:root {
  color-scheme: dark;
  --bg: #0c1018;
  --panel: #151b26;
  --panel-2: #1b2331;
  --border: #2a3445;
  --text: #f3f6fb;
  --muted: #9ba9bc;
  --accent: #6fa8ff;
  --accent-strong: #4f8ff4;
  --danger: #ff6b7a;
  --success: #66d39e;
  --shadow: 0 18px 55px rgba(0,0,0,.32);
  --radius: 16px;
  --footer-h: 48px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; background: var(--bg); color: var(--text); }
body { min-height: 100dvh; display: flex; flex-direction: column; overflow-x: hidden; }
button, input, textarea, select { font: inherit; }
button, .button-link { min-height: 44px; border: 1px solid transparent; border-radius: 11px; padding: .65rem .95rem; background: var(--accent-strong); color: white; font-weight: 700; cursor: pointer; text-decoration: none; display: inline-flex; align-items: center; justify-content: center; gap: .35rem; }
button:hover, .button-link:hover { filter: brightness(1.08); }
button:disabled { opacity: .45; cursor: not-allowed; }
button.secondary, .button-link.secondary { background: var(--panel-2); border-color: var(--border); color: var(--text); }
button.danger, .danger { color: var(--danger); border-color: rgba(255,107,122,.35); background: transparent; }
button.danger-solid, .danger-solid { background: #8f2936; border-color: #a93645; color: white; }
button.small, .button-link.small { min-height: 38px; padding: .45rem .7rem; font-size: .9rem; }
button.active { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset; }
input, textarea, select { width: 100%; border: 1px solid var(--border); background: #0f1520; color: var(--text); border-radius: 10px; padding: .72rem .78rem; outline: none; }
input:focus, textarea:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(111,168,255,.12); }
textarea { resize: vertical; min-height: 92px; }
label { display: grid; gap: .38rem; font-weight: 650; }
h1, h2, h3, p { margin-top: 0; }
a { color: #91baff; }
.hidden { display: none !important; }
.muted { color: var(--muted); }
.tiny { font-size: .86rem; }
.prewrap { white-space: pre-wrap; overflow-wrap: anywhere; }
.breakable { overflow-wrap: anywhere; word-break: break-word; }
.screen { flex: 1 0 auto; width: 100%; min-height: calc(100dvh - var(--footer-h)); }
.screen.narrow { display: grid; place-items: center; padding: clamp(16px, 4vw, 48px); }
.panel { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: clamp(16px, 2.5vw, 26px); }
.hero-panel { width: min(100%, 460px); }
.brand-lockup { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
.brand-icon { width: 48px; height: 48px; object-fit: contain; border-radius: 12px; }
.brand, .small-brand { font-weight: 800; }
.brand-header { display: flex; align-items: center; gap: 7px; min-width: 0; }
.header-icon { width: 30px; height: 30px; object-fit: contain; border-radius: 8px; flex: none; }
.stack { display: grid; gap: 14px; }
.stack.compact { gap: 10px; }
.toolbar { display: flex; gap: 9px; align-items: center; }
.wrap-toolbar { flex-wrap: wrap; }
.compact-toolbar { gap: 6px; }
.centered { justify-content: center; }
.inline-input { display: flex; gap: 8px; align-items: stretch; }
.inline-input > input { min-width: 0; }
.section-heading { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 16px; }
.section-heading h1, .section-heading h2, .section-heading h3 { margin-bottom: 0; }
.topbar { min-height: 58px; padding: 9px max(12px, env(safe-area-inset-left)) 9px max(12px, env(safe-area-inset-right)); display: grid; grid-template-columns: auto minmax(0,1fr) auto; align-items: center; gap: 12px; border-bottom: 1px solid var(--border); background: rgba(12,16,24,.96); position: sticky; top: 0; z-index: 20; }
.topbar > :nth-child(2) { min-width: 0; text-align: center; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.topbar-action { grid-column: 3; justify-self: end; width: max-content; max-width: 100%; white-space: nowrap; }
.content-wrap { width: min(1180px, 100%); margin: 0 auto; padding: clamp(14px, 2.7vw, 30px); }
.set-list { display: grid; gap: 10px; }
.set-row { display: grid; grid-template-columns: minmax(0,1fr) auto auto auto; gap: 8px; align-items: center; background: var(--panel); border: 1px solid var(--border); border-radius: 14px; padding: 10px; }
.set-main { text-align: left; justify-content: flex-start; flex-direction: column; align-items: flex-start; background: transparent; border-color: transparent; color: var(--text); min-width: 0; }
.set-main strong, .set-main span { max-width: 100%; overflow: hidden; text-overflow: ellipsis; }
.set-main span { color: var(--muted); font-weight: 500; font-size: .9rem; }
.empty-state { text-align: center; color: var(--muted); }
.card-edit-row { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr) auto; gap: 9px; align-items: start; }
.card-edit-row textarea { min-height: 112px; }
.icon-button { width: 44px; padding: 0; }
.editor-actions { justify-content: flex-end; }

