/* ==========================================================================
   EDUCLASH — "Đấu trường tri thức"
   Hai lớp giao diện:
   - Lớp GAME (navy, viền pixel, nút arcade, số liệu font pixel): header, hero,
     đấu trường, bảng xếp hạng, hồ sơ.
   - Lớp HỌC (nền sáng, chữ dễ đọc): danh sách đề, trình đọc tài liệu, form.
   Màu mang nghĩa: vàng = xu / đấu trường, xanh ngọc = học tập / đúng, đỏ = máu / sai.
   ========================================================================== */

:root {
    /* Ink — navy thương hiệu (giữ nhận diện cũ) */
    --ink: #0F1D33;
    --ink-2: #172A47;
    --ink-3: #22395E;
    --ink-line: rgba(255, 255, 255, 0.12);
    --on-ink: #F3F6FB;
    --on-ink-2: #B7C3D6;

    /* Paper — nền đọc, ánh xanh rất nhẹ theo navy */
    --paper: #F2F5FA;
    --surface: #FFFFFF;
    --surface-2: #F7F9FC;
    --line: #DAE1EC;
    --line-strong: #C3CEDD;
    --text: #0F1D33;
    --text-2: #3F4D63;
    --text-3: #5A677C;

    /* Màu nghĩa */
    --study: #10B981;
    --study-deep: #047857;
    --study-soft: #DDF7EC;
    --coin: #F5B70A;
    --coin-deep: #7A5200;
    --coin-soft: #FFF3CC;
    --hp: #E5484D;
    --hp-deep: #B4232A;
    --hp-soft: #FDE4E5;
    --info: #2F6FEB;
    --info-soft: #E3ECFE;

    /* Bậc hạng */
    --tier-dong: #B4692A;
    --tier-bac: #7D8BA1;
    --tier-vang: #D99A00;
    --tier-bachkim: #1A8FB8;
    --tier-kimcuong: #7C4DDB;

    /* Chữ */
    --font: "Be Vietnam Pro", "Segoe UI", system-ui, -apple-system, sans-serif;
    --font-pixel: "Silkscreen", "Courier New", monospace; /* chỉ dùng cho số & nhãn ASCII */

    --fs-xs: 0.75rem;
    --fs-sm: 0.875rem;
    --fs-md: 1rem;
    --fs-lg: 1.125rem;
    --fs-xl: 1.375rem;
    --fs-2xl: 1.75rem;
    --fs-3xl: clamp(2rem, 1.4rem + 2.4vw, 3.25rem);

    /* Không gian & hình khối */
    --gutter: clamp(16px, 4vw, 32px);
    --radius: 10px;
    --radius-lg: 14px;
    --pixel: 4px;
    --shadow-1: 0 1px 2px rgba(15, 29, 51, 0.06), 0 2px 8px rgba(15, 29, 51, 0.05);
    --shadow-2: 0 4px 10px rgba(15, 29, 51, 0.08), 0 12px 28px rgba(15, 29, 51, 0.08);
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --tabbar-h: 64px;

    /* Bootstrap dùng chung bảng màu */
    --bs-body-font-family: var(--font);
    --bs-body-color: var(--text);
    --bs-body-bg: var(--paper);
    --bs-border-color: var(--line);
    --bs-primary: var(--info);
    --bs-primary-rgb: 47, 111, 235;
    --bs-success: var(--study-deep);
    --bs-success-rgb: 4, 120, 87;
    --bs-danger: var(--hp-deep);
    --bs-danger-rgb: 180, 35, 42;
    --bs-warning-rgb: 245, 183, 10;
    --bs-link-color: var(--study-deep);
    --bs-link-color-rgb: 4, 120, 87;
    --bs-link-hover-color: var(--ink);
    --bs-secondary-color: var(--text-3);
    --bs-border-radius: var(--radius);
}

/* ---------- Nền tảng ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-padding-top: 88px; }

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    font-family: var(--font);
    font-size: var(--fs-md);
    line-height: 1.6;
    color: var(--text);
    background: var(--paper);
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

main { flex: 1 0 auto; }

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font);
    font-weight: 800;
    color: inherit;
    letter-spacing: -0.02em;
    line-height: 1.2;
    margin-top: 0;
    text-wrap: balance;
}

p { text-wrap: pretty; }

a { color: var(--study-deep); text-underline-offset: 3px; }
a:hover { color: var(--ink); }

::selection { background: var(--coin); color: var(--ink); }

:focus-visible {
    outline: 3px solid var(--coin);
    outline-offset: 2px;
    border-radius: 4px;
}

input, select, textarea { caret-color: var(--study-deep); }

* { scrollbar-width: thin; scrollbar-color: var(--line-strong) transparent; }

.num, .pixel {
    font-family: var(--font-pixel);
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.02em;
}

.visually-hidden-focusable:not(:focus):not(:focus-within) {
    position: absolute !important;
    width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap;
}

.skip-link {
    position: absolute;
    left: 12px;
    top: 12px;
    z-index: 2000;
    background: var(--coin);
    color: var(--ink);
    font-weight: 700;
    padding: 10px 16px;
    border-radius: 6px;
}

.wrap {
    width: 100%;
    max-width: 1200px;
    margin-inline: auto;
    padding-inline: var(--gutter);
}
.wrap--narrow { max-width: 920px; }
.wrap--form { max-width: 760px; }

.icon {
    width: 1.15em;
    height: 1.15em;
    flex: none;
    vertical-align: -0.2em;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}
.icon--fill { fill: currentColor; }

