.hyd {
    --hyd-primary: #0ea5e9;
    --hyd-primary-dark: #0284c7;
    --hyd-primary-light: #e0f2fe;
    --hyd-bg: #fff;
    --hyd-border: rgba(14, 165, 233, 0.15);
    --hyd-divider: rgba(14, 165, 233, 0.1);
    --hyd-surface: #f8fafc;
    --hyd-text: #1e293b;
    --hyd-text-muted: #64748b;
    --hyd-input-bg: #f8fafc;
    --hyd-input-border: #e2e8f0;
    --hyd-visual-bg: #f0f9ff;
    --hyd-visual-border: #e0f2fe;
    --hyd-alert-bg: #fff1f2;
    --hyd-alert-color: #e11d48;
    --hyd-alert-border: #ffe4e6;

    width: 100%;
    max-width: 720px;
    margin: 0 auto;
  }

  .theme-dark .hyd {
    --hyd-bg: #0f172a;
    --hyd-border: rgba(14, 165, 233, 0.2);
    --hyd-divider: rgba(14, 165, 233, 0.12);
    --hyd-surface: #1e293b;
    --hyd-text: #f1f5f9;
    --hyd-text-muted: #94a3b8;
    --hyd-input-bg: #1e293b;
    --hyd-input-border: #334155;
    --hyd-visual-bg: rgba(14, 165, 233, 0.06);
    --hyd-visual-border: rgba(14, 165, 233, 0.15);
    --hyd-alert-bg: rgba(225, 29, 72, 0.12);
    --hyd-alert-color: #fb7185;
    --hyd-alert-border: rgba(225, 29, 72, 0.2);
  }

  .hyd__card {
    background: var(--hyd-bg);
    border: 2px solid var(--hyd-border);
    border-radius: 2rem;
    box-shadow: 0 20px 60px rgba(14, 165, 233, 0.08);
    overflow: hidden;
  }

  .hyd__section {
    padding: 2rem;
  }

  .hyd__section--bordered {
    border-top: 1px solid var(--hyd-divider);
  }

  
  .hyd__main-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  @media (min-width: 560px) {
    .hyd__main-grid {
      grid-template-columns: 1fr auto;
      gap: 2rem;
      align-items: start;
    }
  }

  
  .hyd__controls {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }

  .hyd__group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
  }

  .hyd__group-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .hyd__group-title {
    margin: 0;
    font-size: 0.7rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--hyd-text-muted);
    display: flex;
    align-items: center;
    gap: 0.4rem;
  }

  .hyd__group-icon {
    width: 1rem;
    height: 1rem;
    display: flex;
    align-items: center;
  }

  .hyd__group-icon svg {
    width: 100%;
    height: 100%;
  }

  .hyd__weather-btn {
    background: var(--hyd-primary-light);
    color: var(--hyd-primary);
    border: none;
    width: 2rem;
    height: 2rem;
    border-radius: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s, color 0.2s;
    flex-shrink: 0;
  }

  .theme-dark .hyd__weather-btn {
    background: rgba(14, 165, 233, 0.15);
  }

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

  .hyd__weather-icon svg,
  .hyd__weather-btn svg {
    width: 1rem;
    height: 1rem;
  }

  .hyd__spinner {
    width: 1rem;
    height: 1rem;
    border: 2px solid rgba(14, 165, 233, 0.25);
    border-top-color: var(--hyd-primary);
    border-radius: 50%;
    animation: hyd-spin 0.8s linear infinite;
    display: none;
  }

  .hyd__weather-btn[data-loading="true"] .hyd__spinner { display: block; }
  .hyd__weather-btn[data-loading="true"] .hyd__weather-icon { display: none; }

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

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

  .hyd__field {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
  }

  .hyd__label {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--hyd-text-muted);
  }

  .hyd__input {
    background: var(--hyd-input-bg);
    border: 1.5px solid var(--hyd-input-border);
    border-radius: 0.75rem;
    padding: 0.65rem 0.75rem;
    font-size: 1rem;
    font-weight: 700;
    color: var(--hyd-text);
    width: 100%;
    box-sizing: border-box;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
  }

  .hyd__input:focus {
    border-color: var(--hyd-primary);
    box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.12);
  }

  
  .hyd__intensity-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
  }

  .hyd__intensity-btn {
    background: var(--hyd-input-bg);
    border: 1.5px solid var(--hyd-input-border);
    border-radius: 0.75rem;
    padding: 0.6rem 0.25rem;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--hyd-text-muted);
    cursor: pointer;
    transition: all 0.2s;
  }

  .hyd__intensity-btn:hover {
    border-color: var(--hyd-primary);
    color: var(--hyd-primary);
  }

