:root{color-scheme:light;--bg: #f3f5f8;--surface: #ffffff;--surface-2: #eef2f7;--text: #161a22;--muted: #667085;--border: #dce2ea;--beijing: #2563eb;--beijing-soft: rgba(37, 99, 235, .16);--changsha: #ea580c;--changsha-soft: rgba(234, 88, 12, .16);--trip: #059669;--trip-soft: rgba(5, 150, 105, .17);--neutral: #cbd5e1;--shadow: 0 10px 26px rgba(17, 24, 39, .08);--radius: 10px;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif}@media(prefers-color-scheme:dark){:root{color-scheme:dark;--bg: #10131a;--surface: #181d27;--surface-2: #111722;--text: #f2f4f8;--muted: #9aa4b5;--border: #2b3444;--beijing: #60a5fa;--beijing-soft: rgba(96, 165, 250, .2);--changsha: #fb923c;--changsha-soft: rgba(251, 146, 60, .2);--trip: #34d399;--trip-soft: rgba(52, 211, 153, .2);--neutral: #475569;--shadow: 0 12px 32px rgba(0, 0, 0, .35)}}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);line-height:1.5;-webkit-tap-highlight-color:transparent}button,textarea{font:inherit}button{cursor:pointer}button:disabled{cursor:wait;opacity:.7}.app-shell{width:min(1280px,100%);margin:0 auto;padding:20px}.topbar{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;padding:10px 0 20px}.eyebrow{margin:0 0 4px;color:var(--muted);font-size:.82rem;font-weight:650;text-transform:uppercase}h1,h2,h3,p{margin-top:0}h1{margin-bottom:0;font-size:clamp(1.6rem,4vw,2.35rem);letter-spacing:0}h2{margin-bottom:0;font-size:1rem}h3{margin-bottom:8px;font-size:.96rem}.text-btn,.chip,.primary,.secondary{min-height:42px;border:1px solid var(--border);border-radius:8px;background:var(--surface);color:var(--text);padding:9px 13px}.text-btn:hover,.chip:hover,.primary:hover,.secondary:hover{border-color:var(--text)}.summary-band,.controls,.panel,.notice{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);box-shadow:var(--shadow)}.summary-band{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(320px,.65fr);gap:20px;align-items:center;padding:22px;margin-bottom:18px}.summary-copy h2{max-width:760px;margin-bottom:8px;font-size:clamp(1.35rem,3vw,2rem);letter-spacing:0}.summary-copy p,.muted,.section-head span,.date-range,.flight small,.weekend-card span{color:var(--muted)}.summary-copy p{margin-bottom:0}.stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}.stat{min-height:88px;border:1px solid var(--border);border-radius:8px;background:var(--surface-2);padding:12px}.stat span{display:block;font-size:1.75rem;font-weight:800;line-height:1}.stat small{display:block;margin-top:8px;color:var(--muted)}.stat.beijing span{color:var(--beijing)}.stat.changsha span{color:var(--changsha)}.stat.trip span{color:var(--trip)}.controls{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;margin-bottom:18px;padding:14px}.legend,.filters{display:flex;flex-wrap:wrap;gap:10px;align-items:center}.legend-item{display:inline-flex;align-items:center;gap:8px;color:var(--muted);font-size:.88rem}.swatch{width:14px;height:14px;border-radius:4px;border:1px solid var(--border)}.swatch.beijing{background:var(--beijing)}.swatch.changsha{background:var(--changsha)}.swatch.trip{background:var(--trip)}.chip.active{border-color:var(--text);background:var(--surface-2);font-weight:700}.panel,.notice{padding:18px;margin-bottom:18px}.notice{border-color:var(--changsha)}.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin-bottom:14px}.timeline-scroll{overflow-x:auto;padding-bottom:6px}.timeline-inner{min-width:720px}.timeline-track{position:relative;height:58px;overflow:hidden;border:1px solid var(--border);border-radius:10px;background:repeating-linear-gradient(90deg,transparent,transparent calc(12.5% - 1px),var(--border) calc(12.5% - 1px),var(--border) 12.5%)}.timeline-track:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;background:linear-gradient(90deg,var(--neutral) 0 var(--pre-pct),transparent var(--pre-pct) 100%);opacity:.35;pointer-events:none}.timeline-seg{position:absolute;top:4px;bottom:4px;min-width:3px;overflow:hidden;border:1px