/* ---------- Nút arcade ---------- */
.btn-arcade {
    --b-bg: var(--surface);
    --b-fg: var(--ink);
    --b-edge: var(--line-strong);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    min-height: 44px;
    padding: 0.6rem 1.15rem;
    font: 700 var(--fs-sm)/1.2 var(--font);
    color: var(--b-fg);
    background: var(--b-bg);
    border: 2px solid var(--b-edge);
    border-radius: 8px;
    box-shadow: 0 var(--pixel) 0 0 var(--b-edge);
    text-decoration: none;
    cursor: pointer;
    transition: transform 0.12s var(--ease-out), box-shadow 0.12s var(--ease-out), background-color 0.15s;
    white-space: nowrap;
}
.btn-arcade:hover { color: var(--b-fg); transform: translateY(-1px); box-shadow: 0 calc(var(--pixel) + 1px) 0 0 var(--b-edge); }
.btn-arcade:active { transform: translateY(var(--pixel)); box-shadow: 0 0 0 0 var(--b-edge); }
.btn-arcade:disabled, .btn-arcade.is-disabled {
    cursor: not-allowed;
    opacity: 0.55;
    transform: none;
    box-shadow: 0 var(--pixel) 0 0 var(--b-edge);
}
.btn-arcade--gold { --b-bg: var(--coin); --b-fg: var(--ink); --b-edge: #B98500; }
.btn-arcade--green { --b-bg: var(--study); --b-fg: #04281D; --b-edge: var(--study-deep); }
.btn-arcade--dark { --b-bg: var(--ink-2); --b-fg: var(--on-ink); --b-edge: #050C18; }
.btn-arcade--danger { --b-bg: var(--hp); --b-fg: #FFFFFF; --b-edge: var(--hp-deep); }
.btn-arcade--ghost { --b-bg: transparent; --b-fg: var(--on-ink); --b-edge: var(--ink-line); box-shadow: none; }
.btn-arcade--ghost:hover { background: rgba(255, 255, 255, 0.06); box-shadow: none; }
.btn-arcade--sm { min-height: 36px; padding: 0.4rem 0.8rem; font-size: var(--fs-xs); }
.btn-arcade--lg { min-height: 52px; padding: 0.8rem 1.6rem; font-size: var(--fs-md); }
.btn-arcade--block { width: 100%; }

.link-arrow {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-weight: 700;
    font-size: var(--fs-sm);
    color: var(--study-deep);
    text-decoration: none;
}
.link-arrow:hover { color: var(--ink); text-decoration: underline; }

/* ---------- Chip ---------- */
.chip {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.2rem 0.55rem;
    font-size: var(--fs-xs);
    font-weight: 700;
    line-height: 1.4;
    border-radius: 6px;
    background: var(--surface-2);
    color: var(--text-2);
    border: 1px solid var(--line);
    white-space: nowrap;
}
.chip--code { font-family: var(--font-pixel); letter-spacing: 0.04em; background: var(--ink); color: var(--on-ink); border-color: var(--ink); }
.chip--green { background: var(--study-soft); color: var(--study-deep); border-color: transparent; }
.chip--gold { background: var(--coin-soft); color: var(--coin-deep); border-color: transparent; }
.chip--red { background: var(--hp-soft); color: var(--hp-deep); border-color: transparent; }
.chip--blue { background: var(--info-soft); color: #1D4DB5; border-color: transparent; }

.tier { --t: var(--tier-dong); color: var(--t); background: color-mix(in srgb, var(--t) 12%, white); border-color: color-mix(in srgb, var(--t) 35%, white); }
.tier--bac { --t: var(--tier-bac); }
.tier--vang { --t: var(--tier-vang); }
.tier--bachkim { --t: var(--tier-bachkim); }
.tier--kimcuong { --t: var(--tier-kimcuong); }

/* ---------- Header (lớp game) ---------- */
.topbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--ink);
    color: var(--on-ink);
    border-bottom: 1px solid var(--ink-line);
}
.topbar__inner {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    min-height: 68px;
}
.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    color: var(--on-ink);
    text-decoration: none;
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: -0.03em;
}
.brand:hover { color: var(--on-ink); }
.brand__mark { width: 34px; height: 34px; flex: none; }
.brand__clash { color: var(--coin); }

.mainnav { display: flex; align-items: center; gap: 0.25rem; margin-inline: auto; }
.mainnav a {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    min-height: 40px;
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
    color: var(--on-ink-2);
    font-weight: 600;
    font-size: var(--fs-sm);
    text-decoration: none;
    transition: color 0.15s, background-color 0.15s;
}
.mainnav a:hover { color: var(--on-ink); background: rgba(255, 255, 255, 0.06); }
.mainnav a[aria-current="page"] { color: var(--on-ink); background: var(--ink-3); box-shadow: inset 0 -3px 0 var(--study); }
.mainnav a.mainnav__arena { color: var(--coin); }
.mainnav a.mainnav__arena[aria-current="page"] { box-shadow: inset 0 -3px 0 var(--coin); }

.topbar__user { display: flex; align-items: center; gap: 0.6rem; margin-left: auto; }
.mainnav + .topbar__user { margin-left: 0; }

.stat-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    min-height: 36px;
    padding: 0.25rem 0.7rem;
    border-radius: 8px;
    background: var(--ink-2);
    border: 1px solid var(--ink-line);
    color: var(--on-ink);
    font-size: var(--fs-sm);
    text-decoration: none;
}
.stat-pill:hover { color: var(--on-ink); background: var(--ink-3); }
.stat-pill .num { font-size: 0.8rem; }
.stat-pill--coin .icon { color: var(--coin); }
.stat-pill--elo .icon { color: var(--study); }

.user-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    min-height: 40px;
    padding: 0.2rem 0.6rem 0.2rem 0.25rem;
    background: transparent;
    border: 1px solid var(--ink-line);
    border-radius: 999px;
    color: var(--on-ink);
    font: 600 var(--fs-sm)/1 var(--font);
    cursor: pointer;
}
.user-btn:hover { background: rgba(255, 255, 255, 0.06); }
.user-btn__name { max-width: 14ch; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.avatar {
    --size: 32px;
    width: var(--size);
    height: var(--size);
    flex: none;
    display: inline-grid;
    place-items: center;
    border-radius: 50%;
    overflow: hidden;
    background: var(--ink-3);
    color: var(--on-ink);
    font-weight: 800;
    font-size: calc(var(--size) * 0.42);
}
.avatar img { width: 100%; height: 100%; object-fit: cover; }
.avatar--sm { --size: 26px; }
.avatar--lg { --size: 56px; }
.avatar--xl { --size: 88px; }

