/* Reset & base */
*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --color-bg: #0f0f0f;
  --color-text: #fafafa;
  --color-text-muted: #a3a3a3;
  --color-text-soft: #e5e5e5;
  --color-primary: #facc15;
  --color-primary-dark: #eab308;
  --color-primary-darker: #ca8a04;
  --color-primary-darkest: #a16207;
  --color-primary-light: #fef08a;
  --color-placeholder: #737373;
  --color-btn-text: #0a0a0a;
  --color-border: rgba(255, 255, 255, 0.12);
  --color-border-focus: #eab308;
  --shadow-focus: rgba(234, 179, 8, 0.25);
  --shadow-btn-hover: rgba(234, 179, 8, 0.45);
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: 'Manrope', -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
}

.page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 7rem 1.25rem 1.25rem;
  max-width: 56rem;
  margin: 0 auto;
}


/* Header */
.header .title {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.header .subtitle {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  font-weight: 400;
}

.header {
  text-align: center;
  margin: 2.5rem 0 0.5rem;
  padding-top: 0;
  width: 100%;
  max-width: 24rem;
}

/* Main */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  align-items: center;
  width: 100%;
  max-width: 24rem;
}

.content-left {
  width: 100%;
}

/* Form */
.calculator {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--color-border);
  border-radius: 1rem;
  padding: 1.5rem;
  margin-bottom: 0.75rem;
}

.field {
  margin-bottom: 1.25rem;
}

.field:last-of-type {
  margin-bottom: 1.5rem;
}

.label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-soft);
  margin-bottom: 0.375rem;
}

.input {
  width: 100%;
  padding: 0.75rem 1rem;
  font: inherit;
  font-size: 1rem;
  color: var(--color-text);
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

/* Ввод только с клавиатуры — скрыть стрелки числа */
.input[type="number"] {
  -moz-appearance: textfield;
  appearance: textfield;
}

.input[type="number"]::-webkit-outer-spin-button,
.input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.input::placeholder {
  color: var(--color-placeholder);
}

.input:hover {
  border-color: rgba(255, 255, 255, 0.25);
}

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

.input:invalid:not(:placeholder-shown) {
  border-color: var(--color-primary-darker);
}

.error {
  display: block;
  font-size: 0.8125rem;
  color: var(--color-primary-dark);
  margin-top: 0.25rem;
  min-height: 1.25em;
}

.btn {
  width: 100%;
  padding: 0.875rem 1.25rem;
  font: inherit;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-btn-text);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  border: none;
  border-radius: 0.5rem;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s;
}

.btn:hover {
  box-shadow: 0 4px 14px var(--shadow-btn-hover);
}

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

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

/* Result */
.result {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--color-border);
  border-radius: 1rem;
  padding: 1.5rem;
  margin-bottom: 0.75rem;
  text-align: center;
}

.result[hidden] {
  display: none;
}

.result-value {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.25rem;
}

.result-category {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text-soft);
  margin-bottom: 0.5rem;
}

.result-desc {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.result-category--severe_deficit,
.result-category--deficit { color: var(--color-primary-light); }
.result-category--normal { color: var(--color-primary); }
.result-category--pre_obese,
.result-category--obese1 { color: var(--color-primary-dark); }
.result-category--obese2 { color: var(--color-primary-darker); }
.result-category--obese3 { color: var(--color-primary-darkest); }

/* Scale */
.scale {
  margin-bottom: 1rem;
}

.scale-title {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin: 0 0 0.75rem;
  text-align: center;
}

.scale-bar {
  display: flex;
  border-radius: 0.5rem;
  overflow: hidden;
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.scale-segment {
  flex: 1;
  padding: 0.4rem 0.2rem;
  text-align: center;
  color: var(--color-btn-text);
  font-size: 0.625rem;
}

.scale-segment.severe-deficit,
.scale-segment.deficit { background: var(--color-primary-light); }
.scale-segment.normal { background: var(--color-primary); }
.scale-segment.pre-obese,
.scale-segment.obese1 { background: var(--color-primary-dark); }
.scale-segment.obese2 { background: var(--color-primary-darker); }
.scale-segment.obese3 { background: var(--color-primary-darkest); }

/* Footer */
.footer {
  padding: 1rem 0;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--color-placeholder);
}

.footer p {
  margin: 0;
}

.footer-title {
  font-weight: 600;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
}

.footer-formula {
  color: var(--color-primary);
  font-weight: 600;
}

.footer-formula code {
  font-family: inherit;
  background: transparent;
  padding: 0;
}

/* Tablet and up */
@media (min-width: 480px) {
  .page {
    padding: 6rem 2rem 2rem;
  }

  .title {
    font-size: 1.5rem;
  }

  .calculator,
  .result {
    padding: 1.75rem;
  }

  .scale-bar {
    font-size: 0.75rem;
  }

  .scale-segment {
    padding: 0.6rem 0.35rem;
  }
}

/* Web: одна страница без прокрутки */
@media (min-width: 768px) {
  html,
  body {
    height: 100%;
    overflow: hidden;
  }

  .page {
    height: 100vh;
    max-height: 100vh;
    overflow: hidden;
    padding: 6rem 1.5rem 1.5rem;
    justify-content: center;
  }

  .header {
    flex-shrink: 0;
    margin-bottom: 0.5rem;
    padding-top: 0;
  }

  .title {
    font-size: 1.15rem;
    margin: 0 0 0.25rem;
  }

  .subtitle {
    font-size: 0.6875rem;
  }

  .main {
    flex: 1 1 0;
    min-height: 0;
    gap: 1.5rem;
    align-items: center;
  }

  .content-left {
    display: flex;
    flex-direction: column;
    gap: 0;
  }

  .calculator {
    padding: 1rem;
    margin-bottom: 0.75rem;
  }

  .field {
    margin-bottom: 0.6rem;
  }

  .field:last-of-type {
    margin-bottom: 1rem;
  }

  .label {
    font-size: 0.8125rem;
    margin-bottom: 0.25rem;
  }

  .input {
    padding: 0.5rem 0.75rem;
    font-size: 0.9375rem;
  }

  .btn {
    padding: 0.5rem 1rem;
    font-size: 0.9375rem;
  }

  .result {
    padding: 0.75rem 1rem;
    margin-bottom: 0.75rem;
  }

  .result-value {
    font-size: 1.5rem;
    margin-bottom: 0.125rem;
  }

  .result-category {
    font-size: 0.9375rem;
    margin-bottom: 0.25rem;
  }

  .result-desc {
    font-size: 0.75rem;
  }

  .scale {
    margin-bottom: 0;
  }

  .scale-title {
    font-size: 0.75rem;
    margin: 0 0 0.35rem;
  }

  .scale-bar {
    font-size: 0.5625rem;
  }

  .scale-segment {
    padding: 0.3rem 0.15rem;
    font-size: 0.5rem;
  }

  .footer {
    flex-shrink: 0;
    padding: 0.35rem 0;
    font-size: 0.6875rem;
  }

  /* Когда результат показан — футер прижат вниз, контент выше прокручивается */
  .page.has-result {
    justify-content: flex-start;
  }

  .page.has-result .main {
    overflow-y: auto;
    flex: 1 1 0;
    min-height: 0;
  }

  .page.has-result .footer {
    margin-top: auto;
    flex-shrink: 0;
  }
}