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

:root {
  --color-bg: #FAFAF9;
  --color-bg-alt: #F4F3EF;
  --color-surface: #FFFFFF;
  --color-text: #1A1A1A;
  --color-text-secondary: #5C5C5C;
  --color-text-muted: #999999;
  --color-accent: #B8935A;
  --color-accent-hover: #9A7A42;
  --color-accent-light: rgba(184, 147, 90, 0.08);
  --color-border: #E8E6E1;
  --color-border-light: #F0EFEB;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "SimSun", "STSong", Georgia, serif;
  --max-width: 1080px;
  --nav-height: 64px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  /* 锚点不被固定导航遮挡 */
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  /* 防止固定导航遮挡顶部内容 */
  padding-top: var(--nav-height);
}

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

img {
  max-width: 100%;
  display: block;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(250, 250, 249, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
  transition: all 0.3s ease;
  height: var(--nav-height);
}

.nav.scrolled {
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--color-text);
}

.nav-logo-sub {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}

.nav-links {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-links a {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  transition: color 0.2s;
}

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

.nav-cta {
  padding: 8px 20px;
  background: var(--color-accent);
  color: #fff !important;
  border-radius: 6px;
  font-weight: 500;
  transition: background 0.2s;
}

.nav-cta:hover {
  background: var(--color-accent-hover);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 110;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Section Shared ===== */
.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
}

section {
  padding: 100px 0;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
  letter-spacing: 0.03em;
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-secondary);
  font-size: 1.05rem;
  margin-bottom: 56px;
  line-height: 1.6;
}

/* ===== Hero ===== */
.hero {
  padding: 100px 0 80px;
  text-align: center;
  background: var(--color-bg);
}

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
}

.hero-brand {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.hero-tag {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--color-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 32px;
  padding: 6px 18px;
  border: 1px solid var(--color-accent);
  border-radius: 100px;
  font-weight: 500;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 6vw, 3.5rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0.02em;
  margin-bottom: 28px;
  word-break: break-word;
}

.hero-highlight {
  color: var(--color-accent);
}

.hero-values {
  font-size: 0.95rem;
  color: var(--color-accent);
  letter-spacing: 0.06em;
  margin-bottom: 32px;
  font-weight: 500;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  line-height: 1.9;
  max-width: 560px;
  margin: 0 auto 40px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn-primary {
  display: inline-block;
  padding: 14px 36px;
  background: var(--color-accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  font-family: var(--font-sans);
  text-align: center;
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(184, 147, 90, 0.3);
}

.btn-secondary {
  display: inline-block;
  padding: 14px 36px;
  background: transparent;
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.25s ease;
  font-family: var(--font-sans);
  text-align: center;
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn-full {
  width: 100%;
  display: block;
}

/* ===== About ===== */
.about {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-light);
  border-bottom: 1px solid var(--color-border-light);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 72px;
  align-items: start;
}

.about-lead {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 20px;
  line-height: 1.8;
}

.about-text p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  line-height: 1.85;
}

.about-stats {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.stat-card {
  background: var(--color-bg-alt);
  border-radius: 12px;
  padding: 28px 24px;
  text-align: center;
  border: 1px solid var(--color-border-light);
}

.stat-number {
  display: block;
  font-family: var(--font-serif);
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.2;
}

.stat-plus {
  font-size: 1.2rem;
  vertical-align: super;
}

.stat-label {
  display: block;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-top: 4px;
}

/* ===== Philosophy ===== */
.philosophy {
  background: var(--color-bg);
}

.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.philosophy-item {
  text-align: center;
  padding: 40px 28px;
}

.philosophy-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  border-radius: 16px;
  background: var(--color-accent-light);
  color: var(--color-accent);
  margin-bottom: 24px;
}

.philosophy-item h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.philosophy-item p {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ===== Knowledge Base ===== */
.knowledge {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-light);
  border-bottom: 1px solid var(--color-border-light);
}

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

.knowledge-card {
  display: block;
  padding: 36px 32px;
  border: 1px solid var(--color-border-light);
  border-radius: 12px;
  background: var(--color-bg);
  transition: all 0.3s ease;
  cursor: pointer;
}

