/* ── Number System Tool ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --accent:    #6366f1;
  --accent2:   #4f46e5;
  --accent-bg: rgba(99,102,241,.1);
  --surface:   #0f172a;
  --card:      #111827;
  --card2:     #1e293b;
  --border:    #1e293b;
  --border2:   #334155;
  --text:      #f1f5f9;
  --text2:     #94a3b8;
  --text3:     #64748b;
  --radius:    14px;
  --mono:      'Courier New', Courier, monospace;
}

body { background: var(--surface); color: var(--text); font-family: system-ui, sans-serif; line-height: 1.6; }

/* ── header ── */
.site-header { position: sticky; top: 0; z-index: 200; background: rgba(15,23,42,.95); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); }
.header-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; height: 60px; display: flex; align-items: center; justify-content: space-between; }
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-icon { width: 32px; height: 32px; }
.logo-text { font-size: 1.05rem; font-weight: 700; color: var(--text); }
.nav-links { display: flex; gap: 24px; }
.nav-links a { color: var(--text2); text-decoration: none; font-size: .875rem; transition: color .15s; }
.nav-links a:hover { color: var(--text); }
@media(max-width:640px) { .nav-links { display: none; } }

/* ── hero ── */
.hero { padding: 52px 24px 36px; text-align: center; max-width: 660px; margin: 0 auto; }
.hero-badge { display: inline-flex; align-items: center; gap: 6px; padding: 5px 14px; background: var(--accent-bg); border: 1px solid rgba(99,102,241,.3); border-radius: 999px; font-size: .78rem; font-weight: 600; color: var(--accent); margin-bottom: 18px; }
.hero h1 { font-size: clamp(1.6rem,4vw,2.4rem); font-weight: 800; line-height: 1.2; margin-bottom: 12px; }
.hero h1 span { background: linear-gradient(135deg,#6366f1,#a78bfa); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero p { color: var(--text2); font-size: 1rem; }

/* ── tool wrap ── */
.tool-wrap { max-width: 860px; margin: 0 auto; padding: 0 20px 80px; }

/* ── tab bar ── */
.tab-bar { display: flex; gap: 6px; margin-bottom: 24px; background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 6px; flex-wrap: wrap; }
.tab-btn { flex: 1; min-width: 120px; padding: 9px 14px; border: none; border-radius: 10px; font-size: .82rem; font-weight: 600; cursor: pointer; transition: background .15s, color .15s; background: transparent; color: var(--text2); white-space: nowrap; }
.tab-btn.active { background: var(--accent); color: #fff; }

/* ── section card ── */
.s-card { background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 24px; margin-bottom: 16px; }
.s-title { font-size: .9rem; font-weight: 700; color: var(--text); margin-bottom: 18px; display: flex; align-items: center; gap: 8px; }
.s-title svg { width: 17px; height: 17px; color: var(--accent); }

/* ── base converter ── */
.cv-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media(max-width:500px) { .cv-grid { grid-template-columns: 1fr; } }

.cv-field { display: flex; flex-direction: column; gap: 6px; }
.cv-label { display: flex; align-items: center; justify-content: space-between; }
.cv-label span { font-size: .78rem; font-weight: 600; color: var(--text2); }
.cv-badge { font-size: .7rem; font-weight: 700; padding: 2px 8px; border-radius: 999px; background: var(--accent-bg); color: var(--accent); border: 1px solid rgba(99,102,241,.25); }
.cv-input-wrap { display: flex; gap: 6px; }
.cv-input {
  flex: 1; background: var(--card2); border: 1px solid var(--border2); border-radius: 10px;
  color: var(--text); font-size: .9rem; padding: 10px 14px; outline: none;
  transition: border-color .18s, box-shadow .18s; font-family: var(--mono);
}
.cv-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(99,102,241,.15); }
.cv-input::placeholder { color: var(--text3); font-family: system-ui; }
.cv-copy { width: 36px; height: 36px; background: var(--card2); border: 1px solid var(--border2); border-radius: 8px; display: flex; align-items: center; justify-content: center; cursor: pointer; color: var(--text3); transition: all .15s; flex-shrink: 0; margin-top: auto; }
.cv-copy:hover, .cv-copy.ok { background: var(--accent-bg); color: var(--accent); border-color: rgba(99,102,241,.3); }
.cv-copy svg { width: 14px; height: 14px; }

