/* ============================================================
   Kosten-Splitter – Stylesheet
   Mobile-first, Light/Dark via prefers-color-scheme
   ============================================================ */

:root {
  /* Farbpalette (Light) – Petrol/Cyan mit warmem Amber-Akzent */
  --color-bg: #f4f7f8;
  --color-surface: #ffffff;
  --color-surface-alt: #e9f0f2;
  --color-border: #d5e0e4;
  --color-text: #16262b;
  --color-text-muted: #5b7078;
  --color-primary: #0e7490;
  --color-primary-strong: #0a5a70;
  --color-primary-contrast: #ffffff;
  --color-accent: #d97706;
  --color-accent-soft: #fdf1e0;
  --color-positive: #15803d;
  --color-positive-soft: #e3f4e8;
  --color-negative: #b91c1c;
  --color-negative-soft: #fbe7e7;
  --color-danger: #b91c1c;
  --color-bar-track: #e2eaee;
  --shadow-card: 0 1px 3px rgba(22, 38, 43, 0.10);
  --shadow-modal: 0 12px 40px rgba(22, 38, 43, 0.25);
  --radius: 12px;
  --radius-small: 8px;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-head: "Sora", "Inter", system-ui, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0d181c;
    --color-surface: #14232a;
    --color-surface-alt: #1b2f37;
    --color-border: #2b414b;
    --color-text: #e6eef1;
    --color-text-muted: #93a8b0;
    --color-primary: #22b8d4;
    --color-primary-strong: #57cbe0;
    --color-primary-contrast: #05171c;
    --color-accent: #f2a340;
    --color-accent-soft: #33270f;
    --color-positive: #4ade80;
    --color-positive-soft: #10301c;
    --color-negative: #f87171;
    --color-negative-soft: #3a1414;
    --color-danger: #f87171;
    --color-bar-track: #22363e;
    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.45);
    --shadow-modal: 0 12px 40px rgba(0, 0, 0, 0.6);
  }
}

* { box-sizing: border-box; }

html { font-size: 16px; }

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3 {
  font-family: var(--font-head);
  line-height: 1.25;
  margin: 0 0 0.5rem;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

/* ---------- Header ---------- */

.app-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 20;
}

.header-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 0.6rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--color-text);
}

.brand-name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.05rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.group-select {
  max-width: 11rem;
}

/* ---------- Buttons & Inputs ---------- */

.btn {
  font: inherit;
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: var(--radius-small);
  padding: 0.5rem 0.9rem;
  cursor: pointer;
  background: var(--color-surface-alt);
  color: var(--color-text);
  transition: filter 120ms ease, background 120ms ease;
}

.btn:hover:not(:disabled) { filter: brightness(0.96); }
.btn:disabled { opacity: 0.55; cursor: not-allowed; }

.btn-primary {
  background: var(--color-primary);
  color: var(--color-primary-contrast);
}

.btn-secondary {
  background: var(--color-surface);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-ghost {
  background: transparent;
  border-color: var(--color-border);
}

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

.btn-premium {
  background: var(--color-accent-soft);
  border-color: var(--color-accent);
  color: var(--color-accent);
  font-size: 0.85rem;
}

.btn-mini {
  padding: 0.2rem 0.6rem;
  font-size: 0.8rem;
}

.linklike {
  background: none;
  border: none;
  padding: 0;
  font: inherit;
  color: var(--color-primary);
  text-decoration: underline;
  cursor: pointer;
}

input[type="text"],
input[type="date"],
input[type="number"],
select,
textarea {
  font: inherit;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  padding: 0.45rem 0.6rem;
  width: 100%;
}

input:focus-visible,
select:focus-visible,
textarea:focus-visible,
.btn:focus-visible,
.tab:focus-visible,
.linklike:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

label { font-size: 0.9rem; font-weight: 500; display: block; }
label > input, label > select, label > textarea { margin-top: 0.25rem; }

/* ---------- Layout ---------- */

.app-main {
  flex: 1;
  width: 100%;
  max-width: 760px;
  margin: 0 auto;
  padding: 1rem 1rem 3rem;
}

