/* ===================== GOC HOC CUA BE ===================== */
:root {
    --nen: #fff8ec;
    --chu: #3b3355;
    --chu-nhat: #7a7393;
    --tim: #7c5cff;
    --hong: #ff6fa5;
    --cam: #ff9f43;
    --vang: #ffd23f;
    --xanh: #2ec4b6;
    --xanh-duong: #4ea8ff;
    --do: #ff5a5f;
    --trang: #ffffff;
    --bong: 0 6px 0 rgba(59, 51, 85, .12), 0 10px 24px rgba(59, 51, 85, .08);
    --bo: 22px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: 'Nunito', system-ui, sans-serif;
    color: var(--chu);
    background: var(--nen);
    background-image:
        radial-gradient(circle at 10% 20%, rgba(255, 210, 63, .25) 0 60px, transparent 61px),
        radial-gradient(circle at 90% 10%, rgba(78, 168, 255, .18) 0 90px, transparent 91px),
        radial-gradient(circle at 85% 85%, rgba(255, 111, 165, .15) 0 110px, transparent 111px);
    background-attachment: fixed;
    min-height: 100vh;
}

h1, h2, h3, .logo, button, .nut { font-family: 'Baloo 2', 'Nunito', sans-serif; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; }

/* ---------- Thanh tren ---------- */
.thanh-tren {
    position: sticky; top: 0; z-index: 10;
    display: flex; align-items: center; justify-content: space-between; gap: 8px;
    padding: 10px 16px;
    background: rgba(255, 255, 255, .9);
    backdrop-filter: blur(6px);
    box-shadow: 0 2px 12px rgba(59, 51, 85, .08);
}
.logo { font-size: 1.5rem; font-weight: 800; color: var(--tim); white-space: nowrap; }
.thanh-phai { display: flex; align-items: center; gap: 8px; }
.nut-tron {
    width: 44px; height: 44px; border-radius: 50%;
    display: grid; place-items: center; font-size: 1.4rem;
    background: #fff3c4;
}
.the-be {
    display: flex; align-items: center; gap: 6px;
    padding: 4px 12px 4px 4px; border-radius: 999px;
    background: #efe9ff; font-weight: 800;
}
.the-be:empty { display: none; }
.the-be .anh { width: 36px; height: 36px; border-radius: 50%; background: #fff; display: grid; place-items: center; font-size: 1.4rem; overflow: hidden; }
.the-be .anh img { width: 100%; height: 100%; object-fit: cover; }
.the-be .sao { color: #d48a00; }
.nut-bo-me { font-size: .85rem; color: var(--chu-nhat); padding: 6px 10px; border-radius: 12px; }
.nut-bo-me:hover { background: #eee; }

@media (max-width: 600px) {
    .logo span, .nut-bo-me { display: none; }
}

.noi-dung { max-width: 1100px; margin: 0 auto; padding: 20px 16px 120px; }
.dang-tai { text-align: center; font-size: 1.5rem; padding: 80px 0; color: var(--chu-nhat); }

/* ---------- Tieu de & nut ---------- */
.chao { font-size: clamp(1.8rem, 5vw, 2.6rem); margin: 8px 0 4px; }
.phu-de { color: var(--chu-nhat); margin: 0 0 20px; font-size: 1.1rem; }
.dong-tieu-de { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; flex-wrap: wrap; }
.dong-tieu-de h1 { margin: 0; font-size: clamp(1.6rem, 4.5vw, 2.3rem); }
.dong-tieu-de h1 img { height: 1.2em; vertical-align: middle; }

.nut {
    border: 0; cursor: pointer;
    font-size: 1.15rem; font-weight: 700;
    padding: 12px 22px; border-radius: 18px;
    background: var(--tim); color: #fff;
    box-shadow: 0 5px 0 rgba(0, 0, 0, .18);
    transition: transform .08s, box-shadow .08s;
    display: inline-flex; align-items: center; gap: 8px; justify-content: center;
}
.nut:active { transform: translateY(4px); box-shadow: 0 1px 0 rgba(0, 0, 0, .18); }
.nut:disabled { opacity: .5; cursor: default; }
.nut.phu { background: #fff; color: var(--chu); box-shadow: 0 5px 0 #e3dcef; }
.nut.xanh { background: var(--xanh); }
.nut.cam { background: var(--cam); }
.nut.hong { background: var(--hong); }
.nut.to { font-size: 1.4rem; padding: 16px 30px; }
.nut-quay-lai {
    width: 48px; height: 48px; border-radius: 50%; border: 0; cursor: pointer;
    background: #fff; box-shadow: var(--bong); font-size: 1.4rem;
}

