:root {
  --navy-900: #001f5c;
  --navy-800: #003080;
  --navy-700: #0a4aad;
  --teal-400: #30e0b0;
  --teal-300: #5af0c4;
  --teal-100: #d9fff3;
  --ink: #12233f;
  --muted: #51607a;
  --line: rgba(0, 48, 128, 0.12);
  --surface: rgba(255, 255, 255, 0.86);
  --shadow: 0 18px 50px rgba(0, 32, 96, 0.12);
  --radius: 18px;
  --font-body: "Noto Sans JP", "Noto Sans SC", "Segoe UI", sans-serif;
  --font-display: "Outfit", "Noto Sans JP", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--font-body);
  background: #f4f8ff;
  line-height: 1.6;
}

.page-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(920px 480px at 12% -10%, rgba(48, 224, 176, 0.28), transparent 60%),
    radial-gradient(800px 520px at 90% 0%, rgba(10, 74, 173, 0.18), transparent 55%),
    linear-gradient(180deg, #eef5ff 0%, #f7fbff 42%, #ffffff 100%);
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

.container {
  width: min(1120px, calc(100% - 2rem));
  margin-inline: auto;
}

.container.narrow {
  width: min(760px, calc(100% - 2rem));
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: rgba(255, 255, 255, 0.78);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  min-height: 76px;
}

.brand img {
  width: 160px;
  height: auto;
}

.nav {
  display: flex;
  gap: 1rem;
  margin-left: 0.5rem;
  flex: 1;
}

.nav a {
  color: var(--navy-800);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav a:hover {
  color: var(--navy-700);
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.lang-label {
  color: var(--muted);
  font-size: 0.8rem;
  margin-right: 0.25rem;
}

.lang-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--navy-800);
  border-radius: 999px;
  padding: 0.35rem 0.7rem;
  font: inherit;
  font-size: 0.8rem;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.lang-btn:hover,
.lang-btn.is-active {
  background: var(--navy-800);
  border-color: var(--navy-800);
  color: #fff;
}

.lang-btn.is-active {
  box-shadow: inset 0 0 0 1px rgba(48, 224, 176, 0.55);
}

.site-main {
  padding-bottom: 4rem;
}

.hero {
  padding: 4.5rem 0 2.5rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2rem;
  align-items: center;
  min-height: min(62vh, 560px);
}

.eyebrow {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--navy-800);
  font-size: 1.05rem;
}

.year-badge {
  display: inline-flex;
  align-items: center;
  margin: 0 0 0.85rem;
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
  background: rgba(48, 224, 176, 0.18);
  color: var(--navy-800);
  font-weight: 700;
  font-size: 0.88rem;
  border: 1px solid rgba(48, 224, 176, 0.55);
}

.hero-copy h1,
.tool-page h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 4vw, 3.4rem);
  line-height: 1.15;
  color: var(--navy-900);
  max-width: 14ch;
}

.lede {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 36rem;
}

.hero-actions {
  margin-top: 1.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 48px;
  padding: 0.75rem 1.35rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--teal-400), var(--teal-300));
  color: var(--navy-900);
  box-shadow: 0 10px 24px rgba(48, 224, 176, 0.35);
}

.btn-primary:hover {
  box-shadow: 0 14px 28px rgba(48, 224, 176, 0.45);
}

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--navy-800);
}

.hero-visual {
  position: relative;
  min-height: 320px;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(2px);
  animation: float 7s ease-in-out infinite;
}

.orb-a {
  width: 220px;
  height: 220px;
  right: 8%;
  top: 8%;
  background: rgba(48, 224, 176, 0.35);
}

.orb-b {
  width: 160px;
  height: 160px;
  left: 10%;
  bottom: 12%;
  background: rgba(10, 74, 173, 0.22);
  animation-delay: -2.5s;
}

.hero-panel {
  position: absolute;
  inset: 18% 8% 18% 18%;
  display: grid;
  align-content: center;
  gap: 0.55rem;
  padding: 1.75rem;
  border-radius: 28px;
  background:
    linear-gradient(160deg, rgba(0, 48, 128, 0.96), rgba(0, 31, 92, 0.92)),
    #003080;
  color: #fff;
  box-shadow: var(--shadow);
  animation: rise 0.8s ease both;
}

.hero-panel-label {
  font-family: var(--font-display);
  color: var(--teal-400);
  letter-spacing: 0.12em;
  font-size: 0.8rem;
}

.hero-panel strong {
  font-size: 1.45rem;
  line-height: 1.3;
}

.hero-panel span:last-child {
  color: rgba(255, 255, 255, 0.78);
}

.section {
  padding: 2rem 0 1rem;
}

.section-title {
  margin: 0 0 1.25rem;
  font-family: var(--font-display);
  color: var(--navy-900);
  font-size: 1.6rem;
}

