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

:root {
  color-scheme: light;
  --bg: #f7f7f9;
  --surface: #ffffff;
  --text: #1b1f23;
  --muted: #5b6168;
  --primary: #2f74ff;
  --primary-dark: #1e54c8;
  --danger: #c62828;
  --border: #d6d8db;
  --shadow: 0 10px 28px rgba(15, 23, 42, 0.08);
  --flip-bg: #101317;
  --flip-shadow: 0 8px 18px rgba(15, 23, 42, 0.2);
  --flip-border: rgba(255, 255, 255, 0.12);
  --flip-text: #f7f7f9;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
}

@font-face {
  font-family: "Digital";
  src: url("fonts/digital.ttf") format("truetype");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Bolder";
  src: url("fonts/bolder.ttf") format("truetype");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

body {
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  padding: 32px 16px 48px;
}

@media (max-width: 768px) {
  body {
    padding: 20px 12px 32px;
  }
}

@media (max-width: 480px) {
  body {
    padding: 16px 10px 24px;
  }
}

.app {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.app__header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.app__controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.app__control {
  display: grid;
  gap: 6px;
  font-size: 0.85rem;
  color: var(--muted);
}

.app__control select {
  padding: 8px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #fff;
  font-size: 0.95rem;
  touch-action: manipulation;
}

@media (max-width: 768px) {
  .app__controls {
    gap: 10px;
  }
  
  .app__control {
    font-size: 0.8rem;
    gap: 4px;
  }
  
  .app__control select {
    padding: 7px 10px;
    font-size: 0.9rem;
  }
}

@media (max-width: 480px) {
  .app__controls {
    gap: 8px;
    width: 100%;
  }
  
  .app__control {
    font-size: 0.75rem;
    flex: 1;
    min-width: 0;
  }
  
  .app__control select {
    padding: 6px 8px;
    font-size: 0.85rem;
  }
}

@media (max-width: 768px) and (orientation: landscape) {
  .app__controls {
    flex-wrap: nowrap;
  }
}

.app__header h1 {
  font-size: 2rem;
  margin-bottom: 6px;
}

.app__subtitle {
  color: var(--muted);
  font-size: 0.95rem;
}

@media (max-width: 768px) {
  .app__header h1 {
    font-size: 1.6rem;
  }
  
  .app__subtitle {
    font-size: 0.85rem;
  }
}

@media (max-width: 480px) {
  .app__header h1 {
    font-size: 1.4rem;
  }
  
  .app__subtitle {
    font-size: 0.8rem;
  }
}

.panel {
  background: var(--surface);
  padding: 20px;
  border-radius: 16px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  overflow-x: hidden;
  min-width: 0;
}

.panel h2 {
  font-size: 1.2rem;
  margin-bottom: 16px;
}

@media (max-width: 768px) {
  .panel {
    padding: 16px;
    border-radius: 12px;
  }
  
  .panel h2 {
    font-size: 1.1rem;
    margin-bottom: 12px;
  }
}

@media (max-width: 480px) {
  .panel {
    padding: 12px;
    border-radius: 10px;
  }
  
  .panel h2 {
    font-size: 1rem;
    margin-bottom: 10px;
  }
}

.form {
  display: grid;
  gap: 16px;
}

.form__field {
  display: grid;
  gap: 8px;
  font-size: 0.95rem;
}

.form__field input {
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 1rem;
  background: #fff;
  touch-action: manipulation;
}

.form__field input:focus {
  outline: 2px solid rgba(47, 116, 255, 0.35);
  border-color: var(--primary);
}

@media (max-width: 768px) {
  .form {
    gap: 14px;
  }
  
  .form__field {
    gap: 6px;
    font-size: 0.9rem;
  }
  
  .form__field input {
    padding: 9px 11px;
    font-size: 0.95rem;
  }
}

@media (max-width: 480px) {
  .form {
    gap: 12px;
  }
  
  .form__field {
    gap: 5px;
    font-size: 0.85rem;
  }
  
  .form__field input {
    padding: 8px 10px;
    font-size: 0.9rem;
  }
}

.btn {
  border: none;
  border-radius: 10px;
  padding: 10px 16px;
  font-size: 0.95rem;
  cursor: pointer;
  transition: transform 0.08s ease, background 0.2s ease;
  touch-action: manipulation;
}