.study-screen { height: calc(100dvh - var(--footer-h)); min-height: 0; display: flex; flex-direction: column; overflow: hidden; }
.study-topbar { position: relative; }
.study-title-wrap { overflow: hidden; text-overflow: ellipsis; }
.study-wrap { width: min(980px, 100%); margin: 0 auto; padding: clamp(8px, 1.6vw, 16px); display: flex; flex: 1 1 auto; min-height: 0; flex-direction: column; align-items: stretch; gap: clamp(6px, 1vh, 10px); overflow: hidden; }
.mode-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; }
.study-toolbar { display: flex; justify-content: center; gap: 7px; }
.flashcard { width: min(100%, 820px); height: clamp(180px, 43dvh, 500px); flex: 1 1 clamp(180px, 43dvh, 500px); margin: 0 auto; padding: 0; background: transparent; border: 0; perspective: 1300px; min-height: 150px; max-height: 500px; min-width: 0; }
.flashcard-inner { --flip-angle: 0deg; width: 100%; min-width: 0; height: 100%; position: relative; display: block; transform-style: preserve-3d; transform: rotateX(var(--flip-angle)); transition: transform .42s cubic-bezier(.2,.75,.25,1); }
.flashcard-face { position: absolute; inset: 0; min-width: 0; display: grid; place-items: center; padding: clamp(18px, 5vw, 54px); background: linear-gradient(145deg, #1d2635, #111722); border: 1px solid #39475d; border-radius: clamp(16px, 2vw, 24px); backface-visibility: hidden; box-shadow: var(--shadow); overflow: hidden; }
.flashcard-back { transform: rotateX(180deg); }
.flashcard-text { display: block; width: 100%; min-width: 0; max-width: 100%; max-height: 100%; overflow-y: auto; overflow-x: hidden; overscroll-behavior: contain; font-size: clamp(1.25rem, 3.2vw, 2.25rem); line-height: 1.35; font-weight: 750; white-space: pre-wrap; overflow-wrap: anywhere; word-break: break-word; tab-size: 4; }
.study-meta-row { display: flex; justify-content: center; align-items: center; gap: 10px; flex-wrap: wrap; }
.study-controls { display: grid; grid-template-columns: minmax(54px, .65fr) minmax(70px, 1fr) minmax(70px, 1fr) minmax(54px, .65fr); gap: 9px; width: min(100%, 620px); margin: 0 auto; }
.study-controls button { min-height: 54px; font-size: 1.25rem; }
.mark-button.forgot { background: #782d39; }
.mark-button.remember { background: #23724e; }
.nav-button { font-size: 1.4rem !important; }
.keyboard-help { text-align: center; margin-bottom: 0; }
.memorization-summary { display: flex; justify-content: center; align-items: center; gap: 8px; flex-wrap: wrap; flex: 0 0 auto; }
.study-screen.mode-memorization .flashcard { max-height: 440px; }
.study-screen.mode-memorization .study-wrap { gap: clamp(5px, .8vh, 8px); }
.mastered-panel { width: min(100%, 680px); max-height: min(80dvh, 720px); overflow: auto; }
.mastered-panel-header { display: flex; justify-content: space-between; align-items: center; gap: 10px; position: sticky; top: -1px; background: var(--panel); padding-bottom: 8px; }
.mastered-panel-header h3 { margin: 0; }
.mastered-list { display: grid; gap: 8px; }
.mastered-row { display: grid; grid-template-columns: minmax(0,1fr) auto; gap: 8px; align-items: center; padding: 9px; border: 1px solid var(--border); border-radius: 10px; }
.mastered-row span { overflow-wrap: anywhere; }
.memorization-complete, .challenge-complete { text-align: center; width: min(100%, 700px); margin: 0 auto; }
.memorization-complete { display: grid; gap: 12px; justify-items: center; }
.challenge-summary { display: grid; grid-template-columns: repeat(4, minmax(75px,1fr)) auto; gap: 7px; align-items: stretch; }
.challenge-pill { background: var(--panel); border: 1px solid var(--border); border-radius: 11px; padding: 7px 10px; display: flex; flex-direction: column; align-items: center; justify-content: center; }
.challenge-label { color: var(--muted); font-size: .75rem; }
.challenge-results-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 8px; }
.challenge-results-grid > div { background: var(--panel-2); border-radius: 11px; padding: 10px; display: grid; gap: 4px; }
.challenge-results-grid span { color: var(--muted); font-size: .8rem; }
.challenge-result-badge { display: inline-block; background: rgba(102,211,158,.13); color: var(--success); border: 1px solid rgba(102,211,158,.35); border-radius: 999px; padding: 5px 10px; margin-bottom: 10px; }