.dropdown-menu {
    --bs-dropdown-border-color: var(--line);
    --bs-dropdown-link-active-bg: var(--study-soft);
    --bs-dropdown-link-active-color: var(--ink);
    border-radius: var(--radius);
    box-shadow: var(--shadow-2);
    padding: 0.4rem;
    min-width: 240px;
}
.dropdown-item { border-radius: 6px; display: flex; align-items: center; gap: 0.6rem; padding: 0.55rem 0.7rem; font-size: var(--fs-sm); font-weight: 500; }
.dropdown-item .icon { color: var(--text-3); }
.dropdown-header-card { padding: 0.6rem 0.7rem 0.7rem; border-bottom: 1px solid var(--line); margin-bottom: 0.35rem; }
.dropdown-header-card strong { display: block; font-size: var(--fs-sm); }
.dropdown-header-card span { font-size: var(--fs-xs); color: var(--text-3); }

/* ---------- Thanh tab dưới đáy (mobile) ---------- */
.tabbar { display: none; }

@media (max-width: 860px) {
    .mainnav, .stat-pill--elo, .user-btn__name, .topbar .btn-hide-sm { display: none; }
    .topbar__inner { min-height: 58px; gap: 0.75rem; }
    .brand { font-size: 1.1rem; }
    .brand__mark { width: 30px; height: 30px; }

    .tabbar {
        position: fixed;
        inset: auto 0 0 0;
        z-index: 1000;
        display: grid;
        grid-template-columns: repeat(5, 1fr);
        height: calc(var(--tabbar-h) + env(safe-area-inset-bottom, 0px));
        padding-bottom: env(safe-area-inset-bottom, 0px);
        background: var(--ink);
        border-top: 1px solid var(--ink-line);
    }
    .tabbar a {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 3px;
        color: var(--on-ink-2);
        font-size: 0.68rem;
        font-weight: 600;
        text-decoration: none;
    }
    .tabbar a .icon { width: 22px; height: 22px; }
    .tabbar a[aria-current="page"] { color: var(--on-ink); }
    .tabbar a[aria-current="page"] .icon { color: var(--study); }
    .tabbar a.tabbar__arena .icon { color: var(--coin); }
    .tabbar a.tabbar__arena { color: var(--coin); }

    body { padding-bottom: calc(var(--tabbar-h) + env(safe-area-inset-bottom, 0px)); }
}

/* ---------- Footer ---------- */
.site-footer {
    margin-top: 72px;
    background: var(--ink);
    color: var(--on-ink-2);
    font-size: var(--fs-sm);
}
.site-footer__inner {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 1rem 2rem;
    padding-block: 28px;
}
.site-footer a { color: var(--on-ink); }
.site-footer strong { color: var(--on-ink); }

/* ---------- Thông báo toàn cục (TempData) ---------- */
.flash {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-top: 16px;
    padding: 0.85rem 1rem;
    border-radius: var(--radius);
    border: 1px solid;
    font-size: var(--fs-sm);
}
.flash--ok { background: var(--study-soft); border-color: #A7E8CF; color: #064E3B; }
.flash--err { background: var(--hp-soft); border-color: #F6B7BA; color: #7F1D1D; }
.flash .btn-close { margin-left: auto; }

/* ---------- Đầu trang ---------- */
.page-head { padding-block: 28px 8px; }
.page-head__row {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
    justify-content: space-between;
    gap: 1rem 2rem;
}
.page-head h1 { font-size: var(--fs-2xl); margin: 0; }
.page-head__lede { color: var(--text-2); margin: 0.4rem 0 0; max-width: 62ch; }

.crumbs {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.35rem;
    margin: 0 0 0.75rem;
    padding: 0;
    list-style: none;
    font-size: var(--fs-sm);
    color: var(--text-3);
}
.crumbs li { display: inline-flex; align-items: center; gap: 0.35rem; min-width: 0; }
.crumbs li + li::before { content: "/"; color: var(--line-strong); }
.crumbs a { color: var(--text-2); text-decoration: none; font-weight: 500; }
.crumbs a:hover { color: var(--study-deep); text-decoration: underline; }
.crumbs [aria-current] { color: var(--text); font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 40ch; }

/* ---------- Section ---------- */
.section { margin-top: 40px; }
.section-head {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem 1.5rem;
    margin-bottom: 18px;
}
.section-head h2 { font-size: var(--fs-xl); margin: 0; }
.section-head__actions { display: flex; flex-wrap: wrap; align-items: center; gap: 0.75rem; }

/* ---------- Ô tìm kiếm ---------- */
.search {
    display: flex;
    align-items: center;
    width: min(100%, 380px);
    background: var(--surface);
    border: 2px solid var(--line);
    border-radius: 10px;
    padding-left: 0.75rem;
    transition: border-color 0.15s;
}
.search:focus-within { border-color: var(--study); }
.search .icon { color: var(--text-3); }
.search input {
    flex: 1;
    min-width: 0;
    min-height: 42px;
    padding: 0.5rem 0.6rem;
    border: 0;
    background: transparent;
    font: 500 var(--fs-sm)/1.2 var(--font);
    color: var(--text);
}
.search input:focus { outline: none; }
.search input::placeholder { color: var(--text-3); }
.search button {
    align-self: stretch;
    padding: 0 0.95rem;
    border: 0;
    border-left: 2px solid var(--line);
    background: var(--surface-2);
    color: var(--ink);
    font: 700 var(--fs-sm)/1 var(--font);
    border-radius: 0 8px 8px 0;
    cursor: pointer;
}
.search button:hover { background: var(--study-soft); }

.filter-note {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
    font-size: var(--fs-sm);
    color: var(--text-2);
    margin: -6px 0 16px;
}

/* ---------- HERO trang chủ ---------- */
.hero {
    position: relative;
    background:
        linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px) 0 0 / 24px 24px,
        linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px) 0 0 / 24px 24px,
        var(--ink);
    color: var(--on-ink);
    overflow: hidden;
}
.hero__inner {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 48px;
    align-items: center;
    padding-block: 56px 64px;
}
.hero h1 {
    font-size: var(--fs-3xl);
    letter-spacing: -0.035em;
    line-height: 1.08;
    margin: 0 0 18px;
}
.hero h1 em { font-style: normal; color: var(--coin); }
.hero__lede { font-size: var(--fs-lg); color: var(--on-ink-2); max-width: 46ch; margin: 0 0 28px; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 14px; }
.hero__steps {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1.25rem;
    margin: 28px 0 0;
    padding: 0;
    list-style: none;
    font-size: var(--fs-sm);
    color: var(--on-ink-2);
}
.hero__steps li { display: inline-flex; align-items: center; gap: 0.45rem; }
.hero__steps .icon { color: var(--study); }