solid rgba(255,255,255,.35);border-radius:8px;padding:0 6px;color:#fff;text-align:left;text-shadow:0 1px 2px rgba(0,0,0,.4);transition:transform .15s,opacity .15s,filter .15s}.timeline-seg:hover,.timeline-seg.selected{transform:translateY(-1px);z-index:2}.timeline-seg span{position:absolute;right:6px;bottom:6px;left:6px;overflow:hidden;font-size:.66rem;text-overflow:ellipsis;white-space:nowrap}.timeline-seg.beijing{background:var(--beijing)}.timeline-seg.changsha{background:var(--changsha)}.timeline-seg.trip{background:var(--trip)}.dim{opacity:.24;filter:grayscale(.4)}.timeline-axis{position:relative;min-height:22px;margin-top:10px;color:var(--muted);font-size:.76rem}.timeline-axis span{position:absolute;transform:translate(-2px);white-space:nowrap}.content-grid{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:18px;align-items:start}.content-grid.lower{grid-template-columns:repeat(2,minmax(0,1fr))}.side-stack{display:grid;gap:18px}.calendars{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px 24px}.month h3{margin-bottom:10px}.month-grid{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:8px}.dow{padding:3px 0;color:var(--muted);font-size:.72rem;text-align:center}.cell{aspect-ratio:1;width:100%;min-width:0;border:1px solid transparent;border-radius:8px;background:var(--surface-2);color:var(--text);display:grid;place-items:center;position:relative;transition:outline .12s,opacity .15s}.cell.pad{opacity:.2;pointer-events:none}.cell small{position:absolute;bottom:4px;font-size:.58rem;line-height:1}.cell.beijing{background:var(--beijing-soft);border-color:#2563eb3d}.cell.changsha{background:var(--changsha-soft);border-color:#ea580c3d}.cell.trip{background:var(--trip-soft);border-color:#0596693d}.cell.neutral{color:var(--muted);border-color:var(--border)}.cell.weekend{outline:2px solid var(--text);outline-offset:1px}.detail-panel textarea{width:100%;resize:vertical;border:1px solid var(--border);border-radius:8px;background:var(--surface-2);color:var(--text);padding:10px}.range-editor{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-bottom:10px}.range-editor label{display:grid;gap:6px;color:var(--muted);font-size:.82rem}.range-editor input{min-width:0;min-height:40px;border:1px solid var(--border);border-radius:8px;background:var(--surface-2);color:var(--text);padding:8px 9px}.primary{width:100%;margin-top:10px;background:var(--text);color:var(--surface)}.secondary{width:100%;margin-bottom:12px}.next-route{margin-bottom:0;font-weight:700}.flight-groups,.weekends{display:grid;gap:14px}.flight-group{display:grid;gap:8px}.flight-group h3{margin-bottom:2px}.flight,.weekend-card{width:100%;border:1px solid var(--border);border-radius:8px;background:var(--surface-2);color:var(--text);text-align:left}.flight{display:flex;align-items:flex-start;gap:10px;min-height:62px;padding:10px}.flight.done{opacity:.55}.check{width:22px;height:22px;flex:0 0 auto;border:1px solid var(--border);border-radius:6px;display:grid;place-items:center;font-weight:800}.flight-body{display:grid;gap:3px;min-width:0}.flight-body strong{overflow-wrap:anywhere}.weekends{grid-template-columns:repeat(2,minmax(0,1fr))}.weekend-card{display:grid;gap:4px;padding:12px}.weekend-card:hover,.flight:hover{border-color:var(--text)}.loading{min-height:180px;display:grid;place-items:center;color:var(--muted)}@media(min-width:1160px){.calendars{grid-template-columns:repeat(3,minmax(0,1fr))}}@media(max-width:920px){.summary-band,.content-grid,.content-grid.lower{grid-template-columns:1fr}.side-stack{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:680px){.app-shell{padding:14px}.topbar,.controls,.section-head{align-items:stretch;flex-direction:column}.top-actions,.top-actions .text-btn{width:100%}.stats,.calendars,.side-stack,.weekends,.range-editor{grid-template-columns:1fr}.month-grid{gap:6px}.cell{border-radius:7px;font-size:.84rem}}