:root {
  --bg: #0a0e1a;
  --surface: #111827;
  --surface2: #1a2235;
  --border: #1e2d47;
  --accent: #00d4ff;
  --accent2: #ff6b35;
  --accent3: #00ff88;
  --text: #e8edf5;
  --muted: #6b7a99;
  --gold: #ffd700;
}
* { margin:0; padding:0; box-sizing:border-box; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Noto Sans JP', sans-serif;
  min-height: 100vh;
  overflow-x: hidden;
}
body::before {
  content:'';
  position:fixed; inset:0;
  background-image:
    linear-gradient(rgba(0,212,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,212,255,0.03) 1px, transparent 1px);
  background-size: 50px 50px;
  pointer-events:none; z-index:0;
}
.container { max-width:960px; margin:0 auto; padding:0 20px; position:relative; z-index:1; }

/* Header */
header { padding:48px 0 24px; text-align:center; }
.badge {
  display:inline-block;
  background:linear-gradient(135deg,rgba(0,212,255,.15),rgba(0,255,136,.1));
  border:1px solid rgba(0,212,255,.3);
  color:var(--accent);
  font-family:'JetBrains Mono',monospace;
  font-size:11px; letter-spacing:3px;
  padding:6px 16px; border-radius:2px;
  text-transform:uppercase; margin-bottom:20px;
}
h1 {
  font-family:'Bebas Neue',sans-serif;
  font-size:clamp(36px,8vw,72px); letter-spacing:4px; line-height:1;
  background:linear-gradient(135deg,#fff 0%,var(--accent) 50%,var(--accent3) 100%);
  -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text;
  margin-bottom:10px;
}
.subtitle { color:var(--muted); font-size:13px; letter-spacing:1px; }

/* Tabs */
.tab-nav {
  display:flex; gap:4px; margin:32px 0 0;
  background:var(--surface); border:1px solid var(--border);
  border-radius:8px; padding:4px; overflow-x:auto; scrollbar-width:none;
}
.tab-nav::-webkit-scrollbar { display:none; }
.tab-btn {
  flex:1; min-width:130px; padding:12px 10px;
  background:transparent; border:none;
  color:var(--muted); font-family:'Noto Sans JP',sans-serif;
  font-size:13px; font-weight:500; cursor:pointer;
  border-radius:6px; transition:all .2s; white-space:nowrap;
  display:flex; align-items:center; justify-content:center; gap:5px;
}
.tab-btn:hover { color:var(--text); background:var(--surface2); }
.tab-btn.active {
  background:linear-gradient(135deg,rgba(0,212,255,.2),rgba(0,255,136,.1));
  color:var(--accent); border:1px solid rgba(0,212,255,.3);
}

/* Panels */
.calc-panel { display:none; padding:28px 0 48px; }
.calc-panel.active { display:block; animation:fadeUp .3s ease; }
@keyframes fadeUp { from{opacity:0;transform:translateY(8px)} to{opacity:1;transform:translateY(0)} }

.panel-title {
  font-family:'Bebas Neue',sans-serif;
  font-size:26px; letter-spacing:2px; color:var(--accent); margin-bottom:6px;
}
.panel-desc { color:var(--muted); font-size:13px; line-height:1.6; margin-bottom:24px; }

/* Form */
.form-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(220px,1fr)); gap:14px; margin-bottom:20px; }
.form-group { display:flex; flex-direction:column; gap:6px; }
label { font-size:11px; font-weight:700; color:var(--muted); letter-spacing:1.5px; text-transform:uppercase; font-family:'JetBrains Mono',monospace; }
.input-wrap { position:relative; }
select, input[type="number"] {
  width:100%; background:var(--surface2); border:1px solid var(--border);
  border-radius:6px; padding:11px 14px; color:var(--text);
  font-family:'JetBrains Mono',monospace; font-size:14px;
  outline:none; transition:border-color .2s,box-shadow .2s;
  appearance:none; -webkit-appearance:none;
}
select {
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%236b7a99' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat:no-repeat; background-position:right 12px center; padding-right:36px; cursor:pointer;
}
select option { background:var(--surface2); color:var(--text); }
select:focus, input:focus { border-color:var(--accent); box-shadow:0 0 0 3px rgba(0,212,255,.1); }
.unit { position:absolute; right:12px; top:50%; transform:translateY(-50%); color:var(--muted); font-size:12px; font-family:'JetBrains Mono',monospace; pointer-events:none; }
input::-webkit-inner-spin-button { -webkit-appearance:none; }

/* Presets */
.presets { display:flex; flex-wrap:wrap; gap:5px; margin-top:6px; }
.preset {
  padding:4px 9px; background:var(--surface2); border:1px solid var(--border);
  border-radius:4px; color:var(--muted); font-family:'JetBrains Mono',monospace;
  font-size:11px; cursor:pointer; transition:all .15s;
}
.preset:hover { border-color:var(--accent); color:var(--accent); }