.btn:active {
  transform: scale(0.98);
}

@media (max-width: 768px) {
  .btn {
    padding: 9px 14px;
    font-size: 0.9rem;
  }
}

@media (max-width: 480px) {
  .btn {
    padding: 8px 12px;
    font-size: 0.85rem;
  }
}

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

.btn--primary:hover {
  background: var(--primary-dark);
}

.btn--secondary {
  background: rgba(47, 116, 255, 0.12);
  color: var(--primary-dark);
}

.btn--secondary[hidden] {
  display: none;
}

.btn--ghost {
  background: transparent;
  color: var(--danger);
  border: 1px solid rgba(198, 40, 40, 0.3);
}

.btn--danger {
  background: var(--danger);
  color: #fff;
}

.counter-list {
  display: grid;
  gap: 16px;
}

.counter {
  padding: 16px;
  border-radius: 14px;
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 16px;
  background: #fff;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
  min-width: 0;
  width: 100%;
  box-sizing: border-box;
}

.counter:hover {
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.08);
  transform: translateY(-2px);
}

.counter__title {
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.counter__main {
  width: 100%;
}

.counter__time {
  margin-top: 12px;
  width: 100%;
  min-width: 0;
  box-sizing: border-box;
}

@media (min-width: 769px) {
  .counter {
    flex-direction: column;
    align-items: stretch;
  }
  
  .counter__main {
    width: 100%;
  }
  
  .counter__actions {
    width: 100%;
    margin-top: 4px;
  }
}

@media (max-width: 768px) {
  .counter {
    padding: 14px;
    gap: 12px;
    flex-direction: column;
    align-items: stretch;
  }
  
  .counter__main {
    width: 100%;
  }
  
  .counter__title {
    font-size: 1rem;
    margin-bottom: 4px;
  }
  
  .counter__time {
    margin-top: 8px;
  }
  
  .counter__actions {
    width: 100%;
    margin-top: 4px;
  }
}

@media (max-width: 480px) {
  .counter {
    padding: 12px;
    gap: 10px;
    flex-direction: column;
    align-items: stretch;
  }
  
  .counter__main {
    width: 100%;
  }
  
  .counter__title {
    font-size: 0.95rem;
    margin-bottom: 4px;
  }
  
  .counter__time {
    margin-top: 6px;
  }
  
  .counter__actions {
    width: 100%;
    margin-top: 4px;
  }
}

@media (max-width: 768px) and (orientation: landscape) {
  .counter {
    flex-direction: row;
    padding: 10px 12px;
    align-items: center;
  }
  
  .counter__main {
    flex: 1;
    min-width: 0;
  }
  
  .counter__actions {
    flex-shrink: 0;
    width: auto;
  }
}

.flip-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(110px, 1fr));
  gap: 18px;
  width: 100%;
  min-width: 0;
  box-sizing: border-box;
}

.flip-unit {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.flip-label {
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  font-weight: 700;
  color: var(--muted);
}

@media (max-width: 768px) {
  .flip-grid {
    gap: 14px;
  }
  
  .flip-label {
    font-size: 0.7rem;
    gap: 6px;
  }
}

@media (max-width: 768px) and (orientation: landscape) {
  .panel {
    padding: 12px;
    overflow-x: hidden;
  }
  
  .counter {
    min-width: 0;
    overflow-x: hidden;
  }
  
  .counter__main {
    min-width: 0;
    overflow-x: hidden;
  }
  
  .counter__time {
    min-width: 0;
    overflow-x: hidden;
  }
  
  .flip-grid {
    grid-template-columns: repeat(6, minmax(60px, 1fr));
    gap: 6px;
    min-width: 0;
    width: 100%;
  }
  
  .flip-unit {
    min-width: 0;
  }
  
  .flip-card {
    height: clamp(85px, 14vh, 110px);
    min-width: 0;
  }
  
  .flip-card__top,
  .flip-card__bottom,
  .flip-card__flip-top,
  .flip-card__flip-bottom {
    font-size: clamp(3rem, 11vw, 6.5rem) !important;
  }
  