/* ---------- Tab lop ---------- */
.tab-lop { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 20px; }
.tab-lop a {
    padding: 8px 18px; border-radius: 999px; background: #fff; font-weight: 800;
    box-shadow: 0 3px 0 #e3dcef;
}
.tab-lop a.chon { background: var(--tim); color: #fff; box-shadow: 0 3px 0 #5a3fd6; }

/* ---------- Luoi the ---------- */
.luoi { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 18px; }
.the {
    background: var(--trang); border-radius: var(--bo); box-shadow: var(--bong);
    padding: 18px; cursor: pointer; position: relative;
    transition: transform .15s;
    display: flex; flex-direction: column; gap: 6px;
}
.the:hover { transform: translateY(-4px) rotate(-.5deg); }
.the .hinh-the { height: 110px; display: grid; place-items: center; border-radius: 16px; margin-bottom: 6px; overflow: hidden; }
.the .hinh-the img { max-height: 110px; object-fit: contain; }
.the .hinh-the .emoji { font-size: 4.2rem; line-height: 1; }
.the h3 { margin: 0; font-size: 1.45rem; line-height: 1.1; }
.the .vi { color: var(--chu-nhat); font-weight: 700; }
.the .xong { position: absolute; top: 12px; right: 12px; font-size: 1.6rem; }
.mau-0 .hinh-the { background: #ffe3ee; } .mau-1 .hinh-the { background: #e0f4ff; }
.mau-2 .hinh-the { background: #fff1c9; } .mau-3 .hinh-the { background: #dcf8f4; }
.mau-4 .hinh-the { background: #ece6ff; } .mau-5 .hinh-the { background: #ffe8d6; }

.thanh-tien-do { height: 10px; background: #eee8f7; border-radius: 99px; overflow: hidden; margin-top: 6px; }
.thanh-tien-do > div { height: 100%; background: linear-gradient(90deg, var(--xanh), var(--xanh-duong)); border-radius: 99px; }

.danh-sach-bai { display: grid; gap: 14px; }
.bai {
    display: flex; align-items: center; gap: 16px;
    background: #fff; border-radius: var(--bo); box-shadow: var(--bong); padding: 16px 20px; cursor: pointer;
}
.bai:hover { transform: translateY(-2px); }
.bai .so {
    flex: none; width: 56px; height: 56px; border-radius: 18px; display: grid; place-items: center;
    background: var(--vang); font: 800 1.6rem 'Baloo 2', sans-serif;
}
.bai.da-xong .so { background: var(--xanh); color: #fff; }
.bai h3 { margin: 0; font-size: 1.3rem; }
.bai .mo-ta { color: var(--chu-nhat); font-size: .95rem; }
.bai .mui-ten { margin-left: auto; font-size: 1.6rem; }

/* ---------- Chon be ---------- */
.chon-be { display: flex; flex-wrap: wrap; justify-content: center; gap: 24px; margin-top: 30px; }
.chon-be .the { width: 220px; align-items: center; text-align: center; }
.chon-be .anh-be { width: 120px; height: 120px; border-radius: 50%; background: #fff3c4; display: grid; place-items: center; font-size: 4rem; overflow: hidden; }
.chon-be .anh-be img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- Bai hoc / the tu ---------- */
.gioi-thieu { background: #fff; border-radius: var(--bo); padding: 16px 20px; box-shadow: var(--bong); margin-bottom: 18px; font-size: 1.1rem; }
.video { position: relative; padding-top: 56.25%; border-radius: var(--bo); overflow: hidden; margin-bottom: 18px; box-shadow: var(--bong); }
.video iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }

.tab-che-do { display: inline-flex; background: #fff; border-radius: 999px; padding: 5px; box-shadow: var(--bong); margin-bottom: 20px; flex-wrap: wrap; }
.tab-che-do button {
    border: 0; background: transparent; cursor: pointer; padding: 10px 18px; border-radius: 999px;
    font: 700 1.05rem 'Baloo 2', sans-serif; color: var(--chu);
}
.tab-che-do button.chon { background: var(--hong); color: #fff; }