.knowledge-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
  transform: translateY(-2px);
}

.knowledge-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin-bottom: 16px;
  padding: 4px 10px;
  background: var(--color-accent-light);
  border-radius: 4px;
}

.knowledge-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.knowledge-card p {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

.knowledge-link {
  font-size: 0.9rem;
  color: var(--color-accent);
  font-weight: 500;
}

/* ===== Services ===== */
.services {
  background: var(--color-bg);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.service-card {
  display: block;
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: 12px;
  padding: 40px 32px;
  transition: all 0.3s ease;
}

.service-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
}

.service-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border-light);
}

.service-card p {
  color: var(--color-text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 20px;
}

.service-card ul {
  list-style: none;
  padding: 0;
}

.service-card ul li {
  position: relative;
  padding-left: 20px;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 8px;
}

.service-card ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  opacity: 0.5;
}

/* ===== Social Proof ===== */
.social-proof {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-light);
  border-bottom: 1px solid var(--color-border-light);
}

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

.social-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 36px 24px;
  border: 1px solid var(--color-border-light);
  border-radius: 12px;
  transition: all 0.3s ease;
  text-align: center;
}

.social-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
}

.social-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.wechat-icon {
  background: #E8F5E2;
  color: #07C160;
}

.video-icon {
  background: #FFF0E0;
  color: #FA7834;
}

.xhs-icon {
  background: #FFE8E8;
  color: #FF2442;
}

.social-name {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.social-desc {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ===== Contact ===== */
.contact {
  background: var(--color-bg-alt);
}

.contact-form {
  max-width: 560px;
  margin: 0 auto;
  background: var(--color-surface);
  padding: 48px 40px;
  border-radius: 16px;
  border: 1px solid var(--color-border-light);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.03);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.form-group {
  margin-bottom: 24px;
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--color-text);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  transition: all 0.2s ease;
  outline: none;
  -webkit-appearance: none;
  appearance: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-light);
  background: var(--color-surface);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--color-text-muted);
}

.form-group select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23999' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
  cursor: pointer;
}

.form-note {
  margin-top: 16px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  text-align: center;
  line-height: 1.5;
}

/* ===== Contact Success State ===== */
.contact-success {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 56px 32px;
  animation: fadeInUp 0.4s ease;
}

.contact-success-icon {
  margin-bottom: 24px;
}

.contact-success h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: 12px;
}

.contact-success p {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  max-width: 420px;
  line-height: 1.7;
  margin-bottom: 28px;
}

.contact-success p strong {
  color: var(--color-accent);
  font-weight: 600;
}

.contact-success .btn-primary {
  padding: 12px 40px;
  font-size: 1rem;
}

/* ===== Footer ===== */
.footer {
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.7);
  padding: 48px 0;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-logo {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
}

.footer-brand p {
  font-size: 0.9rem;
  margin-top: 4px;
  color: rgba(255, 255, 255, 0.5);
}

.footer-links {
  display: flex;
  gap: 24px;
  font-size: 0.85rem;
  flex-wrap: wrap;
  align-items: center;
}

.footer-icp {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.8rem;
  opacity: 0.7;
  transition: opacity 0.2s;
}

.footer-icp:hover {
  opacity: 1;
  text-decoration: underline;
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: var(--color-text);
  color: #fff;
  padding: 14px 28px;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 500;
  z-index: 200;
  opacity: 0;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ===== Checkbox Group ===== */
.checkbox-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.checkbox-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border: 1.5px solid var(--color-border);
  border-radius: 8px;
  background: var(--color-bg);
  cursor: pointer;
  transition: all 0.2s ease;
  user-select: none;
}

.checkbox-item:hover {
  border-color: var(--color-accent);
  background: var(--color-accent-light);
}

.checkbox-item:has(input:checked) {
  border-color: var(--color-accent);
  background: var(--color-accent-light);
}

.checkbox-item input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border: 2px solid var(--color-border);
  border-radius: 4px;
  flex-shrink: 0;
  position: relative;
  cursor: pointer;
  transition: all 0.15s ease;
  background: var(--color-surface);
  margin: 0;
  padding: 0;
}

