/* ── Date Difference Calculator — CSS ── */
:root{
  --bg:#0f0f14;--bg-card:#1e1e28;--bg-surface:#18181f;
  --primary:#818cf8;--secondary:#6366f1;
  --accent:#a78bfa;
  --text:#e8e8f0;--text-muted:#9999b8;--text-faint:#555570;
  --border:rgba(255,255,255,.08);--border-strong:rgba(255,255,255,.14);
  --radius:14px;--radius-sm:8px;
  --font:'Inter',system-ui,sans-serif;--font-mono:'Fira Code','Cascadia Code',monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
body{background:var(--bg);color:var(--text);font-family:var(--font);font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
code{font-family:var(--font-mono);font-size:.85em;background:rgba(129,140,248,.1);color:#a5b4fc;padding:2px 6px;border-radius:4px}

/* ── Header ── */
.site-header{background:rgba(15,15,20,.9);backdrop-filter:blur(14px);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100;padding:0 24px;height:58px;display:flex;align-items:center}
.header-inner{width:100%;max-width:1100px;margin:0 auto;display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:9px;text-decoration:none}
.logo-icon{width:32px;height:32px;flex-shrink:0}
.logo-text{font-size:.97rem;font-weight:700;color:var(--text);letter-spacing:-.01em}
.main-nav{display:flex;gap:6px}
.nav-link{padding:5px 12px;border-radius:var(--radius-sm);font-size:.84rem;font-weight:500;color:var(--text-muted);text-decoration:none;transition:color .15s,background .15s}
.nav-link:hover,.nav-link.active{color:var(--text);background:rgba(255,255,255,.06)}

/* ── Wrap ── */
.main-wrap{max-width:1100px;margin:0 auto;padding:28px 24px 80px}
@media(max-width:640px){.main-wrap{padding:18px 14px 60px}}

/* ── Hero ── */
.tool-hero{text-align:center;padding:28px 0 22px}
.tool-badge{display:inline-flex;align-items:center;gap:5px;padding:4px 12px;background:rgba(129,140,248,.12);color:var(--primary);border-radius:20px;font-size:.73rem;font-weight:600;margin-bottom:12px}
.tool-title{font-size:clamp(1.6rem,4vw,2.2rem);font-weight:800;letter-spacing:-.02em;margin-bottom:8px}
.gradient-title{background:linear-gradient(135deg,var(--primary) 0%,var(--accent) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.tool-subtitle{font-size:.97rem;color:var(--text-muted);max-width:560px;margin:0 auto}

/* ── Ad slot ── */
.ad-slot{background:rgba(255,255,255,.02);border:1px dashed rgba(255,255,255,.07);border-radius:var(--radius);display:flex;align-items:center;justify-content:center;min-height:90px;font-size:.75rem;color:var(--text-faint);text-align:center;padding:12px}

/* ── Main card ── */
.main-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;margin-bottom:18px}
.card-header{padding:14px 20px;border-bottom:1px solid var(--border);background:rgba(255,255,255,.02);display:flex;align-items:center;gap:9px}
.card-header-icon{width:30px;height:30px;border-radius:8px;background:rgba(129,140,248,.12);display:flex;align-items:center;justify-content:center;flex-shrink:0}
.card-header-icon svg{width:13px;height:13px;color:var(--primary)}
.card-title{font-size:.82rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--text-faint)}
.card-body{padding:22px 22px 18px}

/* ── Date input row ── */
.date-row{display:grid;grid-template-columns:1fr 48px 1fr;gap:0;align-items:end;margin-bottom:14px}
@media(max-width:640px){.date-row{grid-template-columns:1fr;gap:10px}.date-sep{display:none!important}}
.date-sep{display:flex;align-items:center;justify-content:center;height:42px;font-size:1.2rem;color:var(--text-faint);padding-top:20px}
.date-field{display:flex;flex-direction:column;gap:5px}
.field-label{font-size:.75rem;font-weight:600;color:var(--text-muted)}
.date-input-wrap{position:relative}
.date-input{width:100%;padding:10px 36px 10px 12px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-size:.88rem;font-family:var(--font);transition:border-color .15s;outline:none;-webkit-appearance:none}
.date-input:focus{border-color:rgba(129,140,248,.5);box-shadow:0 0 0 3px rgba(129,140,248,.08)}
.date-input::-webkit-calendar-picker-indicator{opacity:0;position:absolute;right:0;top:0;width:100%;height:100%;cursor:pointer}
.date-cal-icon{position:absolute;right:10px;top:50%;transform:translateY(-50%);pointer-events:none;color:var(--text-faint)}

