/* Dòng chảy lịch sử Việt Nam — theo bản thiết kế "Lượt 2" (Claude Design). */
html,body{margin:0;height:100%}
body{background:var(--nen);color:var(--muc);font-family:'Noto Sans',system-ui,sans-serif}
a{color:var(--muc);text-decoration-thickness:2px}a:hover{color:var(--muc-2)}
input:focus-visible,button:focus-visible{outline:3px solid var(--chon);outline-offset:1px}
details>summary{list-style:none}details>summary::-webkit-details-marker{display:none}
button{font:inherit;color:var(--muc)}
.goc{position:relative;height:100vh;height:100dvh;width:100%;overflow:hidden;background:var(--nen);display:flex;flex-direction:column}

/* nút sticker */
.nut{height:50px;padding:0 14px;flex:none;border:2px solid var(--vien);border-radius:14px;background:var(--be-mat);
  box-shadow:0 4px 0 var(--vien);font:700 15px 'Noto Sans',sans-serif;cursor:pointer;white-space:nowrap}
.nut:active{transform:translateY(3px);box-shadow:0 1px 0 var(--vien)}
.nut.vuong{width:50px;padding:0;font-size:19px}
.nut.chon{background:var(--chon)}
.nut.chinh{background:var(--muc);color:var(--tren-muc)}

/* đầu trang */
.dau{flex:none;height:72px;box-sizing:border-box;display:flex;align-items:center;gap:14px;padding:0 20px;background:var(--be-mat);border-bottom:2px solid var(--vien);position:relative;z-index:30}
.logo{width:44px;height:44px;flex:none;border:2px solid var(--vien);border-radius:14px;box-shadow:0 4px 0 var(--vien);overflow:hidden;display:flex;flex-direction:column}
.logo i{flex:1}.logo i+i{border-top:2px solid var(--vien)}
.ten-trang{font-family:'Noto Serif',serif;font-weight:800;font-size:22px;letter-spacing:-0.01em;white-space:nowrap}
.phu-de{font-size:13px;color:var(--muc-2);font-weight:500;white-space:nowrap}
.tim{position:relative;width:300px}
.tim input{width:100%;box-sizing:border-box;height:50px;padding:0 16px;border:2px solid var(--vien);border-radius:14px;background:var(--nen);color:var(--muc);font:500 15px 'Noto Sans',sans-serif;box-shadow:inset 0 3px 0 var(--mo)}
.ket-qua{position:absolute;top:58px;left:0;right:0;background:var(--be-mat);border:2px solid var(--vien);border-radius:16px;box-shadow:0 4px 0 var(--vien);padding:6px;display:flex;flex-direction:column;gap:2px;z-index:50}
.ket-qua button{display:flex;align-items:center;gap:10px;min-height:50px;padding:6px 10px;border:0;border-radius:10px;background:transparent;text-align:left;cursor:pointer}
.ket-qua button:hover{background:var(--mo)}
.ket-qua b{display:block;font-size:14px}.ket-qua small{display:block;font-size:12px;color:var(--muc-2)}
.chuyen-thang{display:flex;height:50px;box-sizing:border-box;border:2px solid var(--vien);border-radius:14px;box-shadow:0 4px 0 var(--vien);overflow:hidden;background:var(--be-mat)}
.chuyen-thang button{padding:0 14px;border:0;background:var(--be-mat);font:700 14px 'Noto Sans',sans-serif;cursor:pointer}
.chuyen-thang button+button{border-left:2px solid var(--vien)}
.chuyen-thang button.chon{background:var(--chon)}