.khung-the-tu { max-width: 560px; margin: 0 auto; text-align: center; }
.the-tu {
    background: #fff; border-radius: 30px; box-shadow: var(--bong); padding: 26px 22px;
    border: 6px solid #ffe3ee; animation: hien .35s ease;
}
@keyframes hien { from { transform: scale(.9) rotate(-2deg); opacity: 0; } to { transform: none; opacity: 1; } }
.the-tu .hinh-lon { height: 200px; display: grid; place-items: center; cursor: pointer; }
.the-tu .hinh-lon img { max-height: 200px; border-radius: 18px; }
.the-tu .hinh-lon .emoji { font-size: 9rem; line-height: 1; }
.the-tu .tu { font: 800 clamp(2.6rem, 9vw, 3.6rem) 'Baloo 2', sans-serif; color: var(--tim); margin: 8px 0 0; cursor: pointer; line-height: 1.1; }
.the-tu .phien-am { color: var(--chu-nhat); font-size: 1.2rem; }
.the-tu .nghia { font-size: 1.6rem; font-weight: 800; color: var(--hong); margin-top: 6px; }
.the-tu .vi-du { margin-top: 14px; background: #f6f2ff; border-radius: 16px; padding: 10px 14px; cursor: pointer; }
.the-tu .vi-du .en { font-weight: 800; font-size: 1.15rem; }
.the-tu .vi-du .vi { color: var(--chu-nhat); }
.dieu-khien { display: flex; justify-content: center; gap: 10px; margin-top: 18px; flex-wrap: wrap; }
.dieu-khien .nut { min-width: 64px; }
.cham-tien-do { display: flex; justify-content: center; gap: 6px; margin-top: 16px; flex-wrap: wrap; }
.cham-tien-do span { width: 12px; height: 12px; border-radius: 50%; background: #e3dcef; }
.cham-tien-do span.chon { background: var(--hong); transform: scale(1.3); }
.ket-qua-noi { min-height: 28px; margin-top: 10px; font-weight: 800; font-size: 1.15rem; }
.ket-qua-noi.dung { color: #109c8f; } .ket-qua-noi.sai { color: var(--do); }

.luoi-tu { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 14px; }
.o-tu { background: #fff; border-radius: 20px; box-shadow: var(--bong); padding: 14px; text-align: center; cursor: pointer; }
.o-tu .emoji { font-size: 3.4rem; }
.o-tu img { height: 80px; object-fit: contain; }
.o-tu b { display: block; font: 800 1.4rem 'Baloo 2', sans-serif; color: var(--tim); }
.o-tu small { color: var(--chu-nhat); font-weight: 700; }

.sao-nho { color: #f5b400; letter-spacing: 2px; }
.sao-nho .tat { color: #ddd; }

/* ---------- Luyen tap ---------- */
.khung-cau { max-width: 720px; margin: 0 auto; }
.dau-cau { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.dau-cau .thanh-tien-do { flex: 1; height: 16px; margin: 0; }
.dau-cau .thanh-tien-do > div { background: linear-gradient(90deg, var(--vang), var(--cam)); transition: width .3s; }
.cau-hoi { background: #fff; border-radius: 28px; box-shadow: var(--bong); padding: 24px; text-align: center; animation: hien .3s ease; }
.cau-hoi .de { font: 800 clamp(1.4rem, 4.5vw, 2rem) 'Baloo 2', sans-serif; margin: 0 0 12px; }
.cau-hoi .hinh-cau { height: 170px; display: grid; place-items: center; margin-bottom: 10px; }
.cau-hoi .hinh-cau img { max-height: 170px; border-radius: 16px; }
.cau-hoi .hinh-cau .emoji { font-size: 7rem; }
.nut-loa {
    width: 110px; height: 110px; border-radius: 50%; border: 0; cursor: pointer; font-size: 3.4rem;
    background: var(--xanh-duong); color: #fff; box-shadow: 0 6px 0 #2a7fd6; margin: 6px auto 16px; display: grid; place-items: center;
    animation: dap 1.6s infinite;
}
@keyframes dap { 50% { transform: scale(1.06); } }
.nut-loa.nho { width: 48px; height: 48px; font-size: 1.4rem; box-shadow: 0 3px 0 #2a7fd6; animation: none; display: inline-grid; margin: 0 0 0 8px; vertical-align: middle; }

