:root{
  --bg:#f6f7f4; --card:#ffffff; --ink:#16231f; --muted:#5b6b66; --line:#dfe5e1;
  --accent:#0f766e; --accent-ink:#ffffff; --accent-soft:#d9f0ec;
  --warm:#b45309; --warm-soft:#fdf0d9;
  --q1:#fde4e1; --q2:#d9f0ec; --q3:#fdf0d9; --q4:#e8e8ee;
  --c-lop:#cfe3fb; --c-tuhoc:#cdeedd; --c-sinhhoat:#fde7c2; --c-nghi:#e5dbf5;
  --radius:14px; --shadow:0 1px 2px rgba(20,40,35,.06),0 6px 20px rgba(20,40,35,.06);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0e1614; --card:#16211e; --ink:#e8efec; --muted:#9bb0a9; --line:#26362f;
    --accent:#2dd4bf; --accent-ink:#06201c; --accent-soft:#12332e;
    --warm:#fbbf24; --warm-soft:#33280f;
    --q1:#3a1d1a; --q2:#12332e; --q3:#33280f; --q4:#23232d;
    --c-lop:#1c3552; --c-tuhoc:#16382a; --c-sinhhoat:#3d2f12; --c-nghi:#2e2444;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 6px 20px rgba(0,0,0,.3);
  }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;-webkit-text-size-adjust:100%}
.wrap{max-width:1080px;margin:0 auto;padding:0 16px}
a{color:var(--accent)}
h1,h2,h3{line-height:1.25;margin:0 0 .5em}
h1{font-size:clamp(1.9rem,5vw,2.8rem);letter-spacing:-.02em}
h2{font-size:1.5rem}
h3{font-size:1.15rem}
p{margin:0 0 1em}
.muted{color:var(--muted)}
.skip{position:absolute;left:-999px;top:0;background:var(--accent);color:var(--accent-ink);padding:8px 12px;z-index:50}
.skip:focus{left:8px;top:8px}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:6px}

/* header */
.top{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.bar{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:58px;flex-wrap:wrap;padding-top:6px;padding-bottom:6px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;color:var(--ink);text-decoration:none}
.logo{display:grid;place-items:center;width:34px;height:34px;border-radius:10px;background:var(--accent-soft);font-size:1.2rem}
nav{display:flex;gap:4px;flex-wrap:wrap}
nav a{padding:8px 12px;border-radius:999px;color:var(--muted);text-decoration:none;font-weight:600;font-size:.95rem}
nav a:hover{background:var(--accent-soft);color:var(--ink)}
nav a.on{background:var(--accent);color:var(--accent-ink)}

main{padding-top:28px;padding-bottom:56px;min-height:70vh;outline:none}
.foot{border-top:1px solid var(--line);padding:22px 0;font-size:.9rem;color:var(--muted)}
.foot p{margin:0 0 4px}

/* hero */
.hero{padding:32px 0 8px}
.eyebrow{display:inline-block;font-weight:700;font-size:.8rem;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);margin-bottom:10px}
.hero p.lead{font-size:1.15rem;color:var(--muted);max-width:60ch}
.quote{margin:22px 0 0;padding:18px 20px;border-left:4px solid var(--accent);background:var(--card);border-radius:0 var(--radius) var(--radius) 0;box-shadow:var(--shadow);font-size:1.1rem}
.quote cite{display:block;margin-top:6px;font-size:.85rem;color:var(--muted);font-style:normal}
.cta{display:flex;gap:10px;flex-wrap:wrap;margin-top:20px}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);background:var(--card);color:var(--ink);padding:9px 16px;border-radius:999px;font:inherit;font-weight:600;cursor:pointer;text-decoration:none;min-height:42px}
.btn:hover{border-color:var(--accent)}
.btn.pri{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}
.btn.sm{padding:4px 10px;min-height:32px;font-size:.85rem}
.btn.ghost{background:transparent}

