:root {
  --bg: #0d0f13;
  --bg-elevated: #14171d;
  --surface: #191d25;
  --surface-hover: #1f2430;
  --border: #262b36;
  --border-soft: #1d212a;
  --text: #e8eaef;
  --text-dim: #8b93a3;
  --text-faint: #5b6272;

  --accent: #5b8cff;
  --accent-dim: #3a5ecc;
  --accent-soft: rgba(91, 140, 255, 0.12);

  --green: #3ecf8e;
  --amber: #e0a63a;
  --red: #e0605a;

  --font-display: "Sora", sans-serif;
  --font-body: "IBM Plex Sans", sans-serif;
  --font-mono: "IBM Plex Mono", monospace;

  --radius: 10px;
  --shadow: 0 8px 24px -8px rgba(0, 0, 0, 0.5);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
}

/* --- header --- */

.app-header {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 32px 40px 24px;
  border-bottom: 1px solid var(--border-soft);
}

.app-header__text h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  margin: 0 0 4px;
  letter-spacing: -0.01em;
  color: var(--text);
}

.app-header__text p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.88rem;
}

.app-header__actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 14px;
}

.source-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-faint);
  border: 1px solid var(--border);
  padding: 5px 10px;
  border-radius: 20px;
  white-space: nowrap;
  text-decoration: none;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.source-tag[href="#"] {
  pointer-events: none;
}

.source-tag:hover {
  color: var(--text-dim);
  border-color: var(--accent-dim);
}

.btn {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.85rem;
  border: none;
  border-radius: 8px;
  padding: 10px 16px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: background 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}

.btn--primary {
  background: var(--accent);
  color: #060810;
  box-shadow: 0 4px 14px -4px rgba(91, 140, 255, 0.5);
}

.btn--primary:hover {
  background: #6f99ff;
  transform: translateY(-1px);
}

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

.btn--primary:disabled {
  opacity: 0.5;
  cursor: progress;
  transform: none;
}

.btn__icon {
  display: inline-block;
  font-size: 0.95rem;
}

.btn--primary.is-loading .btn__icon {
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* --- mobile tabs (hidden on desktop, see @media below) --- */

.mobile-tabs {
  display: none;
}

/* --- board --- */

.board {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(300px, 1fr);
  gap: 20px;
  padding: 24px 40px 56px;
  align-items: start;
  overflow-x: auto;
}

.column {
  background: var(--bg-elevated);
  border: 1px solid var(--border-soft);
  border-radius: 12px;
  min-height: 60vh;
  display: flex;
  flex-direction: column;
}

.column__head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border-soft);
}

.column__head h2 {
  font-family: var(--font-display);
  font-size: 0.92rem;
  font-weight: 600;
  margin: 0;
  letter-spacing: 0.01em;
  color: var(--text);
}

.column__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

.column__head--working .column__dot {
  background: var(--green);
  box-shadow: 0 0 8px rgba(62, 207, 142, 0.6);
}

.column__head--uncertain .column__dot {
  background: var(--amber);
  box-shadow: 0 0 8px rgba(224, 166, 58, 0.6);
}

.column__head--outdated .column__dot {
  background: var(--red);
  box-shadow: 0 0 8px rgba(224, 96, 90, 0.6);
}

.column__count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-faint);
  background: var(--surface);
  padding: 2px 8px;
  border-radius: 10px;
}

.column__drop {
  flex: 1;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-height: 200px;
  transition: background 0.15s ease, box-shadow 0.15s ease;
  border-radius: 0 0 12px 12px;
}

.column__drop.is-dragover {
  background: var(--accent-soft);
  box-shadow: inset 0 0 0 1.5px var(--accent-dim);
}

.column__empty {
  margin: auto 0;
  text-align: center;
  color: var(--text-faint);
  font-size: 0.82rem;
  padding: 30px 10px;
}

/* --- cards --- */

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 13px 13px 11px;
  cursor: grab;
  box-shadow: var(--shadow);
  transition: transform 0.14s ease, box-shadow 0.14s ease, border-color 0.14s ease, opacity 0.14s ease, background 0.14s ease;
}

.card:hover {
  transform: translateY(-2px);
  border-color: #34394a;
  background: var(--surface-hover);
}

.card:active {
  cursor: grabbing;
}

.card.is-dragging {
  opacity: 0.35;
  transform: scale(0.98);
}

.card__top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
}

.card__code {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.94rem;
  color: var(--text);
  letter-spacing: 0.01em;
  word-break: break-all;
}

