/* =========================================================
   Osama Elgizawy ("the Prof in Chemistry") — index page design
   Light: floating white navbar, graph-paper hero, the surname set in periodic-table tiles,
   photo on a wine triangle with chemistry stickers, hand-drawn buttons and highlights.
   Palette sampled from landing.png (wine jacket, sand backdrop, element tiles) / logo.png (black script)
   Loaded after index-custom-new.css. Page skin is scoped to
   body.mk-home; .mk-nav is shared with login/register/terms/privacy
   ========================================================= */
@import url('https://fonts.googleapis.com/css2?family=Baloo+Bhaijaan+2:wght@400..800&display=swap');

:root {
    --og-body: 'Baloo Bhaijaan 2', Almarai, sans-serif;
    --og-wine: #7b1f2e;       /* jacket */
    --og-wine-2: #5a1320;
    --og-rose: #b8475a;
    --og-blush: #f6e3e4;
    --og-sand: #ead7bd;       /* backdrop */
    --og-cream: #fbf7f0;
    --og-paper: #ffffff;
    --og-ink: #1c1718;
    --og-dim: #6b6260;
    --og-line: rgba(28, 23, 24, 0.1);
    --og-t1: #7b1f2e;         /* tile outlines */
    --og-t2: #2f8f5b;
    --og-t3: #e0a100;
    --og-t4: #31496b;
    --og-shadow: 0 18px 44px rgba(90, 19, 32, 0.1);
    --og-hand: 255px 18px 225px 18px / 18px 225px 18px 255px;   /* hand-drawn outline */
    --og-hatch: repeating-linear-gradient(-45deg, rgba(123, 31, 46, 0.16) 0 2px, transparent 2px 7px);
    --og-mono: Consolas, 'Courier New', monospace;
    --og-ease: cubic-bezier(0.16, 1, 0.3, 1);
    --og-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ---------- Body font ----------
   This file is only loaded by the home, login, register, privacy and terms pages, so the rounded body font
   stays on those pages. Headings keep CooperArabic (.font-cop); icon fonts are not touched. */
html body,
html body .Almarai,
html body .form-control,
html body .form-select,
html body .form-label,
html body .btn,
html body input,
html body select,
html body textarea,
html body button,
html body label,
html body .select2-container,
html body .swal2-popup {
    font-family: var(--og-body);
}

html body .font-cop {
    font-family: CooperArabic, sans-serif;
}

html body .material-symbols-outlined {
    font-family: 'Material Symbols Outlined';
}

/* ---------- Navbar (shared): a white card floating over the page ---------- */
.fixed-top.mk-nav {
    top: 14px;
    left: 0;
    right: 0;
    width: min(1300px, calc(100% - 28px)) !important;
    margin-inline: auto;
    padding: 0.55rem 1.2rem !important;
    background: rgba(255, 255, 255, 0.96) !important;
    -webkit-backdrop-filter: blur(14px);
    backdrop-filter: blur(14px);
    border: 1px solid var(--og-line);
    border-radius: 18px;
    box-shadow: 0 14px 40px rgba(90, 19, 32, 0.1) !important;
}

.mk-nav .mk-logo {
    display: block;
    height: 54px;
    width: auto;
}

.mk-nav .btn-text {
    display: flex;
    flex-direction: row;
    gap: 6px;
    margin: 0;
    white-space: nowrap;
}

.mk-nav .login-btn,
.mk-nav .register-btn {
    padding: 0.6rem 1.3rem;
    margin: 0 4px;
    font-size: 0.98rem;
    border: 2px solid transparent;
    transition: transform 0.35s var(--og-ease), box-shadow 0.35s ease, background 0.35s ease, border-color 0.35s ease;
}

/* "sign in": plain text */
.mk-nav .login-btn {
    background: transparent;
    border-radius: 12px;
    box-shadow: none;
}

.mk-nav .login-btn .text-part-1 { color: var(--og-ink); }
.mk-nav .login-btn .text-part-2,
.mk-nav .login-btn .arrow-icon { color: var(--og-wine); }

.mk-nav .login-btn svg[stroke="white"],
.mk-nav .login-btn svg [stroke="white"] { stroke: var(--og-wine); }
.mk-nav .login-btn svg [fill="white"] { fill: var(--og-wine); }