/* sections + cards */
.sec{margin-top:44px}
.sec>h2{display:flex;align-items:baseline;justify-content:space-between;gap:12px}
.sec>h2 a{font-size:.9rem;font-weight:600}
.grid{display:grid;gap:14px;grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
a.card{display:block;color:inherit;text-decoration:none;transition:transform .15s,border-color .15s}
a.card:hover{transform:translateY(-2px);border-color:var(--accent)}
.card .ic{font-size:1.6rem;display:block;margin-bottom:6px}
.card h3{margin-bottom:.3em}
.card p{margin:0;color:var(--muted);font-size:.95rem}
.tag{display:inline-block;font-size:.75rem;font-weight:700;padding:2px 9px;border-radius:999px;background:var(--accent-soft);color:var(--accent);margin-bottom:8px}

.cycle{display:grid;gap:10px;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));counter-reset:c}
.cycle div{counter-increment:c;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px;position:relative}
.cycle div::before{content:counter(c);display:inline-grid;place-items:center;width:26px;height:26px;border-radius:50%;background:var(--accent);color:var(--accent-ink);font-weight:700;font-size:.85rem;margin-bottom:6px}
.cycle b{display:block}
.cycle span{font-size:.9rem;color:var(--muted)}

/* filter chips */
.chips{display:flex;gap:8px;flex-wrap:wrap;margin:12px 0 18px}
.chip{border:1px solid var(--line);background:var(--card);color:var(--ink);padding:6px 14px;border-radius:999px;font:inherit;font-size:.9rem;font-weight:600;cursor:pointer}
.chip[aria-pressed="true"]{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}

/* article */
.crumb{font-size:.9rem;margin-bottom:14px}
.article{max-width:74ch}
.article h1{margin-bottom:.3em}
.article h2{margin-top:1.6em;font-size:1.3rem}
.article ul,.article ol{padding-left:1.3em;margin:0 0 1em}
.article li{margin-bottom:.4em}
.callout{background:var(--warm-soft);border-left:4px solid var(--warm);padding:12px 16px;border-radius:0 10px 10px 0;margin:1.2em 0}
.callout.ok{background:var(--accent-soft);border-color:var(--accent)}
.pager{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;margin-top:34px}
.table-wrap{overflow-x:auto;margin:0 0 1em}
table.t{border-collapse:collapse;width:100%;min-width:480px;font-size:.95rem}
table.t th,table.t td{border:1px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}
table.t th{background:var(--accent-soft)}

/* tools */
.tool{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
.row{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-bottom:12px}
.row input[type=text],.row input[type=number],.row input[type=date],.row select,.inp{font:inherit;padding:8px 12px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--ink);min-height:42px}
.row input[type=text]{flex:1 1 200px;min-width:0}
.row label{display:flex;align-items:center;gap:6px;font-size:.95rem}
.row input[type=checkbox]{width:18px;height:18px;accent-color:var(--accent)}
.hint{font-size:.9rem;color:var(--muted)}

.matrix{display:grid;grid-template-columns:auto 1fr 1fr;gap:8px}
.matrix .ax{display:grid;place-items:center;text-align:center;font-size:.8rem;font-weight:700;color:var(--muted)}
.matrix .ax.v{writing-mode:vertical-rl;transform:rotate(180deg)}
.q{border-radius:12px;padding:12px;min-height:170px;border:1px solid var(--line)}
.q h4{margin:0 0 2px;font-size:.95rem}
.q small{display:block;color:var(--muted);margin-bottom:8px}
.q1{background:var(--q1)}.q2{background:var(--q2)}.q3{background:var(--q3)}.q4{background:var(--q4)}
.item{display:flex;align-items:center;gap:6px;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:5px 6px 5px 10px;margin-bottom:6px;font-size:.92rem}
.item span{flex:1;min-width:0;overflow-wrap:anywhere}
.item.done span{text-decoration:line-through;color:var(--muted)}
.item select{font:inherit;font-size:.8rem;border:1px solid var(--line);border-radius:8px;background:var(--bg);color:var(--ink);padding:2px;max-width:64px}
.ibtn{border:0;background:transparent;color:var(--muted);cursor:pointer;font-size:1rem;padding:4px 6px;border-radius:6px;min-width:30px;min-height:30px}
.ibtn:hover{background:var(--accent-soft);color:var(--ink)}
.meter{height:10px;border-radius:99px;background:var(--line);overflow:hidden;margin:6px 0}
.meter i{display:block;height:100%;background:var(--accent);width:0;transition:width .3s}

