:root {
    --bg-main: radial-gradient(circle at 8% 0%, #fff9ec 0%, #f3f8ff 45%, #eef7f2 100%);
    --panel-bg: rgba(255, 255, 255, 0.84);
    --panel-border: rgba(31, 58, 93, 0.12);
    --panel-shadow: 0 20px 40px rgba(17, 37, 59, 0.08);
    --text-primary: #14243a;
    --text-secondary: #4f6278;
    --accent: #0f847a;
    --accent-strong: #0b665f;
    --danger-bg: #fff0ef;
    --danger-border: #eb8f87;
    --danger-text: #a7332d;
    --chip-bg: #ebf7f6;
    --chip-border: #9accc7;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--bg-main);
    color: var(--text-primary);
    font-family: "Manrope", "Segoe UI", sans-serif;
}

#root {
    padding: 24px 16px 56px;
}

.app-shell {
    width: min(1040px, 100%);
    margin: 0 auto;
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.app-header {
    margin: 12px 0 8px;
    animation: rise-in 420ms ease-out;
}

.app-title {
    margin: 0;
    font-family: "Fraunces", Georgia, serif;
    font-size: clamp(2rem, 4.8vw, 3.25rem);
    letter-spacing: 0.01em;
}

.app-subtitle {
    margin: 12px auto 0;
    width: min(680px, 100%);
    color: var(--text-secondary);
    font-size: 0.98rem;
    line-height: 1.45;
}

.panel,
.known-panel {
    background: var(--panel-bg);
    border: 1px solid var(--panel-border);
    border-radius: 18px;
    padding: 18px;
    box-shadow: var(--panel-shadow);
    backdrop-filter: blur(6px);
    animation: rise-in 500ms ease-out;
}

.panel-title {
    margin: 0;
    font-family: "Fraunces", Georgia, serif;
    font-size: 1.25rem;
}

.panel-content {
    margin-top: 14px;
}

.import-group {
    display: inline-flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    margin-bottom: 14px;
}

.input-label {
    font-size: 0.84rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #49627a;
}

.panel-actions {
    margin-top: 14px;
}

.dataset-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.dataset-item {
    display: inline-flex;
    flex-direction: column;
    align-items: stretch;
    min-width: 150px;
}

.dataset-btn {
    width: 100%;
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
}

.dataset-delete-subaction {
    width: 100%;
    border: 0;
    border-top: 1px solid #f2c5bf;
    border-bottom-left-radius: 10px;
    border-bottom-right-radius: 10px;
    background: transparent;
    color: #a7332d;
    font-size: 0.77rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    padding: 0.38rem 0.5rem 0.44rem;
    cursor: pointer;
    text-decoration: underline;
    text-underline-offset: 0.16em;
    transition: color 140ms ease, background-color 160ms ease;
}

.dataset-delete-subaction:hover {
    background: #fff3f1;
    color: #8f2521;
}

.dataset-delete-subaction:focus-visible {
    outline: 2px solid rgba(167, 51, 45, 0.26);
    outline-offset: 1px;
}

.dataset-btn.is-selected {
    border-color: #0f847a;
    background: #e4f7f6;
    color: #0c5551;
    font-weight: 700;
}

.inline-create-row {
    margin-top: 12px;
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.toolbar-actions,
.flashcard-actions,
.form-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.form-actions,
.flashcard-actions,
.toolbar-actions {
    margin-top: 12px;
}

.unknown-panel {
    padding-bottom: 22px;
}

.unknown-meta {
    margin-top: 8px;
}

.known-actions-group {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
}

.field-row {
    margin-bottom: 12px;
}

.text-input,
.file-input {
    width: min(360px, 100%);
    padding: 0.65rem 0.78rem;
    border-radius: 10px;
    border: 1px solid #c9d8e4;
    background: #fff;
    font-family: inherit;
    font-size: 0.95rem;
}

.text-input:focus,
.file-input:focus {
    outline: 2px solid rgba(15, 132, 122, 0.25);
    border-color: var(--accent);
}

.file-input {
    display: inline-block;
}

.btn {
    border: 1px solid transparent;
    border-radius: 11px;
    padding: 0.58rem 0.92rem;
    font-family: inherit;
    font-weight: 600;
    font-size: 0.92rem;
    cursor: pointer;
    transition: transform 140ms ease, box-shadow 160ms ease, background-color 180ms ease;
}

.btn-small {
    padding: 0.38rem 0.62rem;
    font-size: 0.82rem;
}

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

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background: var(--accent);
    color: #f7fffe;
    box-shadow: 0 10px 18px rgba(11, 102, 95, 0.22);
}