.cv-custom-row { display: flex; align-items: flex-end; gap: 10px; margin-top: 4px; }
.cv-custom-row .cv-field { flex: 1; }
.cv-base-field { display: flex; flex-direction: column; gap: 6px; width: 100px; }
.cv-base-input { background: var(--card2); border: 1px solid var(--border2); border-radius: 10px; color: var(--text); font-size: .9rem; padding: 10px 14px; outline: none; font-family: var(--mono); width: 100%; transition: border-color .18s; }
.cv-base-input:focus { border-color: var(--accent); }

.cv-bin-grouped { font-size: .75rem; color: var(--text3); font-family: var(--mono); margin-top: 2px; letter-spacing: .05em; }
.cv-err { margin-top: 10px; padding: 9px 14px; background: rgba(248,113,113,.1); border: 1px solid rgba(248,113,113,.3); border-radius: 8px; color: #f87171; font-size: .83rem; }
.cv-clear { margin-top: 16px; padding: 8px 20px; background: var(--card2); border: 1px solid var(--border2); border-radius: 999px; color: var(--text2); font-size: .8rem; cursor: pointer; transition: background .15s, color .15s; }
.cv-clear:hover { background: rgba(248,113,113,.12); color: #f87171; border-color: rgba(248,113,113,.3); }

/* ── bitwise ── */
.bw-inputs { display: grid; grid-template-columns: 1fr auto 1fr; gap: 12px; align-items: end; margin-bottom: 16px; }
@media(max-width:540px) { .bw-inputs { grid-template-columns: 1fr; } }
.bw-sep { font-size: 1.1rem; font-weight: 800; color: var(--accent); text-align: center; padding-bottom: 10px; }
.bw-field { display: flex; flex-direction: column; gap: 6px; }
.bw-field label { font-size: .78rem; font-weight: 600; color: var(--text2); }
.bw-input { background: var(--card2); border: 1px solid var(--border2); border-radius: 10px; color: var(--text); font-size: .9rem; padding: 10px 14px; outline: none; font-family: var(--mono); width: 100%; transition: border-color .18s; }
.bw-input:focus { border-color: var(--accent); }

.bw-base-row { display: flex; align-items: center; gap: 8px; margin-bottom: 14px; }
.bw-base-row span { font-size: .78rem; color: var(--text3); }
.bw-base-btn { padding: 5px 12px; border: 1px solid var(--border2); border-radius: 999px; background: var(--card2); color: var(--text2); font-size: .78rem; font-weight: 600; cursor: pointer; transition: all .15s; }
.bw-base-btn.active { background: var(--accent-bg); border-color: rgba(99,102,241,.4); color: var(--accent); }

.bw-ops { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.bw-op-btn { padding: 7px 16px; border: 1px solid var(--border2); border-radius: 10px; background: var(--card2); color: var(--text2); font-size: .8rem; font-weight: 600; cursor: pointer; font-family: var(--mono); transition: all .15s; }
.bw-op-btn:hover { border-color: var(--accent); color: var(--accent); }
.bw-op-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.bw-bits-row { display: flex; align-items: center; gap: 8px; margin-bottom: 16px; }
.bw-bits-row span { font-size: .78rem; color: var(--text3); }

.calc-btn { padding: 10px 28px; background: linear-gradient(135deg, var(--accent), #a78bfa); border: none; border-radius: 10px; color: #fff; font-size: .875rem; font-weight: 700; cursor: pointer; display: flex; align-items: center; gap: 8px; transition: opacity .18s, transform .15s; }
.calc-btn:hover { opacity: .9; transform: translateY(-1px); }
.calc-btn svg { width: 15px; height: 15px; }

.bw-result { background: var(--card2); border: 1px solid var(--border2); border-radius: 12px; padding: 20px; margin-top: 16px; }
.bw-result-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 12px; margin-bottom: 16px; }
@media(max-width:500px) { .bw-result-grid { grid-template-columns: 1fr 1fr; } }
.bw-res-item label { font-size: .7rem; font-weight: 600; color: var(--text3); text-transform: uppercase; letter-spacing: .06em; display: block; margin-bottom: 4px; }
.bw-res-item .val { font-size: 1rem; font-weight: 800; color: var(--text); font-family: var(--mono); }
.bw-res-item .val.accent { color: var(--accent); }

.bit-strip { display: flex; flex-wrap: wrap; gap: 3px; }
.bit-cell { width: 22px; height: 26px; display: flex; align-items: center; justify-content: center; border-radius: 5px; font-size: .75rem; font-family: var(--mono); font-weight: 700; border: 1px solid var(--border2); }
.bit-cell.one { background: var(--accent-bg); border-color: rgba(99,102,241,.35); color: var(--accent); }
.bit-cell.zero { background: var(--card); color: var(--text3); }

