.btn,
.form-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 700;
  line-height: 1;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.btn:hover,
.form-button:hover {
  transform: translateY(-1px);
}

.btn-primary,
.form-button {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-strong));
  color: #021014;
  box-shadow: 0 16px 36px rgba(34, 211, 238, 0.24);
}

.btn-secondary {
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: rgba(255, 255, 255, 0.08);
  color: var(--color-text);
}

.section-heading {
  display: grid;
  gap: 16px;
}

.section-heading__title {
  color: var(--color-text);
  font-size: 40px;
  font-weight: 700;
  line-height: 1.2;
}

.section-heading__lead {
  color: var(--color-text-muted);
  font-size: 16px;
  line-height: 1.6;
}

.section-motion {
  transform: translateY(10px);
  transition: transform 520ms cubic-bezier(0.22, 1, 0.36, 1);
  will-change: transform;
}

.section-motion.is-in-view {
  transform: translateY(0);
  will-change: auto;
}

@media (prefers-reduced-motion: reduce) {
  .section-motion,
  .section-motion.is-in-view {
    transform: none;
    transition: none;
  }
}

.content-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(18px);
}

.form-field {
  display: grid;
  gap: 8px;
}

.form-label {
  color: var(--color-text);
  font-size: 14px;
  font-weight: 600;
}

.form-input,
.form-textarea {
  width: 100%;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.06);
  color: var(--color-text);
  outline: none;
}

.form-input {
  height: 50px;
  padding: 0 14px;
}

.form-textarea {
  min-height: 120px;
  padding: 14px;
  resize: vertical;
}

.form-input:focus,
.form-textarea:focus {
  border-color: rgba(116, 247, 209, 0.7);
  box-shadow: 0 0 0 3px rgba(116, 247, 209, 0.12);
}

.admin-form-message,
.form-message {
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  background: rgba(116, 247, 209, 0.12);
  color: var(--color-primary);
  font-size: 14px;
}

.site-toast {
  position: fixed;
  left: 50%;
  bottom: 48px;
  z-index: 1000;
  max-width: calc(100% - 40px);
  padding: 14px 24px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: rgba(11, 16, 32, 0.92);
  color: var(--color-text);
  font-size: 15px;
  font-weight: 600;
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(18px);
  opacity: 0;
  transform: translate(-50%, 16px);
  transition: opacity var(--motion-fast) var(--motion-ease-out), transform var(--motion-fast) var(--motion-ease-out);
}

.site-toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (max-width: 768px) {
  .section-heading__title {
    font-size: 30px;
  }

  .section-motion {
    transform: translateY(6px);
    transition-duration: 360ms;
  }
}

@media (prefers-reduced-motion: reduce) {
  .section-motion,
  .section-motion.is-in-view {
    transform: none;
    transition: none;
  }
}

/* QQ 快捷登录弹窗（纯前端展示，无后台） */
.login-modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.login-modal.is-open {
  display: flex;
}

.login-modal__overlay {
  position: absolute;
  inset: 0;
  background: rgba(5, 7, 15, 0.55);
  backdrop-filter: blur(6px);
}

.login-modal__panel {
  position: relative;
  width: 100%;
  max-width: 380px;
  padding: 32px 28px 26px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 30px 80px rgba(5, 18, 40, 0.45);
  text-align: center;
}

.login-modal__close {
  position: absolute;
  top: 14px;
  right: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 999px;
  background: rgba(5, 103, 207, 0.08);
  color: #1f2937;
  cursor: pointer;
  transition: background 160ms ease;
}

.login-modal__close:hover {
  background: rgba(5, 103, 207, 0.16);
}

.login-modal__title {
  color: #0b1220;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.3;
}

.login-modal__hint {
  margin-top: 8px;
  color: #6b7280;
  font-size: 14px;
}

.login-modal__qq {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  height: 48px;
  margin-top: 24px;
  border: 0;
  border-radius: 999px;
  background: #0567cf;
  color: #ffffff;
  font-size: 15px;
  font-weight: 700;
  box-shadow: 0 12px 28px rgba(0, 98, 204, 0.28);
  cursor: pointer;
  transition: transform 160ms ease, background 160ms ease;
}

.login-modal__qq:hover {
  transform: translateY(-1px);
  background: #0066d1;
}

.login-modal__qq img {
  width: 22px;
  height: 22px;
  border-radius: 6px;
  object-fit: contain;
}

.login-modal__footnote {
  margin-top: 16px;
  color: #9ca3af;
  font-size: 12px;
}

@media (max-width: 480px) {
  .login-modal__panel {
    padding: 28px 20px 22px;
  }
}