@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;600;700&display=swap');

:root {
  --brand: #E53935;
  --brand-soft: rgba(229, 57, 53, 0.12);
  --brand-glow: rgba(229, 57, 53, 0.25);
  --bg-main: #0f0f0f;
  --bg-card: #1a1a1a;
  --bg-card-hover: #222222;
  --bg-muted: #2a2a2a;
  --text: #ffffff;
  --text-secondary: #b0b0b0;
  --text-muted: #6e6e6e;
  --border: rgba(255, 255, 255, 0.06);
}

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

body {
  font-family: 'Noto Sans SC', -apple-system, sans-serif;
  background:
    radial-gradient(ellipse at 20% 0%, var(--brand-glow) 0%, transparent 50%),
    linear-gradient(170deg, rgba(15,15,15,0.85) 0%, rgba(15,15,15,1) 100%);
  background-color: var(--bg-main);
  color: var(--text);
  min-height: 100vh;
}

/* ======== 导航 ======== */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem 2.5rem;
  max-width: 1400px;
  margin: 0 auto;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: inherit;
}

.nav-logo-img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  flex-shrink: 0;
  object-fit: contain;
}

.nav-logo span {
  font-size: 1.1rem;
  font-weight: 600;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.8rem;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--brand);
}

/* ======== Hero 主区域 ======== */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 2rem 3.5rem;
  align-items: center;
  min-height: calc(100vh - 80px);
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-right { order: 1; }
  .hero-left { order: 2; }
  .hero-logo { justify-content: center; }
  .feature-tags { justify-content: center; }
  .download-meta { align-items: center; }
}

/* ======== Hero 左侧品牌区 ======== */
.hero-logo {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.hero-logo-img {
  width: 64px;
  height: 64px;
  border-radius: 16px;
  flex-shrink: 0;
  object-fit: contain;
  box-shadow: 0 4px 20px var(--brand-glow);
}

.hero-logo-text {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.hero-logo-text .brand {
  color: var(--text);
}

.hero-logo-text .sub {
  color: var(--text-muted);
  font-weight: 400;
  font-size: 1.4rem;
}

.hero-slogan {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.25rem;
  font-weight: 400;
  line-height: 1.6;
}

/* 功能标签 */
.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.feature-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.7rem;
  background: var(--brand-soft);
  border: 1px solid rgba(229, 57, 53, 0.2);
  border-radius: 6px;
  font-size: 0.78rem;
  color: #f08080;
  font-weight: 500;
}

.feature-tag i {
  font-size: 0.7rem;
}

/* 简介信息 */
.intro {
  background: var(--bg-card);
  border-radius: 14px;
  padding: 1.2rem 1.5rem;
  margin-bottom: 1.5rem;
  border-left: 3px solid var(--brand);
}

.intro h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--brand);
}

.intro p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* 下载按钮 */
.download-row {
  display: flex;
  gap: 0.875rem;
}

.download-platform {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--brand);
  color: #fff;
  padding: 0.85rem 1.5rem;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.2s, transform 0.15s, box-shadow 0.2s;
  box-shadow: 0 2px 12px var(--brand-glow);
}

.download-platform:hover {
  opacity: 0.9;
  transform: translateY(-1px);
  box-shadow: 0 4px 20px var(--brand-glow);
}

.download-platform i {
  font-size: 1.15rem;
}

.download-meta {
  margin-top: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.download-links {
  display: flex;
  gap: 1.5rem;
}

.download-links a {
  color: var(--text-muted);
  font-size: 0.82rem;
  text-decoration: none;
  transition: color 0.2s;
}

.download-links a:hover {
  color: var(--brand);
}

.version-info {
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

/* ======== Hero 右侧翻译演示 ======== */
.hero-right {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.translate-demo {
  background: var(--bg-card);
  border-radius: 16px;
  border: 1px solid var(--border);
  overflow: hidden;
  max-width: 500px;
  width: 100%;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.4);
}

/* 翻译标签栏 */
.translate-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
}

.translate-tabs .tab {
  padding: 0.75rem 1rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
  white-space: nowrap;
}

.translate-tabs .tab.active {
  color: var(--brand);
  border-bottom-color: var(--brand);
  font-weight: 600;
}

.translate-tabs .tab:hover:not(.active) {
  color: var(--text-secondary);
}

/* 语言选择栏 */
.translate-lang-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.7rem 1.2rem;
  border-bottom: 1px solid var(--border);
}

.lang-tag {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.25rem 0.65rem;
  border-radius: 6px;
  background: var(--bg-muted);
  cursor: pointer;
  transition: all 0.2s;
}