/* thanh công cụ */

/* dòng thời gian (desktop) */
.khung-tl{position:absolute;top:72px;left:0;bottom:0;display:flex;flex-direction:column}
.cuon{flex:1;min-height:0;overflow-x:auto;overflow-y:auto;position:relative;border-top:2px solid var(--vien)}
.ruot{--d:0px;display:flex;height:calc(792px + var(--d));position:relative}
.nhan-lan{position:sticky;left:0;z-index:12;width:120px;flex:none;height:calc(792px + var(--d));background:var(--nen);border-right:2px solid var(--vien);box-sizing:border-box}
.nhan-lan div{position:absolute;left:0;right:0;display:flex;align-items:center;padding:0 12px;font-size:13px;font-weight:800}
.nhan-lan .nho{font-size:12px;font-weight:600;color:var(--muc-2)}
.nb-dong .nhan-lan .nb{display:none}
/* nút đóng/mở dải nước lân cận (mặc định đóng) */
.nb-nut{position:absolute;left:8px;right:8px;box-sizing:border-box;padding:0 8px;border:2px solid var(--vien);border-radius:999px;background:var(--be-mat);color:var(--muc);font:800 12px 'Noto Sans',sans-serif;text-align:left;cursor:pointer;white-space:nowrap}
.nb-nut[aria-expanded="true"]{background:var(--chon)}
.nb-dai{left:0;right:0;height:26px;box-sizing:border-box;padding:0 12px;border:1.5px dashed var(--vien-mo);border-radius:6px;background:var(--lan-can);color:var(--muc-2);font:600 12px 'Noto Sans',sans-serif;text-align:left;cursor:pointer;z-index:3}
.mat{position:relative;flex:none;height:calc(792px + var(--d));touch-action:pan-x pan-y;user-select:none;cursor:crosshair}
.mat>*{position:absolute}
.svg0{left:0;top:0;width:1px;height:1px;overflow:visible;pointer-events:none}
.o-doi{box-sizing:border-box;border:1.5px solid var(--vien);border-radius:6px;z-index:3;display:flex;align-items:center;justify-content:center;padding:0 3px;overflow:hidden;font-weight:700;line-height:1.15;text-align:center}
.nhan-dong{z-index:4;font-family:'Noto Serif',serif;font-weight:800;text-transform:uppercase;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;pointer-events:none}
.chip-vua{transform:translateX(-50%);z-index:7;height:22px;padding:0 9px;display:flex;align-items:center;background:var(--muc);color:var(--tren-muc);border:2px solid var(--vien);border-radius:999px;box-shadow:0 2px 0 var(--vien);font-size:11.5px;font-weight:800;white-space:nowrap;pointer-events:none}
.the-moc{-webkit-backdrop-filter:blur(3px) saturate(1.1);backdrop-filter:blur(3px) saturate(1.1);width:156px;height:58px;box-sizing:border-box;padding:5px 8px;border:2px solid var(--vien);border-radius:12px;box-shadow:0 3px 0 var(--vien);cursor:pointer;overflow:hidden;z-index:5;display:flex;flex-direction:column;gap:1px;text-align:left}
.the-moc:active,.vien-chuyen:active{transform:translateY(3px);box-shadow:none}
.the-moc .n{display:flex;align-items:center;gap:4px;height:14px;line-height:14px;font-family:'Noto Serif',serif;font-weight:800;font-size:11.5px;white-space:nowrap;overflow:hidden;flex:none}
.the-moc .t{font-size:12px;line-height:1.25;font-weight:600;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.sgk{font-family:'Noto Sans',sans-serif;font-size:8.5px;line-height:10px;height:12px;box-sizing:border-box;font-weight:800;padding:0 4px;border:1.5px solid var(--vien);border-radius:999px;background:var(--dong-lytran)}
.vien-chuyen{-webkit-backdrop-filter:blur(3px) saturate(1.1);backdrop-filter:blur(3px) saturate(1.1);height:26px;box-sizing:border-box;padding:0 12px 0 4px;display:flex;align-items:center;gap:6px;border:2px solid var(--vien);border-radius:999px;box-shadow:0 3px 0 var(--vien);cursor:pointer;white-space:nowrap;z-index:5}
.vien-chuyen i{width:20px;height:20px;font-size:11px}
.tron{width:26px;height:26px;flex:none;border-radius:50%;background:var(--be-mat);border:1.5px solid var(--vien);display:flex;align-items:center;justify-content:center;font-size:14px;font-style:normal}
.vien-chuyen span{font-size:12px;font-weight:700}
.them-chuyen{position:absolute;z-index:6;height:18px;min-width:22px;padding:0 5px;border:2px solid var(--vien);border-radius:999px;background:var(--muc);color:var(--tren-muc);font:800 10.5px 'Noto Serif',serif;cursor:pointer;line-height:1}
.cham{border-radius:50%;border:1.5px solid var(--vien);box-sizing:border-box}
.vach-nam{width:1px;height:calc(704px + var(--d));background:var(--vien-mo);opacity:0.45}
.gay{top:0;height:calc(704px + var(--d));border-left:2px dashed var(--vien-mo);z-index:1}
.ghi{top:calc(752px + var(--d));height:26px;padding:0 10px;display:flex;align-items:center;background:var(--be-mat);border:2px solid var(--vien);border-radius:999px;font-size:12px;font-weight:700;white-space:nowrap;z-index:2}
.dau-moc{height:22px;padding:0 8px;display:flex;align-items:center;background:var(--be-mat);border:2px solid var(--vien);border-radius:999px;font-size:11px;font-weight:800;white-space:nowrap;z-index:4}
.lan-nb{box-sizing:border-box;border-radius:6px;font-size:11px;font-weight:600;color:var(--muc-2);padding:0 6px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.vach{top:0;width:0;height:calc(732px + var(--d));border-left:2px dashed var(--muc);z-index:8;pointer-events:none}
.tay{top:calc(730px + var(--d));width:92px;height:54px;box-sizing:border-box;background:var(--muc);color:var(--tren-muc);border:2px solid var(--vien);border-radius:16px;box-shadow:0 4px 0 var(--vien);z-index:9;cursor:grab;display:flex;flex-direction:column;align-items:center;justify-content:center;line-height:1}
.tay b,.tay-m b{font-family:'Noto Serif',serif;font-weight:800;font-size:21px}
.tay small,.tay-m small{font-size:10px;font-weight:800;letter-spacing:0.06em}
.truyen-thuyet-nhan{padding:10px 12px;box-sizing:border-box;background:color-mix(in srgb,var(--loai-truyen) 78%,transparent);-webkit-backdrop-filter:blur(3px);backdrop-filter:blur(3px);border:2px dashed var(--vien);border-radius:14px;z-index:4}
.truyen-thuyet-nhan b{display:block;font-family:'Noto Serif',serif;font-weight:800;font-size:15px}
.truyen-thuyet-nhan span{display:block;font-size:12px;line-height:1.4;margin-top:4px;font-weight:500}

