/* Deutsch — futuristic HUD design.
   Black ground with a faint blue grid. Greys and blues only for the interface.
   Flashcards are light panels that stand out from the dark.
   Angular shapes: square edges with cut corners, no rounding.
   der / die / das keep three colours (a learning device) but muted: steel blue, dusty rose, slate teal.
   Type: Saira (UI) + Saira Semi Condensed (German words, numbers). */

:root {
  --bg: #040609;
  --panel: #0C121A;
  --panel-2: #121A25;
  --line: #1E2A38;
  --line-strong: #2F4155;
  --ink: #E8EEF6;
  --ink-2: #9AA9BC;
  --ink-3: #64748A;
  --blue: #3D8BFF;
  --blue-2: #6FB1FF;
  --blue-ink: #FFFFFF;
  --glow: 0 0 0 1px rgba(61, 139, 255, 0.35), 0 0 24px rgba(61, 139, 255, 0.25);

  /* The flashcard surface */
  --card: #E7ECF3;
  --card-2: #D8DFE9;
  --card-ink: #0B111A;
  --card-ink-2: #4A5869;
  --card-line: #C3CCD8;

  /* der / die / das: distinct but calm */
  --der: #2F62C9;
  --die: #B04A63;
  --das: #2F8077;
  /* versions for dark backgrounds */
  --der-d: #6E9BF0;
  --die-d: #D78297;
  --das-d: #6DB6AC;

  --again: #D78297;
  --cut: 14px;
  --font: "Saira", system-ui, sans-serif;
  --font-word: "Saira Semi Condensed", "Saira", system-ui, sans-serif;
  --tabs-h: 66px;
  color-scheme: dark;
}

* { box-sizing: border-box; border-radius: 0; }
html, body { margin: 0; }
body {
  background-color: var(--bg);
  background-image:
    radial-gradient(1100px 600px at 50% -10%, rgba(61, 139, 255, 0.16), transparent 70%),
    linear-gradient(rgba(111, 177, 255, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(111, 177, 255, 0.045) 1px, transparent 1px);
  background-size: 100% 100%, 32px 32px, 32px 32px;
  background-attachment: fixed;
  color: var(--ink);
  font: 400 17px/1.5 var(--font);
  -webkit-font-smoothing: antialiased;
  min-height: 100dvh;
}
button, input, select { font: inherit; color: inherit; border-radius: 0; }
button { cursor: pointer; }
:focus-visible { outline: 2px solid var(--blue-2); outline-offset: 3px; }

/* Cut-corner shape used across panels and buttons */
.cut { clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, var(--cut) 100%, 0 calc(100% - var(--cut))); }

#app {
  max-width: 560px;
  margin: 0 auto;
  padding: max(22px, env(safe-area-inset-top)) 16px calc(var(--tabs-h) + 28px + env(safe-area-inset-bottom));
}
body.studying #app { padding-bottom: 24px; }

h1, h2, h3 { margin: 0; line-height: 1.1; }
h1 { font: 600 36px/1.05 var(--font-word); letter-spacing: -0.005em; }
h2 { font: 600 20px/1.2 var(--font-word); letter-spacing: 0.01em; }
p { margin: 0; }
.muted { color: var(--ink-2); }
.small { font-size: 15px; }
.stack > * + * { margin-top: 16px; }
.stack-lg > * + * { margin-top: 28px; }
.label { color: var(--ink-3); font: 500 13px/1.3 var(--font); letter-spacing: 0.06em; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 52px; padding: 0 22px;
  border: 1px solid var(--line-strong); background: var(--panel-2); font-weight: 600;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
}
.btn:hover { border-color: var(--blue); background: #16212F; }
.btn-primary {
  background: linear-gradient(180deg, #4A95FF, #2A6FE0); color: var(--blue-ink); border: none;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25);
  letter-spacing: 0.02em;
}
.btn-primary:hover { background: linear-gradient(180deg, #5BA1FF, #3479EA); }
.btn-block { width: 100%; }
.btn-text { background: none; border: none; padding: 0 4px; min-height: 40px; color: var(--ink-2); font-weight: 600; }
.btn-text:hover { color: var(--blue-2); }
.btn:disabled { opacity: 0.4; cursor: default; }

/* ---------- forms ---------- */
.field { display: grid; gap: 6px; }
.field label { font-weight: 600; font-size: 15px; color: var(--ink-2); }
.field input {
  min-height: 52px; padding: 0 14px;
  border: 1px solid var(--line-strong); background: rgba(12, 18, 26, 0.85);
}
.field input:focus { border-color: var(--blue); box-shadow: var(--glow); outline: none; }
.error { color: var(--again); font-weight: 600; }