.pomo{display:grid;place-items:center;text-align:center;padding:10px 0}
.ring{position:relative;width:min(260px,70vw);aspect-ratio:1}
.ring svg{width:100%;height:100%;transform:rotate(-90deg)}
.ring circle{fill:none;stroke-width:10}
.ring .bg{stroke:var(--line)}
.ring .fg{stroke:var(--accent);stroke-linecap:round;transition:stroke-dashoffset .25s linear}
.ring.brk .fg{stroke:var(--warm)}
.ring .time{position:absolute;inset:0;display:grid;place-content:center;font-size:2.8rem;font-weight:700;font-variant-numeric:tabular-nums}
.ring .time small{font-size:.9rem;font-weight:600;color:var(--muted)}

.step{display:flex;gap:8px;align-items:center;padding:8px 0;border-bottom:1px dashed var(--line)}
.step input[type=checkbox]{width:20px;height:20px;accent-color:var(--accent);flex:none}
.step .d{flex:none;font-weight:700;color:var(--accent);min-width:56px;font-size:.9rem}
.step .tx{flex:1;min-width:0;overflow-wrap:anywhere}
.step.done .tx{text-decoration:line-through;color:var(--muted)}
.step .m{flex:none;font-size:.85rem;color:var(--muted)}

.sched{overflow-x:auto}
.sched table{border-collapse:separate;border-spacing:3px;min-width:560px;width:100%}
.sched th{font-size:.8rem;color:var(--muted);font-weight:700;padding:4px}
.sched td.h{font-size:.78rem;color:var(--muted);text-align:right;padding-right:6px;white-space:nowrap}
.cell{height:28px;border-radius:6px;border:1px solid var(--line);background:var(--bg);cursor:pointer;width:100%;padding:0;font-size:.7rem;color:var(--ink)}
.cell.lop{background:var(--c-lop)}.cell.tuhoc{background:var(--c-tuhoc)}.cell.sinhhoat{background:var(--c-sinhhoat)}.cell.nghi{background:var(--c-nghi)}
.legend{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0}
.legend button{display:flex;align-items:center;gap:6px;border:2px solid transparent;border-radius:999px;padding:4px 12px;font:inherit;font-size:.85rem;cursor:pointer;color:var(--ink);background:var(--bg)}
.legend button[aria-pressed="true"]{border-color:var(--accent)}
.legend i{width:14px;height:14px;border-radius:4px;border:1px solid var(--line);display:inline-block}
.sum{display:flex;gap:14px;flex-wrap:wrap;font-size:.9rem;margin-top:8px}

.weeks .w{display:grid;grid-template-columns:70px 1fr;gap:10px;padding:10px 0;border-bottom:1px dashed var(--line);align-items:start}
.weeks .w b{color:var(--accent)}
.ev{display:inline-flex;align-items:center;gap:4px;border-radius:999px;padding:3px 4px 3px 10px;margin:0 6px 6px 0;font-size:.88rem;border:1px solid var(--line);background:var(--bg)}
.ev.thi{background:var(--q1)}.ev.deadline{background:var(--q3)}.ev.dean{background:var(--q2)}

.people{display:grid;gap:10px;grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}
.people .card h3{margin-bottom:2px}
.people .card small{color:var(--accent);font-weight:700}