/* tranh nền mỗi thời kỳ: phủ cả hàng mốc và hàng câu chuyện */
.anh-tk{top:0;height:374px;box-sizing:border-box;border-right:2px solid var(--vien);overflow:hidden;background:var(--mo)}
.anh-tk img{width:100%;height:100%;object-fit:cover;display:block}
.anh-tk::after{content:"";position:absolute;inset:0;background:linear-gradient(to bottom,transparent 55%,color-mix(in srgb,var(--nen) 35%,transparent))}
.anh-tk .soc{position:absolute;inset:0;background:repeating-linear-gradient(135deg,var(--ve-1) 0 14px,var(--ve-2) 14px 28px)}
.anh-tk .cap{position:absolute;z-index:1;background:color-mix(in srgb,var(--be-mat) 74%,transparent)!important;-webkit-backdrop-filter:blur(3px);backdrop-filter:blur(3px);left:8px;top:192px;max-width:calc(100% - 16px);height:24px;box-sizing:border-box;padding:0 10px;line-height:20px;background:var(--be-mat);border:2px solid var(--vien);border-radius:999px;font-size:11px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.anh-tk .cap b{font-family:'Noto Serif',serif;font-weight:800;text-transform:uppercase}

/* bảng "Cùng lúc ấy" */
.bang{position:absolute;right:0;bottom:0;background:var(--be-mat);display:flex;flex-direction:column;z-index:20;box-sizing:border-box;overflow:hidden}
.bang-dau{flex:none;padding:16px 16px 14px;border-bottom:2px solid var(--vien);display:flex;flex-direction:column;gap:10px}
.bang-than{flex:1;min-height:0;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:20px}
.muc-tieu{font-family:'Noto Serif',serif;font-weight:800;font-size:15px}
.nam-to{font-family:'Noto Serif',serif;font-weight:800;font-size:44px;line-height:1;letter-spacing:-0.02em}
.nam-to small{font-size:18px;margin-left:6px}
.vien{height:22px;padding:0 8px;display:inline-flex;align-items:center;border:2px solid var(--vien);border-radius:999px;font-size:11.5px;font-weight:800}
.o-viet{display:flex;gap:12px;padding:12px;border:2px solid var(--vien);border-radius:16px;background:var(--be-mat);box-shadow:0 3px 0 var(--vien)}
.o-viet .mau{width:20px;height:20px;flex:none;margin-top:2px;border:2px solid var(--vien);border-radius:6px}
.o-viet .noi{font-size:11.5px;font-weight:700;color:var(--muc-2)}
.o-viet .ten{font-family:'Noto Serif',serif;font-weight:700;font-size:16px;line-height:1.25}
.o-viet p{margin:0;font-size:14px;line-height:1.45}
.o-viet .sub{font-size:13px;color:var(--muc-2)}
.hop{padding:12px 14px;border:2px solid var(--vien);border-radius:16px;font-size:14px;line-height:1.45}
.dong-moc{display:flex;align-items:center;gap:10px;min-height:52px;padding:6px 12px;border:2px solid var(--vien);border-radius:14px;box-shadow:0 3px 0 var(--vien);text-align:left;cursor:pointer;width:100%}
.dong-moc .nm{font-family:'Noto Serif',serif;font-weight:800;font-size:14px;min-width:70px}
.dong-moc b{display:block;font-size:14px;line-height:1.3}.dong-moc small{display:block;font-size:12px;color:var(--muc-2);font-weight:600}
.dong-chuyen{display:flex;align-items:center;gap:10px;min-height:56px;padding:6px 12px 6px 6px;border:2px solid var(--vien);border-radius:999px;box-shadow:0 3px 0 var(--vien);text-align:left;cursor:pointer;width:100%}
.dong-chuyen .tron{width:40px;height:40px;border-width:2px;font-size:19px}
.dong-chuyen small{display:block;font-size:11.5px;font-weight:800}.dong-chuyen b{display:block;font-size:14px;line-height:1.3}
.ds-nb{display:flex;flex-direction:column;border:2px solid var(--vien);border-radius:16px;overflow:hidden;background:var(--be-mat)}
.ds-nb div{display:flex;justify-content:space-between;gap:8px;padding:9px 12px}
.ds-nb div+div{border-top:2px solid var(--mo)}
.ds-nb b{font-size:14px;line-height:1.3}.ds-nb span{font-size:11.5px;font-weight:700;color:var(--muc-2);white-space:nowrap}

/* lọc */
.loc{position:absolute;z-index:45;background:var(--be-mat);border:2px solid var(--vien);border-radius:20px;box-shadow:0 5px 0 var(--vien);padding:16px;display:flex;flex-direction:column;gap:12px;box-sizing:border-box}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{height:50px;padding:0 14px;border:2px solid var(--vien);border-radius:14px;box-shadow:0 3px 0 var(--vien);font:700 14px 'Noto Sans',sans-serif;cursor:pointer;display:flex;align-items:center;gap:8px}
.chip.tat{background:var(--be-mat)!important;box-shadow:none;opacity:.6}
.chip.loai{border-radius:999px;padding:0 14px 0 6px}
.chip.loai i{width:34px;height:34px;border-radius:50%;background:var(--be-mat);border:1.5px solid var(--vien);display:flex;align-items:center;justify-content:center;font-size:17px;font-style:normal}

