body {
    margin: 0;
    min-height: 100vh;
    color: #14223a;
    font-family: var(--ui-font-sans, "Avenir Next", "PingFang SC", sans-serif);
    background:
        radial-gradient(circle at 8% 2%, rgba(88, 126, 255, 0.22), transparent 34%),
        radial-gradient(circle at 90% 0%, rgba(93, 162, 255, 0.16), transparent 32%),
        linear-gradient(180deg, #f6f8ff 0%, #eef3fb 54%, #f8fbff 100%);
}

body.admin-page::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background-image:
        linear-gradient(rgba(20, 85, 217, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(20, 85, 217, 0.04) 1px, transparent 1px);
    background-size: 44px 44px;
    mask-image: radial-gradient(circle at 50% 0, black 0 68%, transparent 100%);
}

.admin-shell {
    width: min(1480px, calc(100% - 24px));
    margin: 12px auto 18px;
    display: grid;
    grid-template-columns: 250px minmax(0, 1fr);
    gap: 16px;
}

.admin-sidebar {
    position: sticky;
    top: 12px;
    align-self: start;
    display: grid;
    gap: 14px;
    padding: 16px;
    border-radius: 28px;
    border: 1px solid rgba(146, 170, 214, 0.38);
    background: rgba(255, 255, 255, 0.84);
    backdrop-filter: blur(10px);
    box-shadow: 0 16px 28px rgba(45, 71, 124, 0.12);
}

.sidebar-brand {
    display: flex;
    gap: 10px;
    align-items: center;
}

.brand-dot {
    width: 14px;
    height: 14px;
    border-radius: 4px;
    background: linear-gradient(145deg, #2f67f6, #7ea4ff);
    box-shadow: 0 4px 10px rgba(50, 94, 214, 0.36);
}

.sidebar-brand h1 {
    margin: 0;
    font-size: 16px;
    line-height: 1.1;
    letter-spacing: 0.03em;
}

.sidebar-brand p {
    margin: 3px 0 0;
    color: #7488aa;
    font-size: 12px;
    font-family: var(--ui-font-mono, "SF Mono", Menlo, monospace);
    letter-spacing: 0.04em;
}

.sidebar-nav {
    display: grid;
    gap: 6px;
}

.sidebar-nav a {
    text-decoration: none;
    color: #2c4065;
    font-size: 14px;
    font-weight: 700;
    border-radius: 14px;
    padding: 10px 12px;
    border: 1px solid transparent;
    transition: all 160ms ease;
}

.sidebar-nav a:hover {
    background: rgba(66, 107, 220, 0.08);
    border-color: rgba(66, 107, 220, 0.18);
}

.sidebar-nav a.is-active {
    background: linear-gradient(145deg, #dce8ff, #edf4ff);
    border-color: rgba(66, 107, 220, 0.24);
    color: #21438f;
}

.sidebar-note {
    border: 1px solid #d8e3f7;
    border-radius: 16px;
    background: #f8fbff;
    padding: 12px;
}

.sidebar-note p {
    margin: 0 0 8px;
    font-size: 13px;
    color: #5f769f;
    font-weight: 700;
}

.sidebar-note ol {
    margin: 0;
    padding-left: 18px;
    color: #395274;
    font-size: 12px;
    display: grid;
    gap: 4px;
}

.admin-main {
    border-radius: 30px;
    border: 1px solid rgba(146, 170, 214, 0.3);
    background: rgba(255, 255, 255, 0.86);
    backdrop-filter: blur(10px);
    box-shadow: 0 20px 36px rgba(41, 63, 111, 0.13);
    padding: 16px;
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 14px;
}

.admin-header h2 {
    margin: 0;
    font-size: clamp(22px, 2.5vw, 32px);
    line-height: 1.08;
    letter-spacing: -0.02em;
}

.admin-header p {
    margin: 6px 0 0;
    color: #7287a6;
    font-size: 14px;
}