/* ---------- auth ---------- */
.auth { padding-top: 12vh; }
.wordmark { font: 700 76px/0.9 var(--font-word); letter-spacing: -0.02em; color: var(--ink); }
.wordmark span { background: linear-gradient(180deg, #FFFFFF, #8FB8F0); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* ---------- home ---------- */
.home-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.level-chip {
  display: inline-block; padding: 3px 10px; border: 1px solid var(--blue); color: var(--blue-2);
  font: 600 14px/1.4 var(--font-word); letter-spacing: 0.06em; background: rgba(61, 139, 255, 0.08);
}

/* The hero: how far through the level you are */
.hud {
  position: relative; padding: 22px 20px 20px;
  background: linear-gradient(180deg, rgba(18, 26, 37, 0.92), rgba(10, 15, 22, 0.92));
  border: 1px solid var(--line-strong);
}
.hud::before, .hud::after { content: ""; position: absolute; width: 18px; height: 18px; border-color: var(--blue); border-style: solid; }
.hud::before { top: -1px; left: -1px; border-width: 2px 0 0 2px; }
.hud::after { bottom: -1px; right: -1px; border-width: 0 2px 2px 0; }
.hud-top { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; }
.hud-num { font: 600 64px/0.95 var(--font-word); letter-spacing: -0.02em; color: #FFFFFF; text-shadow: 0 0 28px rgba(61, 139, 255, 0.45); }
.hud-num small { font-size: 26px; color: var(--ink-2); text-shadow: none; margin-left: 2px; }
.segments { display: grid; grid-template-columns: repeat(40, 1fr); gap: 3px; margin: 16px 0 10px; height: 12px; }
.segments i { background: var(--line); }
.segments i.on { background: var(--blue); box-shadow: 0 0 8px rgba(61, 139, 255, 0.6); }
.segments i.part { background: linear-gradient(90deg, var(--blue) var(--p, 50%), var(--line) var(--p, 50%)); }
.hud-foot { display: flex; justify-content: space-between; gap: 12px; color: var(--ink-2); font-size: 15px; }

.today { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line-strong); background: rgba(12, 18, 26, 0.9); }
.today div { padding: 14px 16px; }
.today div + div { border-left: 1px solid var(--line); }
.today strong { display: block; font: 600 34px/1 var(--font-word); color: #FFFFFF; }
.today span { color: var(--ink-3); font-size: 14px; }

.start { min-height: 64px; font-size: 20px; }
@media (prefers-reduced-motion: no-preference) {
  .start { animation: pulse 3.2s ease-in-out infinite; }
  @keyframes pulse { 0%, 100% { box-shadow: inset 0 1px 0 rgba(255,255,255,0.25), 0 0 0 rgba(61,139,255,0); } 50% { box-shadow: inset 0 1px 0 rgba(255,255,255,0.25), 0 0 28px rgba(61,139,255,0.45); } }
}

.drill-entry {
  display: grid; grid-template-columns: auto 1fr; gap: 16px; align-items: center;
  width: 100%; padding: 16px; text-align: left;
  background: rgba(12, 18, 26, 0.9); border: 1px solid var(--line-strong);
}
.drill-entry:hover { border-color: var(--blue); }
.drill-entry .arts { display: grid; grid-template-columns: repeat(3, 8px); gap: 4px; height: 42px; }
.drill-entry .arts i:nth-child(1) { background: var(--der-d); }
.drill-entry .arts i:nth-child(2) { background: var(--die-d); }
.drill-entry .arts i:nth-child(3) { background: var(--das-d); }
.drill-entry strong { display: block; font: 600 22px/1.1 var(--font-word); }

/* ---------- study card ---------- */
.study-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
.progressbar { flex: 1; height: 4px; background: var(--line); overflow: hidden; }
.progressbar i { display: block; height: 100%; background: var(--blue); box-shadow: 0 0 10px rgba(61,139,255,0.8); width: 0; transition: width 0.25s ease; }

.card {
  position: relative;
  background: linear-gradient(170deg, var(--card) 0%, var(--card-2) 100%);
  color: var(--card-ink);
  min-height: 56dvh;
  padding: 26px 22px 22px 34px;
  display: flex; flex-direction: column;
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
  box-shadow: 0 0 40px rgba(61, 139, 255, 0.12);
}
/* Gender band down the left edge */
.card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 8px;
  background: var(--band, var(--card-line));
}
.card[data-art="der"] { --band: var(--der); }
.card[data-art="die"] { --band: var(--die); }
.card[data-art="das"] { --band: var(--das); }
.card[data-kind="phrase"] { --band: #7C8DA3; }