.lang-tag.active {
  color: #fff;
  background: var(--brand);
}

.swap-icon {
  color: var(--text-muted);
  font-size: 0.75rem;
  cursor: pointer;
  transition: color 0.2s;
}

.swap-icon:hover {
  color: var(--brand);
}

.lang-extra {
  display: flex;
  gap: 0.5rem;
  margin-left: auto;
}

.lang-extra span {
  font-size: 0.75rem;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.2rem 0.45rem;
  border-radius: 4px;
  transition: all 0.15s;
}

.lang-extra span:hover {
  color: var(--text-secondary);
  background: var(--bg-muted);
}

/* 翻译主体 */
.translate-demo-body {
  padding: 1.2rem 1.3rem;
}

.translate-input {
  position: relative;
  margin-bottom: 0.5rem;
}

.translate-input p {
  font-size: 0.9rem;
  color: var(--text);
  line-height: 1.7;
  padding-bottom: 0.5rem;
}

.char-count {
  position: absolute;
  bottom: 0;
  right: 0;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.translate-divider {
  display: flex;
  align-items: center;
  margin: 0.6rem 0;
  gap: 0.75rem;
}

.translate-divider::before,
.translate-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.engine-badge {
  font-size: 0.68rem;
  color: var(--brand);
  background: var(--brand-soft);
  padding: 0.2rem 0.6rem;
  border-radius: 10px;
  white-space: nowrap;
  font-weight: 500;
}

.engine-badge i {
  margin-right: 0.2rem;
}

.translate-output p {
  font-size: 0.85rem;
  color: #e0a0a0;
  line-height: 1.7;
  font-style: italic;
}

/* 翻译底栏 */
.translate-demo-footer {
  display: flex;
  gap: 1.2rem;
  padding: 0.75rem 1.3rem;
  border-top: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.015);
  flex-wrap: wrap;
}

.translate-demo-footer span {
  font-size: 0.72rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.translate-demo-footer i {
  margin-right: 0.25rem;
  color: var(--brand);
  font-size: 0.68rem;
}

@media (max-width: 900px) {
  .translate-demo { max-width: 100%; }
  .lang-extra { display: none; }
}

/* ======== 特性卡片区 ======== */
.features-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem 2rem;
}

.features-section h2 {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  text-align: center;
  color: var(--text);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

@media (max-width: 900px) {
  .features-grid { grid-template-columns: 1fr; }
}

.feature-card {
  background: var(--bg-card);
  border-radius: 14px;
  padding: 1.5rem;
  border: 1px solid var(--border);
  transition: transform 0.2s, border-color 0.2s;
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  transform: translateY(-3px);
  border-color: rgba(229, 57, 53, 0.2);
}

.feature-card-label {
  position: absolute;
  top: 0;
  right: 1.5rem;
  background: var(--brand);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 0 0 6px 6px;
  letter-spacing: 0.05em;
}

.feature-card-icon {
  width: 42px;
  height: 42px;
  background: var(--brand-soft);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.feature-card-icon i {
  font-size: 1.1rem;
  color: var(--brand);
}

.feature-card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.feature-card p {
  font-size: 0.83rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ======== FAQ 卡片区 ======== */
.knowledge-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 2rem 1.5rem;
}

.knowledge-section h2 {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  text-align: center;
  color: var(--text);
}

.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

@media (max-width: 900px) {
  .knowledge-grid { grid-template-columns: 1fr; }
}

.knowledge-card {
  background: var(--bg-card);
  border-radius: 14px;
  padding: 1.2rem 1.4rem;
  border: 1px solid var(--border);
  border-top: 3px solid var(--brand);
  transition: transform 0.2s;
}

.knowledge-card:hover {
  transform: translateY(-2px);
}

.knowledge-card h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--text);
}

.knowledge-card p {
  font-size: 0.83rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ======== 用户评价区 ======== */
.reviews-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 2rem 3rem;
}

.reviews-section h2 {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  text-align: center;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

@media (max-width: 900px) {
  .reviews-grid { grid-template-columns: 1fr; }
}

.review-card {
  background: var(--bg-card);
  border-radius: 14px;
  padding: 1.2rem 1.4rem;
  border: 1px solid var(--border);
}

.review-stars {
  color: #ffd700;
  font-size: 0.85rem;
  margin-bottom: 0.6rem;
  letter-spacing: 1px;
}

.review-text {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.review-avatar {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  object-fit: cover;
}

.review-name {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text);
}

.review-meta {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* ======== 页脚 ======== */
footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border);
  margin: 0 2rem;
}

.footer-brand {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

.footer-info {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 0.3rem;
}

.footer-copy {
  font-size: 0.72rem;
  color: var(--text-muted);
}