.cac-lua-chon { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; margin-top: 12px; }
.lua-chon {
    border: 3px solid #e3dcef; background: #fff; border-radius: 20px; cursor: pointer;
    padding: 16px; font: 700 1.35rem 'Baloo 2', sans-serif; color: var(--chu);
    box-shadow: 0 4px 0 #e3dcef; transition: transform .1s;
}
.lua-chon:hover { transform: translateY(-2px); border-color: var(--tim); }
.lua-chon .emoji { font-size: 4rem; display: block; }
.lua-chon img { height: 110px; object-fit: contain; display: block; margin: 0 auto; }
.lua-chon.dung { background: #dcf8f4; border-color: var(--xanh); box-shadow: 0 4px 0 var(--xanh); }
.lua-chon.sai { background: #ffe1e2; border-color: var(--do); box-shadow: 0 4px 0 var(--do); animation: lac .35s; }
@keyframes lac { 25% { transform: translateX(-8px); } 75% { transform: translateX(8px); } }

.o-nhap {
    width: 100%; max-width: 360px; font: 800 1.8rem 'Baloo 2', sans-serif; text-align: center;
    padding: 10px 14px; border-radius: 18px; border: 3px solid #e3dcef; outline: none; color: var(--tim);
}
.o-nhap:focus { border-color: var(--tim); }

.hang-sap-xep { min-height: 70px; display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; align-items: center;
    border: 3px dashed #e3dcef; border-radius: 18px; padding: 10px; margin: 10px 0; }
.manh-tu {
    border: 0; cursor: pointer; padding: 10px 16px; border-radius: 14px; background: var(--vang);
    font: 800 1.3rem 'Baloo 2', sans-serif; color: var(--chu); box-shadow: 0 4px 0 #d9ab00;
}
.hang-sap-xep .manh-tu { background: #efe9ff; box-shadow: 0 4px 0 #cfc3ff; }

.phan-hoi {
    position: fixed; left: 0; right: 0; bottom: 0; z-index: 20;
    padding: 18px 16px 24px; display: flex; justify-content: center;
    transform: translateY(110%); transition: transform .25s;
}
.phan-hoi.hien { transform: none; }
.phan-hoi .ben-trong { max-width: 720px; width: 100%; display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.phan-hoi.dung { background: #d7f7f2; } .phan-hoi.sai { background: #ffe1e2; }
.phan-hoi .loi-nhan { flex: 1; font: 800 1.5rem 'Baloo 2', sans-serif; min-width: 200px; }
.phan-hoi .loi-nhan small { display: block; font: 700 1.05rem 'Nunito', sans-serif; }

.ket-qua { text-align: center; background: #fff; border-radius: 30px; box-shadow: var(--bong); padding: 30px 20px; max-width: 560px; margin: 0 auto; animation: hien .4s; }
.ket-qua .sao-lon { font-size: 4.2rem; letter-spacing: 6px; }
.ket-qua .sao-lon .tat { filter: grayscale(1); opacity: .3; }
.ket-qua h2 { font-size: 2.2rem; margin: 6px 0; }

/* ---------- Huy hieu ---------- */
.luoi-huy-hieu { display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 16px; }
.huy-hieu { background: #fff; border-radius: var(--bo); box-shadow: var(--bong); padding: 18px; text-align: center; }
.huy-hieu .emoji { font-size: 4rem; }
.huy-hieu img { height: 90px; }
.huy-hieu.khoa { filter: grayscale(1); opacity: .55; }
.huy-hieu b { display: block; font: 800 1.2rem 'Baloo 2', sans-serif; }