/* ── Swap button ── */
.swap-btn{display:flex;align-items:center;justify-content:center;width:36px;height:36px;background:rgba(129,140,248,.08);border:1px solid rgba(129,140,248,.2);border-radius:50%;color:var(--primary);cursor:pointer;transition:all .15s;margin:0 auto;margin-top:20px;flex-shrink:0}
.swap-btn:hover{background:rgba(129,140,248,.16);transform:rotate(180deg)}

/* ── Options row ── */
.options-row{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:18px;padding:14px 16px;background:rgba(255,255,255,.02);border-radius:var(--radius-sm);border:1px solid var(--border)}
.option-group{display:flex;align-items:center;gap:8px}
.option-label{font-size:.78rem;font-weight:600;color:var(--text-muted)}
.toggle-switch{width:34px;height:18px;border-radius:9px;position:relative;cursor:pointer;transition:background .2s}
.toggle-knob{position:absolute;top:2px;left:2px;width:14px;height:14px;border-radius:50%;background:#fff;transition:transform .2s}

/* ── Big result display ── */
.result-hero{text-align:center;padding:28px 20px 22px;background:linear-gradient(135deg,rgba(129,140,248,.06),rgba(167,139,250,.04));border-radius:var(--radius-sm);border:1px solid rgba(129,140,248,.15);margin-bottom:18px}
.result-hero-days{font-size:clamp(3rem,10vw,5.5rem);font-weight:900;letter-spacing:-.03em;line-height:1;background:linear-gradient(135deg,var(--primary),var(--accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent}
.result-hero-label{font-size:.88rem;color:var(--text-muted);margin-top:6px}
.result-hero-caption{font-size:.8rem;color:var(--text-faint);margin-top:4px}

/* ── Result breakdown grid ── */
.breakdown-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(130px,1fr));gap:10px;margin-bottom:18px}
.breakdown-chip{background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius-sm);padding:14px 12px;text-align:center;transition:border-color .15s,background .15s;cursor:default}
.breakdown-chip:hover{border-color:rgba(129,140,248,.3);background:rgba(129,140,248,.04)}
.chip-val{font-family:var(--font-mono);font-size:1.35rem;font-weight:800;color:var(--primary);line-height:1.2}
.chip-label{font-size:.72rem;color:var(--text-faint);margin-top:4px}

/* ── YMD breakdown ── */
.ymd-row{display:flex;align-items:center;justify-content:center;gap:8px;flex-wrap:wrap;padding:14px;background:rgba(255,255,255,.02);border-radius:var(--radius-sm);border:1px solid var(--border);margin-bottom:18px}
.ymd-part{text-align:center}
.ymd-val{font-family:var(--font-mono);font-size:1.5rem;font-weight:800;color:var(--text)}
.ymd-label{font-size:.7rem;color:var(--text-faint);margin-top:2px}
.ymd-sep{font-size:1.2rem;color:var(--border-strong);align-self:center;margin-top:-10px}

/* ── Timeline bar ── */
.timeline-wrap{margin-bottom:18px}
.timeline-label{font-size:.75rem;color:var(--text-faint);margin-bottom:6px;display:flex;justify-content:space-between}
.timeline-bar{height:10px;background:rgba(255,255,255,.06);border-radius:5px;overflow:hidden}
.timeline-fill{height:100%;background:linear-gradient(90deg,var(--secondary),var(--accent));border-radius:5px;transition:width .6s cubic-bezier(.4,0,.2,1)}

/* ── Extra info rows ── */
.extra-rows{display:flex;flex-direction:column;gap:7px}
.extra-row{display:flex;align-items:center;justify-content:space-between;padding:9px 12px;background:var(--bg-surface);border-radius:var(--radius-sm);border:1px solid var(--border)}
.extra-label{font-size:.78rem;color:var(--text-faint)}
.extra-val{font-size:.84rem;font-weight:600;color:var(--text);font-family:var(--font-mono)}
.copy-btn{display:inline-flex;align-items:center;gap:4px;padding:3px 8px;background:rgba(129,140,248,.08);border:1px solid rgba(129,140,248,.2);border-radius:4px;color:var(--primary);font-size:.7rem;font-weight:600;cursor:pointer;flex-shrink:0;transition:all .15s}
.copy-btn:hover{background:rgba(129,140,248,.16)}

