:root{
  --bg:#f5f7fb;
  --bg-deep:#eef2f8;
  --surface:rgba(255,255,255,.88);
  --surface-solid:#ffffff;
  --surface-soft:#f8fafc;
  --text:#111827;
  --muted:#6b7280;
  --muted-2:#94a3b8;
  --line:rgba(148,163,184,.22);
  --line-strong:rgba(100,116,139,.28);
  --accent:#5b5cf0;
  --accent-2:#8b5cf6;
  --accent-soft:#f1efff;
  --accent-deep:#4338ca;
  --holiday:#e5484d;
  --success:#15803d;
  --shadow-sm:0 8px 24px rgba(15,23,42,.06);
  --shadow-md:0 20px 50px rgba(15,23,42,.08);
  --shadow-lg:0 32px 90px rgba(15,23,42,.14);
  --radius-xl:30px;
  --radius-lg:22px;
  --radius-md:16px;
  --radius-sm:12px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  color:var(--text);
  font-family:Inter,"Noto Sans JP","Hiragino Kaku Gothic ProN","Yu Gothic",sans-serif;
  line-height:1.7;
  background:
    radial-gradient(circle at 8% 0%,rgba(91,92,240,.10),transparent 28rem),
    radial-gradient(circle at 92% 12%,rgba(139,92,246,.08),transparent 24rem),
    linear-gradient(180deg,#fbfcff 0%,var(--bg) 34%,var(--bg-deep) 100%);
  min-height:100vh;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  pointer-events:none;
  background-image:linear-gradient(rgba(148,163,184,.035) 1px,transparent 1px),linear-gradient(90deg,rgba(148,163,184,.035) 1px,transparent 1px);
  background-size:32px 32px;
  mask-image:linear-gradient(to bottom,rgba(0,0,0,.7),transparent 75%);
}

a{color:inherit}
button,input,select{font:inherit}
button{touch-action:manipulation}
.container{width:min(1160px,calc(100% - 32px));margin-inline:auto}

.site-header{
  position:sticky;
  top:0;
  z-index:40;
  padding:12px 0;
  background:rgba(245,247,251,.68);
  backdrop-filter:blur(22px) saturate(140%);
  -webkit-backdrop-filter:blur(22px) saturate(140%);
}
.header-inner{
  min-height:62px;
  padding:0 14px 0 16px;
  display:flex;
  align-items:center;
  gap:26px;
  border:1px solid rgba(255,255,255,.8);
  background:rgba(255,255,255,.72);
  border-radius:20px;
  box-shadow:0 10px 30px rgba(15,23,42,.06),inset 0 1px 0 rgba(255,255,255,.9);
}
.brand{display:flex;align-items:center;gap:11px;text-decoration:none;font-weight:850;letter-spacing:-.035em}
.brand-mark{
  display:grid;
  place-items:center;
  width:38px;
  height:38px;
  border-radius:13px;
  color:#fff;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));
  box-shadow:0 10px 22px rgba(91,92,240,.30),inset 0 1px 0 rgba(255,255,255,.35);
}
.desktop-nav{display:flex;align-items:center;gap:6px;margin-left:auto}
.desktop-nav a{
  padding:9px 12px;
  border-radius:10px;
  color:var(--muted);
  text-decoration:none;
  font-size:.9rem;
  font-weight:700;
  transition:.2s ease;
}
.desktop-nav a:hover{color:var(--text);background:rgba(91,92,240,.07)}
.header-cta{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:40px;
  padding:0 16px;
  border-radius:12px;
  color:#fff;
  text-decoration:none;
  font-size:.88rem;
  font-weight:800;
  background:linear-gradient(135deg,#111827,#273449);
  box-shadow:0 8px 18px rgba(15,23,42,.14);
}