.admin-shell { display: grid; gap: 16px; }
.admin-tabs { display: flex; gap: 7px; overflow-x: auto; padding-bottom: 3px; scrollbar-width: thin; }
.admin-tabs button { flex: 0 0 auto; }
.admin-tab-panel { display: grid; gap: 16px; }
.metrics-grid { display: grid; grid-template-columns: repeat(6,minmax(0,1fr)); gap: 10px; }
.metric { background: var(--panel); border: 1px solid var(--border); border-radius: 13px; padding: 15px; display: grid; gap: 4px; }
.metric strong { font-size: clamp(1.25rem,2.5vw,1.8rem); }
.metric span { color: var(--muted); }
.admin-two-col { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 16px; }
.admin-user-list, .audit-list { display: grid; gap: 8px; }
.admin-user-row { display: grid; grid-template-columns: minmax(0,1fr) auto; gap: 10px; align-items: center; border: 1px solid var(--border); border-radius: 12px; padding: 11px; }
.admin-user-summary { display: grid; gap: 4px; min-width: 0; }
.admin-user-summary > span { color: var(--muted); overflow-wrap: anywhere; }
.user-title-row { display: flex; gap: 8px; align-items: center; }
.admin-user-actions { display: flex; gap: 7px; flex-wrap: wrap; justify-content: flex-end; }
.status-badge { display: inline-flex; width: max-content; border-radius: 999px; padding: 3px 8px; font-size: .76rem; border: 1px solid var(--border); }
.status-badge.active { color: var(--success); border-color: rgba(102,211,158,.4); }
.status-badge.disabled { color: var(--danger); border-color: rgba(255,107,122,.4); }
.audit-row, .access-row { border-bottom: 1px solid var(--border); padding: 9px 2px; display: grid; gap: 3px; }
.audit-row span, .access-row span { color: var(--muted); font-size: .86rem; }
.compact-form { max-width: 650px; }
.toggle-line { display: flex; align-items: center; gap: 10px; }
.toggle-line input { width: auto; min-width: 20px; height: 20px; }
.icon-preview-row { display: flex; align-items: center; gap: 12px; }
.admin-icon-preview { width: 64px; height: 64px; object-fit: contain; border-radius: 13px; background: var(--panel-2); border: 1px solid var(--border); }