/* ── Presets ── */
.presets-section{margin-bottom:18px}
.presets-label{font-size:.75rem;font-weight:600;color:var(--text-faint);text-transform:uppercase;letter-spacing:.06em;margin-bottom:8px}
.presets-grid{display:flex;flex-wrap:wrap;gap:7px}
.preset-btn{padding:6px 12px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text-muted);font-size:.78rem;font-weight:600;cursor:pointer;transition:all .15s}
.preset-btn:hover{border-color:rgba(129,140,248,.4);color:var(--text);background:rgba(129,140,248,.06)}

/* ── Empty state ── */
.empty-state{text-align:center;padding:36px 20px;color:var(--text-faint);font-size:.88rem}
.empty-icon{font-size:2.5rem;margin-bottom:10px}

/* ── Page sections ── */
.page-section{margin-top:48px}
.section-head{margin-bottom:22px}
.section-title{font-size:1.25rem;font-weight:700;letter-spacing:-.015em;margin-bottom:6px}
.section-desc{font-size:.88rem;color:var(--text-muted)}
.section-divider{height:1px;background:var(--border);margin:48px 0}

.steps-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.step-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:20px}
.step-number{width:28px;height:28px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;font-size:.75rem;font-weight:800;display:flex;align-items:center;justify-content:center;margin-bottom:10px}
.step-title{font-size:.9rem;font-weight:700;margin-bottom:5px}
.step-desc{font-size:.82rem;color:var(--text-muted);line-height:1.6}

.features-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
.feature-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:20px}
.feature-icon{font-size:1.5rem;margin-bottom:10px}
.feature-title{font-size:.88rem;font-weight:700;margin-bottom:5px}
.feature-desc{font-size:.8rem;color:var(--text-muted);line-height:1.6}

.faq-list{display:flex;flex-direction:column;gap:8px}
.faq-item{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-sm);overflow:hidden}
.faq-item.open{border-color:var(--border-strong)}
.faq-q{width:100%;display:flex;align-items:center;justify-content:space-between;padding:14px 18px;background:none;border:none;color:var(--text);font-size:.9rem;font-weight:600;text-align:left;cursor:pointer;gap:12px}
.faq-icon{color:var(--primary);font-size:1.1rem;transition:transform .2s;flex-shrink:0}
.faq-item.open .faq-icon{transform:rotate(45deg)}
.faq-a{display:none;padding:0 18px 14px}
.faq-item.open .faq-a{display:block}
.faq-a p{font-size:.86rem;color:var(--text-muted);line-height:1.7}
.faq-a p+p{margin-top:8px}

.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:14px}
.related-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:18px;text-decoration:none;transition:border-color .2s,transform .2s;display:flex;flex-direction:column;gap:8px}
.related-card:hover{border-color:rgba(129,140,248,.4);transform:translateY(-2px);text-decoration:none}
.related-icon{width:36px;height:36px;border-radius:9px;display:flex;align-items:center;justify-content:center}
.related-icon svg{width:16px;height:16px;stroke:#fff}
.related-name{font-size:.88rem;font-weight:600;color:var(--text)}
.related-desc{font-size:.78rem;color:var(--text-muted);flex:1}
.related-link{font-size:.76rem;color:var(--primary);font-weight:600;margin-top:4px}

.site-footer{background:var(--bg-surface);border-top:1px solid var(--border);padding:48px 24px 28px}
.footer-grid{max-width:1200px;margin:0 auto 32px;display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:32px}
@media(max-width:768px){.footer-grid{grid-template-columns:1fr 1fr}}
@media(max-width:480px){.footer-grid{grid-template-columns:1fr}}
.footer-brand-text{font-size:.82rem;color:var(--text-faint);margin-top:8px;max-width:220px;line-height:1.6}
.footer-heading{font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.07em;color:var(--text-faint);margin-bottom:12px}
.footer-links{display:flex;flex-direction:column;gap:8px}
.footer-links a{font-size:.84rem;color:var(--text-muted);text-decoration:none;transition:color .15s}
.footer-links a:hover{color:var(--text)}
.footer-bottom{max-width:1200px;margin:0 auto;padding-top:20px;border-top:1px solid var(--border);display:flex;justify-content:space-between;font-size:.78rem;color:var(--text-faint);flex-wrap:wrap;gap:8px}

.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%) translateY(20px);background:#1e1e28;border:1px solid rgba(129,140,248,.4);color:var(--text);padding:10px 20px;border-radius:var(--radius-sm);font-size:.84rem;font-weight:500;opacity:0;pointer-events:none;transition:all .25s;z-index:9999;white-space:nowrap}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0)}