.section-title {
  font-size: 1.05rem;
  margin-top: 1.5rem;
}

.section-subtitle {
  font-size: 0.95rem;
  margin-top: 1.5rem;
}

.danger-title { color: var(--color-danger); }

.hint {
  color: var(--color-text-muted);
  font-size: 0.85rem;
  margin: 0.25rem 0 0.75rem;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  padding: 1rem;
  margin-bottom: 1rem;
}

.btn-row {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 0.5rem;
}

/* ---------- Empty State ---------- */

.empty-state { padding-top: 2rem; }

.empty-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  padding: 2rem 1.5rem;
  text-align: center;
}

.empty-emoji { font-size: 3rem; margin-bottom: 0.5rem; }

.empty-card p {
  color: var(--color-text-muted);
  max-width: 34rem;
  margin: 0.5rem auto 1.25rem;
}

.empty-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---------- Group head & tabs ---------- */

.group-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin: 0.5rem 0 0.75rem;
}

.group-title { font-size: 1.3rem; margin: 0; }

.tabbar {
  display: flex;
  gap: 0.25rem;
  background: var(--color-surface-alt);
  border-radius: var(--radius);
  padding: 0.25rem;
  overflow-x: auto;
}

.tab {
  flex: 1;
  font: inherit;
  font-weight: 600;
  font-size: 0.9rem;
  border: none;
  background: transparent;
  color: var(--color-text-muted);
  border-radius: var(--radius-small);
  padding: 0.45rem 0.5rem;
  cursor: pointer;
  white-space: nowrap;
}

.tab.is-active {
  background: var(--color-surface);
  color: var(--color-text);
  box-shadow: var(--shadow-card);
}

.tab-panel { animation: fadein 160ms ease; }

@keyframes fadein {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: none; }
}

/* ---------- Salden ---------- */

.balance-list,
.settle-list,
.expense-list,
.member-list,
.category-stats,
.premium-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.balance-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.65rem 0.9rem;
  margin-bottom: 0.5rem;
}

.balance-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.5rem;
}

.balance-name { font-weight: 600; }

.balance-amount { font-weight: 600; font-variant-numeric: tabular-nums; }
.balance-amount.pos { color: var(--color-positive); }
.balance-amount.neg { color: var(--color-negative); }
.balance-amount.zero { color: var(--color-text-muted); }

.balance-desc {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.balance-bar {
  position: relative;
  height: 8px;
  margin-top: 0.45rem;
  background: var(--color-bar-track);
  border-radius: 4px;
  overflow: hidden;
}

.balance-bar-fill {
  position: absolute;
  top: 0;
  height: 100%;
  border-radius: 4px;
}

.balance-bar-fill.pos { background: var(--color-positive); left: 50%; }
.balance-bar-fill.neg { background: var(--color-negative); right: 50%; }

.settle-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.6rem 0.9rem;
  margin-bottom: 0.5rem;
}

.settle-item input[type="checkbox"] {
  width: 1.2rem;
  height: 1.2rem;
  accent-color: var(--color-primary);
}

.settle-text { flex: 1; }
.settle-text strong { font-variant-numeric: tabular-nums; }

.settle-empty,
.list-empty {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  background: var(--color-surface-alt);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
}

.share-row {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

/* ---------- Verlauf ---------- */

.filter-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin: 0.5rem 0 1rem;
}

.expense-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.65rem 0.9rem;
  margin-bottom: 0.5rem;
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
}

.expense-item.is-settlement { border-left: 4px solid var(--color-accent); }

.expense-main { min-width: 0; }

.expense-desc { font-weight: 600; overflow-wrap: anywhere; }

.expense-meta {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.expense-side {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.35rem;
  flex-shrink: 0;
}

.expense-amount { font-weight: 600; font-variant-numeric: tabular-nums; }

.expense-actions { display: flex; gap: 0.35rem; }

.icon-btn {
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  padding: 0.15rem 0.5rem;
  cursor: pointer;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.icon-btn:hover { color: var(--color-text); }

/* ---------- Statistik ---------- */

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.stat-label { font-size: 0.8rem; color: var(--color-text-muted); }
.stat-value { font-family: var(--font-head); font-weight: 700; font-size: 1.15rem; }