  .flip-card__digit {
    height: 200%;
  }
  
  .flip-label {
    font-size: 0.6rem;
    gap: 4px;
  }
  
  body.view-calculator .flip-card__top,
  body.view-calculator .flip-card__bottom,
  body.view-calculator .flip-card__flip-top,
  body.view-calculator .flip-card__flip-bottom {
    font-size: clamp(3.2rem, 12vw, 7rem) !important;
  }
  
  body.view-bolder .flip-card__top,
  body.view-bolder .flip-card__bottom,
  body.view-bolder .flip-card__flip-top,
  body.view-bolder .flip-card__flip-bottom {
    font-size: clamp(2.4rem, 9vw, 5.5rem) !important;
  }
}

.flip-card {
  position: relative;
  width: 100%;
  height: clamp(110px, 15vw, 150px);
  perspective: 900px;
  border-radius: 16px;
  box-shadow: var(--flip-shadow);
}

.flip-card__top,
.flip-card__bottom,
.flip-card__flip-top,
.flip-card__flip-bottom {
  position: absolute;
  left: 0;
  width: 100%;
  height: 50%;
  display: flex;
  justify-content: center;
  font-weight: 800;
  font-size: clamp(2.5rem, 8vw, 5rem);
  color: var(--flip-text);
  background: var(--flip-bg);
  border: 1px solid var(--flip-border);
  backface-visibility: hidden;
  overflow: hidden;
  font-variant-numeric: tabular-nums;
}

.flip-card__top,
.flip-card__flip-top {
  align-items: flex-start;
}

.flip-card__bottom,
.flip-card__flip-bottom {
  align-items: flex-end;
}

.flip-card::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 2px solid #ffffff;
  border-radius: 16px;
  pointer-events: none;
  z-index: 3;
}

body.view-calculator .flip-card {
  background: #0b0f12;
}

body.view-calculator .flip-card::before {
  border-color: rgba(255, 255, 255, 0.4);
}

body.view-calculator .flip-card__top,
body.view-calculator .flip-card__bottom,
body.view-calculator .flip-card__flip-top,
body.view-calculator .flip-card__flip-bottom {
  background: #0b0f12;
  color: #8cff9e;
  border-color: rgba(140, 255, 158, 0.18);
  box-shadow: none;
  font-family: "Digital", "Segoe UI", system-ui, sans-serif;
  letter-spacing: 0.08em;
  font-size: 5.1rem;
}

body.view-calculator .flip-card__top {
  height: 100%;
  border-radius: 14px;
}

body.view-calculator .flip-card__bottom,
body.view-calculator .flip-card__flip,
body.view-calculator .flip-card__flip-top,
body.view-calculator .flip-card__flip-bottom {
  display: none;
}

body.view-calculator .flip-card__top .flip-card__digit {
  height: 100%;
  text-shadow: 0 0 12px rgba(140, 255, 158, 0.55);
}

body.view-bolder .flip-card__top,
body.view-bolder .flip-card__bottom,
body.view-bolder .flip-card__flip-top,
body.view-bolder .flip-card__flip-bottom {
  background: #0d1b2a;
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.18);
  box-shadow: none;
  font-family: "Bolder", "Segoe UI", system-ui, sans-serif;
  letter-spacing: 0.04em;
  font-size: 3.4rem;
}

body.view-bolder .flip-card::before {
  border-color: rgba(255, 255, 255, 0.6);
}

body.view-bolder .flip-card__top {
  height: 100%;
  border-radius: 14px;
}

body.view-bolder .flip-card__bottom,
body.view-bolder .flip-card__flip,
body.view-bolder .flip-card__flip-top,
body.view-bolder .flip-card__flip-bottom {
  display: none;
}

body.view-bolder .flip-card__top .flip-card__digit {
  height: 100%;
}

.flip-card__top,
.flip-card__bottom {
  z-index: 1;
}

.flip-card__top {
  top: 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px 14px 0 0;
}

.flip-card__bottom {
  bottom: 0;
  border-top: none;
  border-radius: 0 0 14px 14px;
}

.flip-card__flip {
  position: absolute;
  inset: 0;
  perspective: 900px;
  pointer-events: none;
  visibility: hidden;
  z-index: 2;
}

.flip-card__flip-top {
  top: 0;
  transform-origin: bottom;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px 14px 0 0;
}

.flip-card__flip-bottom {
  bottom: 0;
  transform-origin: top;
  transform: rotateX(90deg);
  border-radius: 0 0 14px 14px;
}

.flip-card__digit {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 200%;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 200%;
}

.flip-card__bottom .flip-card__digit,
.flip-card__flip-bottom .flip-card__digit {
  top: -100%;
}

