*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --um-deep: #0d5c5a;
    --um-teal: #0f8b7e;
    --um-coral: #ff6b57;
    --um-coral-soft: #ff8a63;
    --um-ink: #10312f;
    --um-muted: #4b6f6c;
    --um-line: #cfe6e1;
    --um-mint: #f4fbfa;
    --um-mint-deep: #e7f5f2;
    --um-card: #ffffff;
    --um-night: #072a29;
    --um-sans: "Verdana", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    --um-serif: "Cambria", "Georgia", "Times New Roman", serif;
    --um-r-s: 10px;
    --um-r-m: 18px;
    --um-r-l: 28px;
    --um-sh-s: 0 6px 18px rgba(13, 92, 90, .07);
    --um-sh-m: 0 16px 38px rgba(13, 92, 90, .12);
    --um-sh-l: 0 28px 64px rgba(7, 42, 41, .18);
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--um-serif);
    background:
        radial-gradient(ellipse at 88% -4%, rgba(15, 139, 126, .16), transparent 46%),
        radial-gradient(ellipse at 4% 10%, rgba(255, 107, 87, .09), transparent 40%),
        linear-gradient(180deg, var(--um-mint) 0%, var(--um-mint-deep) 100%);
    color: var(--um-ink);
    line-height: 1.74;
    font-size: 16px;
}

a {
    color: var(--um-deep);
    text-decoration: none;
    transition: color .2s ease;
}
a:hover { color: var(--um-coral); }

/* ---------- header ---------- */
.um-topbar {
    padding: 20px 20px 18px;
    background: rgba(244, 251, 250, .88);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(13, 92, 90, .14);
}
.um-topbar__inner {
    max-width: 1180px;
    margin: 0 auto;
    text-align: center;
}
.um-topbar__brand {
    display: inline-block;
    font-family: var(--um-sans);
    font-size: 20px;
    font-weight: 700;
    letter-spacing: .34em;
    text-indent: .34em;
    text-transform: uppercase;
    color: var(--um-deep);
}
.um-topbar__brand:hover { color: var(--um-teal); }

/* ---------- masthead ---------- */
.um-masthead {
    max-width: 1180px;
    margin: 0 auto;
    padding: 56px 24px 30px;
}
.um-masthead__kicker {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    padding: 6px 15px;
    margin-bottom: 16px;
    border-radius: 999px;
    background: linear-gradient(135deg, rgba(255, 107, 87, .13), rgba(15, 139, 126, .12));
    border: 1px solid rgba(255, 107, 87, .32);
    font-family: var(--um-sans);
    font-size: 11.5px;
    font-weight: 700;
    letter-spacing: .16em;
    text-transform: uppercase;
    color: #b3402f;
}
.um-masthead__title {
    max-width: 900px;
    font-size: clamp(27px, 4.4vw, 46px);
    line-height: 1.2;
    color: var(--um-deep);
    margin-bottom: 14px;
}
.um-masthead__lead {
    max-width: 720px;
    font-size: 17px;
    line-height: 1.8;
    color: var(--um-muted);
}

/* ---------- two-column doc layout ---------- */
.um-doc {
    max-width: 1180px;
    margin: 0 auto;
    padding: 0 24px 80px;
}
.um-doc__grid {
    display: grid;
    grid-template-columns: 270px minmax(0, 1fr);
    gap: 34px;
    align-items: start;
}

.um-doc__side { position: relative; }
.um-doc__toc {
    position: sticky;
    top: 22px;
    background: var(--um-card);
    border: 1px solid var(--um-line);
    border-left: 4px solid var(--um-teal);
    border-radius: var(--um-r-m);
    box-shadow: var(--um-sh-s);
    padding: 20px 18px;
}
.um-doc__toc-head {
    display: block;
    font-family: var(--um-sans);
    font-size: 11.5px;
    font-weight: 700;
    letter-spacing: .18em;
    text-transform: uppercase;
    color: var(--um-teal);
    cursor: pointer;
    list-style: none;
}
.um-doc__toc-head::-webkit-details-marker { display: none; }
.um-doc__toc-head::after {
    content: "";
    float: right;
    width: 8px;
    height: 8px;
    margin-top: 6px;
    border-right: 2px solid var(--um-coral);
    border-bottom: 2px solid var(--um-coral);
    transform: rotate(45deg);
    transition: transform .2s ease;
}
.um-doc__toc[open] .um-doc__toc-head::after { transform: rotate(-135deg); margin-top: 9px; }

