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

html, body {
  background: #f4f6f9;
  color: #1f2937;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

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

/* ===== 顶部导航 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #e8ebf0;
  box-shadow: 0 1px 3px rgba(16, 24, 40, 0.04);
}
.header-inner {
  max-width: 1120px;
  height: 64px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 40px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.logo-mark {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: linear-gradient(135deg, #3b82f6, #2563eb);
  color: #fff;
  font-size: 17px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.28);
}
.logo-text {
  font-size: 17px;
  font-weight: 600;
  color: #111827;
  letter-spacing: 0.5px;
}

.site-nav {
  display: flex;
  gap: 6px;
  flex: 1;
}
.site-nav a {
  padding: 7px 14px;
  font-size: 14px;
  color: #4b5563;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}
.site-nav a:hover {
  background: #eff6ff;
  color: #2563eb;
}

.auth-area {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.auth-area button {
  font-family: inherit;
  font-size: 14px;
  padding: 8px 18px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s;
}
.auth-login {
  background: transparent;
  border: 1px solid #d1d9e4;
  color: #374151;
}
.auth-login:hover {
  border-color: #93c5fd;
  color: #2563eb;
  background: #f8fbff;
}
.auth-register {
  background: #2563eb;
  border: 1px solid #2563eb;
  color: #fff;
}
.auth-register:hover {
  background: #1d4ed8;
  border-color: #1d4ed8;
}
.auth-username {
  font-size: 14px;
  color: #374151;
  margin-right: 4px;
  max-width: 140px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.auth-logout {
  background: transparent;
  border: 1px solid #d1d9e4;
  color: #6b7280;
}
.auth-logout:hover {
  border-color: #fca5a5;
  color: #dc2626;
  background: #fef2f2;
}

/* ===== 主内容通用 ===== */
.site-main {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px 60px;
  min-height: 80vh;
}

/* ===== 1. 首屏 ===== */
.hero {
  padding: 80px 0 56px;
  text-align: center;
}
.hero h1 {
  font-size: 38px;
  font-weight: 700;
  color: #111827;
  letter-spacing: 2px;
  margin-bottom: 14px;
}
.hero p {
  font-size: 16px;
  color: #6b7280;
}

/* ===== 2. 核心模块卡片 ===== */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 80px;
}
.tool-card {
  background: #fff;
  border: 1px solid #e8ebf0;
  border-radius: 12px;
  padding: 28px 24px;
  cursor: pointer;
  transition: transform 0.18s, box-shadow 0.18s, border-color 0.18s;
  box-shadow: 0 1px 2px rgba(16, 24, 40, 0.03);
}
.tool-card:hover {
  transform: translateY(-3px);
  border-color: #bfdbfe;
  box-shadow: 0 10px 28px rgba(37, 99, 235, 0.10);
}
.tool-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}
.icon-app  { background: #eff6ff; color: #2563eb; }
.icon-mail { background: #f0fdf4; color: #16a34a; }
.icon-chat { background: #fef3c7; color: #d97706; }
.tool-icon svg { width: 24px; height: 24px; }
.tool-card h3 { font-size: 16px; font-weight: 600; color: #111827; margin-bottom: 8px; }
.tool-card p { font-size: 13px; color: #6b7280; line-height: 1.6; margin-bottom: 16px; }
.tool-enter { font-size: 13px; color: #2563eb; font-weight: 500; }

/* ===== 3. 工具介绍 (Features) ===== */
.section-header {
  text-align: center;
  margin-bottom: 40px;
}
.section-header h2 {
  font-size: 26px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 12px;
}
.section-header p {
  font-size: 15px;
  color: #6b7280;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 80px;
}
.feature-card {
  background: #fff;
  border: 1px solid #e8ebf0;
  border-radius: 12px;
  padding: 32px;
}
.feature-icon {
  font-size: 28px;
  margin-bottom: 16px;
}
.feature-card h4 {
  font-size: 18px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 12px;
}
.feature-card p {
  font-size: 14px;
  color: #6b7280;
  line-height: 1.6;
}

/* ===== 4. 优势说明 & 占位媒体 (Advantages) ===== */
.advantage-section {
  display: flex;
  align-items: center;
  gap: 60px;
  margin-bottom: 80px;
  padding: 40px;
  background: #fff;
  border-radius: 16px;
  border: 1px solid #e8ebf0;
}

.adv-media {
  flex: 1;
}
.media-placeholder {
  width: 100%;
  height: 320px;
  background: #f9fafb;
  border: 2px dashed #d1d9e4;
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: #9ca3af;
  gap: 12px;
}
.media-placeholder svg {
  width: 48px;
  height: 48px;
  opacity: 0.5;
}
.media-placeholder span {
  font-size: 14px;
  letter-spacing: 2px;
}

.adv-text {
  flex: 1.2;
}
.adv-text h2 {
  font-size: 24px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 24px;
}
.adv-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.adv-list li {
  font-size: 14px;
  color: #4b5563;
  line-height: 1.7;
  position: relative;
  padding-left: 20px;
}
.adv-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  top: 0;
  color: #2563eb;
  font-weight: bold;
}
.adv-list strong {
  color: #111827;
}

/* ===== 5. 数据面板 (Stats) ===== */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 60px;
  padding: 40px 20px;
  background: #eff6ff;
  border-radius: 16px;
}
.stat-item {
  text-align: center;
}
.stat-num {
  font-size: 32px;
  font-weight: 700;
  color: #2563eb;
  margin-bottom: 8px;
  font-family: "Segoe UI", sans-serif;
}
.stat-label {
  font-size: 14px;
  color: #4b5563;
}