/* ---------- Thong bao & phao hoa ---------- */
.thong-bao {
    position: fixed; top: 76px; left: 50%; transform: translate(-50%, -150%); z-index: 30;
    background: var(--chu); color: #fff; padding: 12px 22px; border-radius: 16px; font-weight: 800;
    transition: transform .3s, opacity .3s; max-width: 90vw; text-align: center;
    opacity: 0; pointer-events: none;
}
.thong-bao.hien { transform: translate(-50%, 0); opacity: 1; }
.phao-hoa { position: fixed; top: -40px; font-size: 2rem; z-index: 40; pointer-events: none; animation: roi linear forwards; }
@keyframes roi { to { transform: translateY(110vh) rotate(540deg); } }

.trong { text-align: center; padding: 50px 20px; color: var(--chu-nhat); font-size: 1.2rem; }
.trong .emoji { font-size: 5rem; display: block; }

/* ===================== 4 KY NANG ===================== */
.bang-game {
    display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
    background: linear-gradient(120deg, #2ec4b6, #4ea8ff); color: #fff;
    border-radius: var(--bo); padding: 16px 20px; margin-bottom: 20px; box-shadow: var(--bong);
}
.bang-game .to { font-size: 3rem; }
.bang-game > span:nth-child(2) { flex: 1; min-width: 200px; font-size: 1.05rem; }
.bang-game b { font: 800 1.4rem 'Baloo 2', sans-serif; }
.tieu-de-ky-nang { margin: 22px 0 10px; font-size: 1.5rem; }
.dong-ho { font: 800 1.3rem 'Baloo 2', sans-serif; background: #fff; padding: 4px 12px; border-radius: 12px; box-shadow: 0 3px 0 #e3dcef; }
.dong-ho.gap { background: var(--do); color: #fff; animation: dap .6s infinite; }
.bai-doc, .bai-nghe { background: #fff; border-radius: 20px; box-shadow: var(--bong); padding: 14px 18px; margin-bottom: 14px; font-size: 1.2rem; line-height: 1.7; }
.bai-doc summary { font: 800 1.2rem 'Baloo 2', sans-serif; cursor: pointer; }
.bai-nghe { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; justify-content: center; }
.cau-noi { font: 800 clamp(1.6rem, 6vw, 2.4rem) 'Baloo 2', sans-serif; color: var(--tim); margin: 10px 0; line-height: 1.3; }
.cau-noi .tu-dung { color: #109c8f; }
.cau-noi .tu-sai { color: var(--do); text-decoration: underline wavy; }
.o-viet { max-width: 560px; font-size: 1.5rem; resize: vertical; text-align: left; }
.chip { display: inline-block; background: #efe9ff; border-radius: 999px; padding: 4px 12px; margin: 2px; font-weight: 800; }
.lac { animation: lac .35s; }

/* ===================== TRO CHOI ===================== */
.ban-do { position: relative; max-width: 640px; margin: 10px auto 40px; padding: 10px 0 30px; }
.ban-do::before { content: ''; position: absolute; left: 50%; top: 0; bottom: 0; border-left: 6px dashed #f2c66d; transform: translateX(-50%); z-index: 0; }
.cap {
    position: relative; z-index: 1; width: 140px; margin-bottom: 18px;
    display: flex; flex-direction: column; align-items: center; text-align: center;
    background: #fff; border-radius: 24px; padding: 10px 8px; box-shadow: var(--bong); cursor: pointer;
}
.cap .so-cap { font-size: 2.4rem; line-height: 1.1; }
.cap b { font: 800 1.15rem 'Baloo 2', sans-serif; }
.cap small { color: var(--chu-nhat); font-weight: 700; line-height: 1.2; }
.cap.qua { background: #dcf8f4; }
.cap.khoa { filter: grayscale(1); opacity: .55; cursor: default; }
.cap.hien-tai { outline: 4px solid var(--cam); animation: dap 1.2s infinite; }
.kho-bau { text-align: center; font-size: 4rem; }

.khung-game { max-width: 820px; margin: 0 auto; }
.thanh-game { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; flex-wrap: wrap; }
.thanh-game b { font: 800 1.3rem 'Baloo 2', sans-serif; }
.thong-tin-game { margin-left: auto; background: #fff; border-radius: 14px; padding: 6px 14px; font-weight: 800; box-shadow: 0 3px 0 #e3dcef; }