.hero{
  position:relative;
  display:grid;
  grid-template-columns:minmax(0,1.08fr) minmax(340px,.92fr);
  gap:72px;
  align-items:center;
  padding:104px 0 64px;
}
.hero::after{
  content:"";
  position:absolute;
  width:420px;
  height:420px;
  right:-160px;
  top:10px;
  border-radius:50%;
  background:radial-gradient(circle,rgba(91,92,240,.12),transparent 70%);
  filter:blur(10px);
  pointer-events:none;
}
.hero-copy{position:relative;z-index:1}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:8px;
  margin:0 0 14px;
  color:var(--accent-deep);
  font-size:.72rem;
  font-weight:900;
  letter-spacing:.16em;
}
.eyebrow::before{content:"";width:22px;height:1px;background:currentColor;opacity:.55}
.hero h1{
  margin:0;
  max-width:760px;
  font-size:clamp(3.2rem,7.2vw,6.8rem);
  line-height:.94;
  letter-spacing:-.075em;
  font-weight:900;
}
.hero h1 span{
  background:linear-gradient(100deg,var(--accent) 0%,var(--accent-2) 65%,#a855f7 100%);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
}
.lead{
  max-width:690px;
  margin:28px 0 0;
  color:var(--muted);
  font-size:clamp(1rem,1.5vw,1.16rem);
  line-height:1.9;
}
.hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:34px}
.primary-action,.secondary-action{
  min-height:52px;
  padding:0 20px;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  border-radius:14px;
  text-decoration:none;
  font-weight:850;
  transition:transform .18s ease,box-shadow .18s ease,background .18s ease;
}
.primary-action{
  color:#fff;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));
  box-shadow:0 14px 28px rgba(91,92,240,.26);
}
.primary-action:hover{transform:translateY(-2px);box-shadow:0 18px 34px rgba(91,92,240,.32)}
.secondary-action{border:1px solid var(--line);background:rgba(255,255,255,.72);box-shadow:var(--shadow-sm)}
.secondary-action:hover{transform:translateY(-2px);background:#fff}

.today-panel{
  position:relative;
  z-index:1;
  overflow:hidden;
  padding:30px;
  border-radius:var(--radius-xl);
  color:#fff;
  background:
    linear-gradient(145deg,rgba(255,255,255,.09),transparent 45%),
    linear-gradient(145deg,#171a2b 0%,#20254a 52%,#3f3cbb 130%);
  box-shadow:var(--shadow-lg),inset 0 1px 0 rgba(255,255,255,.16);
}
.today-panel::before{
  content:"";
  position:absolute;
  width:220px;
  height:220px;
  right:-90px;
  top:-90px;
  border-radius:50%;
  background:radial-gradient(circle,rgba(167,139,250,.7),transparent 68%);
  filter:blur(6px);
}
.today-panel::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(120deg,transparent 30%,rgba(255,255,255,.04) 50%,transparent 70%);
  pointer-events:none;
}
.panel-label{position:relative;margin:0;color:#c4b5fd;font-size:.7rem;font-weight:900;letter-spacing:.18em}
.today-date{position:relative;margin-top:12px;font-size:clamp(1.9rem,4vw,3rem);line-height:1.15;font-weight:900;letter-spacing:-.055em}
.today-stats{position:relative;display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:30px}
.today-stats>div{
  min-height:124px;
  padding:18px;
  border:1px solid rgba(255,255,255,.10);
  border-radius:18px;
  background:rgba(255,255,255,.07);
  backdrop-filter:blur(10px);
}
.stat-label{display:block;color:#cbd5e1;font-size:.72rem;font-weight:800}
.today-stats strong{display:block;margin-top:8px;font-size:1.18rem;letter-spacing:-.025em}
.today-stats small{display:block;margin-top:4px;color:#aeb7c7}

.tool-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin:4px auto 36px}
.tool-link-card{
  position:relative;
  display:grid;
  grid-template-columns:auto 1fr;
  column-gap:13px;
  row-gap:2px;
  align-items:center;
  padding:20px;
  border:1px solid var(--line);
  border-radius:20px;
  background:rgba(255,255,255,.74);
  backdrop-filter:blur(14px);
  text-decoration:none;
  box-shadow:0 10px 28px rgba(15,23,42,.04);
  transition:transform .2s ease,border-color .2s ease,box-shadow .2s ease,background .2s ease;
}
.tool-link-card::after{content:"↗";position:absolute;right:16px;top:14px;color:#cbd5e1;font-size:.85rem}
.tool-link-card:hover{transform:translateY(-4px);border-color:rgba(91,92,240,.25);background:#fff;box-shadow:0 18px 42px rgba(15,23,42,.08)}
.tool-icon{
  grid-row:1/3;
  display:grid;
  place-items:center;
  width:46px;
  height:46px;
  border-radius:14px;
  color:var(--accent-deep);
  background:linear-gradient(135deg,#f3f1ff,#ebe8ff);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.8);
  font-weight:900;
}
.tool-link-card strong{font-size:.98rem;letter-spacing:-.02em}
.tool-link-card small{color:var(--muted);font-size:.82rem}