.legal-screen { padding-bottom: 20px; }
.legal-document { width: min(900px, calc(100% - 28px)); margin: 22px auto; box-shadow: none; }
.legal-document h2 { margin-top: 1.8rem; font-size: 1.16rem; }
.legal-document p { line-height: 1.65; color: #d8e0ec; }

.site-footer { min-height: var(--footer-h); padding: 9px max(14px, env(safe-area-inset-right)) calc(9px + env(safe-area-inset-bottom)) max(14px, env(safe-area-inset-left)); border-top: 1px solid var(--border); color: var(--muted); display: flex; justify-content: center; align-items: center; gap: 18px; flex-wrap: wrap; font-size: .84rem; background: #0a0e15; }
.footer-links { display: flex; gap: 14px; }

.message { position: fixed; left: 50%; top: 12px; transform: translateX(-50%); width: min(92vw, 720px); z-index: 100; border: 1px solid rgba(255,107,122,.45); background: #3a1d24; color: #ffdfe3; border-radius: 12px; padding: 10px 14px; box-shadow: var(--shadow); text-align: center; }
.message.success { border-color: rgba(102,211,158,.45); background: #163629; color: #dcfff0; }
.modal-layer { position: fixed; inset: 0; z-index: 90; background: rgba(0,0,0,.72); display: grid; place-items: center; padding: max(14px, env(safe-area-inset-top)) max(14px, env(safe-area-inset-right)) max(14px, env(safe-area-inset-bottom)) max(14px, env(safe-area-inset-left)); overflow: auto; }
.modal-card { width: min(100%, 520px); max-height: 90dvh; overflow: auto; }
.wide-modal { width: min(100%, 900px); }
.modal-actions { justify-content: flex-end; margin-top: 16px; flex-wrap: wrap; }
.error-text { color: var(--danger); min-height: 1em; }
.inset-panel { margin-top: 14px; padding: 12px; box-shadow: none; background: var(--panel-2); }
.csv-map-grid { margin-top: 12px; }
.csv-preview { display: grid; gap: 7px; margin-top: 9px; max-height: 32dvh; overflow: auto; }
.csv-preview-row { display: grid; grid-template-columns: minmax(0,1fr) auto minmax(0,1fr); gap: 8px; align-items: start; padding: 7px 0; border-bottom: 1px solid var(--border); }
.csv-preview-row:last-child { border-bottom: 0; }
.csv-preview-row span { white-space: pre-wrap; overflow-wrap: anywhere; }
.csv-preview-arrow { color: var(--muted); }
#modal-text { white-space: pre-wrap; overflow-wrap: anywhere; }
.detail-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 8px; margin-bottom: 18px; }
.detail-grid > div { background: var(--panel-2); border: 1px solid var(--border); border-radius: 10px; padding: 9px; display: grid; gap: 3px; }
.detail-grid span { color: var(--muted); font-size: .78rem; }
.span-detail { grid-column: 1 / -1; }
.detail-list { display: grid; gap: 7px; margin-bottom: 16px; }
.session-row { display: grid; grid-template-columns: minmax(0,1fr) auto; gap: 8px; align-items: center; border: 1px solid var(--border); border-radius: 10px; padding: 9px; }
.session-row > div { display: grid; gap: 3px; }
.session-row span { color: var(--muted); font-size: .82rem; overflow-wrap: anywhere; }