/* "register": the hatched, hand-drawn button */
.mk-nav .register-btn {
    color: var(--og-ink);
    background: var(--og-hatch), var(--og-blush);
    border-color: var(--og-wine);
    border-radius: var(--og-hand);
    box-shadow: none;
}

.mk-nav .register-btn .text-part-1 { color: var(--og-ink); }
.mk-nav .register-btn .text-part-3,
.mk-nav .register-btn .register-icon { color: var(--og-wine); }

.mk-nav .register-btn svg[stroke="white"],
.mk-nav .register-btn svg [stroke="white"] { stroke: var(--og-wine); }
.mk-nav .register-btn svg [fill="white"] { fill: var(--og-wine); }

.mk-nav .login-btn:hover {
    transform: translateY(-2px);
    background: var(--og-blush);
    border-color: transparent;
    box-shadow: none;
}

.mk-nav .register-btn:hover {
    transform: translateY(-2px) rotate(-1deg);
    background: var(--og-hatch), #f0d2d5;
    box-shadow: 0 10px 22px rgba(123, 31, 46, 0.18);
}

.mk-nav .login-btn:focus-visible,
.mk-nav .register-btn:focus-visible,
.og-btn:focus-visible {
    outline: 3px solid var(--og-t3);
    outline-offset: 3px;
}

.mk-nav .welcome-message {
    color: var(--og-ink);
}

.mk-nav #notificationsDropdown {
    color: var(--og-dim);
}

.mk-nav .btn-danger {
    background: var(--og-wine);
    border: 0;
    border-radius: 12px !important;
    color: #ffffff !important;
    font-weight: 700;
    box-shadow: 0 10px 24px rgba(123, 31, 46, 0.28);
}

/* ---------- Page shell ---------- */
.mk-home {
    color: var(--og-ink);
    background-color: var(--og-paper);
}

.mk-home .mt-12 {
    margin-top: 0;
}

/* ---------- Hero ---------- */
.og-hero {
    position: relative;
    overflow: hidden;
    overflow: clip;
    isolation: isolate;
    padding: 165px 0 4.5rem;
    background:
        radial-gradient(46% 60% at 0% 12%, rgba(184, 71, 90, 0.14) 0%, transparent 70%),
        radial-gradient(42% 55% at 100% 0%, rgba(234, 215, 189, 0.75) 0%, transparent 72%),
        var(--og-cream);
}

/* graph paper */
.og-hero::before {
    content: '';
    position: absolute;
    z-index: -1;
    inset: 0;
    background-image:
        linear-gradient(rgba(28, 23, 24, 0.045) 1px, transparent 1px),
        linear-gradient(90deg, rgba(28, 23, 24, 0.045) 1px, transparent 1px);
    background-size: 44px 44px;
    -webkit-mask: linear-gradient(#000 55%, transparent 100%);
    mask: linear-gradient(#000 55%, transparent 100%);
    pointer-events: none;
}

.og-hero-in {
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: 3rem;
}

.og-in {
    animation: ogUp 1s var(--og-ease) both;
    animation-delay: calc(0.85s + var(--d, 0s));
}

@keyframes ogUp {
    from { opacity: 0; transform: translateY(28px); }
    to { opacity: 1; transform: none; }
}

/* the name: first name plain, surname one letter per element tile */
.og-title {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
    gap: 0.5rem 1.1rem;
    margin: 0 0 1.4rem;
    font-size: clamp(2rem, 3.05vw, 2.9rem);
    line-height: 1.25;
    color: var(--og-ink);
}

.og-title-first {
    padding-bottom: 0.35em;
}

.og-tiles {
    display: inline-flex;
    align-items: flex-end;
    gap: clamp(3px, 0.5vw, 7px);
    direction: rtl;
}

.og-tile {
    --c: var(--og-t1);
    position: relative;
    display: grid;
    place-items: end center;
    width: 1.18em;
    height: calc(1.5em + var(--up, 0em));
    padding-bottom: 0.08em;
    line-height: 1.2;
    border: 2px solid var(--c);
    background: rgba(255, 255, 255, 0.55);
    transition: transform 0.45s var(--og-spring), background 0.3s ease;
}

.og-tile:nth-child(4n+2) { --c: var(--og-t2); --up: 0.22em; }
.og-tile:nth-child(4n+3) { --c: var(--og-t3); }
.og-tile:nth-child(4n+4) { --c: var(--og-t4); --up: 0.34em; }

