/* ============================================
   住宅ローン 借入可能額・返済額計算ツール
   Design System: Green Finance Theme
   ============================================ */

:root {
  --primary: #1a6b3a;
  --primary-hover: #155730;
  --primary-light: #e8f5ee;
  --primary-rgb: 26, 107, 58;
  --accent: #2d9e60;
  --accent-light: #d4edda;
  --bg: #f9f7f4;
  --surface: #ffffff;
  --text: #1a1a2e;
  --text-muted: #6b7280;
  --text-weak: #9ca3af;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.08);
  --shadow-hover: 0 4px 16px rgba(0,0,0,0.10), 0 1px 4px rgba(0,0,0,0.06);
  --shadow-btn: 0 2px 8px rgba(26, 107, 58, 0.35);
  --transition: 0.15s ease;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
}

/* ---- Reset & Base ---- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'BIZ UDPGothic', 'Hiragino Sans', 'Yu Gothic Medium', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  overflow-x: hidden;
  -webkit-text-size-adjust: 100%;
}

/* ---- Typography ---- */
h1, h2, h3 {
  font-family: 'Outfit', 'BIZ UDPGothic', sans-serif;
  font-weight: 700;
  letter-spacing: 0.01em;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ---- Container ---- */
.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 var(--space-5);
}

/* ---- Header ---- */
header {
  background: linear-gradient(135deg, #1a6b3a 0%, #155730 60%, #0f4225 100%);
  color: #fff;
  padding: var(--space-8) var(--space-5) var(--space-6);
  text-align: center;
}

.header-inner {
  max-width: 860px;
  margin: 0 auto;
}

.site-logo {
  display: inline-block;
  font-family: 'Outfit', sans-serif;
  font-size: 0.8125rem;
  font-weight: 600;
  color: rgba(255,255,255,0.75);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
  text-decoration: none;
}

.site-logo:hover {
  color: #fff;
  text-decoration: none;
}

header h1 {
  font-size: clamp(1.3rem, 4vw, 1.9rem);
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: var(--space-2);
}

header .subtitle {
  font-size: 0.9375rem;
  opacity: 0.88;
  max-width: 540px;
  margin: 0 auto;
}

/* ---- Ad Unit ---- */
.ad-unit {
  min-height: 0;
  margin: var(--space-6) auto;
  max-width: 860px;
  padding: 0 var(--space-5);
}

/* ---- Tab Group ---- */
.tab-group {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
  margin-top: var(--space-6);
  background: var(--surface);
  border-radius: var(--radius);
  padding: var(--space-2);
  box-shadow: var(--shadow);
}

.tab-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.625rem var(--space-4);
  min-height: 44px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  background: transparent;
  color: var(--text-muted);
  transition: background var(--transition), color var(--transition), box-shadow var(--transition);
}

.tab-btn:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.tab-btn.active {
  background: var(--primary);
  color: #fff;
  box-shadow: var(--shadow-btn);
}

.tab-btn i {
  font-size: 1rem;
}

/* ---- Tab Panel ---- */
.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

/* ---- Card ---- */
.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: var(--space-6);
  box-shadow: var(--shadow);
  border: 1px solid rgba(0,0,0,0.05);
  transition: box-shadow var(--transition);
}

.tool-card {
  margin-bottom: var(--space-5);
}

/* ---- Privacy Notice ---- */
.privacy-notice {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  border-radius: var(--radius-sm);
  padding: var(--space-3) var(--space-4);
  font-size: 0.8125rem;
  color: #166534;
  margin-bottom: var(--space-6);
}

.privacy-notice i {
  font-size: 1rem;
  flex-shrink: 0;
  color: var(--primary);
}

/* ---- Form Grid ---- */
.form-grid {
  display: grid;
  gap: var(--space-5);
  margin-bottom: var(--space-6);
}

@media (min-width: 640px) {
  .form-grid {
    grid-template-columns: 1fr 1fr;
  }
}

/* ---- Field ---- */
.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.field-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: #374151;
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.field-label i {
  color: var(--primary);
}

.field-hint {
  font-size: 0.8125rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ---- Input ---- */
input[type="number"],
input[type="text"],
select {
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.75rem;
  font-size: 1rem;
  font-family: inherit;
  background: var(--surface);
  color: var(--text);
  transition: border-color var(--transition), box-shadow var(--transition);
  min-height: 44px;
  width: 100%;
  -webkit-appearance: none;
  appearance: none;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.15);
}

/* Chrome number input arrows */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  opacity: 1;
}

/* ---- Input with Suffix ---- */
.input-suffix-wrap {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.input-suffix-wrap input {
  flex: 1;
}

.input-suffix {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 600;
  white-space: nowrap;
  min-width: 24px;
}

/* ---- Slider Wrap ---- */
.slider-wrap {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  flex: 1;
  height: 6px;
  background: #e2e8f0;
  border-radius: 100px;
  outline: none;
  cursor: pointer;
  min-height: unset;
  border: none;
  padding: 0;
  transition: background var(--transition);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--primary);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 1px 4px rgba(var(--primary-rgb), 0.4);
  transition: transform var(--transition), box-shadow var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  box-shadow: 0 2px 8px rgba(var(--primary-rgb), 0.5);
}

input[type="range"]:focus {
  box-shadow: none;
}

input[type="range"]:focus::-webkit-slider-thumb {
  box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.2), 0 1px 4px rgba(var(--primary-rgb), 0.4);
}

.slider-wrap input[type="number"] {
  width: 72px;
  flex: none;
  text-align: center;
}

/* ---- Rate Type Toggle ---- */
.rate-type-toggle {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-2);
}