/* thẻ chi tiết */
.phu{position:absolute;inset:0;z-index:60;background:var(--phu-mo);display:flex;align-items:center;justify-content:center;box-sizing:border-box}
.the{width:100%;max-width:980px;max-height:100%;overflow:auto;background:var(--be-mat);border:2px solid var(--vien);border-radius:24px;box-shadow:0 6px 0 var(--vien);box-sizing:border-box}
.the-dau{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:18px 20px 0}
.nhan-loai{height:42px;padding:0 16px 0 6px;display:inline-flex;align-items:center;gap:8px;border:2px solid var(--vien);border-radius:999px;box-shadow:0 3px 0 var(--vien);font-family:'Noto Serif',serif;font-weight:800;font-size:15px}
.nhan-loai i{width:30px;height:30px;border-radius:50%;background:var(--be-mat);border:1.5px solid var(--vien);display:flex;align-items:center;justify-content:center;font-size:16px;font-style:normal}
.vien-to{height:32px;padding:0 12px;display:inline-flex;align-items:center;border:2px solid var(--vien);border-radius:999px;font-size:13px;font-weight:700}
.the h2{margin:0;font-family:'Noto Serif',serif;font-weight:800;font-size:30px;line-height:1.15;letter-spacing:-0.01em;text-wrap:balance}
.the .nam-the{font-family:'Noto Serif',serif;font-weight:800;font-size:40px;line-height:1;color:var(--dong-tuchu-dam)}
.the-than{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:24px;padding:18px 20px 22px;align-items:start}
.cot{display:flex;flex-direction:column;gap:16px;min-width:0}
.the p{margin:0;font-size:16px;line-height:1.65;text-wrap:pretty}
.anh .khung{position:relative;aspect-ratio:4/3;background:var(--be-mat);border:2px solid var(--vien);border-radius:18px;overflow:hidden}
.anh-ve .khung{box-shadow:0 4px 0 var(--vien)}
.anh .khung img{width:100%;height:100%;object-fit:cover;display:block}
.anh .soc-ve{position:absolute;inset:0;background:repeating-linear-gradient(135deg,var(--ve-1) 0 14px,var(--ve-2) 14px 28px)}
.anh .soc-that{position:absolute;inset:0;background:repeating-linear-gradient(0deg,var(--soc-1) 0 6px,var(--soc-2) 6px 12px)}
.anh .nhan-anh{position:absolute;top:12px;left:12px;height:30px;padding:0 12px;display:inline-flex;align-items:center;border:2px solid var(--vien);border-radius:999px;background:var(--be-mat);font-size:12.5px;font-weight:800}
.anh-that .nhan-anh{border-radius:8px;background:var(--muc);color:var(--tren-muc);font-size:12px;letter-spacing:0.06em}
.anh .canh{position:absolute;left:14px;right:14px;bottom:14px;padding:10px 12px;background:var(--be-mat);border:2px solid var(--vien);border-radius:12px;font-family:'Noto Sans',sans-serif;font-size:12.5px;line-height:1.5}
.anh .giua{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;padding:52px 24px 24px;text-align:center;font-family:'Noto Sans',sans-serif;font-size:13px;line-height:1.5;font-weight:600}
.nguon-anh{display:flex;gap:8px;align-items:baseline;font-size:12.5px;margin-top:8px}
.nguon-anh span{flex:1;border-bottom:2px dotted var(--vien-mo);color:var(--muc-2);font-family:'Noto Sans',sans-serif;font-size:11.5px;padding-bottom:2px}
.hop-the{padding:14px 16px;border:2px solid var(--vien);border-radius:16px;box-shadow:0 3px 0 var(--vien)}
.hop-the b{display:block;font-family:'Noto Serif',serif;font-weight:800;font-size:15px;margin-bottom:4px}
.hop-the div{font-size:15px;line-height:1.55}
.nv{display:flex;flex-wrap:wrap;align-items:center;gap:6px}
.nv span{height:30px;padding:0 12px;display:inline-flex;align-items:center;border:2px solid var(--vien);border-radius:999px;background:var(--mo);font-size:13.5px;font-weight:700}
details.nguon{border:2px solid var(--vien);border-radius:14px;background:var(--nen)}
details.nguon summary{min-height:50px;padding:0 14px;display:flex;align-items:center;gap:8px;cursor:pointer;font-size:14px;font-weight:800}
details.nguon ol{margin:0;padding:0 16px 14px 34px;display:flex;flex-direction:column;gap:4px;font-size:13px;line-height:1.45;color:var(--muc-2)}

/* điện thoại */
.dau-m{flex:none;height:60px;box-sizing:border-box;display:flex;align-items:center;gap:8px;padding:0 12px;background:var(--be-mat);border-bottom:2px solid var(--vien);position:relative;z-index:30}
.dau-m .logo{width:36px;height:36px;border-radius:11px;box-shadow:0 3px 0 var(--vien)}
.dau-m .ten-trang{flex:1;min-width:0;font-size:17px;white-space:normal;line-height:1.15}
.dau-m .nut{box-shadow:0 3px 0 var(--vien)}
.vung-m{position:relative;flex:1;min-height:0;border-top:2px solid var(--vien)}
.cuon-m{position:absolute;inset:0;overflow-y:auto;overflow-x:hidden}
.ruot-m{position:relative}
.ruot-m>*{position:absolute}
.vach-m{left:0;right:0;top:180px;height:0;border-top:2px dashed var(--muc);z-index:10;pointer-events:none;position:absolute}
.tay-m{position:absolute;left:4px;top:154px;min-width:76px;height:52px;box-sizing:border-box;padding:0 8px;background:var(--muc);color:var(--tren-muc);border:2px solid var(--vien);border-radius:16px;box-shadow:0 4px 0 var(--vien);z-index:11;display:flex;flex-direction:column;align-items:center;justify-content:center;line-height:1;pointer-events:none}
.tay-m b{font-size:20px}
.the-moc-m{left:210px;right:10px;height:50px;box-sizing:border-box;padding:4px 10px;border:2px solid var(--vien);border-radius:12px;box-shadow:0 3px 0 var(--vien);overflow:hidden;display:flex;flex-direction:column;justify-content:center;text-align:left;cursor:pointer}
.the-moc-m .n{font-family:'Noto Serif',serif;font-weight:800;font-size:12px}
.the-moc-m .t{font-size:12.5px;line-height:1.2;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.vien-chuyen-m{left:210px;right:10px;height:44px;box-sizing:border-box;padding:0 10px 0 4px;display:flex;align-items:center;gap:8px;border:2px solid var(--vien);border-radius:999px;box-shadow:0 3px 0 var(--vien);cursor:pointer;text-align:left}
.vien-chuyen-m .tron{width:32px;height:32px;font-size:16px}
.vien-chuyen-m small{display:block;font-size:10.5px;font-weight:800}.vien-chuyen-m b{display:block;font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.chu-giai-anh{font-size:11px;color:var(--muc-2);padding:0 16px 10px}