/* ── IEEE 754 ── */
.f754-input-row { display: flex; gap: 10px; margin-bottom: 16px; }
.f754-input { flex: 1; background: var(--card2); border: 1px solid var(--border2); border-radius: 10px; color: var(--text); font-size: .9rem; padding: 10px 14px; outline: none; font-family: var(--mono); transition: border-color .18s; }
.f754-input:focus { border-color: var(--accent); }

.f754-result { margin-top: 0; }
.f754-block { background: var(--card2); border: 1px solid var(--border2); border-radius: 12px; padding: 18px; margin-bottom: 12px; }
.f754-block h4 { font-size: .82rem; font-weight: 700; color: var(--text2); margin-bottom: 12px; }
.f754-bit-row { display: flex; flex-wrap: wrap; gap: 2px; margin-bottom: 12px; }
.f754-bit { min-width: 18px; height: 24px; display: flex; align-items: center; justify-content: center; border-radius: 4px; font-size: .7rem; font-family: var(--mono); font-weight: 700; padding: 0 3px; }
.f754-sign { background: rgba(239,68,68,.15); color: #f87171; border: 1px solid rgba(239,68,68,.3); }
.f754-exp  { background: rgba(245,158,11,.12); color: #fbbf24; border: 1px solid rgba(245,158,11,.25); }
.f754-mant { background: rgba(99,102,241,.12); color: #a5b4fc; border: 1px solid rgba(99,102,241,.25); }
.f754-legend { display: flex; gap: 12px; flex-wrap: wrap; font-size: .73rem; }
.f754-dot { width: 10px; height: 10px; border-radius: 3px; display: inline-block; margin-right: 5px; vertical-align: middle; }
.f754-meta { display: grid; grid-template-columns: repeat(3,1fr); gap: 10px; margin-top: 10px; }
@media(max-width:500px) { .f754-meta { grid-template-columns: 1fr 1fr; } }
.f754-meta-item label { font-size: .7rem; color: var(--text3); font-weight: 600; text-transform: uppercase; display: block; margin-bottom: 3px; }
.f754-meta-item .val { font-size: .88rem; font-weight: 700; color: var(--text); font-family: var(--mono); }

/* ── ASCII ── */
.asc-mode-row { display: flex; gap: 8px; margin-bottom: 14px; }
.asc-mode-btn { padding: 6px 16px; border: 1px solid var(--border2); border-radius: 999px; background: var(--card2); color: var(--text2); font-size: .8rem; font-weight: 600; cursor: pointer; transition: all .15s; }
.asc-mode-btn.active { background: var(--accent-bg); border-color: rgba(99,102,241,.4); color: var(--accent); }
.asc-input-row { display: flex; gap: 10px; margin-bottom: 16px; }
.asc-input { flex: 1; background: var(--card2); border: 1px solid var(--border2); border-radius: 10px; color: var(--text); font-size: .9rem; padding: 10px 14px; outline: none; font-family: var(--mono); transition: border-color .18s; }
.asc-input:focus { border-color: var(--accent); }
.asc-result { background: var(--card2); border: 1px solid var(--border2); border-radius: 12px; padding: 20px; }
.asc-char-display { font-size: 3rem; font-weight: 900; color: var(--text); text-align: center; padding: 16px; background: var(--card); border: 1px solid var(--border2); border-radius: 10px; margin-bottom: 16px; font-family: var(--mono); line-height: 1; }
.asc-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 10px; }
@media(max-width:480px) { .asc-grid { grid-template-columns: 1fr 1fr; } }
.asc-item label { font-size: .7rem; color: var(--text3); font-weight: 600; text-transform: uppercase; display: block; margin-bottom: 3px; }
.asc-item { background: var(--card); border: 1px solid var(--border2); border-radius: 8px; padding: 10px 12px; position: relative; }
.asc-item .val { font-size: .88rem; font-weight: 700; color: var(--text); font-family: var(--mono); word-break: break-all; }
.asc-copy { position: absolute; top: 7px; right: 7px; width: 22px; height: 22px; background: var(--card2); border: 1px solid var(--border2); border-radius: 5px; display: flex; align-items: center; justify-content: center; cursor: pointer; color: var(--text3); transition: all .15s; }
.asc-copy:hover { color: var(--accent); }
.asc-copy svg { width: 11px; height: 11px; }
.asc-err { margin-top: 10px; padding: 9px 14px; background: rgba(248,113,113,.1); border: 1px solid rgba(248,113,113,.3); border-radius: 8px; color: #f87171; font-size: .83rem; }

