/* ========================================
   Base CSS - SheetNext 通用样式
   简约现代风格
======================================== */

/* CSS 变量 */
:root {
  --color-bg: rgb(238, 240, 242);
  --color-bg-white: #ffffff;
  --color-text: #37352f;
  --color-text-light: #6b6b6b;
  --color-text-muted: #9b9a97;
  --color-primary: #336699;
  --color-primary-hover: #2b5580;
  --color-border: rgba(55, 53, 47, 0.09);
  --color-border-dark: rgba(55, 53, 47, 0.16);
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, "Apple Color Emoji", Arial, sans-serif, "Segoe UI Emoji", "Segoe UI Symbol";
  --font-size-base: 16px;
  --font-size-sm: 14px;
  --font-size-xs: 12px;
  --font-size-lg: 18px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --shadow-sm: rgba(15, 15, 15, 0.05) 0px 0px 0px 1px, rgba(15, 15, 15, 0.1) 0px 3px 6px;
  --shadow-md: rgba(15, 15, 15, 0.05) 0px 0px 0px 1px, rgba(15, 15, 15, 0.1) 0px 5px 10px, rgba(15, 15, 15, 0.2) 0px 15px 40px;
  --transition: 0.2s ease;
  --container-width: 1300px;
  --header-height: 60px;
}

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

html {
  font-size: var(--font-size-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.5;
  min-height: 100vh;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-primary-hover);
}

img {
  max-width: 100%;
  height: auto;
}

ul, ol {
  list-style: none;
}

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

/* Container */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.header-sticky {
  position: sticky;
  top: 0;
  z-index: 100;
}
.header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
}

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

.header-left,
.header-right {
  display: flex;
  align-items: center;
}

.header-right {
  gap: 16px;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-text);
  font-weight: 600;
  font-size: var(--font-size-lg);
}

.logo-link:hover {
  color: var(--color-text);
}

.logo-link img {
  height: 42px;
  width: auto;
}

.logo-badge {
  padding: 2px 8px;
  font-size: var(--font-size-xs);
  color: var(--color-primary);
  background: rgba(35, 131, 226, 0.12);
  border-radius: 999px;
}

/* Navigation */
.nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  padding: 6px 12px;
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.nav-link:hover {
  background: rgba(55, 53, 47, 0.08);
  color: var(--color-text);
}

.nav-link.active {
  color: var(--color-text);
  font-weight: 500;
}

.nav-link i {
  font-size: 16px;
}

.nav-caret {
  font-size: 14px;
  margin-left: 2px;
  transition: transform var(--transition);
}

.dropdown:hover .nav-caret {
  transform: rotate(180deg);
}

/* Dropdown */
.dropdown {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 180px;
  padding: 6px 0;
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all var(--transition);
}

.dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(4px);
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  transition: background var(--transition);
}

.dropdown-item:hover {
  background: rgba(55, 53, 47, 0.08);
  color: var(--color-text);
}

/* Mobile Menu Toggle */
.menu-toggle {
  display: none;
  width: 32px;
  height: 32px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
}

.menu-toggle:hover {
  background: rgba(55, 53, 47, 0.08);
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--color-text);
  position: relative;
}

.menu-toggle span::before,
.menu-toggle span::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 2px;
  background: var(--color-text);
  left: 0;
}

.menu-toggle span::before { top: -6px; }
.menu-toggle span::after { bottom: -6px; }

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.user-btn {
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(55, 53, 47, 0.08);
  color: var(--color-text-light);
  font-size: 18px;
  cursor: pointer;
  transition: all var(--transition);
  border: 1px solid transparent;
}

.user-btn:hover {
  background: rgba(55, 53, 47, 0.16);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Language Dropdown */
.lang-dropdown {
  position: relative;
}

.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-light);
  background: var(--color-bg-white);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn:hover {
  border-color: var(--color-border-dark);
  color: var(--color-text);
}

.lang-btn i:first-child {
  font-size: 16px;
}

.lang-btn i:last-child {
  font-size: 14px;
  margin-left: 2px;
  transition: transform var(--transition);
}