/* Auto: phụ đề đang đọc */
.chuyen-thang select{border:0;border-left:2px solid var(--vien);background:var(--be-mat);color:var(--muc);font:600 13px 'Noto Sans',sans-serif;padding:0 8px;max-width:210px;cursor:pointer}
.phu-de-doc{position:absolute;z-index:40;left:136px;right:416px;bottom:96px;max-height:132px;overflow:hidden;padding:10px 14px;background:color-mix(in srgb,var(--be-mat) 90%,transparent);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);border:2px solid var(--vien);border-radius:16px;box-shadow:0 4px 0 var(--vien);display:flex;flex-direction:column;gap:4px;pointer-events:none}
.phu-de-doc b{font-family:'Noto Serif',serif;font-weight:800;font-size:15px}
.phu-de-doc span{font-size:14px;line-height:1.45;display:-webkit-box;-webkit-line-clamp:4;-webkit-box-orient:vertical;overflow:hidden}
.phu-de-doc small{font-size:12px;color:var(--muc-2)}
.phu-de-doc.m{left:8px;right:8px;bottom:16px}
.phu-de-doc[hidden]{display:none}
#b-auto{white-space:nowrap;min-width:92px}
.dau .tim{width:240px}

/* tranh riêng của mốc đang kể (chế độ Auto) */
.anh-moc{position:absolute;top:0;height:374px;z-index:4;pointer-events:none;opacity:0;transition:opacity .8s ease;border-bottom:2px solid var(--vien);overflow:hidden}
.anh-moc.hien{opacity:1}
.anh-moc{background:var(--doc)}
.anh-moc .dai{position:absolute;inset:0;opacity:0;transition:opacity .9s ease}
.anh-moc .dai.hien{opacity:1}
.anh-moc .dai img{position:absolute;top:0;height:100%;object-fit:contain}
.anh-moc .khung-giua{position:absolute;top:0;height:100%;overflow:hidden}
.anh-moc .khung-giua img{position:static;display:block;width:100%;height:100%;object-fit:cover;transform-origin:50% 55%}
/* Ken Burns: trong lúc kể, tranh zoom vào rất chậm và lia nhẹ sang một bên, rồi dừng ở cuối */
.anh-moc .giua.chay{animation:ken-burns 28s cubic-bezier(.25,.1,.25,1) forwards}
.anh-moc .giua.lia-trai{--lia:-3%}
.anh-moc .giua.lia-phai{--lia:3%}
@keyframes ken-burns{from{transform:scale(1) translateX(0)}to{transform:scale(1.14) translateX(var(--lia,0))}}
@media (prefers-reduced-motion:reduce){.anh-moc .giua.chay{animation:none}}
.anh-moc .dai img[hidden],.anh-moc .khe[hidden]{display:none}
.anh-moc .truoc,.anh-moc .sau{filter:saturate(.7) brightness(.97);opacity:.85}   /* tranh mốc trước/sau chỉ để lấp hai bên */
.anh-moc .khe{position:absolute;top:0;bottom:0;width:6px;box-sizing:border-box;background:var(--khung);border-left:1px solid var(--vien);border-right:1px solid var(--vien)}

/* chỗ quá nhiều chuyện: chỉ hiện biểu tượng, rê chuột (hoặc chạm/Tab) mới bung tên */
.vien-chuyen.gon span{display:none}
.vien-chuyen.gon:hover,.vien-chuyen.gon:focus-visible{z-index:20;padding:0 12px 0 4px!important;background:var(--be-mat)!important}
.vien-chuyen.gon:hover span,.vien-chuyen.gon:focus-visible span{display:inline}