/* Bảng điểm arcade */
.board {
    background: var(--ink-2);
    border: 2px solid #050C18;
    border-radius: 12px;
    box-shadow: 0 6px 0 0 #050C18, 0 24px 48px rgba(0, 0, 0, 0.35);
    overflow: hidden;
}
.board__head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 14px 18px;
    background: var(--ink-3);
    border-bottom: 2px solid #050C18;
}
.board__title { margin: 0; font-size: var(--fs-md); font-weight: 800; }
.board__live { font-family: var(--font-pixel); font-size: 0.7rem; color: var(--coin); display: inline-flex; align-items: center; gap: 0.4rem; }
.board__live::before { content: ""; width: 8px; height: 8px; background: var(--coin); animation: blink 1.2s steps(2) infinite; }
.board__list { list-style: none; margin: 0; padding: 6px 0; }
.board__row {
    display: grid;
    grid-template-columns: 44px 36px minmax(0, 1fr) auto;
    align-items: center;
    gap: 12px;
    padding: 10px 18px;
}
.board__row + .board__row { border-top: 1px dashed var(--ink-line); }
.board__rank { font-family: var(--font-pixel); font-size: 1rem; color: var(--on-ink-2); }
.board__row:nth-child(1) .board__rank { color: var(--coin); }
.board__row:nth-child(2) .board__rank { color: #CBD5E1; }
.board__row:nth-child(3) .board__rank { color: #E2A36B; }
.board__name { font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.board__name small { display: block; font-weight: 500; color: var(--on-ink-2); font-size: var(--fs-xs); }
.board__score { font-family: var(--font-pixel); font-size: 0.9rem; color: var(--study); }
.board__empty { padding: 22px 18px; color: var(--on-ink-2); font-size: var(--fs-sm); margin: 0; }
.board__foot {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    padding: 12px 18px;
    border-top: 2px solid #050C18;
    background: rgba(0, 0, 0, 0.15);
    font-size: var(--fs-sm);
}
.board__foot a { color: var(--coin); font-weight: 700; text-decoration: none; }
.board__foot a:hover { text-decoration: underline; color: var(--coin); }

.me-strip {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-bottom: 2px solid #050C18;
}
.me-strip div { padding: 12px 18px; }
.me-strip div + div { border-left: 1px solid var(--ink-line); }
.me-strip dt { font-size: var(--fs-xs); color: var(--on-ink-2); font-weight: 600; }
.me-strip dd { margin: 2px 0 0; font-family: var(--font-pixel); font-size: 1rem; }
.me-strip .is-coin { color: var(--coin); }
.me-strip .is-elo { color: var(--study); }

@keyframes blink { 50% { opacity: 0; } }

@media (max-width: 900px) {
    .hero__inner { grid-template-columns: 1fr; gap: 32px; padding-block: 36px 44px; }
}

/* ---------- Trang chủ: "bật máy arcade" (chạy một lần khi tải trang) ----------
   Tiêu đề trồi lên → vạch pixel dưới "vào đấu trường" → bảng điểm mở như màn hình CRT
   → từng hàng người chơi trượt vào theo nấc → điểm Elo đếm lên (script trong Index). */
.hero h1 em { position: relative; display: inline-block; }
.hero h1 em::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -0.14em;
    height: 0.09em;
    background:
        repeating-linear-gradient(90deg, var(--coin) 0 10px, transparent 10px 14px);
    transform-origin: left;
    transform: scaleX(1);
}

@media (prefers-reduced-motion: no-preference) {
    .hero h1 { animation: rise-in 0.7s var(--ease-out) both; }
    .hero h1 em::after { animation: pixel-wipe 0.6s steps(10, end) 0.55s both; }
    .hero__lede { animation: rise-in 0.6s var(--ease-out) 0.12s both; }
    .hero__cta { animation: rise-in 0.6s var(--ease-out) 0.22s both; }
    .hero__steps li { animation: rise-in 0.5s var(--ease-out) both; }
    .hero__steps li:nth-child(1) { animation-delay: 0.34s; }
    .hero__steps li:nth-child(2) { animation-delay: 0.42s; }
    .hero__steps li:nth-child(3) { animation-delay: 0.5s; }

    .hero .board { animation: crt-on 0.5s steps(6, end) 0.25s both; }
    .hero .board__row, .hero .me-strip > div { animation: slot-in 0.4s steps(5, end) both; }
    .hero .me-strip > div:nth-child(1) { animation-delay: 0.7s; }
    .hero .me-strip > div:nth-child(2) { animation-delay: 0.78s; }
    .hero .me-strip > div:nth-child(3) { animation-delay: 0.86s; }
    .hero .board__row:nth-child(1) { animation-delay: 0.8s; }
    .hero .board__row:nth-child(2) { animation-delay: 0.95s; }
    .hero .board__row:nth-child(3) { animation-delay: 1.1s; }
    .hero .board__row:nth-child(1) .board__rank { animation: blink 0.25s steps(2) 1.2s 4; }

    .subject-rail .subject-tile { animation: rise-in 0.5s var(--ease-out) backwards; }
    .subject-rail .subject-tile:nth-child(2) { animation-delay: 0.05s; }
    .subject-rail .subject-tile:nth-child(3) { animation-delay: 0.1s; }
    .subject-rail .subject-tile:nth-child(4) { animation-delay: 0.15s; }
    .subject-rail .subject-tile:nth-child(5) { animation-delay: 0.2s; }
    .subject-rail .subject-tile:nth-child(n + 6) { animation-delay: 0.25s; }