.category-stat {
  margin-bottom: 0.65rem;
}

.category-stat-top {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  margin-bottom: 0.25rem;
}

.category-stat-bar {
  height: 8px;
  background: var(--color-bar-track);
  border-radius: 4px;
  overflow: hidden;
}

.category-stat-fill {
  height: 100%;
  background: var(--color-primary);
  border-radius: 4px;
}

/* ---------- Gruppe verwalten ---------- */

.stacked-form { display: grid; gap: 0.75rem; }

.inline-form {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.inline-form input { flex: 1; }

.member-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  padding: 0.45rem 0.75rem;
  margin-bottom: 0.4rem;
}

.file-btn { position: relative; overflow: hidden; display: inline-block; text-align: center; }
.file-btn input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

/* ---------- Ad-Slot ---------- */

.ad-slot {
  margin-top: 2.5rem;
  min-height: 90px;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ---------- Footer ---------- */

.app-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  padding: 1rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.app-footer p { margin: 0 0 0.35rem; }

.footer-nav {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
}

/* ---------- Modals ---------- */

.modal {
  border: none;
  border-radius: var(--radius);
  padding: 0;
  width: min(94vw, 34rem);
  background: var(--color-surface);
  color: var(--color-text);
  box-shadow: var(--shadow-modal);
}

.modal::backdrop { background: rgba(10, 20, 24, 0.55); }

.modal-box { padding: 1.25rem; }

.modal-box h2 { margin-top: 0; }

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 1.25rem;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 0.75rem;
}

#expenseFields > label { margin-top: 0.75rem; }

.type-toggle {
  display: flex;
  gap: 1rem;
  border: none;
  padding: 0;
  margin: 0 0 0.5rem;
}

.type-toggle label,
.split-modes label {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 500;
}

.participants-set,
.split-set {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  padding: 0.6rem 0.75rem 0.75rem;
  margin-top: 1rem;
}

.participants-set legend,
.split-set legend {
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0 0.25rem;
}

.participant-checks {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 0.35rem;
  margin-top: 0.5rem;
}

.participant-checks label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 400;
}

.split-modes {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
}

.split-inputs {
  margin-top: 0.75rem;
  display: grid;
  gap: 0.4rem;
}

.split-input-row {
  display: grid;
  grid-template-columns: 1fr 7rem;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.split-validation {
  font-size: 0.85rem;
  margin: 0.5rem 0 0;
  min-height: 1.2em;
}

.split-validation.ok { color: var(--color-positive); }
.split-validation.bad { color: var(--color-negative); }

.form-error {
  color: var(--color-negative);
  font-size: 0.85rem;
  margin: 0.75rem 0 0;
}

.premium-list { margin: 0.75rem 0; padding-left: 1.1rem; list-style: disc; }

/* ---------- Hilfe / Erste Schritte ---------- */

.help-btn {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--color-text-muted);
  flex-shrink: 0;
}

.help-btn:hover:not(:disabled) { color: var(--color-text); }

.help-steps {
  margin: 0.75rem 0 0;
  padding-left: 1.25rem;
}

.help-steps li { margin-bottom: 0.6rem; }
.help-steps li:last-child { margin-bottom: 0; }

.help-subtitle {
  font-size: 0.95rem;
  margin: 1.1rem 0 0.35rem;
}

.help-know {
  margin: 0;
  padding-left: 1.1rem;
  list-style: disc;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.help-know li { margin-bottom: 0.3rem; }
.help-know li:last-child { margin-bottom: 0; }

/* ---------- Toast ---------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: 1.25rem;
  transform: translateX(-50%);
  background: var(--color-text);
  color: var(--color-bg);
  padding: 0.6rem 1.1rem;
  border-radius: 999px;
  font-size: 0.9rem;
  box-shadow: var(--shadow-modal);
  z-index: 50;
  max-width: 90vw;
}

/* ---------- Responsive ---------- */

@media (max-width: 480px) {
  .field-row { grid-template-columns: 1fr; }
  .filter-row { grid-template-columns: 1fr; }
  .group-select { max-width: 8rem; }
  .btn-premium { font-size: 0.78rem; padding: 0.4rem 0.6rem; }
}