.um-doc__list {
    list-style: none;
    margin: 14px 0 0;
    padding: 0;
    counter-reset: umtoc;
}
.um-doc__list li { margin: 0 0 2px; }
.um-doc__link {
    display: block;
    padding: 7px 10px 7px 34px;
    position: relative;
    font-family: var(--um-sans);
    font-size: 13px;
    line-height: 1.45;
    color: var(--um-muted);
    border-radius: 8px;
    transition: background .18s ease, color .18s ease;
}
.um-doc__link::before {
    counter-increment: umtoc;
    content: counter(umtoc);
    position: absolute;
    left: 8px;
    top: 7px;
    width: 19px;
    height: 19px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    font-size: 10.5px;
    font-weight: 700;
    color: var(--um-deep);
    background: rgba(15, 139, 126, .14);
}
.um-doc__link:hover {
    background: rgba(15, 139, 126, .08);
    color: var(--um-deep);
}
.um-doc__link:hover::before {
    background: var(--um-coral);
    color: #fff;
}

.um-doc__body { min-width: 0; }
.um-doc__stamp {
    display: inline-block;
    margin-bottom: 22px;
    padding: 8px 16px;
    border-radius: 999px;
    background: rgba(255, 255, 255, .78);
    border: 1px solid var(--um-line);
    font-family: var(--um-sans);
    font-size: 12.5px;
    color: var(--um-muted);
}
.um-doc__stamp strong { color: var(--um-deep); }

.um-doc__section {
    background: var(--um-card);
    border: 1px solid var(--um-line);
    border-radius: var(--um-r-m);
    box-shadow: var(--um-sh-s);
    padding: 30px 34px 26px;
    margin-bottom: 18px;
    scroll-margin-top: 22px;
}
.um-doc__section h2 {
    font-size: clamp(21px, 2.6vw, 28px);
    line-height: 1.24;
    color: var(--um-deep);
    margin-bottom: 14px;
    padding-bottom: 12px;
    border-bottom: 1px solid rgba(13, 92, 90, .12);
}
.um-doc__section h3 {
    font-size: 18px;
    line-height: 1.34;
    color: var(--um-ink);
    margin: 22px 0 9px;
}
.um-doc__section p { color: var(--um-muted); margin-bottom: 14px; }
.um-doc__section p:last-child { margin-bottom: 0; }
.um-doc__section ul,
.um-doc__section ol {
    padding-left: 20px;
    margin: 0 0 15px;
    color: var(--um-muted);
}
.um-doc__section li { margin-bottom: 7px; }
.um-doc__section li::marker { color: var(--um-teal); }
.um-doc__section strong { color: var(--um-ink); }

.um-doc__intro {
    background: linear-gradient(160deg, rgba(15, 139, 126, .08), rgba(255, 255, 255, .96));
}

/* ---------- inner blocks ---------- */
.um-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin: 20px 0 6px;
}
.um-card {
    background: linear-gradient(180deg, #ffffff, #f2fbf9);
    border: 1px solid var(--um-line);
    border-radius: 14px;
    padding: 18px 17px 16px;
    box-shadow: var(--um-sh-s);
}
.um-card__title {
    font-family: var(--um-sans);
    font-size: 14px;
    font-weight: 700;
    color: var(--um-deep);
    margin-bottom: 6px;
}
.um-card__text {
    font-size: 14px;
    line-height: 1.66;
    color: var(--um-muted);
}

.um-callout {
    margin: 20px 0;
    padding: 20px 22px;
    border-radius: 14px;
    background: linear-gradient(135deg, rgba(255, 107, 87, .12), rgba(255, 255, 255, .96));
    border: 1px solid rgba(255, 107, 87, .34);
    border-left: 4px solid var(--um-coral);
}
.um-callout p { margin: 0; color: var(--um-ink); }

