body {
    min-height: 100vh;
    font-family: var(--btir-font);
    color: var(--btir-text);
    background: linear-gradient(160deg, var(--btir-bg) 0%, var(--btir-bg-soft) 100%);
}

.download-header {
    position: sticky;
    top: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    background: var(--btir-surface);
    border-bottom: 1px solid var(--btir-border);
    box-shadow: var(--btir-shadow-sm);
}

.download-back, .download-theme {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-height: 40px;
    padding: 6px 12px;
    color: var(--btir-text-secondary);
    background: transparent;
    border: 0;
    border-radius: 999px;
    font: inherit;
    font-size: 13px;
    text-decoration: none;
    cursor: pointer;
    transition: color var(--btir-transition), background-color var(--btir-transition), transform var(--btir-transition);
}

.download-back:hover, .download-theme:hover {
    color: var(--btir-primary);
    background: var(--btir-primary-soft);
}

.download-theme:active { transform: scale(0.92); }

.download-title { color: var(--btir-primary); font-size: 16px; font-weight: 700; }
.download-theme { width: 40px; padding: 0; margin-left: auto; }
.theme-sun, [data-theme="dark"] .theme-moon { display: none; }
[data-theme="dark"] .theme-sun { display: block; }

.download-main { max-width: 1040px; margin: 32px auto; padding: 0 24px; }
.download-hero {
    display: flex;
    align-items: center;
    gap: 24px;
    padding: 32px;
    margin-bottom: 32px;
    background: linear-gradient(135deg, var(--btir-primary-soft) 0%, var(--btir-surface) 100%);
    border: 1px solid var(--btir-border);
    border-radius: var(--btir-radius-lg);
}

.download-logo {
    width: 68px;
    height: 68px;
    flex-shrink: 0;
    background-color: var(--btir-primary);
    -webkit-mask: url('/assets/icon_exp.png') center / contain no-repeat;
    mask: url('/assets/icon_exp.png') center / contain no-repeat;
}

[data-theme="dark"] .download-logo { background-color: #ffffff; }
h1 { margin-bottom: 10px; color: var(--btir-primary); font-size: 26px; line-height: 1.4; }
.download-hero p:last-child { color: var(--btir-text-secondary); font-size: 14px; line-height: 1.8; }
.download-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.download-card {
    display: flex;
    flex-direction: column;
    padding: 28px;
    background: var(--btir-surface);
    border: 1px solid var(--btir-border);
    border-radius: var(--btir-radius-md);
    box-shadow: var(--btir-shadow-sm);
}

.download-card-heading { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; }
.download-device { display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; width: 54px; height: 54px; color: var(--btir-primary); background: var(--btir-primary-soft); border-radius: var(--btir-radius-md); }
.download-card h2 { font-size: 20px; }
.download-platforms { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0; list-style: none; }
.download-platforms li { display: inline-flex; align-items: center; gap: 7px; padding: 6px 10px; color: var(--btir-accent); background: var(--btir-primary-soft); border-radius: var(--btir-radius-sm); font-size: 14px; font-weight: 600; }
.download-card-note { margin-bottom: 24px; color: var(--btir-text-secondary); font-size: 14px; line-height: 1.8; }
/* 发布查询状态仅供辅助技术播报，避免在页面堆叠技术说明。 */
.download-release-status { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.download-action { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 44px; margin-top: auto; padding: 12px 16px; color: #ffffff; background: linear-gradient(160deg, var(--btir-primary-hover) 0%, var(--btir-primary) 100%); border-radius: var(--btir-radius-sm); text-decoration: none; font-size: 14px; font-weight: 600; transition: all var(--btir-transition); }
.download-action:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(30, 60, 114, 0.32); }
.download-action:active { transform: translateY(0); }
.download-note { margin-top: 24px; text-align: center; color: var(--btir-text-secondary); font-size: 14px; line-height: 1.8; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--btir-accent); outline-offset: 3px; }

@media (max-width: 640px) {
    .download-header { gap: 8px; padding: 10px 12px; }
    .download-main { margin: 20px auto; padding: 0 16px; }
    .download-hero { align-items: flex-start; gap: 16px; padding: 24px 20px; margin-bottom: 24px; }
    .download-logo { width: 44px; height: 44px; }
    h1 { font-size: 21px; }
    .download-grid { grid-template-columns: 1fr; gap: 16px; }
    .download-card { padding: 24px; }
}

@media (max-width: 360px) {
    .download-hero { flex-direction: column; }
    .download-card { padding: 20px; }
}