.admin-header-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

.admin-search {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    border: 1px solid #d8e3f7;
    border-radius: 999px;
    background: #f8fbff;
    padding: 8px 12px;
    color: #98a7c2;
}

.admin-search input {
    border: none;
    background: transparent;
    color: #7a8da9;
    font-size: 13px;
    width: 230px;
    outline: none;
}

.admin-home-link {
    border-radius: 999px;
    background: linear-gradient(145deg, #2d67f7, #4d89ff);
    color: #fff;
    text-decoration: none;
    padding: 9px 14px;
    font-size: 12px;
    font-weight: 800;
    box-shadow: 0 10px 18px rgba(37, 89, 212, 0.24);
}

.admin-overview {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
    margin-bottom: 12px;
}

.overview-card {
    border-radius: 18px;
    border: 1px solid #dbe6f9;
    background: #ffffff;
    padding: 12px 14px;
    display: grid;
    gap: 5px;
    box-shadow: 0 8px 16px rgba(35, 68, 133, 0.08);
}

.overview-card.primary {
    background: linear-gradient(145deg, #1f4fb6, #5178e6);
    border-color: rgba(20, 56, 138, 0.7);
    color: #f2f7ff;
}

.overview-card p {
    margin: 0;
    font-size: 12px;
    color: inherit;
    opacity: 0.72;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-family: var(--ui-font-mono, "SF Mono", Menlo, monospace);
}

.overview-card h3 {
    margin: 0;
    font-size: 20px;
    line-height: 1.1;
}

.overview-card span {
    font-size: 12px;
    color: inherit;
    opacity: 0.8;
}

.admin-card {
    border: 1px solid #d6e2f6;
    border-radius: 20px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 251, 255, 0.98));
    box-shadow: 0 12px 22px rgba(38, 68, 127, 0.08);
    padding: 14px;
}

.unlock-card {
    margin-bottom: 12px;
}

.admin-card h2 {
    margin: 0;
    font-size: 18px;
}

.admin-card p {
    margin: 6px 0 0;
    color: #7086aa;
    font-size: 13px;
}

.status-text {
    min-height: 20px;
    margin-top: 8px;
    color: #6a80a3;
    font-size: 13px;
}

.admin-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
}

#section-homework,
#section-ai,
#section-share {
    grid-column: 1 / -1;
}

.card-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.unlock-row,
.upload-row,
.search-row {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 8px;
    margin-bottom: 8px;
}

.upload-row.drag-over {
    border-radius: 14px;
    box-shadow: 0 0 0 3px rgba(79, 124, 228, 0.22);
    background: #eef3ff;
}

.folder-row {
    grid-template-columns: 1fr 1fr;
}

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

#stt-result {
    width: 100%;
    box-sizing: border-box;
    resize: vertical;
    min-height: 150px;
}

.unlock-row input,
.import-form input,
.import-form select,
.import-form textarea,
.search-row input,
.search-row select,
.upload-row input,
.upload-row select,
.upload-row textarea,
textarea#ai-choice-prompt,
#stt-result {
    border: 1px solid #cfdbf1;
    border-radius: 12px;
    padding: 10px 11px;
    background: #fff;
    color: #1a2d4f;
    font-size: 13px;
}

.unlock-row input:focus,
.import-form input:focus,
.import-form select:focus,
.import-form textarea:focus,
.search-row input:focus,
.search-row select:focus,
.upload-row input:focus,
.upload-row select:focus,
.upload-row textarea:focus,
textarea#ai-choice-prompt:focus,
#stt-result:focus {
    outline: none;
    border-color: #8fb0ef;
    box-shadow: 0 0 0 3px rgba(79, 124, 228, 0.14);
}

.unlock-row button,
.upload-row button,
.import-form button {
    border: none;
    border-radius: 999px;
    padding: 10px 14px;
    background: linear-gradient(145deg, #2f68f7, #4a86ff);
    color: #fff;
    cursor: pointer;
    font-weight: 800;
    font-size: 12px;
    transition: transform 150ms ease, box-shadow 150ms ease;
    box-shadow: 0 8px 16px rgba(41, 89, 211, 0.23);
}

