:root {
  --bg-primary: #f5f7fb;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f8f9fc;
  --bg-input: #f0f2f8;
  --bg-nav: rgba(255, 255, 255, 0.85);
  --border-color: #e2e6ef;
  --border-light: #d0d5e2;
  --text-primary: #1a1d2e;
  --text-secondary: #5c6278;
  --text-muted: #9099b0;
  --accent: #5b6cf7;
  --accent-hover: #4a5be6;
  --accent-light: rgba(91, 108, 247, 0.08);
  --accent-glow: rgba(91, 108, 247, 0.18);
  --success: #22c55e;
  --success-light: rgba(34, 197, 94, 0.1);
  --warning: #f59e0b;
  --warning-light: rgba(245, 158, 11, 0.1);
  --danger: #ef4444;
  --danger-light: rgba(239, 68, 68, 0.1);
  --price-color: #e8453c;
  --tag-auto: #16a34a;
  --tag-recommend: #d97706;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --shadow-xs: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-sm: 0 1px 4px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.07), 0 1px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.08), 0 2px 8px rgba(0,0,0,0.04);
  --shadow-card: 0 1px 3px rgba(0,0,0,0.05), 0 1px 2px rgba(0,0,0,0.03);
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

/* ===== Navbar ===== */
.navbar {
  background: var(--bg-nav);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
}

.nav-container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 28px;
  height: 60px;
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-logo {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary) !important;
  white-space: nowrap;
  letter-spacing: -0.3px;
}

.nav-links {
  display: flex;
  gap: 4px;
}

.nav-link {
  padding: 7px 16px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary) !important;
  font-size: 14px;
  font-weight: 500;
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--text-primary) !important;
  background: var(--bg-input);
}

.nav-link.active {
  color: var(--accent) !important;
  background: var(--accent-light);
}

.nav-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-search {
  cursor: pointer;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  transition: var(--transition);
}

.nav-search:hover {
  background: var(--bg-input);
  color: var(--text-primary);
}

.search-icon {
  font-size: 18px;
}

.nav-auth, .nav-user {
  display: flex;
  align-items: center;
  gap: 4px;
}

.user-name {
  color: var(--accent);
  font-size: 14px;
  font-weight: 500;
  margin-right: 8px;
}

/* ===== Main Content ===== */
.main-content {
  max-width: 1140px;
  margin: 0 auto;
  padding: 36px 28px;
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 36px 28px;
  color: var(--text-muted);
  font-size: 13px;
  border-top: 1px solid var(--border-color);
  margin-top: 56px;
  background: var(--bg-secondary);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  gap: 6px;
  letter-spacing: 0.01em;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 1px 3px rgba(91, 108, 247, 0.3);
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff !important;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(91, 108, 247, 0.35);
}

.btn-primary:active {
  transform: translateY(0);
}

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

.btn-secondary:hover {
  background: var(--bg-input);
  border-color: var(--border-light);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
  box-shadow: 0 1px 3px rgba(239, 68, 68, 0.25);
}

.btn-danger:hover {
  background: #dc2626;
  transform: translateY(-1px);
}

.btn-sm {
  padding: 6px 14px;
  font-size: 13px;
  border-radius: 6px;
}

.btn-block {
  width: 100%;
}

/* ===== Form Elements ===== */
.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 7px;
  letter-spacing: 0.01em;
}

.form-input {
  width: 100%;
  padding: 11px 15px;
  background: var(--bg-input);
  border: 1.5px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  transition: var(--transition);
  outline: none;
}

.form-input:hover {
  border-color: var(--border-light);
}

.form-input:focus {
  border-color: var(--accent);
  background: var(--bg-secondary);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

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

select.form-input {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%239099b0' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 38px;
}

textarea.form-input {
  resize: vertical;
  min-height: 100px;
}

/* ===== Tags ===== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.tag-auto {
  background: var(--success-light);
  color: var(--tag-auto);
}

.tag-recommend {
  background: var(--warning-light);
  color: var(--tag-recommend);
}

/* ===== Card ===== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: var(--transition);
  box-shadow: var(--shadow-card);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(15, 23, 42, 0.45);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
}

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

.modal {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px;
  max-width: 440px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  transform: translateY(16px) scale(0.97);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-lg);
}

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

.modal-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.modal-close {
  float: right;
  background: var(--bg-input);
  border: none;
  color: var(--text-muted);
  font-size: 18px;
  cursor: pointer;
  padding: 6px 10px;
  border-radius: 8px;
  transition: var(--transition);
}

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

/* ===== Toast ===== */
.toast-container {
  position: fixed;
  top: 76px;
  right: 24px;
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.toast {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 22px;
  font-size: 14px;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.35s cubic-bezier(0.4, 0, 0.2, 1), toastOut 0.35s cubic-bezier(0.4, 0, 0.2, 1) 2.65s forwards;
  max-width: 380px;
}

.toast.success {
  border-left: 4px solid var(--success);
}

.toast.error {
  border-left: 4px solid var(--danger);
}

.toast.warning {
  border-left: 4px solid var(--warning);
}

@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px) scale(0.95); }
  to { opacity: 1; transform: translateX(0) scale(1); }
}

@keyframes toastOut {
  from { opacity: 1; transform: translateX(0) scale(1); }
  to { opacity: 0; transform: translateX(40px) scale(0.95); }
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-container {
    padding: 0 16px;
    gap: 12px;
  }

  .nav-search {
    display: none;
  }

  .main-content {
    padding: 24px 16px;
  }
}

@media (max-width: 480px) {
  .nav-logo {
    font-size: 15px;
  }

  .nav-link {
    padding: 6px 10px;
    font-size: 13px;
  }
}