    /* Nút arcade "nảy" nhẹ khi rê chuột vào hero CTA chính */
    .hero__cta .btn-arcade--gold .icon { transition: transform 0.2s var(--ease-out); }
    .hero__cta .btn-arcade--gold:hover .icon { transform: rotate(-12deg) scale(1.1); }
}

@keyframes rise-in { from { opacity: 0; transform: translateY(14px); } }
@keyframes pixel-wipe { from { transform: scaleX(0); } }
@keyframes crt-on {
    from { clip-path: inset(48% 0 48% 0); filter: brightness(2.2); }
    60% { filter: brightness(1.3); }
    to { clip-path: inset(0 0 0 0); filter: none; }
}
@keyframes slot-in { from { opacity: 0; transform: translateX(24px); } }

/* ---------- Môn học: dải bìa sách ---------- */
.subject-rail {
    display: grid;
    grid-auto-flow: column;
    grid-auto-columns: 168px;
    gap: 14px;
    overflow-x: auto;
    padding: 4px 4px 14px;
    margin-inline: -4px;
    scroll-snap-type: x proximity;
}
.subject-tile {
    --c: #334155;
    --tc: #FFFFFF;
    scroll-snap-align: start;
    display: flex;
    flex-direction: column;
    min-height: 196px;
    border-radius: 12px;
    background: var(--surface);
    border: 2px solid var(--line);
    text-decoration: none;
    color: var(--text);
    overflow: hidden;
    transition: transform 0.18s var(--ease-out), border-color 0.15s, box-shadow 0.18s var(--ease-out);
}
.subject-tile:hover { color: var(--text); transform: translateY(-3px); box-shadow: var(--shadow-2); border-color: var(--line-strong); }
.subject-tile__cover {
    position: relative;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 0.5rem;
    padding: 12px 12px 12px 18px;
    background: var(--c);
    color: var(--tc);
}
/* gáy sách */
.subject-tile__cover::before {
    content: "";
    position: absolute;
    inset: 0 auto 0 0;
    width: 8px;
    background: rgba(0, 0, 0, 0.22);
    box-shadow: 1px 0 0 rgba(255, 255, 255, 0.18);
}
.subject-tile__code { font-family: var(--font-pixel); font-size: 0.72rem; opacity: 0.9; }
.subject-tile__name {
    margin: 0;
    font-size: var(--fs-sm);
    font-weight: 800;
    line-height: 1.3;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.subject-tile__foot {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 12px;
    font-size: var(--fs-xs);
    color: var(--text-3);
    font-weight: 600;
}
.subject-tile__foot b { color: var(--study-deep); }
.subject-tile[aria-current="true"] { border-color: var(--study); box-shadow: 0 0 0 3px var(--study-soft); }
.subject-tile[aria-current="true"] .subject-tile__foot b { color: var(--ink); }

/* Trang tất cả môn */
.subject-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 18px;
}
.subject-card {
    --c: #334155;
    --tc: #FFFFFF;
    display: flex;
    flex-direction: column;
    background: var(--surface);
    border: 2px solid var(--line);
    border-radius: 12px;
    overflow: hidden;
}
.subject-card__cover {
    position: relative;
    padding: 18px 18px 18px 24px;
    background: var(--c);
    color: var(--tc);
    min-height: 116px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 0.75rem;
}
.subject-card__cover::before {
    content: "";
    position: absolute;
    inset: 0 auto 0 0;
    width: 10px;
    background: rgba(0, 0, 0, 0.22);
}
.subject-card__cover h2 { margin: 0; font-size: var(--fs-lg); line-height: 1.25; }
.subject-card__body { padding: 14px 18px 18px; display: flex; flex-direction: column; gap: 14px; flex: 1; }
.subject-card__body p { margin: 0; font-size: var(--fs-sm); color: var(--text-2); flex: 1; }
.subject-card__actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }

/* ---------- Thẻ đề cương / đề trắc nghiệm ---------- */
.doc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(100%, 320px), 1fr));
    gap: 18px;
}
.doc-card {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 20px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-1);
    transition: transform 0.18s var(--ease-out), box-shadow 0.18s var(--ease-out), border-color 0.15s;
}
.doc-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-2); border-color: var(--line-strong); }
.doc-card__top { display: flex; align-items: center; justify-content: space-between; gap: 0.5rem; flex-wrap: wrap; }
.doc-card h3 { margin: 0; font-size: var(--fs-lg); line-height: 1.35; }
.doc-card h3 a { color: var(--text); text-decoration: none; }
/* cả thẻ bấm được, vẫn giữ một link duy nhất cho trình đọc màn hình */
.doc-card h3 a::after { content: ""; position: absolute; inset: 0; border-radius: inherit; }
.doc-card h3 a:focus-visible { outline: none; }
.doc-card:has(h3 a:focus-visible) { outline: 3px solid var(--coin); outline-offset: 2px; }
.doc-card__desc {
    margin: 0;
    font-size: var(--fs-sm);
    color: var(--text-2);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.doc-card__meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    margin-top: auto;
    padding-top: 12px;
    border-top: 1px solid var(--line);
    font-size: var(--fs-sm);
    color: var(--text-3);
}
.doc-card__author { display: inline-flex; align-items: center; gap: 0.5rem; min-width: 0; }
.doc-card__author span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.doc-card__go { font-weight: 700; color: var(--study-deep); display: inline-flex; align-items: center; gap: 0.3rem; }
.doc-card--quiz .doc-card__go { color: #1D4DB5; }
.doc-card .avatar { --size: 26px; background: var(--study-soft); color: var(--study-deep); }
.stat-inline { display: inline-flex; align-items: center; gap: 0.3rem; font-weight: 600; }
.stat-inline .icon { color: var(--coin); }

/* ---------- Trạng thái rỗng ---------- */
.empty {
    display: grid;
    justify-items: center;
    gap: 10px;
    text-align: center;
    padding: 48px 24px;
    background: var(--surface);
    border: 2px dashed var(--line-strong);
    border-radius: var(--radius-lg);
}
.empty__icon { width: 48px; height: 48px; color: var(--text-3); }
.empty h3 { margin: 0; font-size: var(--fs-lg); }
.empty p { margin: 0; color: var(--text-2); max-width: 52ch; }