.tool-section{
  position:relative;
  scroll-margin-top:100px;
  margin-bottom:30px;
  padding:40px;
  border:1px solid rgba(255,255,255,.8);
  border-radius:var(--radius-xl);
  background:var(--surface);
  backdrop-filter:blur(18px);
  box-shadow:var(--shadow-md),inset 0 1px 0 rgba(255,255,255,.8);
}
.tool-section::before{
  content:"";
  position:absolute;
  top:0;
  left:34px;
  right:34px;
  height:1px;
  background:linear-gradient(90deg,transparent,rgba(91,92,240,.34),transparent);
}
.section-heading{display:flex;align-items:flex-end;justify-content:space-between;gap:28px}
.section-heading h2,.about h2{margin:0;font-size:clamp(1.9rem,4vw,2.75rem);line-height:1.12;letter-spacing:-.055em}
.section-note{max-width:720px;margin:10px 0 0;color:var(--muted)}

.field{display:grid;gap:8px}
.field span{font-size:.77rem;font-weight:850;color:#475569;letter-spacing:.01em}
.field.compact{min-width:160px}
.field input,.field select,select{
  width:100%;
  min-height:52px;
  padding:0 14px;
  border:1px solid var(--line-strong);
  border-radius:14px;
  background:rgba(255,255,255,.9);
  color:var(--text);
  box-shadow:inset 0 1px 1px rgba(15,23,42,.02);
  transition:border-color .18s ease,box-shadow .18s ease,background .18s ease;
}
.field input:hover,.field select:hover{border-color:rgba(91,92,240,.34)}
.field input:focus,.field select:focus,select:focus{
  outline:none;
  border-color:rgba(91,92,240,.7);
  box-shadow:0 0 0 4px rgba(91,92,240,.10);
  background:#fff;
}

.quick-presets{display:flex;flex-wrap:wrap;gap:9px;margin:22px 0 16px}
.chip{
  min-height:38px;
  padding:0 13px;
  border:1px solid var(--line);
  border-radius:999px;
  color:#64748b;
  background:rgba(255,255,255,.75);
  font-size:.82rem;
  font-weight:800;
  cursor:pointer;
  transition:.18s ease;
}
.chip:hover{color:var(--accent-deep);border-color:rgba(91,92,240,.28);background:var(--accent-soft);transform:translateY(-1px)}

.calculator-card{
  display:grid;
  grid-template-columns:1.2fr .8fr 1fr auto;
  gap:14px;
  align-items:end;
  padding:22px;
  border:1px solid rgba(148,163,184,.16);
  border-radius:20px;
  background:linear-gradient(180deg,rgba(248,250,252,.95),rgba(244,247,251,.82));
}
.calculator-card.two-dates{grid-template-columns:1fr 1fr auto auto}
.submit-button,.ghost-button,.tab-button,.copy-button{font:inherit;cursor:pointer}
.submit-button{
  min-height:52px;
  padding:0 20px;
  border:0;
  border-radius:14px;
  color:#fff;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));
  box-shadow:0 10px 22px rgba(91,92,240,.22);
  font-weight:850;
  transition:transform .18s ease,box-shadow .18s ease;
}
.submit-button:hover{transform:translateY(-2px);box-shadow:0 14px 28px rgba(91,92,240,.28)}
.ghost-button{
  min-height:52px;
  padding:0 16px;
  border:1px solid var(--line);
  border-radius:14px;
  color:var(--text);
  background:#fff;
  font-weight:800;
}
.ghost-button:hover{background:#f8fafc}

.summary-card,.result-card{
  position:relative;
  overflow:hidden;
  margin-top:20px;
  padding:22px 24px;
  border:1px solid rgba(91,92,240,.16);
  border-radius:18px;
  background:linear-gradient(135deg,rgba(245,243,255,.95),rgba(238,242,255,.88));
}
.summary-card::before,.result-card::before{
  content:"";
  position:absolute;
  left:0;
  top:0;
  bottom:0;
  width:4px;
  background:linear-gradient(var(--accent),var(--accent-2));
}
.summary-card strong,.result-card strong{font-size:1.5rem;letter-spacing:-.035em}
.result-card:empty{display:none}
.result-meta{margin-top:6px;color:var(--muted)}
.result-actions{margin-top:16px}
.copy-button{
  min-height:38px;
  padding:0 12px;
  border:1px solid rgba(91,92,240,.2);
  border-radius:10px;
  color:var(--accent-deep);
  background:rgba(255,255,255,.78);
  font-size:.8rem;
  font-weight:800;
}
.copy-button:hover{background:#fff}