.um-table-wrap { overflow-x: auto; margin: 18px 0 20px; }
.um-table {
    width: 100%;
    min-width: 420px;
    border-collapse: collapse;
    border-radius: 13px;
    overflow: hidden;
    box-shadow: var(--um-sh-s);
    background: var(--um-card);
}
.um-table th {
    background: linear-gradient(135deg, var(--um-deep), var(--um-teal));
    color: #fff;
    text-align: left;
    padding: 13px 15px;
    font-family: var(--um-sans);
    font-size: 13px;
    letter-spacing: .02em;
}
.um-table td {
    padding: 12px 15px;
    border-bottom: 1px solid rgba(13, 92, 90, .1);
    color: var(--um-muted);
    font-size: 15px;
}
.um-table tr:nth-child(even) td { background: rgba(231, 245, 242, .6); }
.um-table tr:last-child td { border-bottom: none; }

.um-steps { display: grid; gap: 14px; margin: 20px 0 6px; }
.um-step {
    display: grid;
    grid-template-columns: 46px minmax(0, 1fr);
    gap: 14px;
    align-items: start;
    padding: 16px 18px 15px;
    background: linear-gradient(180deg, #ffffff, #f2fbf9);
    border: 1px solid var(--um-line);
    border-radius: 14px;
    box-shadow: var(--um-sh-s);
}
.um-step__num {
    width: 46px;
    height: 46px;
    border-radius: 14px;
    display: grid;
    place-items: center;
    font-family: var(--um-sans);
    font-size: 17px;
    font-weight: 700;
    color: #fff;
    background: linear-gradient(135deg, var(--um-teal), var(--um-deep));
}
.um-step__title {
    font-family: var(--um-sans);
    font-size: 14px;
    font-weight: 700;
    color: var(--um-ink);
    margin-bottom: 3px;
}
.um-step__text { font-size: 14.5px; color: var(--um-muted); }

/* ---------- footer ---------- */
.um-footer {
    margin-top: 20px;
    padding: 26px 20px 22px;
    text-align: center;
    font-family: var(--um-sans);
    background: linear-gradient(180deg, #e7f5f2 0%, #dcefeb 100%);
    border-top: 1px solid rgba(13, 92, 90, .16);
}
.um-footer__inner { max-width: 900px; margin: 0 auto; }
.um-footer__nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px 22px;
    margin-bottom: 14px;
}
.um-footer__nav a {
    font-size: 11.5px;
    color: #4b6f6c;
    border-bottom: 1px solid rgba(75, 111, 108, .3);
    padding-bottom: 1px;
}
.um-footer__nav a:hover { color: var(--um-coral); border-bottom-color: rgba(255, 107, 87, .6); }
.um-footer__brand {
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .28em;
    text-indent: .28em;
    text-transform: uppercase;
    color: var(--um-deep);
    margin-bottom: 6px;
}
.um-footer__copy { font-size: 11.5px; color: #5c817d; margin-bottom: 10px; }
.um-footer__note {
    max-width: 720px;
    margin: 0 auto;
    font-size: 11px;
    line-height: 1.7;
    color: #6e918d;
}

/* ---------- adaptive ---------- */
@media (min-width: 941px) {
    .um-doc__toc-head { display: none; }
    .um-doc__list { margin-top: 0; }
}

@media (max-width: 940px) {
    .um-doc__grid { grid-template-columns: minmax(0, 1fr); gap: 20px; }
    .um-doc__toc { position: static; border-left: 1px solid var(--um-line); border-top: 4px solid var(--um-teal); }
    .um-doc__list { max-height: 46vh; overflow-y: auto; }
    .um-masthead { padding-top: 44px; }
}

@media (max-width: 620px) {
    .um-doc { padding: 0 16px 56px; }
    .um-masthead { padding-left: 16px; padding-right: 16px; }
    .um-doc__section { padding: 22px 18px 20px; border-radius: 15px; }
    .um-step { grid-template-columns: 38px minmax(0, 1fr); gap: 11px; }
    .um-step__num { width: 38px; height: 38px; font-size: 15px; border-radius: 12px; }
    .um-topbar__brand { font-size: 16px; letter-spacing: .26em; text-indent: .26em; }
}