/* app.css - Verspielt & motivierend, Türkis/Grün, fluid-responsiv, gerätebewusst. */

:root {
  --brand: #14b8a6;
  --brand-2: #22c55e;
  --brand-strong: #0d9488;
  --pop: #f59e0b;
  --ok: #16a34a;
  --bad: #ef4444;
  --hint: #f59e0b;

  --bg: #eafbf6;
  --bg-2: #d6f5ec;
  --card: #ffffff;
  --text: #0f2b2a;
  --muted: #5b7a78;
  --line: #d6ece8;

  --radius: 22px;
  --radius-sm: 14px;
  --shadow: 0 8px 24px rgba(13, 148, 136, 0.12);
  --shadow-sm: 0 3px 10px rgba(13, 148, 136, 0.1);
  --ring: 0 0 0 4px rgba(20, 184, 166, 0.22);

  /* Fluide Grundgrößen */
  --fs-base: clamp(16px, 1.2vw + 13px, 18px);
  --pad: clamp(14px, 3vw, 22px);
  --gap: clamp(10px, 2vw, 16px);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #06110f;
    --bg-2: #0b1c1a;
    --card: #10211f;
    --text: #dbf3ee;
    --muted: #8bada8;
    --line: #1f3a37;
    --shadow: 0 10px 28px rgba(0, 0, 0, 0.45);
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.4);
  }
}

* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: ui-rounded, "SF Pro Rounded", -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, sans-serif;
  font-size: var(--fs-base);
  color: var(--text);
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
  background: radial-gradient(1200px 600px at 80% -10%, var(--bg-2), transparent 60%),
    radial-gradient(900px 500px at -10% 0%, var(--bg-2), transparent 55%), var(--bg);
  background-attachment: fixed;
  min-height: 100vh;
}

#app {
  width: 100%;
  max-width: 820px;
  margin: 0 auto;
  padding: calc(var(--pad) + env(safe-area-inset-top)) var(--pad)
    calc(28px + env(safe-area-inset-bottom));
}
[data-device='desktop'] #app {
  max-width: 980px;
}

h1 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 0;
  letter-spacing: -0.01em;
}
h2 {
  font-size: clamp(1.1rem, 2vw, 1.3rem);
  margin: 1.3em 0 0.5em;
}

/* --- Header / Hero --- */
.app-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding-top: 6px;
}
.hero {
  display: flex;
  align-items: center;
  gap: 14px;
}
.hero-emoji {
  font-size: clamp(2.4rem, 6vw, 3.2rem);
  filter: drop-shadow(0 6px 10px rgba(13, 148, 136, 0.25));
  animation: floaty 3.5s ease-in-out infinite;
}
.grade {
  font-size: 0.8rem;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff;
  padding: 3px 12px;
  border-radius: 999px;
  vertical-align: middle;
  margin-left: 6px;
  box-shadow: var(--shadow-sm);
}
.tagline,
.chapter-sub {
  color: var(--muted);
  margin: 0.3em 0 0.2em;
}
.device-chip {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--brand-strong);
  background: color-mix(in srgb, var(--brand) 14%, transparent);
  border: 1px solid color-mix(in srgb, var(--brand) 30%, transparent);
  padding: 6px 12px;
  border-radius: 999px;
  white-space: nowrap;
}

/* --- Themen-Kacheln --- */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: var(--gap);
}
.topic-card {
  position: relative;
  text-align: left;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  color: inherit;
  font: inherit;
  overflow: hidden;
  transition: transform 0.12s ease, box-shadow 0.12s ease;
  animation: fadeUp 0.45s backwards;
  animation-delay: calc(var(--i, 0) * 55ms);
}
.topic-card::before {
  content: '';
  position: absolute;
  inset: 0 0 auto 0;
  height: 5px;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
}
.topic-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}
.topic-card:active {
  transform: translateY(0) scale(0.98);
}
.topic-icon {
  font-size: 1.9rem;
  display: block;
  margin-bottom: 6px;
}
.topic-title {
  display: block;
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 12px;
}

/* --- Mastery-Balken --- */
.mastery-bar {
  height: 10px;
  background: color-mix(in srgb, var(--brand) 12%, var(--line));
  border-radius: 999px;
  overflow: hidden;
}
.mastery-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  border-radius: 999px;
  transition: width 0.5s cubic-bezier(0.34, 1.4, 0.5, 1);
}
.mastery-label {
  display: block;
  font-size: 0.82rem;
  color: var(--muted);
  margin-top: 6px;
  font-weight: 600;
}

/* --- Topic-Header / Tabs --- */
.topic-header {
  padding-top: 4px;
}
.topic-header h1 {
  margin-top: 6px;
  font-size: clamp(1.3rem, 3vw, 1.7rem);
}
.back-btn {
  background: none;
  border: none;
  color: var(--brand-strong);
  font: inherit;
  font-weight: 700;
  padding: 6px 0;
  cursor: pointer;
}
.mastery-mini {
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 600;
}
.tabs {
  display: flex;
  gap: 6px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 5px;
  margin: 14px 0 18px;
  box-shadow: var(--shadow-sm);
}
.tab {
  flex: 1;
  border: none;
  background: none;
  color: var(--muted);
  font: inherit;
  font-weight: 700;
  padding: 11px;
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.15s ease;
}
.tab-active {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff;
  box-shadow: var(--shadow-sm);
}

/* --- Erklärung --- */
.block {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin-bottom: 12px;
  box-shadow: var(--shadow-sm);
  animation: fadeUp 0.4s backwards;
}
.badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--pop);
  color: #fff;
  padding: 3px 10px;
  border-radius: 8px;
  margin-right: 8px;
}
.badge-ex {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
}
.block ol {
  margin: 8px 0 0;
  padding-left: 22px;
}
.block li {
  margin: 5px 0;
}