  .hyd__intensity-btn--active {
    background: var(--hyd-primary);
    color: #fff;
    border-color: var(--hyd-primary);
    box-shadow: 0 4px 12px rgba(14, 165, 233, 0.25);
  }

  
  .hyd__visual {
    background: var(--hyd-visual-bg);
    border: 1.5px solid var(--hyd-visual-border);
    border-radius: 1.5rem;
    padding: 2rem 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
  }

  @media (min-width: 560px) {
    .hyd__visual {
      min-width: 160px;
    }
  }

  .hyd__bottle {
    width: 80px;
    height: 200px;
    background: #fff;
    border: 6px solid #fff;
    border-radius: 20px 20px 40px 40px;
    overflow: hidden;
    position: relative;
    box-shadow: 0 8px 24px rgba(14, 165, 233, 0.1), inset 0 0 12px rgba(0,0,0,0.02);
  }

  .theme-dark .hyd__bottle {
    background: #1e293b;
    border-color: #334155;
  }

  .hyd__bottle-fill {
    position: absolute;
    bottom: 0;
    width: 100%;
    background: linear-gradient(to top, var(--hyd-primary), #38bdf8);
    transition: height 0.8s cubic-bezier(0.34, 1.56, 0.64, 1);
    height: 42%;
  }

  .hyd__wave {
    position: absolute;
    width: 300%;
    height: 300%;
    background: rgba(255,255,255,0.3);
    top: -285%;
    left: -100%;
    border-radius: 42%;
    animation: hyd-wave 10s linear infinite;
    pointer-events: none;
  }

  .hyd__wave::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: rgba(255,255,255,0.2);
    border-radius: 40%;
    animation: hyd-wave 14s linear infinite reverse;
  }

  @keyframes hyd-wave {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
  }

  .hyd__total {
    text-align: center;
  }

  .hyd__total-value {
    display: block;
    font-size: 3.5rem;
    font-weight: 900;
    line-height: 1;
    color: var(--hyd-primary);
  }

  .hyd__total-unit {
    display: block;
    font-size: 0.65rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--hyd-text-muted);
    margin-top: 0.25rem;
  }

  
  .hyd__stats-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  @media (min-width: 560px) {
    .hyd__stats-grid {
      grid-template-columns: repeat(3, 1fr);
    }
  }

  .hyd__stat {
    background: var(--hyd-surface);
    border: 1.5px solid var(--hyd-divider);
    border-radius: 1rem;
    padding: 1rem;
    display: flex;
    flex-direction: column;
  }

  .hyd__stat-label {
    font-size: 0.65rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--hyd-text-muted);
    margin-bottom: 0.4rem;
  }

  .hyd__stat-value {
    font-size: 0.95rem;
    font-weight: 800;
    color: var(--hyd-text);
  }

  .hyd__stat-help {
    font-size: 0.7rem;
    color: var(--hyd-text-muted);
    margin: 0.4rem 0 0;
    line-height: 1.4;
  }

  
  .hyd__urine-track {
    display: flex;
    height: 10px;
    border-radius: 5px;
    overflow: hidden;
    margin-top: 0.5rem;
    border: 2px solid var(--hyd-bg);
  }

  .hyd__urine-seg { flex: 1; }
  .hyd__urine-seg--1 { background: #fef9c3; }
  .hyd__urine-seg--2 { background: #fef08a; }
  .hyd__urine-seg--3 { background: #fde047; }
  .hyd__urine-seg--4 { background: #facc15; }
  .hyd__urine-seg--5 { background: #eab308; }
  .hyd__urine-seg--6 { background: #ca8a04; }
  .hyd__urine-seg--7 { background: #a16207; }

  .hyd__urine-icons {
    display: flex;
    justify-content: space-between;
    margin-top: 0.35rem;
  }

  .hyd__urine-good svg { color: #22c55e; width: 1rem; height: 1rem; }
  .hyd__urine-bad svg { color: #ef4444; width: 1rem; height: 1rem; }

  
  .hyd__section--alert {
    padding-top: 1.25rem;
    padding-bottom: 1.25rem;
  }

  .hyd__alert {
    background: var(--hyd-alert-bg);
    border: 1.5px solid var(--hyd-alert-border);
    border-radius: 0.875rem;
    padding: 0.875rem 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--hyd-alert-color);
  }

  .hyd__alert-icon {
    flex-shrink: 0;
    width: 1.25rem;
    height: 1.25rem;
  }

  .hyd__alert-icon svg {
    width: 100%;
    height: 100%;
  }

  .hyd__alert-text {
    font-size: 0.85rem;
    font-weight: 600;
    line-height: 1.4;
  }