/* Fetch button */
.fetch-btn {
  display:inline-flex; align-items:center; gap:5px;
  margin-top:7px; padding:6px 12px;
  background:rgba(0,212,255,.07); border:1px solid rgba(0,212,255,.25);
  border-radius:4px; color:var(--accent);
  font-family:'JetBrains Mono',monospace; font-size:11px;
  cursor:pointer; transition:all .2s;
}
.fetch-btn:hover { background:rgba(0,212,255,.16); }
.fetch-btn:disabled { opacity:.5; cursor:not-allowed; }
.spin { display:inline-block; animation:spin 1s linear infinite; }
@keyframes spin { to{transform:rotate(360deg)} }
.rate-status { font-size:11px; font-family:'JetBrains Mono',monospace; margin-top:3px; min-height:15px; }
.rate-status.ok { color:var(--accent3); }
.rate-status.err { color:var(--accent2); }

/* Calc button */
.calc-btn {
  width:100%; padding:15px; margin-bottom:20px;
  background:linear-gradient(135deg,var(--accent),var(--accent3));
  border:none; border-radius:6px; color:#0a0e1a;
  font-family:'Bebas Neue',sans-serif; font-size:17px; letter-spacing:3px;
  cursor:pointer; transition:all .2s; position:relative; overflow:hidden;
}
.calc-btn::before { content:''; position:absolute; inset:0; background:linear-gradient(135deg,rgba(255,255,255,.2),transparent); opacity:0; transition:opacity .2s; }
.calc-btn:hover::before { opacity:1; }
.calc-btn:hover { transform:translateY(-1px); box-shadow:0 8px 24px rgba(0,212,255,.3); }
.calc-btn:active { transform:translateY(0); }

/* Result */
.result-box { background:var(--surface); border:1px solid var(--border); border-radius:8px; padding:22px; display:none; animation:fadeUp .3s ease; }
.result-box.show { display:block; }
.result-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(170px,1fr)); gap:14px; }
.result-item { background:var(--surface2); border-radius:6px; padding:14px; border-left:3px solid var(--accent); }
.result-item.pos { border-left-color:var(--accent3); }
.result-item.neg { border-left-color:var(--accent2); }
.result-item.neu { border-left-color:var(--muted); }
.rlabel { font-family:'JetBrains Mono',monospace; font-size:11px; color:var(--muted); letter-spacing:1.5px; text-transform:uppercase; margin-bottom:6px; }
.rval {
  font-family:'Bebas Neue',sans-serif; font-size:clamp(22px,4vw,36px); letter-spacing:1px;
  color: var(--gold);
  background:linear-gradient(135deg,var(--gold),var(--accent2));
  -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text; line-height:1.1;
}
.rnote { font-size:12px; color:var(--muted); margin-top:10px; }

/* Error */
.err-msg { background:rgba(255,107,53,.1); border:1px solid rgba(255,107,53,.3); border-radius:6px; padding:11px 14px; color:var(--accent2); font-size:13px; margin-bottom:12px; display:none; }
.err-msg.show { display:block; }

/* Info */
.info { background:rgba(0,212,255,.05); border:1px solid rgba(0,212,255,.15); border-radius:6px; padding:13px 15px; font-size:12px; color:var(--muted); line-height:1.7; margin-top:14px; }
.info strong { color:var(--accent); }

.divider { height:1px; background:linear-gradient(90deg,transparent,var(--border),transparent); margin:36px 0; }
footer { text-align:center; padding:28px 0; border-top:1px solid var(--border); color:var(--muted); font-size:12px; line-height:1.8; }

/* Guide accordion */
.guide {
  border:1px solid rgba(0,212,255,.2); border-radius:8px;
  margin-top:18px; overflow:hidden;
}
.guide-toggle {
  width:100%; display:flex; align-items:center; justify-content:space-between;
  padding:13px 16px; background:rgba(0,212,255,.06);
  border:none; cursor:pointer; color:var(--accent);
  font-family:'JetBrains Mono',monospace; font-size:12px; letter-spacing:1px;
  text-align:left; transition:background .2s;
}
.guide-toggle:hover { background:rgba(0,212,255,.12); }
.guide-arrow { transition:transform .3s; font-size:10px; }
.guide-toggle.open .guide-arrow { transform:rotate(180deg); }
.guide-body {
  display:none; padding:16px 18px;
  background:rgba(0,0,0,.2); color:var(--muted);
  font-size:12px; line-height:1.8;
  border-top:1px solid rgba(0,212,255,.1);
}
.guide-body.show { display:block; animation:fadeUp .2s ease; }
.guide-body h4 { color:var(--text); font-size:13px; margin:10px 0 4px; }
.guide-body h4:first-child { margin-top:0; }
.guide-body .formula {
  background:var(--surface2); border-left:3px solid var(--accent);
  border-radius:4px; padding:8px 12px; margin:6px 0;
  font-family:'JetBrains Mono',monospace; font-size:12px; color:var(--text);
}
.guide-body .ex {
  background:rgba(0,255,136,.05); border-left:3px solid var(--accent3);
  border-radius:4px; padding:8px 12px; margin:6px 0;
  font-family:'JetBrains Mono',monospace; font-size:11px; color:var(--accent3);
}
.guide-body table { width:100%; border-collapse:collapse; margin:8px 0; font-size:12px; }
.guide-body th { background:var(--surface2); color:var(--accent); padding:6px 10px; text-align:left; border:1px solid var(--border); }
.guide-body td { padding:6px 10px; border:1px solid var(--border); color:var(--text); }

@media(max-width:600px) {
  .tab-btn { font-size:11px; padding:9px 8px; min-width:105px; }
  h1 { font-size:40px; }
}