.checkbox-item input[type="checkbox"]:checked {
  background: var(--color-accent);
  border-color: var(--color-accent);
}

.checkbox-item input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 5px;
  top: 2px;
  width: 6px;
  height: 10px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checkbox-label {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  font-weight: 500;
}

.checkbox-item:has(input:checked) .checkbox-label {
  color: var(--color-accent);
  font-weight: 600;
}

/* ===== Auth Button ===== */
.nav-auth-btn {
  font-size: 0.9rem;
  color: var(--color-accent) !important;
  font-weight: 500;
  transition: opacity 0.2s;
}

.nav-auth-btn:hover {
  opacity: 0.7;
}

.nav-auth-btn.logged-in {
  color: var(--color-text-secondary) !important;
}

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  padding: 20px;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-container {
  background: var(--color-surface);
  border-radius: 16px;
  padding: 44px 40px 36px;
  max-width: 440px;
  width: 100%;
  position: relative;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.12);
  transform: translateY(20px);
  transition: transform 0.3s ease;
}

.modal-overlay.active .modal-container {
  transform: translateY(0);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 20px;
  background: none;
  border: none;
  font-size: 1.6rem;
  color: var(--color-text-muted);
  cursor: pointer;
  line-height: 1;
  padding: 4px;
  transition: color 0.2s;
}

.modal-close:hover {
  color: var(--color-text);
}

/* Tabs */
.modal-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 32px;
  border-bottom: 2px solid var(--color-border-light);
}

.modal-tab {
  flex: 1;
  background: none;
  border: none;
  padding: 12px 0;
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text-muted);
  cursor: pointer;
  font-family: var(--font-sans);
  transition: all 0.2s;
  position: relative;
}

.modal-tab.active {
  color: var(--color-accent);
}

.modal-tab.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-accent);
}

/* Auth Form */
.auth-form {
  display: block;
}

.auth-form.hidden {
  display: none;
}

.auth-form .form-group {
  margin-bottom: 20px;
}

.auth-form .form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--color-text);
}

.auth-form .form-group input,
.auth-form .form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  transition: all 0.2s ease;
  outline: none;
  -webkit-appearance: none;
  appearance: none;
}

.auth-form .form-group input:focus,
.auth-form .form-group select:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-light);
  background: var(--color-surface);
}

.auth-form .form-group select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23999' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
  cursor: pointer;
}

.auth-form .required {
  color: #E74C3C;
}

.auth-error {
  color: #E74C3C;
  font-size: 0.85rem;
  margin-bottom: 16px;
  min-height: 20px;
}

.auth-form .form-note {
  margin-top: 12px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  text-align: center;
}

/* ============================================
   Responsive — Tablet (<= 900px)
   ============================================ */
@media (max-width: 900px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-stats {
    flex-direction: row;
  }

  .stat-card {
    flex: 1;
  }

  .philosophy-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .services-grid {
    grid-template-columns: 1fr;
  }

  .knowledge-grid {
    grid-template-columns: 1fr;
  }

  .social-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   Responsive — Mobile (<= 768px)
   ============================================ */
@media (max-width: 768px) {
  section {
    padding: 72px 0;
  }

  .hero {
    padding: 80px 0 60px;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 260px;
    height: 100vh;
    flex-direction: column;
    background: var(--color-surface);
    padding: 96px 32px 32px;
    gap: 24px;
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.08);
    transition: right 0.3s ease;
    align-items: flex-start;
  }

  .nav-links.active {
    right: 0;
  }

  .nav-links a {
    font-size: 1.05rem;
  }

  .nav-cta {
    padding: 12px 24px;
    font-size: 1rem !important;
  }

  .nav-toggle {
    display: flex;
  }

  .hero-title {
    font-size: clamp(1.4rem, 7vw, 2rem);
  }

  .hero-desc {
    font-size: 1rem;
  }

  .philosophy-grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .contact-form {
    padding: 32px 20px;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
    gap: 20px;
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
  }

  /* 统计卡片在手机端改为竖排 */
  .about-stats {
    flex-direction: column;
  }

  .stat-card {
    flex: none;
  }
}

/* ============================================
   Responsive — Small Mobile (<= 480px)
   ============================================ */
@media (max-width: 480px) {
  :root {
    --nav-height: 56px;
  }