/* ════ Lượt 4 · giấy ngà, bản đồ cổ ════ */
:root,[data-theme="sang"]{
  --nen:#F3E8CF;--doc:#FBF6E8;--be-mat:#FDF9EF;--mo:#EFE3C8;--khung:#E6D5B3;
  --muc:#493426;--muc-2:#6E5643;--tren-muc:#FBF6E8;--vien:#8B6B4E;--vien-mo:#C9B48F;
  --chon:#F2D6C4;--gach:#A2452D;--son:#C8321E;
  --lan-can:#DCE2E2;--xam-lam:#8FA2AB;
  --soc-1:#EFE3C8;--soc-2:#E7D7B6;--ve-1:#F1E5CB;--ve-2:#E9DBBC;
  --tranh-cai:#F1E0B5;--phu-mo:rgba(73,52,38,.45);
  --bong:0 1px 0 rgba(73,52,38,.10),0 2px 5px -1px rgba(73,52,38,.20);
  --bong-dai:rgba(73,52,38,.16);
  --dong-hung:#E6C886;--dong-hung-nhat:#F3E4BF;--dong-hung-dam:#8A6A2C;
  --dong-tuchu:#E9CD8E;--dong-tuchu-nhat:#F4E7C6;--dong-tuchu-dam:#8A6A2C;
  --dong-lytran:#DDB86A;--dong-lytran-nhat:#F0DFB4;--dong-lytran-dam:#7E5E22;
  --dong-le:#E4C47C;--dong-le-nhat:#F2E2BA;--dong-le-dam:#83632A;
  --dong-nguyen:#D6AE5E;--dong-nguyen-nhat:#EEDCAE;--dong-nguyen-dam:#76561E;
  --dong-hiendai:#EACF94;--dong-hiendai-nhat:#F5E9CA;--dong-hiendai-dam:#8A6A2C;
  --dong-bac:#CDBFA6;--dong-bac-nhat:#E6DCC9;--dong-bac-dam:#6E5E48;
  --dong-phap:#C6BBA8;--dong-phap-nhat:#E2DACB;--dong-phap-dam:#6A5D4C;
  --dong-champa:#A9BAC2;--dong-champa-nhat:#D5DFE3;--dong-champa-dam:#4E6470;
  --dong-phunam:#9FB2BB;--dong-phunam-nhat:#D0DCE0;--dong-phunam-dam:#4A606B;
  --loai-that:#C3C389;--loai-giai:#D2D3A6;--loai-truyen:#BCC08A;--loai-cotich:#CFCB95;
}
body,.goc{background:#F3E8CF url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 .29 0 0 0 0 .2 0 0 0 0 .15 0 0 0 .06 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E")}
.ten-trang,.nam-to,.muc-tieu,.o-viet .ten,.the h2,.the .nam-the,.nhan-dong,.anh-tk .cap b,.tay b,.tay-m b,.hop-the b,.truyen-thuyet-nhan b,.nhan-loai{font-family:'Noto Serif',serif!important;color:var(--muc)}

/* hình khối chung: bo 3px, viền nâu mảnh, bóng giấy */
#app *{border-radius:3px!important;border-width:1px!important;box-shadow:none!important}
#app .tron,#app .logo{border-radius:50%!important}
#app :is(.nut,.the-moc,.vien-chuyen,.o-viet,.dong-moc,.dong-chuyen,.ds-nb,.the,.loc,.ket-qua,.chip,.hop-the,.chip-vua,.nhan-loai,.the-moc-m,.vien-chuyen-m,.truyen-thuyet-nhan,.anh .khung,.chuyen-thang,.phu-de-doc,.the-thoi,.anh-tk .cap,.dau-moc,.ghi){box-shadow:var(--bong)!important}
.nut:active,.the-moc:active,.vien-chuyen:active{transform:translateY(1px)}
.nut.chon,.chuyen-thang button.chon{background:var(--chon)}
#app .tim input{background:var(--doc);box-shadow:inset 0 1px 2px rgba(73,52,38,.12)!important}

/* đầu trang: mép sách viền kép */
#app .dau{background:var(--khung);border-bottom:4px double var(--vien)!important;overflow:hidden}
.dau>*:not(.tt-trong){position:relative;z-index:1}
.logo{background:none}
.logo img{width:100%;height:100%;object-fit:contain;display:block}
#app .logo{border:0!important;box-shadow:0 1px 2px rgba(59,36,20,.35)!important}   /* mặt trống đã có vành tối riêng */
.ten-trang{font-weight:800;font-size:24px}
.tt-trong{position:absolute;right:430px;top:-70px;width:300px;height:200px;pointer-events:none;opacity:.13;mix-blend-mode:multiply;-webkit-mask-image:radial-gradient(ellipse at center,#000 30%,transparent 70%);mask-image:radial-gradient(ellipse at center,#000 30%,transparent 70%)}
.tt-trong img{width:100%;height:100%;object-fit:cover;filter:grayscale(1) sepia(.8) contrast(1.3)}
.tt-song{position:absolute;left:0;bottom:0;width:300px;height:214px;z-index:13;pointer-events:none;opacity:.22}
.tt-song path{fill:none;stroke:#5F7F95;stroke-width:1.4;stroke-linecap:round}
.tt-song path.nhanh{stroke-width:1}
.tt-song path.cham{stroke:var(--vien);stroke-dasharray:1.5 5;stroke-width:1.5}

/* vùng đọc, cột làn, bảng bên */
#app .cuon{background:var(--doc);border-top:0!important}
.nhan-lan{background:var(--khung)!important;border-right:1px solid var(--vien)!important}
.nhan-lan div{font-family:'Noto Serif',serif;font-weight:700;color:var(--muc)}
.nhan-lan .nho{font-family:'Noto Sans',sans-serif;font-weight:500}
.vach-nam{background:none;border-left:1px dotted var(--vien-mo);opacity:.6;width:0}
.gay{border-left:1px dashed var(--vien-mo)}
.bang{background:var(--khung)}
.bang-dau{background:var(--khung);border-bottom:1px solid var(--vien)!important}
.bang-than{background:var(--doc)}
.nam-to{font-weight:800;font-size:46px}
.muc-tieu{font-weight:700}
.vien{background:var(--doc)}
.o-viet .ten{font-weight:700}

/* mốc lịch sử: đỏ gạch */
.the-moc{-webkit-backdrop-filter:none;backdrop-filter:none}
.the-moc .n{color:var(--gach)}
.the .nam-the{color:var(--gach)!important}
.dong-moc .nm{color:var(--gach)}
.sgk{background:var(--loai-that);color:var(--muc)}