.rate-btn {
  flex: 1;
  padding: 0.4rem var(--space-3);
  min-height: 36px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  background: var(--surface);
  color: var(--text-muted);
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}

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

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

/* ---- Primary Button ---- */
.btn-primary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  width: 100%;
  padding: 0.75rem var(--space-6);
  min-height: 52px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
  transition: background var(--transition), transform 0.12s ease, box-shadow var(--transition);
  box-shadow: var(--shadow-btn);
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(var(--primary-rgb), 0.4);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: none;
}

.btn-primary i {
  font-size: 1.125rem;
}

/* ---- Result Panel ---- */
.result-panel {
  background: linear-gradient(135deg, #f0fdf4, #ecfdf5);
  border: 1px solid #a7f3d0;
  border-radius: var(--radius);
  padding: var(--space-6);
  margin-bottom: var(--space-5);
  animation: fadeInUp 0.25s ease-out;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.result-title {
  font-size: 1.1rem;
  color: var(--text);
  font-weight: 700;
}

/* ---- Ratio Badge ---- */
.ratio-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 0.3rem 0.75rem;
  border-radius: 100px;
  font-size: 0.8125rem;
  font-weight: 700;
  line-height: 1;
}

.ratio-badge.safe {
  background: #dcfce7;
  color: #166534;
}

.ratio-badge.caution {
  background: #fef9c3;
  color: #854d0e;
}

.ratio-badge.danger {
  background: #fee2e2;
  color: #991b1b;
}

/* ---- Result Grid ---- */
.result-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

@media (min-width: 480px) {
  .result-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 700px) {
  .result-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

.result-item {
  background: rgba(255,255,255,0.7);
  border-radius: var(--radius-sm);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.result-item.primary {
  background: var(--surface);
  border: 1px solid #a7f3d0;
  box-shadow: 0 2px 8px rgba(var(--primary-rgb), 0.10);
}

.result-label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-weight: 500;
}

.result-value {
  font-family: 'Outfit', sans-serif;
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  font-weight: 800;
  color: var(--primary);
  line-height: 1.1;
  word-break: break-all;
}

.result-value.sm {
  font-size: clamp(1.3rem, 3.5vw, 1.8rem);
}

.result-unit {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 600;
}

/* ---- Chart ---- */
.chart-wrap {
  position: relative;
  background: rgba(255,255,255,0.8);
  border-radius: var(--radius-sm);
  padding: var(--space-4);
  border: 1px solid rgba(0,0,0,0.06);
  height: 260px;
}

@media (min-width: 640px) {
  .chart-wrap {
    height: 320px;
  }
}

/* ---- Howto Section ---- */
.howto-section {
  margin: var(--space-8) auto;
}

.howto-section h2,
.knowledge-section h2,
.faq-section h2 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.howto-section h2 i,
.knowledge-section h2 i,
.faq-section h2 i {
  color: var(--primary);
}

/* ---- Accordion ---- */
.accordion {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.accordion-item {
  background: var(--surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
  overflow: hidden;
  transition: box-shadow var(--transition);
}

.accordion-item:hover {
  box-shadow: var(--shadow);
}

.accordion-item[open] {
  border-color: #a7f3d0;
}

.accordion-summary {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  min-height: 52px;
  color: var(--text);
  transition: background var(--transition), color var(--transition);
  user-select: none;
}

.accordion-summary::-webkit-details-marker {
  display: none;
}

.accordion-summary::after {
  content: '\f282';
  font-family: 'bootstrap-icons';
  font-size: 1rem;
  color: var(--text-muted);
  margin-left: auto;
  transition: transform 0.2s ease;
}

.accordion-item[open] .accordion-summary::after {
  transform: rotate(180deg);
}

.accordion-summary:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
  font-family: 'Outfit', sans-serif;
}

.accordion-body {
  padding: 0 var(--space-5) var(--space-4);
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.75;
  border-top: 1px solid var(--border);
  padding-top: var(--space-3);
}

/* ---- Knowledge Section ---- */
.knowledge-section {
  margin: var(--space-8) auto;
}

.knowledge-grid {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .knowledge-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.knowledge-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: var(--space-5);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}

.knowledge-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.knowledge-icon {
  width: 44px;
  height: 44px;
  background: var(--primary-light);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: var(--primary);
  margin-bottom: var(--space-3);
}

.knowledge-card h3 {
  font-size: 0.9375rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--text);
}

.knowledge-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.75;
}

/* ---- FAQ Section ---- */
.faq-section {
  margin: var(--space-8) auto;
}

/* ---- Footer ---- */
footer {
  background: #1a1a2e;
  color: rgba(255,255,255,0.6);
  text-align: center;
  padding: var(--space-8) var(--space-5);
  margin-top: var(--space-12);
}

.footer-inner {
  max-width: 860px;
  margin: 0 auto;
}

footer a {
  color: rgba(255,255,255,0.75);
}

footer a:hover {
  color: #fff;
}

.footer-disclaimer {
  font-size: 0.8125rem;
  margin: var(--space-3) 0;
  color: rgba(255,255,255,0.45);
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

footer small {
  font-size: 0.75rem;
}

/* ---- Responsive ---- */
@media (max-width: 639px) {
  .tab-btn {
    font-size: 0.8125rem;
    padding: 0.5rem var(--space-2);
  }

  .card {
    padding: var(--space-4);
  }

  .result-panel {
    padding: var(--space-4);
  }

  .accordion-summary {
    padding: var(--space-3) var(--space-4);
    font-size: 0.875rem;
  }

  .accordion-body {
    padding: 0 var(--space-4) var(--space-3);
    padding-top: var(--space-2);
  }
}