.pi-header { height: 72px; border-bottom: 1px solid var(--pi-border); background: #fff; display: flex; align-items: center; }
.pi-header__inner { width: 100%; max-width: 1240px; margin: 0 auto; padding: 0 20px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.pi-header__left { display: flex; align-items: center; gap: 14px; min-width: 0; }
.pi-back { width: 36px; height: 36px; border-radius: 10px; border: 1px solid var(--pi-border); color: var(--pi-text); display: inline-flex; align-items: center; justify-content: center; text-decoration: none; flex-shrink: 0; }
.pi-title { margin: 0; font-size: 22px; font-weight: 600; line-height: 1.2; }
.pi-lang { height: 36px; border: 1px solid var(--pi-border); border-radius: 10px; padding: 0 36px 0 16px; background: #fff; font-size: 14px; -webkit-appearance: none; -moz-appearance: none; appearance: none; 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 fill='%236f7787' d='M1.41.59 6 5.17 10.59.59 12 2 6 8 0 2z'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 14px center; }

@media (max-width: 900px) { .pi-title { font-size: 22px; } }
@media (max-width: 640px) { .pi-header__inner { padding-left: 14px; padding-right: 14px; } .pi-title { font-size: 19px; } }