/* ===== 维护视图 ===== */
#maintenanceView {
  display: none;
  padding-top: 80px;
  justify-content: center;
}
#maintenanceView.show {
  display: flex;
}
.maint-box {
  width: 100%;
  max-width: 560px;
  background: #fff;
  border: 1px solid #e8ebf0;
  border-radius: 14px;
  padding: 48px 40px;
  text-align: center;
  box-shadow: 0 8px 32px rgba(16, 24, 40, 0.06);
}
.maint-icon {
  width: 58px;
  height: 58px;
  margin: 0 auto 22px;
  border-radius: 50%;
  background: #fff7ed;
  color: #f59e0b;
  display: flex;
  align-items: center;
  justify-content: center;
}
.maint-icon svg { width: 30px; height: 30px; }
.maint-box h2 {
  font-size: 22px;
  font-weight: 600;
  color: #111827;
  letter-spacing: 1px;
  margin-bottom: 18px;
}
.maint-text {
  font-size: 14px;
  color: #6b7280;
  line-height: 2;
  margin-bottom: 30px;
}
.maint-text strong {
  color: #374151;
  font-weight: 600;
}
.maint-back {
  font-family: inherit;
  font-size: 14px;
  padding: 10px 32px;
  border-radius: 8px;
  border: 1px solid #2563eb;
  background: #2563eb;
  color: #fff;
  cursor: pointer;
  letter-spacing: 2px;
  transition: background 0.15s;
}
.maint-back:hover { background: #1d4ed8; }

/* ===== 6. 底部广告区 ===== */
.ad-strip {
  background: #111827;
  padding: 40px 0;
  border-top: 4px solid #374151;
}
.ad-strip-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}
.ad-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
}
.ad-badge {
  font-size: 10px;
  color: #9ca3af;
  border: 1px solid #374151;
  border-radius: 3px;
  padding: 1px 6px;
  letter-spacing: 1px;
}
.ad-head-text {
  font-size: 12px;
  color: #6b7280;
  letter-spacing: 1px;
}

.ad-items {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.ad-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 24px;
  border-radius: 10px;
  background: linear-gradient(120deg, #1b2436 0%, #0f1623 100%);
  border: 1px solid #2a3446;
  transition: border-color 0.18s, box-shadow 0.18s, transform 0.18s;
}
.ad-card:hover {
  border-color: #3b82f6;
  box-shadow: 0 0 26px rgba(59, 130, 246, 0.22);
  transform: translateY(-2px);
}
.ad-card-body { min-width: 0; }
.ad-card-tag {
  display: inline-block;
  font-size: 10px;
  color: #93c5fd;
  border: 1px solid rgba(147, 197, 253, 0.35);
  border-radius: 3px;
  padding: 1px 7px;
  letter-spacing: 1px;
  margin-bottom: 10px;
}
.ad-card-title {
  font-size: 19px;
  font-weight: 700;
  color: #f9fafb;
  letter-spacing: 2px;
  margin-bottom: 6px;
}
.ad-card-desc {
  font-size: 12px;
  color: #9ca3af;
  line-height: 1.6;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.ad-card-btn {
  flex-shrink: 0;
  font-size: 13px;
  color: #fff;
  background: #2563eb;
  border-radius: 6px;
  padding: 9px 20px;
  letter-spacing: 1px;
  transition: background 0.15s;
}
.ad-card:hover .ad-card-btn { background: #3b82f6; }

/* ===== 7. 页面页脚 ===== */
.site-footer {
  background: #0f1623;
  padding: 30px 0;
  text-align: center;
  color: #4b5563;
  font-size: 12px;
  line-height: 1.8;
}
.footer-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 登录注册弹窗 ===== */
.modal {
  position: fixed; inset: 0; display: none;
  align-items: center; justify-content: center;
  background: rgba(15, 23, 42, 0.45);
  backdrop-filter: blur(3px);
  z-index: 100;
}
.modal.show { display: flex; }
.modal-card {
  width: 360px;
  padding: 30px 28px 24px;
  background: #ffffff;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(15, 23, 42, 0.25);
  display: flex;
  flex-direction: column;
  gap: 13px;
}
.modal-title {
  font-size: 17px; font-weight: 600; color: #111827;
  text-align: center; letter-spacing: 2px; margin-bottom: 6px;
}
.modal-card input {
  padding: 11px 14px; background: #f9fafb;
  border: 1px solid #e5e7eb; border-radius: 8px;
  color: #111827; font-family: inherit; font-size: 14px;
  outline: none; transition: border-color 0.15s, box-shadow 0.15s;
}
.modal-card input:focus {
  border-color: #93c5fd; background: #fff;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.10);
}
.modal-error {
  font-size: 12px; color: #dc2626; min-height: 16px;
}
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 4px; }
.modal-actions button {
  padding: 9px 24px; border-radius: 8px;
  font-family: inherit; font-size: 14px; cursor: pointer;
  transition: all 0.15s;
}
.modal-actions .ghost {
  background: transparent; border: 1px solid #d1d9e4; color: #4b5563;
}
.modal-actions .ghost:hover { background: #f9fafb; }
.modal-actions .primary {
  background: #2563eb; border: 1px solid #2563eb; color: #fff;
}
.modal-actions .primary:hover { background: #1d4ed8; }
.modal-actions .primary:disabled { opacity: 0.55; cursor: not-allowed; }

/* 响应式 */
@media (max-width: 860px) {
  .tool-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .advantage-section { flex-direction: column; gap: 30px; }
  .adv-media { width: 100%; }
  .media-placeholder { height: 240px; }
  .stats-bar { grid-template-columns: 1fr 1fr; gap: 30px; }
  .ad-items { grid-template-columns: 1fr; }
}