.og-tile:hover {
    transform: translateY(-6px);
    background: #ffffff;
}

/* atomic number and mass in the corners */
.og-tile::before,
.og-tile::after {
    position: absolute;
    top: 2px;
    direction: ltr;
    font-family: var(--og-mono);
    font-size: 0.15em;
    font-weight: 700;
    line-height: 1.3;
    color: var(--c);
}

.og-tile::before { content: attr(data-n); right: 3px; }
.og-tile::after { content: attr(data-m); left: 3px; }

.og-lead {
    max-width: 540px;
    margin: 0 0 1.7rem;
    font-size: 1.12rem;
    line-height: 2;
    color: var(--og-dim);
}

.og-lead b {
    color: var(--og-wine);
}

.og-cta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.9rem;
}

.og-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.7rem;
    min-height: 58px;
    padding: 0.8rem 2.1rem;
    font-size: 1.2rem;
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: 999px;
    transition: transform 0.4s var(--og-spring), box-shadow 0.35s ease, background 0.35s ease, color 0.35s ease;
}

.og-btn-primary {
    color: #ffffff;
    background: var(--og-wine);
    box-shadow: 0 16px 34px rgba(123, 31, 46, 0.32);
}

.og-btn-primary i {
    display: grid;
    place-items: center;
    width: 30px;
    height: 34px;
    font-size: 0.95rem;
    color: var(--og-wine-2);
    background: var(--og-t3);
    border-radius: 4px 8px 8px 4px;
    transform: rotate(-6deg);
}

.og-btn-primary:hover {
    color: #ffffff;
    transform: translateY(-4px);
    background: var(--og-wine-2);
    box-shadow: 0 24px 46px rgba(123, 31, 46, 0.42);
}

.og-btn-ghost {
    color: var(--og-ink);
    background: var(--og-hatch), rgba(255, 255, 255, 0.7);
    border-color: var(--og-wine);
    border-radius: var(--og-hand);
}

.og-btn-ghost:hover {
    color: var(--og-wine);
    transform: translateY(-4px) rotate(-1deg);
    background: var(--og-hatch), var(--og-blush);
}

.og-points {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem 2rem;
    padding: 0;
    margin: 2.6rem 0 0;
    list-style: none;
}

.og-points li {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    font-size: 1.12rem;
    color: var(--og-ink);
}

.og-points i {
    font-size: 1.15rem;
    color: var(--og-wine);
}

/* photo on a triangle, with stickers */
.og-stage {
    position: relative;
    width: min(600px, 100%);
    margin-inline: auto;
    padding: 34px 26px 30px;
}

.og-tri {
    position: absolute;
    z-index: -1;
    inset: 0 -6% -2% -6%;
    background: linear-gradient(160deg, var(--og-rose) 0%, var(--og-wine) 60%, var(--og-wine-2) 100%);
    clip-path: polygon(50% 0%, 100% 92%, 4% 100%);
    opacity: 0.95;
}

.og-tri::after {
    content: '';
    position: absolute;
    inset: 0;
    background: repeating-linear-gradient(-45deg, rgba(255, 255, 255, 0.07) 0 2px, transparent 2px 12px);
}

.og-photo {
    overflow: hidden;
    background: var(--og-sand);
    border: 7px solid #ffffff;
    border-radius: 26px;
    box-shadow: 0 34px 70px rgba(90, 19, 32, 0.32);
    rotate: 2deg;
    transition: rotate 0.7s var(--og-ease);
}

.og-stage:hover .og-photo {
    rotate: 0deg;
}

.og-photo img {
    display: block;
    width: 100%;
    height: auto;
    aspect-ratio: 5 / 4;
    object-fit: cover;
}

.og-st {
    position: absolute;
    z-index: 2;
    display: grid;
    place-items: center;
    color: var(--og-wine);
    filter: drop-shadow(0 8px 12px rgba(90, 19, 32, 0.22));
    rotate: var(--r, 0deg);
    animation: ogBob 6s ease-in-out infinite;
    animation-delay: var(--dl, 0s);
}

/* formulas, outlined in white like a sticker */
.og-st-text {
    display: block;
    white-space: nowrap;
    direction: ltr;
    font-family: 'Segoe UI', Tahoma, sans-serif;
    font-size: clamp(1.5rem, 2.6vw, 2.1rem);
    font-weight: 900;
    letter-spacing: 0.01em;
    paint-order: stroke fill;
    -webkit-text-stroke: 7px #ffffff;
}