@media (max-width:620px){
  main{padding-top:18px}
  .matrix{grid-template-columns:1fr 1fr}
  .matrix .ax.v{display:none}
  .matrix .ax.corner{display:none}
  .q{min-height:130px}
  .weeks .w{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
@media print{.top,.foot,.cta,.pager,.row,.legend{display:none!important}body{background:#fff;color:#000}.card,.tool{box-shadow:none}}
/* OCEAN-START: chủ đề đại dương, ghi đè biến màu ở trên (xoá khối này để về giao diện cũ) */
:root{
  --bg:#f2fafd; --card:#ffffff; --ink:#0f2a3d; --muted:#4f6b7d; --line:#d3e6ef;
  --accent:#0e6fa8; --accent-ink:#ffffff; --accent-soft:#dff1fa;
  --q2:#dff1fa;
  --grad:linear-gradient(135deg,#1f8cc0,#0b4f86);
  --sea-top:#cdeefa;
  --shadow:0 1px 2px rgba(11,79,134,.08),0 8px 24px rgba(11,79,134,.10);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#061a2b; --card:#0c2740; --ink:#e6f4fc; --muted:#8fb4cb; --line:#1b3f5c;
    --accent:#5cc8f0; --accent-ink:#04172e; --accent-soft:#0f3552;
    --q2:#0f3552;
    --grad:linear-gradient(135deg,#8fe0ee,#3aa9d6);
    --sea-top:#0b3a5c;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35);
  }
}
body{background:linear-gradient(180deg,var(--sea-top) 0,var(--bg) 460px) no-repeat,var(--bg)}
.btn.pri,nav a.on,.chip[aria-pressed="true"],.cycle div::before{background:var(--grad);border-color:transparent}
.logo{background:var(--grad);color:#fff}
a.card:hover{box-shadow:0 0 0 2px var(--accent),var(--shadow)}
.card,.tool,.cycle div{border-radius:18px}
.meter i{background:var(--grad)}
.hero{position:relative;overflow:hidden;border-radius:24px;padding:32px 24px 56px;background:linear-gradient(135deg,var(--accent-soft),transparent 75%)}
.hero::after{content:"";position:absolute;left:0;right:0;bottom:0;height:40px;pointer-events:none;
  background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 800 40' preserveAspectRatio='none'%3E%3Cpath d='M0 20 Q100 0 200 20 T400 20 T600 20 T800 20 V40 H0Z' fill='%230e6fa8' fill-opacity='.16'/%3E%3C/svg%3E") repeat-x 0 0/800px 40px;
  animation:songbien 16s linear infinite}
@keyframes songbien{to{background-position-x:-800px}}
@media (prefers-reduced-motion:reduce){.hero::after{animation:none}}
/* OCEAN-END */

/* ===== Đại dương 3D (js/dai-duong.js) ===== */
.ocean{margin-top:28px}
.oc-stage{position:relative;width:100%;aspect-ratio:16/9;max-height:80vh;border-radius:24px;overflow:hidden;border:1px solid #0b4a73;touch-action:pan-y;user-select:none;-webkit-user-select:none;
  background:radial-gradient(120% 90% at 50% 0%,#2bb8d6 0%,#0c6fa0 38%,#053a66 70%,#021a38 100%);box-shadow:var(--shadow)}
.oc-stage canvas{outline:none}
.oc-stage .vr-open{position:absolute;right:12px;top:12px;z-index:5}
.oc-bar{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin:14px 0 4px}
.oc-bar .muted{flex:1 1 260px;font-size:.92rem;margin:0}
.oc-chips .chip{text-decoration:none}
.vr-host .oc-stage{max-height:none!important;aspect-ratio:auto!important;touch-action:none}
@media (max-width:640px){.oc-stage{aspect-ratio:1/1.05;border-radius:18px}}