.unlock-row button:hover,
.upload-row button:hover,
.import-form button:hover {
    transform: translateY(-1px);
}

.unlock-row button:active,
.upload-row button:active,
.import-form button:active {
    transform: translateY(1px) scale(0.99);
}

.btn-lite {
    border: 1px solid #cfdbf1;
    background: #f4f8ff;
    color: #37517b;
    border-radius: 999px;
    padding: 7px 11px;
    font-size: 12px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 140ms ease, box-shadow 140ms ease;
}

.btn-lite:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 14px rgba(43, 86, 177, 0.12);
}

.btn-lite:active {
    transform: translateY(1px) scale(0.99);
}

.hint {
    margin: 0 0 10px;
    color: #6e84a8;
    font-size: 12px;
}

.mini-title {
    font-size: 14px;
}

.homework-mini-head {
    margin-bottom: 4px;
}

.section-gap-top {
    margin-top: 10px;
}

.student-pick-list {
    max-height: 180px;
}

.dropzone {
    border: 1px dashed #a8c2ef;
    border-radius: 14px;
    background: #f7fbff;
    padding: 14px;
    text-align: center;
    display: grid;
    gap: 4px;
    color: #6480ab;
    font-size: 13px;
    transition: all 160ms ease;
}

.dropzone.drag-over {
    border-color: #2a67f6;
    background: #ebf2ff;
}

textarea#ai-choice-prompt {
    width: 100%;
    min-height: 120px;
    resize: vertical;
    box-sizing: border-box;
    margin-bottom: 8px;
}

.mini-list {
    border: 1px solid #cfdbf1;
    border-radius: 12px;
    background: #fff;
    padding: 10px;
    font-size: 12px;
    color: #6c83a8;
    display: grid;
    gap: 6px;
    max-height: 120px;
    overflow: auto;
}

.mini-list.empty {
    display: block;
}

.inline-fields {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.list-block {
    max-height: 320px;
    overflow: auto;
    border: 1px solid #cfdbf1;
    border-radius: 14px;
    background: #f8fbff;
}

.list-empty {
    padding: 12px;
    color: #6e84a8;
    font-size: 12px;
}

.user-row,
.vocab-row,
.question-row,
.homework-row,
.temp-share-row,
.student-pick-row {
    display: grid;
    gap: 8px;
    align-items: center;
    padding: 10px 11px;
    border-bottom: 1px solid #e2ecfb;
    background: #fff;
}

.user-row {
    grid-template-columns: 1fr auto auto auto auto;
}

.vocab-row {
    grid-template-columns: 1fr auto auto auto;
}

.question-row {
    grid-template-columns: 1fr auto;
}

.homework-row,
.temp-share-row {
    grid-template-columns: 1fr auto auto auto auto;
}

.student-pick-row {
    grid-template-columns: auto 1fr;
}

.student-pick-row input[type="checkbox"] {
    width: 16px;
    height: 16px;
}

.question-meta {
    font-size: 12px;
    color: #6f84a9;
}

.question-content {
    font-size: 12px;
    color: #6a80a3;
    margin-top: 4px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.status-pill {
    display: inline-flex;
    align-items: center;
    padding: 2px 8px;
    border-radius: 999px;
    font-size: 11px;
    font-weight: 700;
}

.status-pill.done {
    background: #e9f7ef;
    color: #257e52;
}

.status-pill.pending {
    background: #edf3ff;
    color: #2f5fb2;
}

.status-pill.progress {
    background: #e9f5ff;
    color: #166493;
}

.status-pill.overdue {
    background: #fff1ed;
    color: #bb4e3c;
}

.filter-row {
    display: flex;
    gap: 8px;
    align-items: center;
}

.filter-row select {
    padding: 6px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 13px;
    background: var(--bg);
    color: var(--text);
}

.pending-row {
    background: #fef7e5;
    border-left: 3px solid #e6a700;
}

.select-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 10px 14px;
    background: #f0f4fa;
    border-radius: 6px;
    margin-bottom: 10px;
    font-size: 13px;
}