.og-st-text sub {
    font-size: 0.6em;
    bottom: -0.2em;
}

.og-st-icon {
    width: var(--w, 66px);
    height: var(--w, 66px);
    font-size: calc(var(--w, 66px) * 0.46);
    color: #ffffff;
    background: var(--bg, var(--og-wine));
    border: 4px solid #ffffff;
    border-radius: 50%;
}

/* an element tile, as on the poster */
.og-st-el {
    width: 74px;
    height: 80px;
    padding: 4px 6px 5px;
    place-items: stretch;
    direction: ltr;
    text-align: left;
    color: #ffffff;
    background: linear-gradient(150deg, var(--bg, #31496b), var(--bg2, #1f3150));
    border: 3px solid #ffffff;
    border-radius: 12px;
}

.og-st-el small {
    font-family: var(--og-mono);
    font-size: 0.62rem;
    font-weight: 700;
    line-height: 1.1;
    opacity: 0.9;
}

.og-st-el b {
    font-family: 'Segoe UI', Tahoma, sans-serif;
    font-size: 1.9rem;
    font-weight: 900;
    line-height: 1;
}

.og-st-1 { --r: -8deg; top: 0; right: -4px; }
.og-st-2 { --r: 7deg; --dl: -2s; top: 16%; left: -18px; }
.og-st-3 { --dl: -4s; --r: -10deg; bottom: 22%; right: -22px; }
.og-st-4 { --r: 9deg; --dl: -1s; --bg: #2a2626; --bg2: #121010; bottom: 2px; left: 6px; }
.og-st-5 { --w: 58px; --bg: var(--og-t3); --dl: -3s; top: 2px; left: 26%; }

@keyframes ogBob {
    0%, 100% { translate: 0 0; }
    50% { translate: 0 -10px; }
}

/* ---------- Sections ---------- */
.og-section {
    padding: 6rem 0 0;
}

.og-head {
    margin: 0 0 2.6rem;
}

/* a brush stroke behind the title */
.og-h2 {
    position: relative;
    display: inline-block;
    margin: 0 0 0.5rem;
    padding: 0.1em 0.5em 0.15em;
    font-size: clamp(2rem, 4.4vw, 3rem);
    line-height: 1.4;
    color: var(--og-ink);
    isolation: isolate;
}

.og-h2::before {
    content: '';
    position: absolute;
    z-index: -1;
    inset: 12% -1% 6% -1%;
    background: var(--og-hatch), var(--og-blush);
    border-radius: 60% 40% 55% 45% / 45% 60% 40% 55%;
    transform: rotate(-1.2deg);
}

.og-h2 em {
    font-style: normal;
    color: var(--og-wine);
}

.og-head p {
    margin: 0;
    line-height: 1.95;
    color: var(--og-dim);
}

/* Chapters: five element tiles that turn over to show what the chapter covers */
.og-chapters {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 1.2rem;
    padding: 0;
    margin: 0;
    list-style: none;
}

.og-el {
    --c: var(--og-wine);
    --c2: var(--og-wine-2);
    position: relative;
    min-width: 0;
    height: 276px;
    perspective: 1100px;
    cursor: pointer;
    outline: none;
}

.og-el:nth-child(5n+2) { --c: #2f8f5b; --c2: #1d6540; }
.og-el:nth-child(5n+3) { --c: #c98a00; --c2: #8f6100; }
.og-el:nth-child(5n+4) { --c: #31496b; --c2: #1f3150; }
.og-el:nth-child(5n+5) { --c: #2a2626; --c2: #121010; }

.og-el-in {
    position: absolute;
    inset: 0;
    transform-style: preserve-3d;
    transition: transform 0.75s var(--og-ease);
}

.og-el:hover .og-el-in,
.og-el:focus .og-el-in,
.og-el:focus-within .og-el-in {
    transform: rotateY(180deg);
}

.og-el:focus-visible .og-el-face {
    outline: 3px solid var(--og-t3);
    outline-offset: 3px;
}

.og-el-face {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    padding: 0.9rem 1rem 1rem;
    border-radius: 20px;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    overflow: hidden;
}

/* front: the element */
.og-el-front {
    align-items: center;
    text-align: center;
    color: #ffffff;
    background: linear-gradient(155deg, var(--c) 0%, var(--c2) 100%);
    border: 4px solid #ffffff;
    box-shadow: 0 18px 36px color-mix(in srgb, var(--c2) 38%, transparent), inset 0 0 0 1px rgba(255, 255, 255, 0.14);
}

