light);
  margin-bottom: 24px;
}

.download-meta {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-bottom: 28px;
}

.download-meta-item {
  text-align: center;
}

.download-meta-item span {
  display: block;
  font-size: 13px;
  color: var(--fg-light);
}

.download-meta-item strong {
  font-size: 15px;
  color: var(--fg);
}

/* Guide Steps */
.guide-steps {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
  margin: 40px 0;
}

.step-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  border: 1px solid var(--border);
}

.step-number {
  width: 36px;
  height: 36px;
  background: var(--accent);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 16px;
  margin: 0 auto 16px;
}

.step-card h4 { font-size: 15px; margin-bottom: 8px; }
.step-card p { font-size: 14px; }

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

.requirement-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--border);
}

.requirement-icon {
  width: 40px;
  height: 40px;
  background: var(--bg-alt);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.requirement-icon svg { width: 20px; height: 20px; color: var(--accent); }

.requirement-card h4 { font-size: 15px; margin-bottom: 8px; }
.requirement-card p { font-size: 14px; }

/* Version Timeline */
.version-list {
  max-width: 700px;
  margin: 0 auto;
}

.version-item {
  display: flex;
  gap: 20px;
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
}

.version-item:last-child { border-bottom: none; }

.version-dot {
  width: 12px;
  height: 12px;
  background: var(--accent);
  border-radius: 50%;
  margin-top: 6px;
  flex-shrink: 0;
}

.version-tag {
  display: inline-block;
  padding: 4px 10px;
  background: rgba(13,115,119,0.1);
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
  border-radius: 4px;
  margin-right: 8px;
}

.version-date {
  font-size: 13px;
  color: var(--fg-light);
}

.version-body h4 { font-size: 15px; margin-bottom: 4px; }
.version-body p { font-size: 14px; }

/* Security Banner */
.security-banner {
  background: linear-gradient(135deg, rgba(13,115,119,0.1) 0%, rgba(249,115,22,0.1) 100%);
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 40px;
}

.security-banner svg {
  width: 32px;
  height: 32px;
  color: var(--accent);
  flex-shrink: 0;
}

.security-banner p {
  font-size: 15px;
  color: var(--fg);
}

/* Article Page */
.article-hero {
  padding: 60px 0;
  background: linear-gradient(135deg, var(--bg) 0%, var(--bg-alt) 100%);
}

.article-header {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.article-title { margin-bottom: 16px; }

.article-desc {
  font-size: 18px;
  margin-bottom: 24px;
}

.keyword-strip {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}

.keyword {
  padding: 6px 14px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 13px;
  color: var(--fg-muted);
}

.article-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  max-width: 1100px;
  margin: 0 auto;
}

.article-content {
  background: var(--card);
  border-radius: var(--radius);
  padding: 40px;
  border: 1px solid var(--border);
}

.article-section {
  margin-bottom: 40px;
}

.article-section:last-child { margin-bottom: 0; }

.article-section h2 {
  font-size: 1.5rem;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent);
}

.article-section h3 {
  font-size: 1.2rem;
  margin: 24px 0 12px;
}

.article-section p {
  margin-bottom: 16px;
  font-size: 16px;
}

.article-section ul {
  margin: 16px 0;
  padding-left: 24px;
}

.article-section li {
  margin-bottom: 8px;
  color: var(--fg-muted);
}

.inline-cta {
  background: linear-gradient(135deg, rgba(13,115,119,0.1) 0%, rgba(249,115,22,0.1) 100%);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  margin: 32px 0;
}

.inline-cta p {
  font-size: 16px;
  margin-bottom: 16px;
  color: var(--fg);
}

/* Sidebar */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.sidebar-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--border);
}

.sidebar-card h3 {
  font-size: 16px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.sidebar-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sidebar-links a,
.sidebar-links button {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  background: var(--bg-alt);
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--fg);
  cursor: pointer;
  width: 100%;
  transition: all 0.2s;
}

.sidebar-links a:hover,
.sidebar-links button:hover {
  background: var(--accent);
  color: #fff;
}

.sidebar-links a svg,
.sidebar-links button svg { width: 16px; height: 16px; }

.sidebar-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.sidebar-stat {
  text-align: center;
  padding: 16px;
  background: var(--bg-alt);
  border-radius: 8px;
}

.sidebar-stat-num {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
}

.sidebar-stat-label {
  font-size: 12px;
  color: var(--fg-light);
}

/* Footer */
.footer {
  background: var(--bg-dark);
  padding: 40px 0;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  color: #fff;
  margin-bottom: 16px;
}

.footer-brand svg { width: 28px; height: 28px; }

.security-line {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 14px;
  color: rgba(255,255,255,0.8);
  margin-bottom: 12px;
}

.security-line svg { width: 16px; height: 16px; color: var(--accent); }

.footer-note {
  font-size: 13px;
  color: rgba(255,255,255,0.5);
  max-width: 600px;
  margin: 0 auto;
}

/* Animations */
@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* Responsive */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-visual { order: -1; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .deep-row { grid-template-columns: 1fr; gap: 40px; }
  .deep-row.reverse { direction: ltr; }
  .reviews-grid { grid-template-columns: repeat(2, 1fr); }
  .guide-steps { grid-template-columns: repeat(3, 1fr); }
  .requirements-grid { grid-template-columns: repeat(2, 1fr); }
  .article-layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .feature-grid { grid-template-columns: 1fr; }
  .platform-grid { grid-template-columns: 1fr; }
  .reviews-grid { grid-template-columns: 1fr; }
  .guide-steps { grid-template-columns: 1fr; }
  .requirements-grid { grid-template-columns: 1fr; }
  .hero-stats { flex-direction: column; gap: 20px; }
  .download-meta { flex-direction: column; gap: 16px; }
  .cta-banner { padding: 40px 24px; }
}