.lang-dropdown:hover .lang-btn i:last-child {
  transform: rotate(180deg);
}

.lang-menu {
  position: absolute;
  top: 100%;
  right: 0;
  min-width: 120px;
  padding: 6px 0;
  margin-top: 4px;
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all var(--transition);
}

.lang-dropdown:hover .lang-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-item {
  display: block;
  padding: 8px 14px;
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  transition: all var(--transition);
}

.lang-item:hover {
  background: rgba(55, 53, 47, 0.08);
  color: var(--color-text);
}

.lang-item.active {
  color: var(--color-primary);
  font-weight: 500;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  white-space: nowrap;
}

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

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

.btn-secondary {
  background: var(--color-bg-white);
  color: var(--color-text);
  border: 1px solid var(--color-border-dark);
}

.btn-secondary:hover {
  background: rgba(55, 53, 47, 0.08);
}

.btn-ghost {
  color: var(--color-text-light);
}

.btn-ghost:hover {
  background: rgba(55, 53, 47, 0.08);
  color: var(--color-text);
}

.btn-lg {
  padding: 12px 24px;
  font-size: var(--font-size-base);
}

/* Reveal Animations */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.scroll-reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* Btn Glow */
.btn-glow {
  position: relative;
  overflow: hidden;
}

.btn-glow::after {
  content: "";
  position: absolute;
  top: -50%;
  left: -60%;
  width: 40%;
  height: 200%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.25), transparent);
  transform: skewX(-20deg);
  animation: btn-shimmer 3s ease-in-out infinite;
}

@keyframes btn-shimmer {
  0% { left: -60%; }
  100% { left: 120%; }
}

/* Section Common */
.section {
  padding: 64px 0;
}

.section-header {
  margin-bottom: 36px;
  max-width: 720px;
}

.section-header.center {
  text-align: center;
  max-width: 620px;
  margin: 0 auto 36px;
}

.section-kicker {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 10px;
  padding: 4px 12px;
  background: rgba(35, 131, 226, 0.08);
  border-radius: 999px;
}

.section-title {
  font-size: clamp(28px, 3vw, 36px);
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: var(--font-size-base);
  color: var(--color-text-light);
  line-height: 1.7;
}

/* Highlight Item */
.highlight-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  background: rgba(255, 255, 255, 0.98);
  font-size: var(--font-size-xs);
  color: #666;
  border: 1px solid #ccc;
  font-weight: 500;
  border-radius: 20px;
}

.highlight-item i {
  font-size: 15px;
}

/* Footer */
.footer {
  padding: 48px 0 24px;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-white);
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 2fr) repeat(3, minmax(0, 1fr));
  gap: 24px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-border);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.footer-logo {
  font-size: var(--font-size-lg);
}

.footer-desc {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  line-height: 1.6;
}

.footer-social {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 4px;
}

.footer-social-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  color: var(--color-text-light);
  background: var(--color-bg-elevated, rgba(0,0,0,0.04));
  transition: color 0.2s, background 0.2s;
}

.footer-social-icon:hover {
  color: var(--color-text);
  background: var(--color-bg-hover, rgba(0,0,0,0.08));
}

.footer-social-icon i {
  font-size: 18px;
}

.footer-social-icon .xhs-icon {
  width: 18px;
  height: 18px;
}

.footer-social-link {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.footer-social-link i {
  font-size: 16px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-title {
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.footer-link {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 18px;
  flex-wrap: wrap;
}

.footer-copy,
.footer-meta {
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
}

.footer-copy {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.footer-copy a,
.footer-meta a {
  color: var(--color-text-muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.footer-divider {
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  padding: 0 6px;
}

.record-icon {
  width: 14px;
  height: 14px;
  display: inline-block;
  vertical-align: middle;
}

.back-to-top {
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.back-to-top:hover,
.footer-link:hover,
.footer-social-link:hover,
.footer-social-icon:hover {
  color: var(--color-text);
}

/* Modal */
body.modal-open {
  overflow: hidden;
}

.modal-overlay,
.app-modal {
  position: fixed;
  inset: 0;
  padding: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 23, 42, 0.52);
  -webkit-backdrop-filter: blur(3px);
  backdrop-filter: blur(3px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  z-index: 1000;
  transition: opacity 0.24s ease, visibility 0s linear 0.24s;
}