/* ---------- Bề mặt ---------- */
.panel {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-1);
}
.panel--pad { padding: clamp(20px, 4vw, 36px); }

.game-panel {
    background: var(--ink-2);
    color: var(--on-ink);
    border: 2px solid #050C18;
    border-radius: 12px;
    box-shadow: 0 6px 0 0 #050C18;
}

/* ---------- Bảng xếp hạng ---------- */
.seg {
    display: inline-flex;
    padding: 4px;
    gap: 4px;
    background: var(--surface);
    border: 2px solid var(--line);
    border-radius: 10px;
}
.seg a {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    min-height: 36px;
    padding: 0.35rem 0.9rem;
    border-radius: 7px;
    font-size: var(--fs-sm);
    font-weight: 700;
    color: var(--text-2);
    text-decoration: none;
}
.seg a:hover { color: var(--ink); background: var(--surface-2); }
.seg a[aria-current="page"] { background: var(--ink); color: var(--on-ink); }

.podium {
    display: flex;
    justify-content: center;
    align-items: flex-end;
    gap: 14px;
    margin: 0 0 22px;
    padding: 0;
    list-style: none;
}
.podium__spot { flex: 0 1 240px; display: flex; flex-direction: column; align-items: center; gap: 8px; text-align: center; min-width: 0; }
.podium__spot .avatar { --size: 56px; box-shadow: 0 0 0 3px var(--surface), 0 0 0 5px var(--medal); }
.podium__name { font-weight: 800; max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.podium__score { font-family: var(--font-pixel); font-size: 0.85rem; color: var(--study-deep); }
.podium__block {
    width: 100%;
    display: grid;
    place-items: center;
    background: var(--ink);
    color: var(--medal);
    border: 2px solid #050C18;
    border-radius: 10px 10px 0 0;
    box-shadow: inset 0 -6px 0 rgba(0, 0, 0, 0.25);
    font-family: var(--font-pixel);
    font-size: 1.6rem;
}
.podium__spot--1 { --medal: var(--coin); order: 2; }
.podium__spot--2 { --medal: #CBD5E1; order: 1; }
.podium__spot--3 { --medal: #E2A36B; order: 3; }
.podium__spot--1 .podium__block { height: 120px; }
.podium__spot--2 .podium__block { height: 88px; }
.podium__spot--3 .podium__block { height: 68px; }
.podium__spot--1 .avatar { --size: 68px; }

.data-table { width: 100%; border-collapse: collapse; font-size: var(--fs-sm); }
.data-table th {
    text-align: left;
    padding: 12px 16px;
    font-size: var(--fs-xs);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-3);
    background: var(--surface-2);
    border-bottom: 1px solid var(--line);
    white-space: nowrap;
}
.data-table td { padding: 12px 16px; border-bottom: 1px solid var(--line); vertical-align: middle; }
.data-table tr:last-child td { border-bottom: 0; }
.data-table tbody tr:hover { background: var(--surface-2); }
.data-table .num-col { text-align: right; white-space: nowrap; }
.rank-no { font-family: var(--font-pixel); color: var(--text-3); }
.player-cell { display: flex; align-items: center; gap: 12px; min-width: 0; }
.player-cell strong { display: block; }
.player-cell > div { min-width: 0; }
.player-cell small { display: block; color: var(--text-3); max-width: 46ch; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.table-scroll { overflow-x: auto; }

/* ---------- Làm bài trắc nghiệm ---------- */
.quiz-bar {
    position: sticky;
    top: 68px;
    z-index: 50;
    margin-top: 20px;
    padding: 12px 16px;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 6px 16px;
    background: var(--ink);
    color: var(--on-ink);
    border-radius: 12px;
    box-shadow: 0 4px 0 #050C18;
}
.quiz-bar__title { font-weight: 700; font-size: var(--fs-sm); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.quiz-bar__timer { font-family: var(--font-pixel); font-size: 1.1rem; color: var(--coin); display: inline-flex; align-items: center; gap: 0.45rem; }
.quiz-bar__timer.is-low { color: var(--hp); animation: blink 1s steps(2) infinite; }
.quiz-bar__progress { grid-column: 1 / -1; display: flex; align-items: center; gap: 12px; font-size: var(--fs-xs); color: var(--on-ink-2); }
.xp-track { flex: 1; height: 10px; background: var(--ink-3); border: 1px solid #050C18; border-radius: 3px; overflow: hidden; }
.xp-fill { height: 100%; width: 100%; background: var(--study); transform-origin: left; transform: scaleX(0); transition: transform 0.35s var(--ease-out); }

@media (max-width: 860px) { .quiz-bar { top: 58px; } }

.q-card { margin-top: 16px; padding: clamp(18px, 3vw, 26px); }
.q-card__head { display: flex; gap: 12px; align-items: flex-start; margin-bottom: 16px; font-size: inherit; float: left; width: 100%; padding: 0; }
.q-card__head + * { clear: left; }
.q-card__no {
    flex: none;
    display: grid;
    place-items: center;
    min-width: 40px;
    height: 32px;
    padding: 0 6px;
    background: var(--ink);
    color: var(--on-ink);
    border-radius: 6px;
    font-family: var(--font-pixel);
    font-size: 0.8rem;
}
.q-card__text { margin: 0; font-size: var(--fs-lg); font-weight: 700; line-height: 1.45; letter-spacing: -0.01em; }
.q-options { display: grid; gap: 10px; }
.q-option {
    position: relative;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 14px;
    background: var(--surface);
    border: 2px solid var(--line);
    border-radius: 10px;
    cursor: pointer;
    transition: border-color 0.15s, background-color 0.15s;
}
.q-option:hover { border-color: var(--line-strong); background: var(--surface-2); }
.q-option input { position: absolute; opacity: 0; pointer-events: none; }
.q-option__key {
    flex: none;
    display: grid;
    place-items: center;
    width: 30px;
    height: 30px;
    border-radius: 6px;
    border: 2px solid var(--line-strong);
    font-family: var(--font-pixel);
    font-size: 0.8rem;
    color: var(--text-2);
    background: var(--surface);
}
.q-option__mark { margin-left: auto; display: none; align-items: center; gap: 0.3rem; font-size: var(--fs-xs); font-weight: 800; }
.q-option:has(input:checked) { border-color: var(--ink); background: #EEF2F8; }
.q-option:has(input:checked) .q-option__key { background: var(--ink); color: var(--on-ink); border-color: var(--ink); }
.q-option:has(input:focus-visible) { outline: 3px solid var(--coin); outline-offset: 2px; }
.is-graded .q-option.is-correct { border-color: var(--study); background: var(--study-soft); }
.is-graded .q-option.is-correct .q-option__key { background: var(--study-deep); border-color: var(--study-deep); color: #FFFFFF; }
.q-option.is-correct .q-option__mark { display: inline-flex; color: var(--study-deep); }
.is-graded .q-option.is-wrong { border-color: var(--hp); background: var(--hp-soft); }
.is-graded .q-option.is-wrong .q-option__key { background: var(--hp-deep); border-color: var(--hp-deep); color: #FFFFFF; }
.q-option.is-wrong .q-option__mark { display: inline-flex; color: var(--hp-deep); }
.is-graded .q-option { cursor: default; }
.q-explain {
    margin-top: 14px;
    padding: 12px 14px;
    border-radius: 10px;
    background: var(--info-soft);
    color: #1E3A8A;
    font-size: var(--fs-sm);
}
.q-card.is-skipped { border-color: #F6C9A0; }