/* Bong bay */
.troi { position: relative; height: min(62vh, 520px); overflow: hidden; border-radius: 26px;
    background: linear-gradient(#bfe6ff, #eaf7ff 70%, #d8f5d0); box-shadow: var(--bong); }
.bong { position: absolute; bottom: -170px; transform: translateX(-50%); border: 0; background: none; cursor: pointer; padding: 0;
    animation-name: bay; animation-timing-function: linear; animation-fill-mode: forwards; }
.bong.no { animation-play-state: paused; pointer-events: none; }
@keyframes bay { to { bottom: 105%; } }
.bong .ruot {
    position: relative; width: 112px; height: 132px; border-radius: 50% 50% 46% 46%; display: grid; place-items: center;
    background: radial-gradient(circle at 32% 28%, rgba(255,255,255,.7) 0 10%, transparent 11%), var(--mau);
    box-shadow: inset -8px -10px 0 rgba(0,0,0,.08);
}
.bong .ruot::after { content: ''; position: absolute; bottom: -34px; left: 50%; width: 2px; height: 34px; background: #9a9a9a; }
.bong .ruot .emoji { font-size: 3.2rem; }
.bong .ruot img { max-width: 76px; max-height: 76px; }
.bong .ruot b { font: 800 1.2rem 'Baloo 2', sans-serif; color: #fff; text-shadow: 0 2px 0 rgba(0,0,0,.25); padding: 0 6px; word-break: break-word; }
.bong.no .ruot { animation: no .45s forwards; }
@keyframes no { 50% { transform: scale(1.35); } to { transform: scale(0); opacity: 0; } }

/* Lat the */
.luoi-the { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.the-lat { height: 118px; border: 0; border-radius: 18px; cursor: pointer; background: var(--tim); color: #fff;
    box-shadow: 0 5px 0 #5a3fd6; font-size: 2.4rem; transition: transform .25s; padding: 6px; }
.the-lat .mat-truoc { display: none; }
.the-lat.lat, .the-lat.xong { background: #fff; color: var(--chu); box-shadow: 0 5px 0 #e3dcef; transform: rotateY(360deg); }
.the-lat.lat .mat-sau, .the-lat.xong .mat-sau { display: none; }
.the-lat.lat .mat-truoc, .the-lat.xong .mat-truoc { display: block; }
.the-lat.xong { background: #dcf8f4; box-shadow: 0 5px 0 var(--xanh); cursor: default; }
.the-lat b { font: 800 1.35rem 'Baloo 2', sans-serif; color: var(--tim); word-break: break-word; }
.the-lat small { font-size: 1rem; font-weight: 800; }
.the-lat .emoji { font-size: 3rem; }
.the-lat img { max-height: 90px; }
@media (max-width: 600px) { .the-lat { height: 92px; } .the-lat b { font-size: 1.05rem; } .the-lat .emoji { font-size: 2.3rem; } }

/* Danh van */
.o-chu-dien { display: flex; justify-content: center; gap: 6px; flex-wrap: wrap; margin: 12px 0; }
.o-trong { width: 46px; height: 56px; border-bottom: 5px solid var(--tim); display: grid; place-items: center;
    font: 800 2rem 'Baloo 2', sans-serif; color: var(--tim); text-transform: lowercase; }
.o-trong.da-dien { animation: hien .25s; }
.khoang { width: 22px; }
.ban-phim { display: flex; justify-content: center; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.phim-chu { width: 54px; height: 58px; border: 0; border-radius: 14px; cursor: pointer; background: var(--vang);
    font: 800 1.7rem 'Baloo 2', sans-serif; color: var(--chu); box-shadow: 0 4px 0 #d9ab00; }
.phim-chu.da-dung { visibility: hidden; }

/* Dua toc do */
.duong-dua { position: relative; height: 64px; background: repeating-linear-gradient(90deg, #555 0 30px, #666 30px 60px);
    border-radius: 16px; margin-bottom: 8px; border-top: 4px dashed #fff; border-bottom: 4px dashed #fff; }
.duong-dua .xe { position: absolute; left: 0; top: 50%; transform: translateY(-50%) scaleX(-1); font-size: 2.6rem; transition: left .4s; }
.duong-dua .dich { position: absolute; right: 8px; top: 50%; transform: translateY(-50%); font-size: 2.4rem; }
.thoi-gian { height: 12px; margin-bottom: 14px; }
.thoi-gian > div { background: linear-gradient(90deg, var(--do), var(--cam)) !important; transition: width 1s linear; }