.card .tag { color: var(--card-ink-2); font-size: 13px; font-weight: 600; letter-spacing: 0.05em; padding-right: 60px; }
.card .prompt { flex: 1; display: flex; flex-direction: column; justify-content: center; gap: 10px; padding: 12px 0; }
.word {
  font: 600 clamp(42px, 11.5vw, 64px)/1.02 var(--font-word);
  letter-spacing: -0.01em; overflow-wrap: anywhere; hyphens: auto;
}
.card[data-kind="phrase"] .word { font-size: clamp(28px, 7.5vw, 40px); line-height: 1.12; font-weight: 500; }
.art { font-weight: 700; }
.art-der { color: var(--der); }
.art-die { color: var(--die); }
.art-das { color: var(--das); }
.english { font-size: 22px; font-weight: 500; }
.prompt-en .english { font: 600 clamp(32px, 8vw, 46px)/1.1 var(--font-word); }
.plural { color: var(--card-ink-2); font-size: 16px; }
.answer { border-top: 1px solid var(--card-line); padding-top: 16px; display: grid; gap: 6px; }

.speak {
  position: absolute; top: 16px; right: 16px;
  width: 50px; height: 50px; border: none;
  background: var(--card-ink); color: #FFFFFF;
  display: grid; place-items: center;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
}
.speak:hover { background: #1A2433; }
.speak.playing { background: var(--blue); }
.speak svg { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: square; stroke-linejoin: miter; }

.reveal { margin-top: 14px; min-height: 62px; font-size: 19px; }
.grades { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; margin-top: 14px; }
.grade {
  min-height: 66px; border: 1px solid var(--line-strong); background: rgba(12, 18, 26, 0.92);
  display: grid; align-content: center; gap: 2px; font-weight: 600;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}
.grade small { font-weight: 400; color: var(--ink-3); font-size: 13px; }
.grade:hover { border-color: var(--blue); }
.grade[data-g="1"] { color: var(--again); }
.grade[data-g="3"] { background: linear-gradient(180deg, #4A95FF, #2A6FE0); border: none; color: #FFFFFF; }
.grade[data-g="3"] small { color: rgba(255, 255, 255, 0.75); }
.keys { text-align: center; color: var(--ink-3); font-size: 13px; margin-top: 12px; }
@media (hover: none) { .keys { display: none; } }

/* ---------- article drill ---------- */
.drill-word { font: 600 clamp(44px, 12vw, 68px)/1 var(--font-word); overflow-wrap: anywhere; }
.drill-en { color: var(--card-ink-2); font-size: 18px; }
.drill-feedback { min-height: 30px; font: 600 22px/1.2 var(--font-word); }
.drill-feedback.right { color: var(--das); }
.drill-feedback.wrong { color: var(--die); }
.drill-buttons { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; margin-top: 14px; }
.drill-btn {
  min-height: 84px; border: 1px solid var(--line-strong); background: rgba(12, 18, 26, 0.92); color: var(--ink);
  font: 600 30px/1 var(--font-word); position: relative;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
}
.drill-btn::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 4px; }
.drill-btn[data-a="der"]::before { background: var(--der-d); }
.drill-btn[data-a="die"]::before { background: var(--die-d); }
.drill-btn[data-a="das"]::before { background: var(--das-d); }
.drill-btn[data-a="der"] { color: var(--der-d); }
.drill-btn[data-a="die"] { color: var(--die-d); }
.drill-btn[data-a="das"] { color: var(--das-d); }
.drill-btn:hover { border-color: var(--blue); }
.drill-btn.dim { opacity: 0.25; }
.score { font: 600 92px/0.9 var(--font-word); color: #FFFFFF; text-shadow: 0 0 30px rgba(61, 139, 255, 0.5); }
.missed .deck-title .art-der { color: var(--der-d); }
.missed .deck-title .art-die { color: var(--die-d); }
.missed .deck-title .art-das { color: var(--das-d); }

/* ---------- topics ---------- */
.level-head { display: flex; align-items: center; gap: 12px; }
.deck-group h2 { margin-bottom: 4px; color: var(--ink-2); }
.deck-list { list-style: none; margin: 10px 0 0; padding: 0; border-top: 1px solid var(--line); }
.deck {
  display: grid; grid-template-columns: 1fr auto; gap: 4px 16px; align-items: center;
  padding: 14px 2px; border-bottom: 1px solid var(--line);
}
.deck.locked { opacity: 0.4; }
.deck-title { font: 600 21px/1.2 var(--font-word); }
.deck-sub { color: var(--ink-2); font-size: 15px; grid-column: 1; }
.deck-meter { grid-column: 1 / -1; height: 3px; background: var(--line); overflow: hidden; margin-top: 6px; }
.deck-meter i { display: block; height: 100%; background: var(--blue); box-shadow: 0 0 6px rgba(61,139,255,0.7); }