/* câu chuyện: olive */
.vien-chuyen{-webkit-backdrop-filter:none;backdrop-filter:none}
.them-chuyen{background:var(--muc);color:var(--tren-muc)}

/* nước lân cận: xanh lam xám */
.lan-nb{color:#3F525C}
.nb-dai,.nb-nut{background:var(--lan-can)}
.nb-nut[aria-expanded="true"]{background:var(--xam-lam);color:#fff}

/* tranh thời kỳ */
.anh-tk{border-right:1px solid var(--vien)!important}
.anh-tk::after{background:linear-gradient(to bottom,transparent 60%,rgba(243,232,207,.35))}
.anh-tk img{filter:sepia(.18) saturate(.92)}
.anh-tk .cap{background:var(--be-mat)!important;-webkit-backdrop-filter:none;backdrop-filter:none;height:26px;line-height:22px;font-size:12px}
.anh-tk .cap b{font-weight:700;letter-spacing:.04em}
.truyen-thuyet-nhan{background:rgba(253,249,239,.92);border-style:dashed!important}

/* đời vua */
.o-doi{border-color:var(--vien)!important}
.chip-vua{background:var(--muc);color:var(--tren-muc)}
.nhan-dong{font-weight:700}

/* thước thời gian 3 cấp, vạch đỏ son, nhãn năm như dấu đóng */
.vach-1,.vach-2,.vach-3{position:absolute;width:0;border-left:1px solid var(--muc)}
#app .vach-1{height:16px;border-left-width:2px!important;margin-left:-1px}
.vach-2{height:10px}
.vach-3{height:5px;border-left-color:var(--muc-2)}
.nhan-nam{transform:translateX(-50%);white-space:nowrap;font-size:11.5px;font-weight:500;color:var(--muc-2)}
#app .nhan-nam.chinh{padding:1px 7px 2px;background:var(--be-mat);border:3px double var(--vien)!important;color:var(--muc);font:700 11.5px 'Noto Serif',serif}
.nhan-nam.dau-thuoc{transform:none;margin-left:4px}
#app .vach{border-left:0!important;width:2px;background:repeating-linear-gradient(to bottom,var(--son) 0 6px,transparent 6px 11px);opacity:.9}   /* vạch năm đang chọn: nét đứt đỏ son */
#app .tay{background:var(--be-mat);color:var(--son);border:4px double var(--son)!important;box-shadow:0 2px 6px rgba(73,52,38,.25)!important}
.tay b,.tay small{color:var(--son)!important}
.ghi{background:var(--be-mat);font-weight:600}
.dau-moc{background:var(--be-mat)}

/* chọn năm ở bảng bên */
.nhap{display:flex;gap:8px}
.nhap input{flex:1;min-width:0;height:44px;box-sizing:border-box;padding:0 12px;border:1px solid var(--vien);background:var(--doc);color:var(--muc);font:500 14px 'Noto Sans',sans-serif}
.nhap .nut{height:44px}
.ds-thoi{display:flex;gap:6px;overflow-x:auto;padding-bottom:4px;scrollbar-width:thin}
.the-thoi{flex:none;display:flex;flex-direction:column;align-items:flex-start;min-height:44px;padding:4px 9px;border:1px solid var(--vien);background:var(--be-mat);cursor:pointer;text-align:left}
.the-thoi b{font:700 12.5px 'Noto Serif',serif;color:var(--muc)}
.the-thoi small{font-size:11px;color:var(--muc-2)}
.the-thoi:hover{background:var(--doc)}
.the-thoi.chon{background:var(--muc);border-color:var(--muc)}
.the-thoi.chon b,.the-thoi.chon small{color:var(--tren-muc)}
.meo-phim{font-size:11.5px;color:var(--muc-2)}

/* thẻ chi tiết */
.the{background:var(--be-mat)}
details.nguon{background:var(--doc)}

/* thẻ câu chuyện: tranh to bên trái (+20% diện tích), hai hộp Ý nghĩa / Sử sách nằm dưới tranh, truyện bên phải */
.the.the-chuyen{max-width:1080px}
.ct-dau{padding:8px 24px 0;display:flex;flex-direction:column;gap:4px}
.ct-thoi{font-size:13.5px;font-weight:600;color:var(--muc-2)}
.ct-than{display:grid;grid-template-columns:minmax(0,56fr) minmax(0,44fr);gap:16px 24px;padding:14px 24px 24px;align-items:start}
.ct-trai,.ct-phai{display:flex;flex-direction:column;gap:14px;min-width:0}
.ct-hop{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px}
.ct-hop .hop-the{padding:12px 14px}
.ct-hop .hop-the div{font-size:14px;line-height:1.5}
.ct-phai p{font-size:16px;line-height:1.7}
.ct-anh .khung{aspect-ratio:4/3}
@media (min-width:1100px){.ct-trai{position:sticky;top:0}}
@media (max-width:760px){.ct-than{grid-template-columns:1fr;padding:12px 14px 18px}.ct-dau{padding:8px 14px 0}}