/* Mua chu */
#oGo { display: block; margin: 0 auto; max-width: 460px; }
.vung-mua { position: relative; height: min(56vh, 460px); overflow: hidden; border-radius: 26px;
    background: linear-gradient(#6c7bd6, #a4b4ff); box-shadow: var(--bong); margin-bottom: 12px; }
.mat-dat { position: absolute; left: 0; right: 0; bottom: 0; height: 40px; background: #7bc96f; text-align: center; font-size: 1.4rem; letter-spacing: 6px; overflow: hidden; }
.giot-chu { position: absolute; top: 0; background: #fff; border-radius: 18px; padding: 6px 12px; text-align: center;
    box-shadow: 0 4px 0 rgba(0,0,0,.15); min-width: 90px; }
.giot-chu .emoji { font-size: 2rem; display: block; line-height: 1.1; }
.giot-chu img { max-height: 40px; display: block; margin: 0 auto; }
.giot-chu b { font: 800 1.25rem 'Baloo 2', sans-serif; color: var(--tim); white-space: nowrap; }
.giot-chu.bat { animation: no .4s forwards; background: #dcf8f4; }
.giot-chu.vo { animation: lac .35s; background: #ffe1e2; }

/* ---------- Toan tieu hoc & Tieng Viet (hoctap.js) ---------- */
.hai-bang { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; margin-bottom: 20px; }
.hai-bang .bang-game { margin-bottom: 0; }
.bang-toan { background: linear-gradient(120deg, #ff9f43, #ffc93c); }
.bang-tv { background: linear-gradient(120deg, #ff6fa5, #7c5cff); }
.luoi-hoc .the h3 { font-size: 1.3rem; }
.hinh-dem { font-size: clamp(2rem, 7vw, 3rem); line-height: 1.3; margin: 4px auto 12px; max-width: 540px; word-break: break-all; letter-spacing: 4px; }
.cau-hoi .de.dai { font-size: clamp(1.15rem, 3.6vw, 1.45rem); text-align: left; line-height: 1.5; }
.ps { display: inline-flex; flex-direction: column; vertical-align: middle; text-align: center; line-height: 1.05; margin: 0 3px; }
.ps > span:first-child { border-bottom: 2px solid currentColor; padding: 0 3px; }
.cac-lua-chon.chu-to .lua-chon { font-size: 2.1rem; }
.cac-lua-chon.nho { grid-template-columns: 1fr; }
.cac-lua-chon.nho .lua-chon { font: 700 1.15rem 'Nunito', sans-serif; text-align: left; padding: 12px 16px; }
.hang-nhap { display: flex; justify-content: center; align-items: center; gap: 10px; flex-wrap: wrap; }
.hang-nhap .o-nhap { max-width: 260px; }
.don-vi { font: 800 1.4rem 'Baloo 2', sans-serif; color: var(--chu-nhat); }
.ban-phim { display: grid; grid-template-columns: repeat(3, 64px); gap: 8px; justify-content: center; margin-top: 14px; }
.ban-phim button { height: 52px; border: 0; border-radius: 14px; background: #f3efff; box-shadow: 0 3px 0 #e3dcef;
    font: 800 1.4rem 'Baloo 2', sans-serif; color: var(--chu); cursor: pointer; }
.ban-phim button:active { transform: translateY(3px); box-shadow: none; }
.ban-phim button:disabled { opacity: .5; cursor: default; }
.danh-van { margin: 12px auto 4px; font-size: 1.15rem; }
.danh-van .van { color: var(--chu-nhat); margin-bottom: 6px; font-size: 1rem; }
.danh-van .chip.cuoi { background: var(--tim); color: #fff; }
.danh-van .gach { margin: 0 2px; color: var(--chu-nhat); }
.phan-hoi .danh-van { margin: 6px 0 0; }
.bai-doc-tv { background: #fff; border-radius: var(--bo); box-shadow: var(--bong); padding: 20px 24px; font-size: 1.25rem; line-height: 1.75; }
@media (max-width: 600px) {
    .nut-tron { width: 38px; height: 38px; font-size: 1.15rem; }
    .bai-doc-tv { padding: 16px; font-size: 1.15rem; }
}