.switch { position: relative; width: 54px; height: 28px; grid-row: 1 / span 2; grid-column: 2; }
.switch input { position: absolute; inset: 0; opacity: 0; margin: 0; cursor: pointer; z-index: 1; }
.switch input:disabled { cursor: default; }
.switch span { position: absolute; inset: 0; background: var(--panel); border: 1px solid var(--line-strong); pointer-events: none; }
.switch span::after {
  content: ""; position: absolute; top: 4px; left: 4px; width: 18px; height: 18px;
  background: var(--ink-3); transition: transform 0.12s;
}
.switch input:checked + span { border-color: var(--blue); background: rgba(61, 139, 255, 0.15); }
.switch input:checked + span::after { transform: translateX(26px); background: var(--blue-2); box-shadow: 0 0 10px rgba(61,139,255,0.8); }
.switch input:focus-visible + span { outline: 2px solid var(--blue-2); outline-offset: 3px; }

/* ---------- progress ---------- */
.stats { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line-strong); background: rgba(12, 18, 26, 0.9); }
.stat { padding: 14px; }
.stat + .stat { border-left: 1px solid var(--line); }
.stat strong { display: block; font: 600 34px/1 var(--font-word); color: #FFFFFF; }
.stat span { color: var(--ink-3); font-size: 14px; }
.chart { display: grid; grid-template-columns: repeat(14, 1fr); gap: 4px; align-items: end; height: 120px; border-bottom: 1px solid var(--line-strong); }
.chart .bar { background: var(--line-strong); min-height: 2px; }
.chart .bar.has { background: linear-gradient(180deg, var(--blue-2), var(--blue)); }
.chart .bar.today { box-shadow: 0 0 12px rgba(61,139,255,0.8); }
.chart-labels { display: flex; justify-content: space-between; color: var(--ink-3); font-size: 13px; margin-top: 6px; }

.settings { background: rgba(12, 18, 26, 0.92); border: 1px solid var(--line-strong); padding: 18px; }
.row { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.row + .row { margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--line); }
.row select, .row input[type="number"] {
  min-height: 44px; padding: 0 10px; border: 1px solid var(--line-strong); background: var(--bg);
  max-width: 55%;
}
.row input[type="number"] { width: 88px; }
.row .switch { grid-row: auto; grid-column: auto; flex: none; }

/* ---------- done ---------- */
.done { padding-top: 8vh; }
.done .big { font: 600 76px/0.95 var(--font-word); color: #FFFFFF; text-shadow: 0 0 30px rgba(61, 139, 255, 0.5); }

/* ---------- tabs ---------- */
.tabs {
  position: fixed; left: 0; right: 0; bottom: 0;
  display: grid; grid-template-columns: repeat(3, 1fr);
  height: calc(var(--tabs-h) + env(safe-area-inset-bottom));
  padding-bottom: env(safe-area-inset-bottom);
  background: rgba(4, 6, 9, 0.82); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-top: 1px solid var(--line-strong);
}
.tabs[hidden] { display: none; }
.tab {
  border: none; background: none; display: grid; place-items: center; align-content: center; gap: 2px;
  color: var(--ink-3); font-size: 13px; font-weight: 600; letter-spacing: 0.03em; position: relative;
}
.tab svg { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: square; }
.tab.active { color: var(--blue-2); }
.tab.active::before { content: ""; position: absolute; top: -1px; left: 30%; right: 30%; height: 2px; background: var(--blue); box-shadow: 0 0 10px rgba(61,139,255,0.9); }

.toast {
  position: fixed; left: 50%; bottom: calc(var(--tabs-h) + 16px + env(safe-area-inset-bottom));
  transform: translateX(-50%); background: var(--panel-2); color: var(--ink); border: 1px solid var(--blue);
  padding: 10px 16px; font-size: 15px; font-weight: 600; z-index: 10; box-shadow: var(--glow);
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}
@media (prefers-reduced-motion: no-preference) {
  .answer { animation: drop 0.18s ease-out; }
  @keyframes drop { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }
  .card { animation: boot 0.22s ease-out; }
  @keyframes boot { from { opacity: 0; transform: translateY(6px); filter: brightness(1.15); } to { opacity: 1; transform: none; filter: none; } }
}