@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

:root {
  --teal: #0D9488;
  --teal-light: #14B8A6;
  --teal-dark: #0F766E;
  --navy: #0F172A;
  --navy-mid: #1E293B;
  --navy-light: #334155;
  --white: #FFFFFF;
  --gray: #F1F5F9;
  --gray-mid: #E2E8F0;
  --text: #0F172A;
  --text-muted: #64748B;
}

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

.area-wrap {
  font-family: 'Inter', sans-serif;
  max-width: 1000px;
  margin: 0 auto;
  padding: 20px;
}

/* Header */
.area-header {
  background: linear-gradient(135deg, var(--navy), var(--navy-mid));
  color: white;
  padding: 40px;
  border-radius: 16px;
  text-align: center;
  margin-bottom: 20px;
}
.area-header-icon { font-size: 48px; margin-bottom: 10px; }
.area-header h2 { font-size: 30px; font-weight: 800; margin-bottom: 6px; }
.area-header p { opacity: 0.7; font-size: 15px; }

/* Unit Bar */
.area-unit-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.area-unit-label { font-weight: 600; color: var(--navy); font-size: 14px; }
.area-unit-btns { display: flex; gap: 8px; flex-wrap: wrap; }
.area-unit-btn {
  padding: 8px 16px;
  border: 2px solid var(--gray-mid);
  border-radius: 8px;
  background: white;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  color: var(--text-muted);
  transition: all 0.2s;
}
.area-unit-btn.active, .area-unit-btn:hover {
  background: var(--teal);
  color: white;
  border-color: var(--teal);
}

/* Shape Grid */
.area-shapes-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 10px;
  margin-bottom: 24px;
}
.area-shape-btn {
  background: white;
  border: 2px solid var(--gray-mid);
  border-radius: 12px;
  padding: 14px 8px;
  cursor: pointer;
  text-align: center;
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}
.area-shape-btn:hover {
  border-color: var(--teal);
  background: rgba(13,148,136,0.05);
}
.area-shape-btn.active {
  border-color: var(--teal);
  background: var(--teal);
  color: white;
}
.area-shape-icon { font-size: 22px; }
.area-shape-btn span { font-size: 11px; font-weight: 600; }

/* Calc Panel */
.area-calc-panel {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 20px;
}

/* Input Side */
.area-input-side {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.area-shape-display {
  background: var(--navy);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  min-height: 200px;
}
#areaCanvas { display: block; }

/* Fields */
.area-fields { display: flex; flex-direction: column; gap: 12px; }
.area-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.area-field label {
  font-size: 12px;
  font-weight: 600;
  color: var(--navy);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.area-field-row {
  display: flex;
  align-items: center;
  border: 2px solid var(--gray-mid);
  border-radius: 10px;
  overflow: hidden;
  transition: border-color 0.2s;
}
.area-field-row:focus-within { border-color: var(--teal); }
.area-field-input {
  flex: 1;
  border: none;
  outline: none;
  padding: 12px 14px;
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
}
.area-field-unit {
  background: var(--gray);
  padding: 12px 12px;
  font-size: 12px;
  font-weight: 600;
  color: var(--teal);
  white-space: nowrap;
}

.area-calc-btn {
  background: var(--teal);
  color: white;
  border: none;
  padding: 14px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  width: 100%;
  transition: background 0.2s;
}
.area-calc-btn:hover { background: var(--teal-dark); }
.area-reset-btn {
  background: white;
  color: var(--navy);
  border: 2px solid var(--gray-mid);
  padding: 10px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
  transition: all 0.2s;
}
.area-reset-btn:hover { border-color: var(--teal); color: var(--teal); }

/* Result Side */
.area-result-side { display: flex; flex-direction: column; gap: 16px; }

.area-result-hero {
  background: linear-gradient(135deg, var(--navy), var(--navy-mid));
  color: white;
  border-radius: 16px;
  padding: 36px;
  text-align: center;
  min-height: 180px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.area-result-icon { font-size: 36px; }
.area-result-label { font-size: 13px; opacity: 0.7; text-transform: uppercase; letter-spacing: 1px; }
.area-result-val { font-size: 44px; font-weight: 800; color: var(--teal-light); }
.area-result-unit { font-size: 14px; opacity: 0.6; }

/* Conversions */
.area-conversions, .area-formula-card {
  background: white;
  border: 1px solid var(--gray-mid);
  border-radius: 14px;
  padding: 20px;
}
.area-section-title { font-size: 15px; font-weight: 700; color: var(--navy); margin-bottom: 14px; }

.area-conv-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.area-conv-item {
  background: var(--gray);
  border-radius: 10px;
  padding: 12px;
  text-align: center;
}
.area-conv-val { font-size: 15px; font-weight: 700; color: var(--teal); }
.area-conv-label { font-size: 11px; color: var(--text-muted); margin-top: 2px; }

.area-formula-text {
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
  background: var(--gray);
  padding: 14px;
  border-radius: 8px;
  font-family: 'Courier New', monospace;
  line-height: 1.6;
}

/* Export */
.area-export-bar { display: flex; gap: 10px; }
.area-export-btn {
  flex: 1;
  background: var(--navy);
  color: white;
  border: none;
  padding: 12px;
  border-radius: 10px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}
.area-export-btn:hover { background: var(--teal); }

/* Responsive */
@media (max-width: 768px) {
  .area-shapes-grid { grid-template-columns: repeat(4, 1fr); }
  .area-calc-panel { grid-template-columns: 1fr; }
  .area-conv-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 480px) {
  .area-shapes-grid { grid-template-columns: repeat(3, 1fr); }
}