.quiz-submit { display: flex; justify-content: center; margin: 28px 0 8px; }

.result-card {
    margin-top: 24px;
    padding: clamp(24px, 4vw, 40px);
    text-align: center;
}
.result-card h2 { font-size: var(--fs-2xl); margin: 10px 0 6px; }
.result-card__score { font-family: var(--font-pixel); font-size: clamp(2.5rem, 8vw, 4rem); line-height: 1; color: var(--coin); margin: 8px 0; }
.result-card__sub { color: var(--on-ink-2); margin: 0 0 22px; }
.stars { display: inline-flex; gap: 8px; }
.stars .icon { width: 34px; height: 34px; color: var(--ink-3); }
.stars .icon.is-on { color: var(--coin); }
.result-card__actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; }

/* ---------- Form & Auth ---------- */
.field { display: grid; gap: 6px; }
.field label, .field .label { font-size: var(--fs-sm); font-weight: 700; color: var(--text); }
.field .req { color: var(--hp-deep); }
.field-hint { font-size: var(--fs-xs); color: var(--text-3); margin: 0; }
.form-control, .form-select {
    min-height: 46px;
    border: 2px solid var(--line);
    border-radius: 10px;
    font-size: var(--fs-md);
    color: var(--text);
    background-color: var(--surface);
}
.form-control::placeholder { color: var(--text-3); }
.form-control:focus, .form-select:focus { border-color: var(--study); box-shadow: 0 0 0 4px var(--study-soft); }
.form-check-input:checked { background-color: var(--study-deep); border-color: var(--study-deep); }
.form-check-input:focus { box-shadow: 0 0 0 4px var(--study-soft); border-color: var(--study); }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.form-grid .span-2 { grid-column: 1 / -1; }
@media (max-width: 640px) { .form-grid { grid-template-columns: 1fr; } }
.form-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 12px; margin-top: 28px; padding-top: 20px; border-top: 1px solid var(--line); }

.auth {
    display: grid;
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    max-width: 980px;
    margin: 40px auto 0;
    overflow: hidden;
}
.auth__side {
    padding: 40px 36px;
    background:
        linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px) 0 0 / 22px 22px,
        linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px) 0 0 / 22px 22px,
        var(--ink);
    color: var(--on-ink);
    display: flex;
    flex-direction: column;
    gap: 22px;
}
.auth__side h2 { font-size: var(--fs-2xl); margin: 0; }
.perk-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.perk-list li { display: grid; grid-template-columns: 36px 1fr; gap: 12px; align-items: start; color: var(--on-ink-2); font-size: var(--fs-sm); }
.perk-list strong { display: block; color: var(--on-ink); font-size: var(--fs-md); }
.perk-icon { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 8px; background: var(--ink-3); border: 1px solid var(--ink-line); }
.perk-icon .icon { color: var(--coin); }
.auth__form { padding: 40px clamp(20px, 4vw, 44px); display: grid; gap: 18px; align-content: start; }
.auth__form h1 { font-size: var(--fs-2xl); margin: 0; }
.auth__form > p { margin: -10px 0 0; color: var(--text-2); }
.auth__switch { text-align: center; font-size: var(--fs-sm); color: var(--text-2); margin: 4px 0 0; }
.pw-field { position: relative; }
.pw-field .form-control { padding-right: 52px; }
.pw-toggle {
    position: absolute;
    right: 6px;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 36px;
    display: grid;
    place-items: center;
    border: 0;
    background: transparent;
    color: var(--text-3);
    border-radius: 6px;
    cursor: pointer;
}
.pw-toggle:hover { color: var(--ink); background: var(--surface-2); }
@media (max-width: 760px) {
    .auth { grid-template-columns: 1fr; margin-top: 20px; }
    .auth__side { padding: 26px 22px; }
    .auth__side .perk-list { display: none; }
}