@media (max-width: 820px) {
  :root { --footer-h: 66px; }
  .content-wrap { padding: 12px; }
  .responsive-heading { align-items: flex-start; flex-direction: column; }
  .set-row { grid-template-columns: minmax(0,1fr) repeat(3,auto); }
  .metrics-grid { grid-template-columns: repeat(2,1fr); }
  .admin-two-col { grid-template-columns: 1fr; }
  .challenge-summary { grid-template-columns: repeat(4,1fr); }
  .challenge-summary > button { grid-column: 1 / -1; }
  .detail-grid { grid-template-columns: repeat(2,1fr); }
  .flashcard { height: clamp(170px, 40dvh, 390px); flex-basis: clamp(170px, 40dvh, 390px); max-height: 390px; }
}

@media (max-width: 560px) {
  :root { --footer-h: 78px; }
  .screen { min-height: calc(100dvh - var(--footer-h)); }
  .topbar { min-height: 52px; gap: 7px; padding-top: max(7px, env(safe-area-inset-top)); }
  .compact-identity { display: none; }
  .small-brand { max-width: 42vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .section-heading { align-items: flex-start; }
  .wrap-toolbar { width: 100%; }
  .wrap-toolbar > button { flex: 1 1 calc(50% - 8px); }
  .set-row { grid-template-columns: 1fr 1fr 1fr; gap: 7px; }
  .set-main { grid-column: 1 / -1; border-bottom: 1px solid var(--border); border-radius: 0; padding-bottom: 10px; }
  .set-row > button:not(.set-main) { width: 100%; padding-left: .4rem; padding-right: .4rem; }
  .card-edit-row { grid-template-columns: 1fr; border: 1px solid var(--border); padding: 9px; border-radius: 12px; }
  .card-edit-row .icon-button { width: 100%; }
  .study-wrap { padding: 7px 9px 10px; gap: 7px; }
  .mode-row { gap: 5px; }
  .mode-row button { min-height: 40px; padding: .42rem .35rem; font-size: .83rem; }
  .flashcard { height: clamp(150px, 36dvh, 330px); flex-basis: clamp(150px, 36dvh, 330px); min-height: 140px; max-height: 330px; }
  .flashcard-face { padding: 16px; }
  .flashcard-text { font-size: clamp(1.05rem, 6vw, 1.6rem); }
  .study-controls { gap: 6px; }
  .study-controls button { min-height: 50px; }
  .memorization-summary { font-size: .82rem; gap: 5px; }
  .memorization-summary > .compact-toolbar { width: 100%; justify-content: center; }
  .memorization-summary > .compact-toolbar button { min-height: 34px; padding: .35rem .55rem; font-size: .8rem; }
  .study-screen.mode-memorization .flashcard { max-height: 290px; }
  .challenge-summary { grid-template-columns: repeat(2,1fr); }
  .challenge-summary > button { grid-column: 1 / -1; }
  .challenge-results-grid { grid-template-columns: repeat(2,1fr); }
  .keyboard-help { display: none; }
  .admin-tabs { margin-inline: -12px; padding-inline: 12px; }
  .metrics-grid { grid-template-columns: 1fr 1fr; }
  .metric { padding: 11px; }
  .admin-user-row { grid-template-columns: 1fr; }
  .admin-user-actions { justify-content: stretch; }
  .admin-user-actions button { flex: 1; }
  .search-form { width: 100%; }
  .detail-grid { grid-template-columns: 1fr; }
  .span-detail { grid-column: auto; }
  .session-row { grid-template-columns: 1fr; }
  .site-footer { flex-direction: column; gap: 5px; padding-top: 8px; padding-bottom: calc(8px + env(safe-area-inset-bottom)); }
  .modal-actions button { flex: 1; }
}

@media (max-height: 700px) and (orientation: landscape) {
  .flashcard { height: 30dvh; flex-basis: 30dvh; min-height: 120px; max-height: 260px; }
  .study-wrap { gap: 5px; }
  .study-controls button { min-height: 44px; }
  .keyboard-help { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation: none !important; transition: none !important; }
}