.tool-list {
  display: grid;
  gap: 1rem;
}

.tool-link {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  align-items: center;
  padding: 1.25rem 1.35rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface);
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.tool-link:hover {
  border-color: rgba(48, 224, 176, 0.7);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.tool-link-icon {
  width: 52px;
  height: 52px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  background: var(--navy-800);
  color: var(--teal-400);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
}

.tool-link h3 {
  margin: 0 0 0.35rem;
  font-size: 1.1rem;
  color: var(--navy-900);
}

.tool-link p {
  margin: 0;
  color: var(--muted);
}

.tool-page {
  padding-top: 3rem;
}

.tax-form,
.tax-results,
.pdf-card {
  margin-top: 2rem;
  padding: 1.5rem;
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.tool-tabs {
  display: flex;
  gap: 0.5rem;
  margin-top: 1.75rem;
}

.tool-tab {
  min-height: 42px;
  padding: 0.55rem 1.1rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--navy-800);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.tool-tab.is-active {
  background: var(--navy-800);
  border-color: var(--navy-800);
  color: #fff;
  box-shadow: inset 0 0 0 1px rgba(48, 224, 176, 0.55);
}

.pdf-status {
  margin: 1rem 0 0;
  padding: 0.75rem 1rem;
  border-radius: 12px;
  background: rgba(48, 224, 176, 0.14);
  color: var(--navy-900);
  font-weight: 600;
}

.pdf-status.is-error {
  background: rgba(180, 40, 60, 0.1);
  color: #8a1f32;
}

.file-drop {
  position: relative;
  display: grid;
  gap: 0.35rem;
  place-items: center;
  min-height: 140px;
  padding: 1.25rem;
  border: 1.5px dashed rgba(0, 48, 128, 0.28);
  border-radius: 16px;
  background: rgba(244, 248, 255, 0.9);
  cursor: pointer;
  text-align: center;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.file-drop:hover {
  border-color: var(--teal-400);
  background: rgba(217, 255, 243, 0.45);
}

.file-drop input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.file-drop-title {
  font-weight: 700;
  color: var(--navy-900);
}

.file-drop-hint {
  color: var(--muted);
  font-size: 0.9rem;
  word-break: break-all;
}

.pdf-meta,
.split-controls,
.split-confirm,
.merge-order {
  margin-top: 1.25rem;
}

.pdf-meta p,
.merge-order-list {
  margin: 0.35rem 0;
}

.split-summary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1rem 0;
}

.split-summary > div {
  padding: 1rem;
  border-radius: 14px;
  background: rgba(0, 48, 128, 0.04);
  border: 1px solid var(--line);
}

.split-summary h3 {
  margin: 0 0 0.5rem;
  color: var(--navy-900);
  font-size: 1rem;
}

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

.merge-order-list {
  padding-left: 1.2rem;
}

.field {
  margin-bottom: 1.15rem;
}

.field label {
  display: block;
  margin-bottom: 0.4rem;
  font-weight: 700;
  color: var(--navy-900);
}

.field-hint {
  margin: 0.4rem 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

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

.input-with-unit {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.65rem;
  align-items: center;
}

input[type="number"],
select {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.7rem 0.9rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
}

input[type="number"]:focus,
select:focus {
  outline: 2px solid rgba(48, 224, 176, 0.55);
  border-color: var(--teal-400);
}

.form-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

.tax-results h2 {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  color: var(--navy-900);
}

.result-grid {
  margin: 0;
  display: grid;
  gap: 0.75rem;
}

.result-grid > div {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line);
}

.result-grid dt {
  color: var(--muted);
}

.result-grid dd {
  margin: 0;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--navy-900);
}

.result-grid .is-emphasis dd {
  color: var(--navy-700);
}

.result-grid .is-highlight {
  border-bottom: none;
  background: linear-gradient(90deg, rgba(48, 224, 176, 0.16), transparent);
  border-radius: 12px;
  padding-inline: 0.75rem;
}

.result-grid .is-highlight dd {
  color: var(--navy-900);
  font-size: 1.1rem;
}

.result-note {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 2rem 0 2.5rem;
  background: rgba(255, 255, 255, 0.7);
}

.footer-inner {
  display: grid;
  gap: 0.4rem;
}

.footer-brand {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--navy-800);
}

.footer-note {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-12px);
  }
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 860px) {
  .header-inner {
    flex-wrap: wrap;
    padding: 0.75rem 0;
  }

  .nav {
    order: 3;
    width: 100%;
    margin: 0;
  }

  .hero {
    padding-top: 2.5rem;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .hero-copy h1,
  .tool-page h1 {
    max-width: none;
  }

  .hero-visual {
    min-height: 240px;
  }

  .hero-panel {
    inset: 10% 0;
  }

  .field-row,
  .split-summary,
  .merge-uploads {
    grid-template-columns: 1fr;
  }

  .lang-label {
    display: none;
  }
}