.og-el-front::before {
    content: '';
    position: absolute;
    inset: 0;
    background: repeating-linear-gradient(-45deg, rgba(255, 255, 255, 0.06) 0 2px, transparent 2px 12px);
    pointer-events: none;
}

.og-el-num {
    align-self: flex-start;
    direction: ltr;
    font-family: var(--og-mono);
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.08em;
}

.og-el-turn {
    position: absolute;
    top: 0.95rem;
    left: 1rem;
    font-size: 0.8rem;
    opacity: 0.6;
}

.og-el-sym {
    margin: auto 0 0.1rem;
    direction: ltr;
    font-family: 'Segoe UI', Tahoma, sans-serif;
    font-size: clamp(3rem, 5vw, 4.4rem);
    font-weight: 900;
    line-height: 1;
    letter-spacing: -0.02em;
    text-shadow: 0 6px 14px rgba(0, 0, 0, 0.22);
}

.og-el-sym sub,
.og-el-sym sup {
    font-size: 0.48em;
}

.og-el-front h3 {
    margin: 0.35rem 0 auto;
    font-size: 1.28rem;
    line-height: 1.5;
    color: #ffffff;
}

.og-el-formula {
    display: block;
    max-width: 100%;
    padding: 0.28rem 0.6rem;
    direction: ltr;
    font-family: var(--og-mono);
    font-size: 0.72rem;
    font-weight: 700;
    white-space: nowrap;
    color: #ffffff;
    background: rgba(255, 255, 255, 0.14);
    border: 1px solid rgba(255, 255, 255, 0.22);
    border-radius: 999px;
}

.og-el-formula sub,
.og-el-formula sup {
    font-size: 0.72em;
}

/* back: what is inside */
.og-el-back {
    color: var(--og-ink);
    background: var(--og-hatch), #ffffff;
    border: 3px solid var(--c);
    box-shadow: 0 18px 36px color-mix(in srgb, var(--c2) 22%, transparent);
    transform: rotateY(180deg);
}

.og-el-back .og-el-num {
    color: var(--c);
}

.og-el-back h4 {
    margin: 0.25rem 0 0.55rem;
    padding-bottom: 0.45rem;
    font-size: 1.16rem;
    line-height: 1.5;
    color: var(--c);
    border-bottom: 2px dashed color-mix(in srgb, var(--c) 35%, transparent);
}

.og-el-back ul {
    display: grid;
    gap: 0.32rem;
    padding: 0;
    margin: 0;
    list-style: none;
}

.og-el-back li {
    position: relative;
    padding-inline-start: 1.05rem;
    font-size: 0.9rem;
    font-weight: 700;
    line-height: 1.65;
    color: var(--og-ink);
}

.og-el-back li::before {
    content: '';
    position: absolute;
    top: 0.62em;
    right: 0;
    width: 7px;
    height: 7px;
    background: var(--c);
    border-radius: 2px;
    rotate: 45deg;
}

.og-chapters-hint {
    margin: 1.2rem 0 0;
    font-size: 0.88rem;
    color: var(--og-dim);
}

.og-chapters-hint i {
    color: var(--og-wine);
}

/* Numbers to memorise: notes taped to a notebook page */
.og-page {
    position: relative;
    padding: 2.6rem 2.2rem 2.4rem;
    padding-inline-start: 4.2rem;
    background-color: var(--og-cream);
    background-image:
        linear-gradient(rgba(49, 73, 107, 0.09) 1px, transparent 1px),
        linear-gradient(90deg, rgba(49, 73, 107, 0.09) 1px, transparent 1px);
    background-size: 26px 26px;
    border: 1px solid var(--og-line);
    border-radius: 26px;
    box-shadow: var(--og-shadow);
}

/* the margin line and the punched holes */
.og-page::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    inset-inline-start: 3rem;
    width: 2px;
    background: rgba(184, 71, 90, 0.45);
}

.og-page::after {
    content: '';
    position: absolute;
    top: 12%;
    bottom: 12%;
    inset-inline-start: 1.05rem;
    width: 18px;
    background: radial-gradient(circle, #ffffff 0 7px, rgba(28, 23, 24, 0.14) 7px 8px, transparent 8px) center top / 18px 33.33% repeat-y;
}