/* bỏ cột tên làn: chỉ còn cờ nổi bám mép trái, rê chuột (hoặc Tab tới) để hiện tên */
#app .nhan-lan{width:0!important;background:none!important;border-right:0!important;overflow:visible}
.co{position:absolute;left:12px;z-index:14;display:flex;align-items:center;gap:8px;padding:0;border:0;background:none;cursor:default}
.co[hidden]{display:none}
.co .la{display:block;width:30px;height:20px;flex:none;transition:width .18s ease,height .18s ease}
.co .la svg{display:block;width:100%;height:100%}
#app .co .la{box-shadow:0 1px 0 rgba(73,52,38,.15),0 2px 5px -1px rgba(73,52,38,.35)!important}
.co b{display:none;padding:4px 10px;background:var(--be-mat);border:1px solid var(--vien);font:700 14px 'Noto Serif',serif;color:var(--muc);white-space:nowrap}
#app .co b{box-shadow:var(--bong)!important}
.co:is(:hover,:focus-visible) .la{width:54px;height:36px}
.co:is(:hover,:focus-visible) b{display:block}
.co:is(:hover,:focus-visible){z-index:16}
.co:hover .la{transform:translateY(-1px)}
.co.nb .la{width:24px;height:16px}
.co.nb:is(:hover,:focus-visible) .la{width:42px;height:28px}
.co.nb b{font-size:12.5px;padding:2px 8px}
.nb-dong .nhan-lan .co.nb{display:none}
#app .nb-nut{left:12px;right:auto;width:auto;padding:0 12px}

/* điện thoại: nhãn năm đang chọn nằm trên nền nâu đậm nên chữ phải sáng */
.tay-m b{color:var(--tren-muc)!important}
.dau-m #b-auto{min-width:0}   /* trên điện thoại nút ▶ vuông như các nút khác, chừa chỗ cho tên trang */
.mat{margin-left:20px}   /* = LE_TRAI trong dong-chay.js */
.nhan-dong .so-nam{text-transform:none;font-weight:600;letter-spacing:0}   /* "· 216 năm" cạnh tên triều đại */
/* ghi chú tranh AI (CLAUDE.md: ghi một lần ở đầu hoặc cuối trang) — dòng nhỏ ở góc dưới */
.ghi-ai{position:absolute;left:16px;bottom:8px;z-index:14;font-size:11px;font-weight:500;color:var(--muc-2);pointer-events:none}
.ghi-ai.m{left:auto;right:10px;bottom:6px;padding:1px 6px;background:color-mix(in srgb,var(--doc) 85%,transparent)}
.tay b i,.tay-m b i{font-style:normal;font-size:10px;font-weight:800;letter-spacing:0.04em;margin-left:3px}   /* "TCN" nhỏ sau số năm */
.tay small,.tay-m small{margin-bottom:1px}

/* thẻ mốc: tranh khổ ngang trải hết bề rộng, dưới chia nội dung | thông tin phụ */
.the.the-moc-ct{max-width:900px}
.mc-tranh{padding:12px 24px 0}
.mc-tranh img{display:block;width:100%;aspect-ratio:21/9;object-fit:cover;border:1px solid var(--vien)}
.mc-than{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:16px 28px;padding:16px 24px 24px;align-items:start}
.mc-chinh,.mc-ben{display:flex;flex-direction:column;gap:14px;min-width:0}
.mc-chinh p{font-size:16px;line-height:1.7}
.mc-ben{padding-left:20px;border-left:1px solid var(--vien-mo)}
.mc-muc{display:flex;flex-direction:column;gap:6px;font-size:14.5px;line-height:1.45}
.mc-muc>b{font-size:13px;color:var(--muc-2)}
.mc-ben .nut.chinh{align-self:stretch;height:44px;font-size:14px}
@media (max-width:760px){.mc-than{grid-template-columns:1fr;padding:12px 14px 18px}.mc-ben{padding-left:0;border-left:0;padding-top:12px;border-top:1px solid var(--vien-mo)}.mc-tranh{padding:10px 14px 0}}

/* thẻ truyện Con Rồng cháu Tiên trong khung "Theo truyền thuyết" */
.tt-rong{display:flex;align-items:center;gap:10px;width:100%;margin-top:10px;padding:6px;border:1px solid var(--vien);background:var(--be-mat);cursor:pointer;text-align:left;font:inherit;color:var(--muc)}
.tt-rong:hover{background:var(--doc)}
.tt-rong img{width:72px;height:54px;flex:none;object-fit:cover;border:1px solid var(--vien-mo)}
.tt-rong span{display:flex;flex-direction:column;gap:1px;min-width:0}
.truyen-thuyet-nhan .tt-rong span{margin-top:0}
.tt-rong b{font:700 13.5px 'Noto Serif',serif}
.tt-rong small{font-size:11.5px;color:var(--muc-2)}
.tt-rong i{font-style:normal;font-size:11.5px;font-weight:700;color:var(--gach)}
.ruot-m .tt-rong{flex-direction:column;align-items:stretch;gap:6px}   /* điện thoại: khung hẹp nên tranh ở trên, chữ ở dưới */
.ruot-m .tt-rong img{width:100%;height:auto;aspect-ratio:4/3}

/* màn hình hẹp (điện thoại) dùng giao diện desktop: đầu trang gọn, bảng "Cùng lúc ấy" phủ toàn màn */
@media (max-width:760px){
  #app .dau{gap:8px;padding:0 10px}
  .dau .phu-de{display:none}
  .dau .ten-trang{font-size:16px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
  .dau>div:has(>.ten-trang){flex:1;min-width:0}
  .dau>div[style*="flex:1"]{display:none}
  .dau .tim{width:96px;flex:none}
  .dau .tim input{padding:0 8px;font-size:13px}
  .dau .nut{width:44px;height:44px;padding:0;font-size:18px}
  #b-auto{min-width:0}
  .dau .ket-qua{position:fixed;top:66px;left:8px;right:8px}
  #bang{width:100%!important;left:0}
  .phu-de-doc{left:8px!important;right:8px!important;bottom:16px}
  .tt-trong{display:none}
}