.modal-overlay.active,
.app-modal.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition: opacity 0.28s ease;
}

.modal-overlay .modal-content,
.app-modal .modal-content {
  background: var(--color-bg-white);
  border: 1px solid rgba(37, 99, 235, 0.14);
  border-radius: 16px;
  box-shadow: 0 20px 60px rgba(15, 23, 42, 0.32);
  width: min(420px, 100%);
  position: relative;
  transform: translateY(16px) scale(0.96);
  opacity: 0;
  transition: transform 0.28s cubic-bezier(0.22, 1, 0.36, 1), opacity 0.2s ease;
}

.modal-overlay.active .modal-content,
.app-modal.active .modal-content {
  transform: translateY(0) scale(1);
  opacity: 1;
}

.modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  color: var(--color-text-muted);
  font-size: 20px;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.modal-close:hover {
  background: rgba(55, 53, 47, 0.08);
  color: var(--color-text);
}

.modal-close:active {
  transform: scale(0.95);
}

.login-modal-panel {
  padding: 22px;
}

.login-modal {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.login-modal-icon {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(34, 197, 94, 0.14);
  color: #16a34a;
  font-size: 24px;
}

.login-modal-title {
  font-size: 20px;
  line-height: 1.3;
  color: var(--color-text);
  margin: 0;
}

.login-modal-subtitle {
  margin: 0;
  font-size: 14px;
  color: var(--color-text-light);
}

.login-modal-qr-wrap {
  margin-top: 4px;
  padding: 10px;
  border-radius: 14px;
  border: 1px solid var(--color-border);
  background: linear-gradient(180deg, #f8fbff 0%, #f2f6ff 100%);
}

.login-modal-qr {
  width: 200px;
  max-width: 52vw;
  display: block;
  border-radius: 10px;
  border: 1px solid var(--color-border);
  background: #fff;
}

.login-modal-agree {
  margin: 8px 0 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--color-text-muted);
}

.login-modal-agree a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

@media (max-width: 480px) {
  .modal-overlay,
  .app-modal {
    padding: 12px;
  }

  .login-modal-panel {
    padding: 18px;
  }

  .login-modal-title {
    font-size: 18px;
  }

  .login-modal-qr {
    width: 176px;
  }
}

/* Loader */
#loader-container {
  position: fixed;
  inset: 0;
  background: rgba(255, 255, 255, 0.9);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

#loader-container.active {
  display: flex;
}

#loader {
  width: 32px;
  height: 32px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Responsive */
@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }

  .header-right {
    gap: 8px;
  }

  .header-cta {
    display: none;
  }

  .lang-dropdown {
    display: none;
  }

  .nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-bg-white);
    flex-direction: column;
    padding: 16px;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
  }

  .nav.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-link {
    width: 100%;
    padding: 12px;
  }

  .dropdown-menu {
    position: static;
    box-shadow: none;
    opacity: 1;
    visibility: visible;
    transform: none;
    padding-left: 16px;
  }

  .footer-top {
    grid-template-columns: 1fr;
    text-align: left;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .reveal, .scroll-reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .btn-glow::after { animation: none; }
}

/* Region redirect banner */
.region-banner {
  background: var(--color-primary);
  color: #fff;
  font-size: var(--font-size-sm);
  padding: 10px 0;
  position: relative;
}
.region-banner-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}
.region-banner-inner > i { font-size: 18px; }
.region-banner-btn {
  color: #fff;
  background: rgba(255,255,255,0.2);
  padding: 3px 14px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-weight: 500;
  transition: background var(--transition);
}
.region-banner-btn:hover { background: rgba(255,255,255,0.35); }
.region-banner-close {
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: #fff;
  font-size: 20px;
  cursor: pointer;
  opacity: 0.7;
  line-height: 1;
}
.region-banner-close:hover { opacity: 1; }
@media (max-width: 768px) {
  .region-banner { font-size: var(--font-size-xs); padding: 8px 40px 8px 0; }
  .region-banner-inner { gap: 6px; }
}