.og-notes {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 2rem 1.6rem;
    padding: 0;
    margin: 0;
    list-style: none;
}

.og-note {
    --bg: #fff3c4;
    --ink: var(--og-wine);
    position: relative;
    height: 100%;
    padding: 1.7rem 1.2rem 1.2rem;
    text-align: center;
    background: var(--bg);
    border-radius: 3px 3px 14px 3px;
    box-shadow: 0 14px 26px rgba(28, 23, 24, 0.14), inset 0 -18px 22px rgba(28, 23, 24, 0.035);
    rotate: var(--r, -1.6deg);
    transition: rotate 0.45s var(--og-spring), translate 0.45s var(--og-spring), box-shadow 0.4s ease;
}

.og-notes > li:nth-child(2n) .og-note { --r: 1.4deg; }
.og-notes > li:nth-child(3n) .og-note { --r: -0.8deg; }
.og-notes > li:nth-child(6n+2) .og-note { --bg: #fbdfe2; }
.og-notes > li:nth-child(6n+3) .og-note { --bg: #dff1e4; --ink: #1d6540; }
.og-notes > li:nth-child(6n+4) .og-note { --bg: #dfe8f6; --ink: #31496b; }
.og-notes > li:nth-child(6n+5) .og-note { --bg: #ffffff; }
.og-notes > li:nth-child(6n+6) .og-note { --bg: #f3e3cd; --ink: #7a4a12; }

.og-note:hover {
    rotate: 0deg;
    translate: 0 -6px;
    box-shadow: 0 24px 40px rgba(28, 23, 24, 0.18), inset 0 -18px 22px rgba(28, 23, 24, 0.035);
}

/* a strip of tape */
.og-note::before {
    content: '';
    position: absolute;
    top: -12px;
    left: 50%;
    width: 92px;
    height: 26px;
    background: rgba(255, 255, 255, 0.55);
    border-inline: 1px dashed rgba(28, 23, 24, 0.12);
    box-shadow: 0 2px 5px rgba(28, 23, 24, 0.1);
    -webkit-backdrop-filter: blur(1px);
    backdrop-filter: blur(1px);
    translate: -50% 0;
    rotate: -3deg;
}

.og-note-tag {
    display: inline-block;
    margin-bottom: 0.5rem;
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--ink);
    opacity: 0.85;
}

/* the number, with a highlighter stroke under it */
.og-note-num {
    display: block;
    direction: ltr;
    font-family: 'Segoe UI', Tahoma, sans-serif;
    font-size: clamp(2.3rem, 4.2vw, 3.3rem);
    font-weight: 900;
    line-height: 1.15;
    letter-spacing: -0.02em;
    color: var(--ink);
}

.og-note-num span {
    padding: 0 0.18em;
    background: linear-gradient(transparent 62%, color-mix(in srgb, var(--ink) 22%, transparent) 62% 92%, transparent 92%);
    border-radius: 4px;
}

.og-note-num sup {
    font-size: 0.5em;
    top: -0.75em;
}

.og-note-num small {
    margin-inline-start: 0.3rem;
    font-family: var(--og-body);
    font-size: 0.95rem;
    font-weight: 700;
    letter-spacing: 0;
}

.og-note p {
    margin: 0.55rem 0 0;
    font-size: 0.98rem;
    font-weight: 600;
    line-height: 1.75;
    color: var(--og-ink);
}

.og-note p bdi {
    font-family: var(--og-mono);
    font-size: 0.9em;
    font-weight: 700;
}

/* Three steps */
.og-steps {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.4rem;
    padding: 0;
    margin: 0;
    list-style: none;
}

.og-step {
    position: relative;
    height: 100%;
    padding: 1.7rem 1.5rem 1.5rem;
    background: var(--og-cream);
    border: 2px solid var(--og-ink);
    border-radius: var(--og-hand);
    transition: transform 0.45s var(--og-spring), background 0.3s ease;
}

.og-steps > li:nth-child(2) .og-step {
    background: var(--og-hatch), var(--og-blush);
    border-color: var(--og-wine);
}

.og-step:hover {
    transform: translateY(-6px) rotate(-0.6deg);
}

.og-step-num {
    position: absolute;
    top: -20px;
    right: 1.4rem;
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    font-size: 1.3rem;
    color: #ffffff;
    background: var(--og-wine);
    border: 3px solid #ffffff;
    border-radius: 50%;
    box-shadow: 0 8px 18px rgba(123, 31, 46, 0.3);
}