/* 1.7 account, data, email, and legal layout */
.auth-alt-actions { margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--border); display: grid; gap: 10px; justify-items: stretch; }
.auth-alt { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.auth-alt > button { flex: 0 0 auto; }
.link-button { min-height: 36px; padding: .35rem .45rem; border: 0; background: transparent; color: #91baff; justify-self: center; font-weight: 650; }
.link-button:hover { text-decoration: underline; filter: none; }
.warning-box { border: 1px solid rgba(255,183,77,.45); background: rgba(255,183,77,.08); border-radius: 11px; padding: 11px 12px; line-height: 1.5; }
.topbar-nav { grid-column: 3; justify-self: end; display: flex; gap: 7px; align-items: center; }
.settings-page { width: min(920px, 100%); }
.settings-page > .panel { gap: 18px; }
.settings-section { display: grid; gap: 10px; padding-top: 16px; border-top: 1px solid var(--border); }
.settings-section > h2, .settings-section > p { margin-bottom: 0; }
.status-line { display: flex; gap: 8px; flex-wrap: wrap; align-items: baseline; }
.account-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 8px; }
.account-grid > div { background: var(--panel-2); border: 1px solid var(--border); border-radius: 11px; padding: 10px; display: grid; gap: 4px; min-width: 0; }
.account-grid span { color: var(--muted); font-size: .8rem; }
.account-grid strong { overflow-wrap: anywhere; }
.danger-zone { border-color: rgba(255,107,122,.35); }
.legal-full-text { white-space: pre-wrap; overflow-wrap: anywhere; word-break: break-word; line-height: 1.7; color: #d8e0ec; }
.legal-document:has(.legal-full-text) { padding: clamp(18px, 3vw, 34px); }
#privacy-text-input, #terms-text-input { min-height: 420px; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; line-height: 1.45; }

/* Keep the study title centered in exactly the same place in every mode. */
.study-topbar { grid-template-columns: 92px minmax(0,1fr) 92px; }
.study-topbar > #study-back { grid-column: 1; justify-self: start; max-width: 92px; }
.study-topbar > .study-title-wrap { grid-column: 2; width: 100%; text-align: center; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.study-topbar > #study-progress { grid-column: 3; justify-self: end; width: 92px; text-align: right; white-space: nowrap; font-variant-numeric: tabular-nums; }

/* Card rows now contain the set button plus Edit/Delete only. */
.set-row { grid-template-columns: minmax(0,1fr) auto auto; }

@media (max-width: 820px) {
  .set-row { grid-template-columns: minmax(0,1fr) auto auto; }
  .account-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
}

@media (max-width: 560px) {
  .auth-alt { flex-direction: column; align-items: stretch; text-align: center; }
  .auth-alt > button { width: 100%; }
  .topbar-nav { gap: 5px; }
  .topbar-nav button { padding-inline: .55rem; font-size: .78rem; }
  .account-grid { grid-template-columns: 1fr; }
  .set-row { grid-template-columns: 1fr 1fr; }
  .set-main { grid-column: 1 / -1; }
  .study-topbar { grid-template-columns: 76px minmax(0,1fr) 76px; }
  .study-topbar > #study-back { max-width: 76px; padding-inline: .45rem; }
  .study-topbar > #study-progress { width: 76px; font-size: .82rem; }
  #privacy-text-input, #terms-text-input { min-height: 52dvh; }
}

/* 1.7.1 stability/status additions */
.small-warning { font-size: .88rem; margin-bottom: 12px; }
.warning-text { color: #ffca80 !important; }
.status-grid { display: grid; gap: 8px; }
.status-grid .status-line { justify-content: space-between; padding: 8px 0; border-bottom: 1px solid var(--border); }
.status-grid .status-line:last-child { border-bottom: 0; }

.critical-text { color: var(--danger) !important; }