/* ---------- Hồ sơ ---------- */
.player-hero {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 20px;
    padding: clamp(20px, 4vw, 32px);
}
.player-hero .avatar { --size: 88px; box-shadow: 0 0 0 3px var(--ink-2), 0 0 0 6px var(--coin); }
.player-hero h1 { margin: 0; font-size: var(--fs-2xl); }
.player-hero__meta { color: var(--on-ink-2); font-size: var(--fs-sm); margin: 2px 0 10px; }
.player-hero__chips { display: flex; flex-wrap: wrap; gap: 8px; }
.stat-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-top: 2px solid #050C18;
}
.stat-grid > div { padding: 16px 20px; }
.stat-grid > div + div { border-left: 1px solid var(--ink-line); }
.stat-grid dt { font-size: var(--fs-xs); color: var(--on-ink-2); font-weight: 600; }
.stat-grid dd { margin: 4px 0 0; font-family: var(--font-pixel); font-size: 1.25rem; }
.stat-grid .is-coin { color: var(--coin); }
.stat-grid .is-elo { color: var(--study); }
@media (max-width: 640px) {
    .stat-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .stat-grid > div:nth-child(3) { border-left: 0; }
    .stat-grid > div:nth-child(n + 3) { border-top: 1px solid var(--ink-line); }
}
.action-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; }
.action-tile {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 18px;
    background: var(--surface);
    border: 2px solid var(--line);
    border-radius: 12px;
    color: var(--text);
    text-decoration: none;
    transition: border-color 0.15s, transform 0.18s var(--ease-out);
}
.action-tile:hover { color: var(--text); border-color: var(--study); transform: translateY(-2px); }
.action-tile .perk-icon { background: var(--study-soft); border-color: transparent; }
.action-tile .perk-icon .icon { color: var(--study-deep); }
.action-tile strong { display: block; }
.action-tile span { font-size: var(--fs-sm); color: var(--text-2); }
.action-tile--danger:hover { border-color: var(--hp); }
.action-tile--danger .perk-icon { background: var(--hp-soft); }
.action-tile--danger .perk-icon .icon { color: var(--hp-deep); }

/* ---------- Tải lên ---------- */
.dropzone {
    display: grid;
    justify-items: center;
    gap: 6px;
    padding: 32px 20px;
    text-align: center;
    background: var(--surface-2);
    border: 2px dashed var(--line-strong);
    border-radius: 12px;
    cursor: pointer;
    transition: border-color 0.15s, background-color 0.15s;
}
.dropzone:hover, .dropzone.is-over { border-color: var(--study); background: var(--study-soft); }
.dropzone:focus-within { outline: 3px solid var(--coin); outline-offset: 2px; }
.dropzone .icon { width: 40px; height: 40px; color: var(--text-3); }
.dropzone strong { font-size: var(--fs-md); }
.dropzone p { margin: 0; font-size: var(--fs-sm); color: var(--text-3); }
.dropzone.has-file { border-style: solid; border-color: var(--study); background: var(--study-soft); }
.dropzone.has-file .icon { color: var(--study-deep); }

.mode-pick { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.mode-pick label {
    position: relative;
    display: grid;
    gap: 4px;
    padding: 14px 16px;
    background: var(--surface);
    border: 2px solid var(--line);
    border-radius: 12px;
    cursor: pointer;
}
.mode-pick input { position: absolute; opacity: 0; }
.mode-pick strong { display: flex; align-items: center; gap: 0.45rem; }
.mode-pick span { font-size: var(--fs-sm); color: var(--text-2); }
.mode-pick label:has(input:checked) { border-color: var(--ink); box-shadow: 0 var(--pixel) 0 var(--ink); }
.mode-pick label:has(input:focus-visible) { outline: 3px solid var(--coin); outline-offset: 2px; }
@media (max-width: 640px) { .mode-pick { grid-template-columns: 1fr; } }

/* ---------- Quản lý đề của tôi ---------- */
.toolbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 18px;
}
.doc-type { display: inline-grid; place-items: center; width: 40px; height: 40px; border-radius: 8px; flex: none; }
.doc-type--outline { background: var(--study-soft); color: var(--study-deep); }
.doc-type--quiz { background: var(--info-soft); color: #1D4DB5; }
.row-actions { display: flex; justify-content: flex-end; gap: 8px; }

/* ---------- Toast & hộp thoại ---------- */
.toast-stack {
    position: fixed;
    right: 16px;
    bottom: 16px;
    z-index: 3000;
    display: grid;
    gap: 10px;
    width: min(380px, calc(100vw - 32px));
}
@media (max-width: 860px) { .toast-stack { bottom: calc(var(--tabbar-h) + 12px); } }
.ec-toast {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 12px 14px;
    background: var(--ink);
    color: var(--on-ink);
    border: 2px solid #050C18;
    border-radius: 10px;
    box-shadow: 0 4px 0 #050C18, var(--shadow-2);
    font-size: var(--fs-sm);
    animation: toast-in 0.28s var(--ease-out);
}
.ec-toast .icon { margin-top: 2px; }
.ec-toast--ok .icon { color: var(--study); }
.ec-toast--err .icon { color: var(--hp); }
.ec-toast--warn .icon { color: var(--coin); }
.ec-toast__close { margin-left: auto; background: none; border: 0; color: var(--on-ink-2); cursor: pointer; padding: 0 2px; font-size: 1.1rem; line-height: 1; }
.ec-toast.is-leaving { opacity: 0; transform: translateY(6px); transition: opacity 0.2s, transform 0.2s; }
@keyframes toast-in { from { opacity: 0; transform: translateY(10px); } }

.ec-dialog {
    border: 2px solid #050C18;
    border-radius: 14px;
    padding: 0;
    width: min(460px, calc(100vw - 32px));
    background: var(--surface);
    color: var(--text);
    box-shadow: 0 6px 0 #050C18, 0 30px 60px rgba(0, 0, 0, 0.35);
}
.ec-dialog::backdrop { background: rgba(15, 29, 51, 0.6); }
.ec-dialog__body { padding: 24px 24px 8px; }
.ec-dialog__body h2 { font-size: var(--fs-xl); margin: 0 0 8px; }
.ec-dialog__body p { margin: 0; color: var(--text-2); }
.ec-dialog__actions { display: flex; justify-content: flex-end; gap: 10px; padding: 18px 24px 24px; }

/* Modal Bootstrap theo bảng màu */
.modal-content { border-radius: 14px; border: 2px solid var(--ink); box-shadow: 0 6px 0 var(--ink); }
.modal-header, .modal-footer { border-color: var(--line); }
.modal-title { font-weight: 800; }

/* ---------- Trang lỗi ---------- */
.oops { text-align: center; padding-block: 64px 24px; }
.oops__code { font-family: var(--font-pixel); font-size: clamp(3rem, 12vw, 6rem); color: var(--hp); line-height: 1; margin: 0 0 12px; }
.oops p { color: var(--text-2); max-width: 52ch; margin: 0 auto 24px; }

/* ---------- Giảm chuyển động ---------- */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}