.og-step h3 {
    margin: 0.4rem 0 0.35rem;
    font-size: 1.5rem;
    line-height: 1.5;
    color: var(--og-ink);
}

.og-step p {
    margin: 0;
    line-height: 1.9;
    color: var(--og-dim);
}

/* ---------- Existing dynamic sections ---------- */
.mk-home .latest-courses-section,
.mk-home .courses-section,
.mk-home .honor-roll-section,
.mk-home .honor-roll-section.bg-light,
.mk-home .student-opinions-section {
    background: transparent !important;
}

.mk-home .latest-courses-section,
.mk-home .courses-section {
    padding-top: 6rem !important;
}

.mk-home .courses-section::before,
.mk-home .honor-roll-section::before,
.mk-home .student-opinions-section::before {
    opacity: 0;
}

.mk-home .section-title,
.mk-home .courses-section .title-main {
    color: var(--og-ink);
}

.mk-home .courses-section .title-accent {
    color: var(--og-wine);
}

.mk-home .courses-section .title-accent + .title-accent {
    color: var(--og-t4);
}

.mk-home .section-subtitle {
    color: var(--og-dim);
}

.mk-home .courses-section .feature-item {
    background: #ffffff;
    border: 1px solid var(--og-line);
    border-radius: 14px;
    box-shadow: 0 10px 26px rgba(90, 19, 32, 0.05);
}

.mk-home .courses-section .feature-item span {
    color: var(--og-ink);
}

.mk-home .courses-section .feature-item .text-primary { color: var(--og-wine) !important; }
.mk-home .courses-section .feature-item .text-success { color: var(--og-t2) !important; }
.mk-home .courses-section .feature-item .text-info { color: var(--og-t4) !important; }

.mk-home .modern-carousel {
    border: 7px solid #ffffff;
    border-radius: 26px;
    box-shadow: 0 30px 70px rgba(90, 19, 32, 0.22);
}

.mk-home .title-decoration {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.9rem;
    margin-top: 1rem;
}

.mk-home .decoration-line {
    flex: 0 0 72px;
    height: 10px;
    background: var(--og-hatch), var(--og-blush);
    border-radius: 999px;
}

.mk-home .decoration-icon {
    display: grid;
    place-items: center;
    flex: 0 0 46px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: var(--og-wine);
    color: #ffffff;
    box-shadow: 0 0 0 4px var(--og-blush);
}

.mk-home .decoration-icon i {
    color: #ffffff !important;
}

.mk-home .latest-courses-section .btn-primary,
.mk-home .student-opinions-section .btn-primary {
    background: var(--og-wine);
    border-color: transparent;
    font-weight: 700;
}

.mk-home .latest-courses-section .btn-outline-primary {
    color: var(--og-ink);
    background: var(--og-hatch), #ffffff;
    border: 2px solid var(--og-wine);
    border-radius: var(--og-hand);
    font-weight: 700;
    padding: 0.65rem 1.7rem;
}

.mk-home .latest-courses-section .btn-outline-primary:hover {
    background: var(--og-hatch), var(--og-blush);
    color: var(--og-wine);
}

.mk-home .latest-courses-section .badge.bg-primary {
    background: var(--og-wine) !important;
}

.mk-home .latest-courses-section .divider-2.bg-info {
    background: var(--og-t3) !important;
}

.mk-home .opinion-card.featured {
    border-color: var(--og-wine);
}

.mk-home .opinion-card .quote-icon {
    color: var(--og-wine);
}

.mk-home .opinion-rating .fa-star.active {
    color: var(--og-t3);
}

.mk-home .footer-with-swave {
    background: transparent;
}

/* scroll-reveal sets overflow hidden; the step numbers sit above their cards */
.mk-home .og-step,
.mk-home .og-steps,
.mk-home .og-steps > li {
    overflow: visible !important;
}

.mk-home .og-chapters,
.mk-home .og-el {
    overflow: visible !important;
}

.mk-home .og-page,
.mk-home .og-notes,
.mk-home .og-notes > li {
    overflow: visible !important;
}

/* ---------- Login / register picture on small screens ----------
   Both posters are tall (3:5 and 2:5). When the picture sits above the form it is cropped to a band,
   so the band is made taller and aimed at the face and the headline instead of the top of the poster. */
@media (max-width: 990px) {
    /* on tablets the picture stays phone-sized and centred, so the crop is the same as on a phone */
    .login-image-card {
        max-width: 540px;
        margin-inline: auto;
        border-radius: 22px !important;
    }