.select-bar label {
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    font-weight: 600;
}

.selectable-row {
    grid-template-columns: auto 1fr auto auto !important;
}

.row-checkbox {
    display: flex;
    align-items: center;
}

.row-checkbox input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.btn-lite.danger {
    color: #d32f2f;
    border-color: #d32f2f;
}

.btn-lite.danger:hover {
    background: #d32f2f;
    color: white;
}

.due-edit-row {
    display: flex;
    gap: 7px;
    flex-wrap: wrap;
    align-items: center;
    margin-top: 7px;
}

.due-edit-row input[type="datetime-local"] {
    flex: 1 1 220px;
    min-width: 160px;
}

#ai-file-list .ai-file-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    align-items: center;
}

#ai-file-list .ai-file-row input {
    width: 100%;
    box-sizing: border-box;
    border: 1px solid #cfdbf1;
    border-radius: 8px;
    padding: 7px 8px;
    font-size: 12px;
}

.advanced-wrap {
    border: 1px solid #cfdbf1;
    border-radius: 16px;
    overflow: hidden;
    background: #fff;
}

.advanced-wrap iframe {
    width: 100%;
    min-height: 860px;
    border: none;
    display: block;
}

.mini-input {
    width: 64px;
    border: 1px solid #cfdbf1;
    border-radius: 8px;
    padding: 7px 8px;
    text-align: center;
}

.action-btn {
    border: none;
    border-radius: 10px;
    padding: 7px 10px;
    cursor: pointer;
    font-size: 12px;
    font-weight: 700;
}

.action-btn.primary {
    background: #e9f0ff;
    color: #1549b6;
}

.action-btn.danger {
    background: #fae8e6;
    color: #bb4030;
}

.copy-modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: rgba(12, 22, 39, 0.38);
    backdrop-filter: blur(3px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
}

.copy-modal-card {
    width: min(620px, 100%);
    background: #ffffff;
    border: 1px solid #cfdbf1;
    border-radius: 20px;
    box-shadow: 0 18px 34px rgba(35, 68, 133, 0.16);
    padding: 16px;
    display: grid;
    gap: 12px;
}

.copy-modal-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.copy-modal-head h3 {
    margin: 0;
    font-size: 17px;
}

.copy-modal-hint {
    margin: 0;
    color: #6f84a9;
    font-size: 13px;
}

.copy-modal-card textarea {
    width: 100%;
    min-height: 160px;
    resize: vertical;
    border: 1px solid #cfdbf1;
    border-radius: 12px;
    padding: 10px 12px;
    font-size: 13px;
    line-height: 1.6;
    color: #183056;
    background: #f9fbff;
    box-sizing: border-box;
}

.copy-modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.copy-modal-actions button {
    border: none;
    border-radius: 999px;
    padding: 10px 14px;
    cursor: pointer;
    font-weight: 700;
}

.copy-modal-actions #copy-modal-done {
    background: linear-gradient(145deg, #2f68f7, #4a86ff);
    color: #fff;
}

.hidden {
    display: none !important;
}

@media (max-width: 1180px) {
    .admin-shell {
        grid-template-columns: 1fr;
    }

    .admin-sidebar {
        position: static;
    }
}

@media (max-width: 980px) {
    .admin-main {
        padding: 12px;
    }

    .admin-grid {
        grid-template-columns: 1fr;
    }

    .admin-overview {
        grid-template-columns: 1fr;
    }

    .admin-header {
        flex-direction: column;
        align-items: stretch;
    }

    .admin-header-right {
        flex-direction: column;
        align-items: stretch;
    }

    .admin-search {
        width: 100%;
    }

    .admin-search input {
        width: 100%;
    }

    .unlock-row,
    .upload-row,
    .search-row,
    .folder-row {
        grid-template-columns: 1fr;
    }

    .user-row,
    .vocab-row,
    .homework-row,
    .temp-share-row {
        grid-template-columns: 1fr;
    }
}