  .section-inner {
    padding: 0 20px;
  }

  .nav-inner {
    padding: 0 20px;
  }

  section {
    padding: 56px 0;
  }

  .hero {
    padding: 64px 0 48px;
  }

  .hero-brand {
    font-size: 0.8rem;
  }

  .hero-tag {
    font-size: 0.75rem;
    padding: 5px 14px;
  }

  .hero-title {
    font-size: clamp(1.2rem, 7vw, 1.6rem);
    margin-bottom: 20px;
  }

  .hero-values {
    font-size: 0.8rem;
    margin-bottom: 20px;
  }

  .hero-desc {
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 28px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-secondary {
    width: 100%;
    text-align: center;
    padding: 14px 20px;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .section-subtitle {
    font-size: 0.9rem;
    margin-bottom: 36px;
  }

  .about-lead {
    font-size: 1.05rem;
  }

  .stat-number {
    font-size: 2rem;
  }

  .philosophy-item {
    padding: 28px 20px;
  }

  .knowledge-card {
    padding: 28px 20px;
  }

  .service-card {
    padding: 32px 20px;
  }

  .social-card {
    padding: 28px 20px;
  }

  .contact-form {
    padding: 28px 16px;
  }

  .checkbox-group {
    grid-template-columns: 1fr;
  }

  .form-group input,
  .form-group select,
  .form-group textarea {
    padding: 14px 14px;
    font-size: 1rem;
  }

  .footer-inner {
    padding: 0 20px;
  }

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

/* ===== 登录下拉菜单 + 个人中心 ===== */

.auth-dropdown {
  position: fixed;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.12);
  min-width: 200px;
  padding: 12px 0;
  z-index: 10000;
}

.auth-dropdown-user {
  padding: 12px 16px;
  border-bottom: 1px solid #f0f0f0;
  margin-bottom: 4px;
}

.auth-dropdown-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: #1a1a2e;
}

.auth-dropdown-phone {
  font-size: 0.8rem;
  color: #888;
  margin-top: 2px;
}

.auth-dropdown-divider {
  height: 1px;
  background: #f0f0f0;
  margin: 4px 0;
}

.auth-dropdown-item {
  display: block;
  padding: 10px 16px;
  color: #444;
  text-decoration: none;
  font-size: 0.9rem;
  transition: background 0.15s;
}

.auth-dropdown-item:hover {
  background: #f7f7fa;
}

.auth-dropdown-logout {
  color: #e74c3c;
}

.auth-dropdown-logout:hover {
  background: #fef2f2;
}

/* 个人中心弹窗 */
.auth-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10001;
  animation: authFadeIn 0.2s ease;
}

.auth-modal {
  background: #fff;
  border-radius: 16px;
  padding: 32px 28px 24px;
  max-width: 380px;
  width: 90%;
  position: relative;
  animation: authSlideUp 0.25s ease;
}

.auth-modal-close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: #999;
  line-height: 1;
}

.auth-modal-header {
  text-align: center;
  margin-bottom: 24px;
}

.auth-avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #4361ee, #7209b7);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 700;
  margin: 0 auto 12px;
}

.auth-modal-header h3 {
  margin: 0 0 4px;
  font-size: 1.1rem;
  color: #1a1a2e;
}

.auth-phone-display {
  font-size: 0.85rem;
  color: #888;
  margin: 0;
}

.auth-profile-info {
  margin-bottom: 20px;
}

.auth-info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid #f5f5f5;
}

.auth-info-row:last-child {
  border-bottom: none;
}

.auth-info-label {
  font-size: 0.85rem;
  color: #888;
}

.auth-info-value {
  font-size: 0.85rem;
  color: #1a1a2e;
  font-weight: 500;
}

.auth-profile-actions {
  text-align: center;
}

.auth-btn-secondary {
  background: #f0f0f5;
  color: #444;
  border: none;
  padding: 10px 28px;
  border-radius: 8px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.15s;
}

.auth-btn-secondary:hover {
  background: #e4e4ec;
}

@keyframes authFadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes authSlideUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}