.sidebar-feature-links { display: grid; gap: 2px; margin-top: 2px; }
.sidebar-feature-toggle .sidebar-quick-icon img { width: 20px; height: 20px; }
.sidebar-feature-chevron { margin-left: auto; padding-left: 8px; transition: transform .15s ease; opacity: .5; }
.sidebar-feature-toggle.is-expanded .sidebar-feature-chevron { transform: rotate(90deg); }
.sidebar-feature-panel { display: grid; gap: 12px; padding: 10px 8px 4px; }
.sidebar-feature-panel[hidden] { display: none !important; }
.study-controls-top { min-height: 32px; display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px; }
.study-mode-switch { flex: 0 0 auto; display: flex; padding: 2px; border-radius: 7px; background: color-mix(in srgb, currentColor 8%, transparent); }
.study-mode-switch button { min-width: 50px; height: 28px; padding: 0 8px; border: 0; border-radius: 5px; background: transparent; color: inherit; font-size: 12px; cursor: pointer; }
.study-mode-switch button[aria-pressed="true"] { background: var(--app-card, #fff); box-shadow: 0 1px 4px rgb(0 0 0 / 12%); font-weight: 700; }
/* 状态是提示不是报错：独占一行、可换行、灰色小字 */
.study-status { order: 3; flex: 1 1 100%; min-width: 0; font-size: 12px; line-height: 1.45; color: var(--app-muted, #777); white-space: normal; overflow-wrap: anywhere; }
.study-status:empty { display: none; }
.study-refresh { flex: 0 0 30px; width: 30px; height: 30px; padding: 0; border: 0; border-radius: 5px; background: transparent; color: inherit; font-size: 22px; cursor: pointer; }
.study-refresh:disabled, .study-mode-switch button:disabled { opacity: .5; cursor: wait; }
.study-vocabulary[hidden], .study-refresh[hidden] { display: none; }
.study-vocabulary { min-height: 37px; overflow: hidden; display: flex; align-items: center; gap: 7px; border-top: 1px solid color-mix(in srgb, currentColor 10%, transparent); color: var(--app-muted, #777); font-size: 12px; }
.study-vocabulary strong { flex: 0 0 auto; color: var(--app-text, #444); font-size: 12px; }
.study-vocabulary span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.study-settings { border-top: 1px solid color-mix(in srgb, currentColor 10%, transparent); padding-top: 8px; }
.study-settings summary { display: flex; align-items: center; gap: 8px; min-height: 30px; list-style: none; cursor: pointer; font-size: 13px; font-weight: 600; }
.study-settings summary::-webkit-details-marker { display: none; }
.study-settings summary::after { content: "›"; margin-left: 4px; opacity: .5; transition: transform .15s ease; }
.study-settings[open] summary::after { transform: rotate(90deg); }
.study-settings summary small { margin-left: auto; font-size: 11px; font-weight: 400; color: var(--app-muted, #777); }
.study-settings-form { display: grid; gap: 6px; padding: 6px 0 4px; }
.study-settings-form label { font-size: 12px; color: var(--app-muted, #777); }
.study-settings-form input { min-width: 0; height: 36px; padding: 0 12px; border: 1px solid color-mix(in srgb, currentColor 14%, transparent); border-radius: 12px; background: rgb(255 255 255 / 55%); color: inherit; font: inherit; font-size: 13px; }
.study-settings-hint { margin: 0; font-size: 11px; line-height: 1.45; color: var(--app-muted, #777); }
.study-settings-actions { display: flex; justify-content: flex-end; }
.study-settings-actions button { height: 30px; padding: 0 16px; border: 0; border-radius: 999px; background: var(--ink, #17171a); color: #fff; font-size: 12px; font-weight: 600; cursor: pointer; }
.theme-night .study-settings-form input { background: rgb(255 255 255 / 8%); }
.theme-night .study-settings-actions button { background: #f2f2f2; color: #17171a; }