.card__copy {
  position: relative;
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: background 0.14s ease, color 0.14s ease, border-color 0.14s ease, transform 0.14s ease;
}

.copy-bubble {
  position: absolute;
  bottom: calc(100% + 8px);
  right: 50%;
  transform: translate(50%, 4px);
  background: var(--green);
  color: #06170f;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.72rem;
  padding: 4px 9px;
  border-radius: 6px;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
  box-shadow: var(--shadow);
  z-index: 5;
}

.copy-bubble::after {
  content: "";
  position: absolute;
  top: 100%;
  right: 50%;
  transform: translateX(50%);
  border: 5px solid transparent;
  border-top-color: var(--green);
}

.copy-bubble.is-visible {
  opacity: 1;
  transform: translate(50%, 0);
}

.card__copy:hover {
  background: var(--accent-soft);
  border-color: var(--accent-dim);
  color: var(--accent);
}

.card__copy.is-copied {
  background: rgba(62, 207, 142, 0.14);
  border-color: var(--green);
  color: var(--green);
  transform: scale(1.08);
}

.card__reward {
  margin: 9px 0 11px;
  font-size: 0.82rem;
  line-height: 1.45;
  color: var(--text-dim);
  min-height: 1.4em;
}

.card__reward.is-empty {
  font-style: italic;
  color: var(--text-faint);
}

.card__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  color: var(--text-faint);
  border-top: 1px solid var(--border-soft);
  padding-top: 8px;
}

.card__drag {
  letter-spacing: 2px;
  opacity: 0.6;
}

/* --- toasts --- */

.toast-stack {
  position: fixed;
  bottom: 22px;
  right: 22px;
  z-index: 10;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: flex-end;
}

.toast {
  font-family: var(--font-body);
  font-size: 0.84rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 12px 16px;
  border-radius: 8px;
  box-shadow: var(--shadow);
  max-width: 320px;
  animation: toast-in 0.2s ease;
}

.toast--error {
  border-color: rgba(224, 96, 90, 0.5);
  color: #ffb8b4;
}

.toast--success {
  border-color: rgba(62, 207, 142, 0.5);
}

@keyframes toast-in {
  from {
    transform: translateY(8px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

/* --- responsive --- */

@media (max-width: 980px) {
  .board {
    padding: 20px 20px 56px;
  }

  .app-header {
    flex-wrap: wrap;
    padding: 24px 20px;
  }

  .app-header__actions {
    margin-left: 0;
    width: 100%;
    justify-content: space-between;
  }
}

/* Below phone width: one column fills the screen at a time, swipe between them,
   and the segmented control at the top jumps + tracks which one is in view. */
@media (max-width: 680px) {
  .mobile-tabs {
    display: flex;
    gap: 6px;
    position: sticky;
    top: 0;
    z-index: 3;
    padding: 10px 16px;
    background: var(--bg);
    border-bottom: 1px solid var(--border-soft);
  }

  .mobile-tabs__btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 0.78rem;
    color: var(--text-dim);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 999px;
    padding: 9px 6px;
    cursor: pointer;
    transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
  }

  .mobile-tabs__btn.is-active {
    background: var(--accent-soft);
    border-color: var(--accent-dim);
    color: var(--text);
  }

  .mobile-tabs__btn.is-dragover {
    background: var(--accent-soft);
    border-color: var(--accent);
    color: var(--text);
    transform: scale(1.05);
    box-shadow: 0 0 0 2px var(--accent-soft);
  }

  .mobile-tabs__dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    flex-shrink: 0;
  }

  .mobile-tabs__dot--working {
    background: var(--green);
  }

  .mobile-tabs__dot--uncertain {
    background: var(--amber);
  }

  .mobile-tabs__dot--outdated {
    background: var(--red);
  }

  .board {
    display: flex;
    grid-auto-columns: unset;
    gap: 16px;
    padding: 16px 16px 40px;
    scroll-snap-type: x mandatory;
    scroll-padding-inline: 16px;
    scrollbar-width: none;
  }

  .board::-webkit-scrollbar {
    display: none;
  }

  .column {
    flex: 0 0 100%;
    scroll-snap-align: start;
    min-height: calc(100vh - 190px);
  }

  .app-header__text p {
    display: none;
  }
}