/* --- Aufgaben-Karte --- */
.problem-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  margin-bottom: 14px;
  animation: fadeUp 0.35s backwards;
}
.problem-prompt {
  font-size: clamp(1.3rem, 3.4vw, 1.6rem);
  font-weight: 700;
  line-height: 1.7;
}
.problem-intro {
  color: var(--muted);
  margin: 8px 0 0;
}
.problem-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.answer-label,
.step-hint {
  display: block;
  margin: 14px 0 6px;
  font-weight: 700;
}
.step-count {
  display: inline-block;
  color: #fff;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  font-weight: 800;
  font-size: 0.78rem;
  padding: 3px 10px;
  border-radius: 999px;
}
.step-hint {
  font-weight: 600;
  margin-top: 10px;
}
.answer-row {
  display: flex;
  gap: 8px;
}
.answer-input {
  flex: 1;
  font-size: 1.4rem;
  font-weight: 700;
  padding: 13px 15px;
  border: 2px solid var(--line);
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--brand) 5%, var(--card));
  color: var(--text);
  min-width: 0;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.answer-input:focus {
  outline: none;
  border-color: var(--brand);
  box-shadow: var(--ring);
}

/* --- Buttons --- */
.btn {
  font: inherit;
  font-weight: 700;
  border-radius: 999px;
  padding: 13px 20px;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  min-height: 50px;
  transition: transform 0.1s ease, box-shadow 0.12s ease, background 0.12s ease;
}
.btn:active {
  transform: translateY(1px) scale(0.98);
}
.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  border-color: transparent;
  color: #fff;
  box-shadow: 0 6px 16px rgba(20, 184, 166, 0.35);
}
.btn-ghost {
  background: transparent;
  color: var(--brand-strong);
  border-color: color-mix(in srgb, var(--brand) 30%, transparent);
}
.btn.wide {
  width: 100%;
  margin-top: 10px;
}
.btn:disabled {
  opacity: 0.5;
}

/* --- Tastenfeld --- */
.keypad {
  margin-top: 14px;
  display: grid;
  gap: 8px;
  max-width: 340px;
}
[data-device='phone'] .keypad {
  max-width: none;
}
[data-device='desktop'] .keypad {
  max-width: 300px;
}
.keypad-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.key {
  font-size: 1.4rem;
  font-weight: 700;
  padding: 15px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  min-height: 56px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.08s ease, background 0.1s ease;
}
.key:active {
  transform: scale(0.94);
  background: color-mix(in srgb, var(--brand) 10%, var(--card));
}
.key-fn {
  color: var(--muted);
}
.key-enter {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff;
  border-color: transparent;
}

/* --- Feedback --- */
.feedback {
  margin-top: 12px;
  font-weight: 700;
  min-height: 1.4em;
}
.feedback.ok {
  color: var(--ok);
  animation: pop 0.35s ease;
}
.feedback.bad {
  color: var(--bad);
  animation: shake 0.35s ease;
}
.feedback.hint {
  color: var(--hint);
}
.done-box {
  text-align: center;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--ok);
  padding: 24px;
  animation: pop 0.5s cubic-bezier(0.34, 1.5, 0.5, 1);
}
.step-box {
  margin-top: 4px;
}

/* --- Test-Auswertung --- */
.test-progress {
  color: var(--muted);
  font-weight: 700;
  margin-bottom: 8px;
}
.result-card {
  text-align: center;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 26px;
  animation: pop 0.5s cubic-bezier(0.34, 1.4, 0.5, 1);
}
.result-score {
  font-size: 2.6rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.result-percent {
  font-size: 1.2rem;
  color: var(--brand-strong);
  font-weight: 800;
}
.result-note {
  color: var(--muted);
}

/* --- Backup --- */
.backup {
  margin-top: 30px;
  border-top: 1px solid var(--line);
  padding-top: 10px;
}
.backup-hint {
  color: var(--muted);
  font-size: 0.9rem;
}
.backup-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.backup-actions label {
  display: inline-flex;
  align-items: center;
}
.backup-msg {
  margin-top: 8px;
  font-size: 0.9rem;
  font-weight: 600;
}
.backup-msg.ok {
  color: var(--ok);
}
.backup-msg.bad {
  color: var(--bad);
}

/* --- Mathe-Formeln --- */
.frac {
  display: inline-flex;
  flex-direction: column;
  vertical-align: middle;
  text-align: center;
  margin: 0 3px;
}
.frac-num {
  display: block;
  padding: 0 5px;
  border-bottom: 2px solid currentColor;
  line-height: 1.25;
}
.frac-den {
  display: block;
  padding: 0 5px;
  line-height: 1.25;
}
sup {
  font-size: 0.7em;
}
.sqrt {
  border-top: 2px solid currentColor;
  padding: 0 3px;
}
.sqrt-rad {
  padding-left: 2px;
}
.error {
  color: var(--bad);
}
.subject-soon {
  opacity: 0.6;
  cursor: default;
  border-style: dashed;
  box-shadow: none;
}
.subject-soon::before {
  background: var(--muted);
}
.concept-note {
  margin-top: 12px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--brand) 10%, var(--card));
  border: 1px solid var(--line);
  color: var(--text);
}

/* --- Animationen --- */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@keyframes pop {
  0% {
    transform: scale(0.82);
    opacity: 0.4;
  }
  60% {
    transform: scale(1.06);
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}
@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-6px);
  }
  75% {
    transform: translateX(6px);
  }
}
@keyframes floaty {
  0%,
  100% {
    transform: translateY(0) rotate(-3deg);
  }
  50% {
    transform: translateY(-8px) rotate(3deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
  }
}