.table-wrap{overflow-x:auto;margin-top:20px;border:1px solid var(--line);border-radius:18px;background:#fff}
table{width:100%;border-collapse:collapse;background:#fff}
th,td{padding:15px 18px;text-align:left;border-bottom:1px solid #eef2f7}
th{font-size:.75rem;color:var(--muted);background:#fafbfc;font-weight:850;letter-spacing:.02em}
tbody tr{transition:background .16s ease}
tbody tr:hover{background:#fafaff}
tbody tr:last-child td{border-bottom:0}
.holiday-name{color:var(--holiday);font-weight:850}
.days-until{color:var(--muted);font-size:.86rem}

.business-tabs{
  display:inline-flex;
  gap:6px;
  margin:24px 0 16px;
  padding:5px;
  border:1px solid rgba(148,163,184,.13);
  border-radius:14px;
  background:#eef2f7;
}
.tab-button{
  min-height:40px;
  padding:0 14px;
  border:0;
  border-radius:10px;
  color:var(--muted);
  background:transparent;
  font-weight:800;
}
.tab-button.is-active{color:var(--text);background:#fff;box-shadow:0 6px 16px rgba(15,23,42,.08)}
.tab-panel{display:none}
.tab-panel.is-active{display:block}

.about{
  display:grid;
  grid-template-columns:.9fr 1.1fr;
  gap:72px;
  padding:68px 0 88px;
}
.about-copy p{margin-top:0;color:var(--muted)}
.small{font-size:.9rem}
.site-footer{padding:28px 0 34px;border-top:1px solid rgba(148,163,184,.18);color:var(--muted);font-size:.86rem}
.footer-inner{display:flex;justify-content:space-between;gap:16px}
.footer-inner a{text-decoration:none}

@media(max-width:960px){
  .hero{grid-template-columns:1fr;gap:38px;padding-top:76px}
  .hero-copy{max-width:860px}
  .today-panel{max-width:760px}
  .tool-grid{grid-template-columns:repeat(2,1fr)}
  .calculator-card,.calculator-card.two-dates{grid-template-columns:1fr 1fr}
  .calculator-card .submit-button,.calculator-card.two-dates .submit-button{grid-column:span 2}
  .about{grid-template-columns:1fr;gap:28px}
}

@media(max-width:720px){
  body{background:linear-gradient(180deg,#fafbff 0%,#f4f6fb 34%,#edf1f7 100%)}
  .site-header{padding:8px 0}
  .header-inner{min-height:56px;border-radius:16px;padding-inline:12px}
  .desktop-nav,.header-cta{display:none}
  .brand{font-size:.94rem}
  .brand-mark{width:34px;height:34px;border-radius:11px}
  .hero{gap:30px;padding:56px 0 42px}
  .hero h1{font-size:clamp(3.25rem,17vw,5.3rem)}
  .lead{margin-top:22px;line-height:1.8}
  .hero-actions{margin-top:28px}
  .primary-action,.secondary-action{width:100%}
  .today-panel{padding:22px;border-radius:24px}
  .today-date{font-size:2rem}
  .today-stats{grid-template-columns:1fr;gap:10px;margin-top:22px}
  .today-stats>div{min-height:auto;padding:16px}
  .tool-grid{grid-template-columns:1fr 1fr;gap:10px;margin-bottom:22px}
  .tool-link-card{grid-template-columns:1fr;padding:16px;min-height:138px;align-content:start}
  .tool-link-card::after{right:14px;top:12px}
  .tool-icon{grid-row:auto;width:42px;height:42px;margin-bottom:8px}
  .tool-link-card strong{font-size:.92rem}
  .tool-section{padding:24px 18px;border-radius:24px;margin-bottom:20px}
  .tool-section::before{left:24px;right:24px}
  .section-heading{align-items:flex-start;flex-direction:column;gap:18px}
  .field.compact{width:100%}
  .calculator-card,.calculator-card.two-dates{grid-template-columns:1fr;padding:16px}
  .calculator-card .submit-button,.calculator-card.two-dates .submit-button{grid-column:auto}
  .submit-button,.ghost-button{width:100%}
  .business-tabs{display:flex;width:100%;overflow-x:auto}
  .tab-button{flex:1;white-space:nowrap;font-size:.82rem}
  .table-wrap{margin-inline:-2px}
  th,td{padding:12px 13px}
  .about{padding:48px 0 64px}
  .footer-inner{flex-direction:column}
}