.flip-card.is-flipping .flip-card__flip-top {
  animation: flipTop 0.55s ease-in forwards;
}

.flip-card.is-flipping .flip-card__flip-bottom {
  animation: flipBottom 0.55s ease-out forwards;
}

.flip-card.is-flipping .flip-card__flip {
  visibility: visible;
}

@keyframes flipTop {
  0% {
    transform: rotateX(0deg);
  }
  100% {
    transform: rotateX(-90deg);
  }
}

@keyframes flipBottom {
  0% {
    transform: rotateX(90deg);
  }
  100% {
    transform: rotateX(0deg);
  }
}

.counter__actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.empty-state {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.95rem;
}

@media (max-width: 720px) {
  .app__header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .app__controls {
    width: 100%;
  }

  .counter {
    flex-direction: column;
    align-items: stretch;
  }

  .counter__main {
    width: 100%;
  }

  .counter__actions {
    width: 100%;
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: flex-start;
    margin-top: 4px;
  }

  .flip-grid {
    grid-template-columns: repeat(3, minmax(90px, 1fr));
    gap: 12px;
  }
}

@media (max-width: 720px) and (orientation: landscape) {
  .counter {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
  
  .counter__main {
    flex: 1;
    min-width: 0;
  }
  
  .counter__actions {
    width: auto;
    flex-shrink: 0;
    margin-top: 0;
  }
}

@media (max-width: 520px) {
  .flip-grid {
    grid-template-columns: repeat(2, minmax(90px, 1fr));
    gap: 10px;
  }

  .flip-card {
    height: clamp(120px, 18vw, 160px);
  }

  .flip-card__top,
  .flip-card__bottom,
  .flip-card__flip-top,
  .flip-card__flip-bottom {
    font-size: clamp(4rem, 16vw, 8rem) !important;
  }

  .flip-card__digit {
    height: 200%;
  }
  
  body.view-calculator .flip-card__top,
  body.view-calculator .flip-card__bottom,
  body.view-calculator .flip-card__flip-top,
  body.view-calculator .flip-card__flip-bottom {
    font-size: clamp(4.2rem, 17vw, 8.5rem) !important;
  }
  
  body.view-bolder .flip-card__top,
  body.view-bolder .flip-card__bottom,
  body.view-bolder .flip-card__flip-top,
  body.view-bolder .flip-card__flip-bottom {
    font-size: clamp(3rem, 12vw, 6rem) !important;
  }
}

@media (max-width: 520px) and (orientation: landscape) {
  .panel {
    padding: 10px;
    overflow-x: hidden;
  }
  
  .counter {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding: 8px 10px;
    min-width: 0;
    overflow-x: hidden;
  }
  
  .counter__main {
    flex: 1;
    min-width: 0;
    overflow-x: hidden;
  }
  
  .counter__time {
    margin-top: 4px;
    min-width: 0;
    overflow-x: hidden;
  }
  
  .counter__actions {
    width: auto;
    flex-shrink: 0;
    margin-top: 0;
  }
  
  .flip-grid {
    grid-template-columns: repeat(6, minmax(50px, 1fr));
    gap: 4px;
    min-width: 0;
    width: 100%;
  }
  
  .flip-unit {
    min-width: 0;
  }
  
  .flip-card {
    height: clamp(75px, 12vh, 100px);
    min-width: 0;
  }
  
  .flip-card__top,
  .flip-card__bottom,
  .flip-card__flip-top,
  .flip-card__flip-bottom {
    font-size: clamp(2.5rem, 10vw, 5.5rem) !important;
  }
  
  .flip-card__digit {
    height: 200%;
  }
  
  .flip-label {
    font-size: 0.55rem;
    gap: 3px;
  }
  
  body.view-calculator .flip-card__top,
  body.view-calculator .flip-card__bottom,
  body.view-calculator .flip-card__flip-top,
  body.view-calculator .flip-card__flip-bottom {
    font-size: clamp(2.7rem, 11vw, 6rem) !important;
  }
  
  body.view-bolder .flip-card__top,
  body.view-bolder .flip-card__bottom,
  body.view-bolder .flip-card__flip-top,
  body.view-bolder .flip-card__flip-bottom {
    font-size: clamp(2rem, 9vw, 4.5rem) !important;
  }
}