.btn-primary:hover {
    background: var(--accent-strong);
}

.btn-secondary {
    background: #f3f8fb;
    color: #1d3551;
    border-color: #cad7e3;
}

.btn-muted {
    background: #f4f0ec;
    color: #4d423b;
    border-color: #d9cbc0;
}

.btn-danger {
    background: var(--danger-bg);
    color: var(--danger-text);
    border-color: var(--danger-border);
}

.status-chip {
    margin: 6px auto 0;
    display: inline-block;
    padding: 8px 14px;
    border-radius: 999px;
    border: 1px solid var(--chip-border);
    background: var(--chip-bg);
    font-weight: 700;
}

.position-counter {
    margin: 6px 0 4px;
    color: var(--text-secondary);
    font-weight: 600;
}

.flashcard {
    margin: 20px auto 8px;
    width: min(88vw, 500px);
    min-height: 210px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 18px;
    border: 1px solid rgba(21, 73, 119, 0.15);
    background: linear-gradient(135deg, #ffffff, #f6fcff 58%, #edf8f6);
    box-shadow: 0 24px 42px rgba(12, 51, 87, 0.12);
    font-family: "Fraunces", Georgia, serif;
    font-size: clamp(2rem, 7vw, 3.25rem);
    line-height: 1.15;
    cursor: pointer;
    user-select: none;
    padding: 22px;
}

.flashcard:hover {
    box-shadow: 0 28px 46px rgba(12, 51, 87, 0.18);
}

.empty-note,
.muted-note {
    color: var(--text-secondary);
}

.known-title {
    margin-bottom: 10px;
}

.known-panel {
    margin-bottom: 24px;
}

.known-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    font-size: 0.95rem;
}

.known-table th,
.known-table td {
    padding: 10px 8px;
    border-bottom: 1px solid #e2ebf2;
}

.known-table th:last-child,
.known-table td:last-child {
    text-align: center;
}

.known-table th {
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: #476078;
}

@keyframes rise-in {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 720px) {
    #root {
        padding: 14px 10px 30px;
    }

    .panel,
    .known-panel {
        padding: 12px;
    }

    .toolbar-actions .btn,
    .flashcard-actions .btn,
    .form-actions .btn,
    .inline-create-row .btn,
    .dataset-item .btn {
        width: min(100%, 320px);
    }

    .text-input,
    .file-input {
        width: min(100%, 420px);
    }

    .app-subtitle {
        font-size: 0.9rem;
    }

    .known-table {
        display: block;
        overflow-x: auto;
    }
}

/* ── Help modal ─────────────────────────────────────────── */

.help-trigger-btn {
    margin-top: 14px;
}

.help-backdrop {
    position: fixed;
    inset: 0;
    z-index: 100;
    background: rgba(20, 36, 58, 0.45);
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 32px 16px 40px;
    overflow-y: auto;
    animation: rise-in 220ms ease-out;
}

.help-modal {
    width: min(720px, 100%);
    text-align: left;
    animation: rise-in 280ms ease-out;
}

.help-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
}

.help-modal-title {
    font-size: 1.4rem;
}

.help-close-btn {
    flex-shrink: 0;
}

/* ── Footer ─────────────────────────────────────────────── */

.app-footer {
    margin-top: 8px;
    padding-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.app-footer a {
    color: var(--accent);
    text-decoration: none;
}

.app-footer a:hover {
    text-decoration: underline;
}

.help-body {
    margin-top: 18px;
    display: flex;
    flex-direction: column;
    gap: 0;
}

.help-section {
    padding: 4px 0 8px;
}

.help-section-title {
    margin: 0 0 10px;
    font-family: "Fraunces", Georgia, serif;
    font-size: 1.1rem;
    color: var(--accent-strong);
}

.help-divider {
    border: none;
    border-top: 1px solid var(--panel-border);
    margin: 14px 0;
}

.help-text {
    margin: 6px 0;
    color: var(--text-primary);
    line-height: 1.55;
    font-size: 0.95rem;
}

.help-text-muted {
    color: var(--text-secondary);
    font-size: 0.88rem;
}

.help-list {
    margin: 8px 0 8px 20px;
    padding: 0;
    line-height: 1.7;
    font-size: 0.93rem;
}

.help-step {
    display: flex;
    gap: 14px;
    align-items: flex-start;
    margin-bottom: 18px;
}

.help-step-number {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    font-weight: 700;
    font-size: 0.88rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 2px;
}

.csv-format-block {
    background: #f3f8fb;
    border: 1px solid #cad7e3;
    border-radius: 8px;
    padding: 8px 14px;
    margin: 8px 0;
    font-size: 0.88rem;
    overflow-x: auto;
}