/* ── info sections ── */
.tis-section { margin-top: 56px; }
.tis-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
@media(max-width:720px)  { .tis-grid { grid-template-columns: 1fr; } }
@media(min-width:720px) and (max-width:960px) { .tis-grid { grid-template-columns: 1fr 1fr; } }
.tis-card { background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 22px; }
.tis-icon { width: 40px; height: 40px; border-radius: 10px; display: flex; align-items: center; justify-content: center; margin-bottom: 14px; }
.tis-icon svg { width: 20px; height: 20px; }
.tis-card h3 { font-size: .95rem; font-weight: 700; margin-bottom: 8px; }
.tis-card p, .tis-card li { font-size: .845rem; color: var(--text2); line-height: 1.7; }
.tis-card ol, .tis-card ul { padding-left: 18px; }
.tis-card li { margin-bottom: 5px; }

/* ── FAQ ── */
.faq-section { margin-top: 56px; }
.faq-section h2 { font-size: 1.2rem; font-weight: 800; margin-bottom: 18px; }
.faq-item { border-bottom: 1px solid var(--border); padding: 15px 0; }
.faq-item:last-child { border-bottom: none; }
.faq-q { font-size: .9rem; font-weight: 700; color: var(--text); cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.faq-q svg { width: 16px; height: 16px; color: var(--text3); flex-shrink: 0; transition: transform .2s; }
.faq-q.open svg { transform: rotate(180deg); }
.faq-a { font-size: .855rem; color: var(--text2); line-height: 1.7; margin-top: 10px; }
.faq-a code { background: var(--card2); padding: 1px 6px; border-radius: 4px; font-family: var(--mono); font-size: .82em; }

/* ── related ── */
.related-section { padding: clamp(24px,4vw,40px) 0; border-top: 1px solid var(--border); }
.related-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; flex-wrap: wrap; gap: 10px; }
.related-title { font-size: 1.2rem; font-weight: 800; color: var(--text); }
.btn-view-all { display: inline-flex; align-items: center; gap: 5px; padding: 7px 16px; border-radius: 999px; font-size: .83rem; font-weight: 600; border: 1px solid var(--border2); color: var(--text2); transition: border-color .15s, color .15s; text-decoration: none; }
.btn-view-all:hover { border-color: var(--accent); color: var(--accent); }
.related-grid { display: grid; grid-template-columns: repeat(auto-fill,minmax(200px,1fr)); gap: 14px; }
.related-tool-card { background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 18px; display: flex; flex-direction: column; gap: 10px; text-decoration: none; transition: border-color .18s, transform .18s, box-shadow .18s; }
.related-tool-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.3); }
.related-tool-icon { width: 40px; height: 40px; border-radius: 10px; display: flex; align-items: center; justify-content: center; }
.related-tool-icon svg { width: 20px; height: 20px; color: #fff; }
.related-tool-name { font-size: .92rem; font-weight: 700; color: var(--text); }
.related-tool-desc { font-size: .8rem; color: var(--text2); line-height: 1.5; flex: 1; }
.related-tool-link { display: inline-flex; align-items: center; gap: 5px; font-size: .8rem; font-weight: 600; color: var(--accent); margin-top: 4px; }
.related-tool-link svg { width: 13px; height: 13px; }
.blog-cards-grid { display: grid; grid-template-columns: repeat(auto-fill,minmax(240px,1fr)); gap: 14px; }
.blog-card-sm { background: var(--card); border: 1px solid var(--border2); border-radius: var(--radius); padding: 20px; display: flex; flex-direction: column; gap: 8px; text-decoration: none; transition: border-color .18s, transform .18s, box-shadow .18s; }
.blog-card-sm:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.3); }
.blog-cat-badge { display: inline-flex; padding: 2px 9px; border-radius: 999px; font-size: .7rem; font-weight: 700; letter-spacing: .05em; text-transform: uppercase; width: fit-content; }
.blog-card-title { font-size: .92rem; font-weight: 700; line-height: 1.4; color: var(--text); }
.blog-card-excerpt { font-size: .8rem; color: var(--text2); line-height: 1.6; flex: 1; }
.blog-card-meta { font-size: .73rem; color: var(--text3); }
.blog-read-link { display: inline-flex; align-items: center; gap: 4px; font-size: .8rem; font-weight: 600; color: var(--accent); margin-top: 4px; }
.blog-read-link svg { width: 12px; height: 12px; }

[x-cloak] { display: none !important; }