:root {
  color-scheme: dark;

  --bg: #000000;
  --text: #ffffff;
  --input-bg: #22232a;
  --border: #2c2c2e;
  --box-bg: #1c1c1e;
  --button: #114634;
  --button-active: #247156;
  --focus-ring: rgba(255, 255, 255, 0.16);
  --unit-width: 22px;
  --unit-offset: 14px;
  --sign-size: 28px;
  --sign-offset: 12px;
  --card-padding: 14px;
  --readonly-text: #b7b7bc;
  --readonly-border: #35353a;
  --readonly-bg: #22232a;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body {
  overscroll-behavior: none;
}

.app {
  height: 100vh;
  height: 100svh;
  height: 100dvh;
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  padding:
    calc(6px + env(safe-area-inset-top))
    26px
    calc(16px + env(safe-area-inset-bottom));
  box-sizing: border-box;
}

.content {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-y: contain;
  padding-bottom: 12px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  margin-top: 2px;
  margin-bottom: 0;
  padding-left: var(--card-padding);
  padding-right: var(--card-padding);
  box-sizing: border-box;
  flex-shrink: 0;
  gap: 12px;
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.logo {
  width: clamp(180px, 50vw, 240px);
  max-width: 70%;
  filter: none;
}

.theme-btn {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--box-bg);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  box-shadow: none;
  outline: none;
  flex-shrink: 0;
  transition:
    transform 0.08s ease,
    background-color 0.15s ease,
    border-color 0.15s ease,
    box-shadow 0.15s ease;
}

.theme-btn:focus-visible {
  box-shadow: 0 0 0 3px var(--focus-ring);
}

.theme-btn:active {
  transform: scale(0.96);
  background: var(--input-bg);
}

.theme-btn img {
  width: 20px;
  height: 20px;
}

.clear-btn img {
  width: 18px;
  height: 18px;
}

.panel-card {
  padding: var(--card-padding);
  border-radius: 18px;
  background: var(--box-bg);
  border: 1px solid var(--border);
  box-sizing: border-box;
}

.field-group + .field-group {
  margin-top: 2px;
}

label {
  display: block;
  margin-top: 14px;
  font-size: 18px;
  text-transform: uppercase;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--text);
}

.panel-card .field-group:first-child label {
  margin-top: 0;
}

input,
.result-display {
  width: 100%;
  padding: 16px;
  margin-top: 6px;
  border-radius: 14px;
  font-size: 24px;
  border: 1px solid var(--border);
  background: var(--input-bg);
  color: var(--text);
  text-align: center;
  box-sizing: border-box;
  appearance: none;
  -webkit-appearance: none;
  transition:
    border-color 0.15s ease,
    box-shadow 0.15s ease,
    background-color 0.15s ease,
    color 0.15s ease;
}

input:focus {
  outline: none;
  border-color: var(--button-active);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

input:disabled {
  opacity: 1;
  color: var(--readonly-text);
  -webkit-text-fill-color: var(--readonly-text);
  cursor: default;
}

.theme-btn:disabled,
.sign-btn:disabled {
  opacity: 1;
  cursor: default;
}

.positive-unit-field,
.signed-unit-field,
.result-unit-field {
  position: relative;
  min-width: 0;
  margin-top: 6px;
}

.positive-unit-field input,
.signed-unit-field input,
.result-unit-field .result-display {
  margin-top: 0;
  padding-right: calc(var(--unit-offset) + var(--unit-width) + 10px);
  padding-left: calc(var(--sign-offset) + var(--sign-size) + 10px);
}

.result-display {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 58px;
  color: var(--readonly-text);
  border-color: var(--readonly-border);
  background: var(--readonly-bg);
}

.unit-suffix {
  position: absolute;
  right: var(--unit-offset);
  top: 50%;
  transform: translateY(-50%);
  width: var(--unit-width);
  text-align: center;
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  opacity: 1;
  pointer-events: none;
}

.sign-static,
.sign-btn,
.result-sign {
  position: absolute;
  left: var(--sign-offset);
  top: 50%;
  transform: translateY(-50%);
  width: var(--sign-size);
  height: var(--sign-size);
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--box-bg);
  color: var(--text);
  font-size: 18px;
  font-weight: 700;
  line-height: 1;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sign-static,
.result-sign {
  pointer-events: none;
}

.result-sign {
  color: var(--readonly-text);
  border-color: var(--readonly-border);
  background: var(--readonly-bg);
}

.result-unit-field .unit-suffix {
  color: var(--readonly-text);
}

.sign-btn {
  padding: 0;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  transition:
    background-color 0.15s ease,
    transform 0.08s ease,
    box-shadow 0.15s ease,
    color 0.15s ease,
    border-color 0.15s ease;
}

.sign-btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--focus-ring);
}

.sign-btn:active {
  background: var(--input-bg);
  transform: translateY(-50%) scale(0.97);
}

.is-disabled input {
  color: var(--readonly-text);
  -webkit-text-fill-color: var(--readonly-text);
  border-color: var(--readonly-border);
  background: var(--readonly-bg);
}

.is-disabled .unit-suffix,
.is-disabled .sign-static,
.is-disabled .sign-btn {
  color: var(--readonly-text);
  border-color: var(--readonly-border);
  background: var(--readonly-bg);
}

input.error {
  border-color: #ef4444;
  box-shadow: 0 0 0 2px rgba(239, 68, 68, 0.15);
}

@media (max-height: 820px) {
  :root {
    --card-padding: 13px;
  }

  .app {
    padding:
      calc(6px + env(safe-area-inset-top))
      20px
      calc(14px + env(safe-area-inset-bottom));
  }

  .top-bar {
    height: 52px;
  }

  label {
    font-size: 16px;
  }

  input,
  .result-display {
    padding-top: 14px;
    padding-bottom: 14px;
    font-size: 22px;
  }

  .unit-suffix,
  .sign-btn,
  .sign-static,
  .result-sign {
    font-size: 16px;
  }
}

@media (max-height: 720px) {
  :root {
    --unit-width: 18px;
    --unit-offset: 12px;
    --sign-size: 24px;
    --sign-offset: 10px;
    --card-padding: 11px;
  }

  .app {
    padding:
      calc(4px + env(safe-area-inset-top))
      16px
      calc(12px + env(safe-area-inset-bottom));
  }

  .top-bar {
    height: 48px;
  }

  .top-actions {
    gap: 8px;
  }

  .logo {
    width: 180px;
  }

  .theme-btn {
    width: 38px;
    height: 38px;
  }

  .theme-btn img {
    width: 18px;
    height: 18px;
  }

  label {
    margin-top: 10px;
    font-size: 15px;
  }

  input,
  .result-display {
    padding-top: 12px;
    padding-bottom: 12px;
    font-size: 20px;
  }

  .positive-unit-field,
  .signed-unit-field,
  .result-unit-field {
    margin-top: 5px;
  }

  .unit-suffix,
  .sign-btn,
  .sign-static,
  .result-sign {
    font-size: 15px;
  }
}

@media (max-width: 420px) {
  .app {
    padding-left: 14px;
    padding-right: 14px;
  }
}