    .login-image-card .main-image {
        height: clamp(300px, 85vw, 460px);
        max-height: none;
        object-fit: cover;
        object-position: 50% 38%;
    }

    .login-image-card .main-image[src*="register"] {
        height: clamp(320px, 95vw, 560px);
        object-position: 50% 37%;
    }
}

/* ---------- Responsive ---------- */
@media (max-width: 1199.98px) {
    .og-chapters { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 991.98px) {
    .og-hero { padding: 135px 0 4rem; }

    .og-hero-in {
        grid-template-columns: 1fr;
        gap: 3rem;
        text-align: center;
    }

    /* photo first, as on the reference */
    .og-stage { order: -1; width: min(440px, 88%); }
    .og-title, .og-cta, .og-points { justify-content: center; }
    .og-lead { margin-inline: auto; }

    .og-head { text-align: center; }
    .og-steps { grid-template-columns: minmax(0, 1fr); gap: 2.2rem; }
    .og-notes { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 575.98px) {
    /* two buttons and the logo share a narrow bar */
    .fixed-top.mk-nav { top: 8px; width: calc(100% - 16px) !important; padding: 0.45rem 0.6rem !important; border-radius: 14px; }
    .mk-nav .mk-logo { height: 40px; }
    .mk-nav .login-btn, .mk-nav .register-btn { padding: 0.42rem 0.7rem; margin: 0 2px; font-size: 0.84rem; }

    .og-hero { padding: 104px 0 3.2rem; }
    .og-title { font-size: clamp(1.75rem, 8.4vw, 2.3rem); gap: 0.2rem 0.7rem; }
    .og-tile { border-width: 1.5px; }
    .og-tile::after { content: none; }
    .og-lead { font-size: 1rem; }
    .og-btn { flex: 1 1 100%; font-size: 1.1rem; }
    .og-points { gap: 0.6rem 1.2rem; margin-top: 2rem; }
    .og-points li { font-size: 1rem; }

    .og-stage { width: 100%; padding: 26px 16px 22px; }
    .og-photo { border-width: 5px; border-radius: 20px; }
    .og-st-icon { --w: 50px; border-width: 3px; }
    .og-st-5 { --w: 44px; }
    .og-st-el { width: 58px; height: 64px; border-radius: 10px; }
    .og-st-el b { font-size: 1.45rem; }
    .og-st-el small { font-size: 0.52rem; }
    .og-st-1 { right: 10px; }
    .og-st-2 { left: -4px; }
    .og-st-3 { right: -6px; }
    .og-st-text { -webkit-text-stroke-width: 5px; }

    .og-section { padding-top: 4.4rem; }
    .og-page { padding: 2rem 0.9rem 1.6rem; padding-inline-start: 2.1rem; border-radius: 20px; }
    .og-page::before { inset-inline-start: 1.5rem; }
    .og-page::after { display: none; }
    .og-notes { gap: 1.5rem 0.8rem; }
    .og-note { padding: 1.4rem 0.6rem 0.9rem; }
    .og-note::before { width: 64px; height: 22px; }
    .og-note-num small { display: block; margin: 0; font-size: 0.85rem; }
    .og-note p { font-size: 0.86rem; line-height: 1.65; }
    .og-chapters { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.8rem; }
    .og-el { height: 236px; }
    /* the fifth tile takes the full row, laid out wide */
    .og-el:last-child { grid-column: 1 / -1; height: 200px; }
    .og-el-face { padding: 0.75rem 0.8rem 0.85rem; border-radius: 18px; }
    .og-el-front h3 { font-size: 1.1rem; }
    .og-el-formula { font-size: 0.62rem; padding: 0.24rem 0.45rem; }
    .og-el-back h4 { font-size: 1.02rem; margin-bottom: 0.4rem; padding-bottom: 0.35rem; }
    .og-el-back li { font-size: 0.82rem; line-height: 1.55; }
    .og-el-back ul { gap: 0.2rem; }
}

@media (prefers-reduced-motion: reduce) {
    .og-in,
    .og-st {
        animation: none !important;
    }

    .og-btn,
    .og-photo,
    .og-tile,
    .og-el-in,
    .og-note,
    .og-step {
        transition: none;
    }
}