:root {
    --bg: #0f0f10;
    --panel: #17181a;
    --panel-2: #1d1f22;
    --border: #2b2d31;
    --text: #e8e8e8;
    --muted: #9aa0a6;
    --accent: #ff7a1a;
    --accent-hover: #ff8f40;
    --accent-dark: #b35100;
    --ok-bg: #14210f;
    --ok-border: #5a8f3c;
    --warn-bg: #2a2205;
    --warn-border: #ffc107;
    --err-bg: #2a1211;
    --err-border: #ef5350;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: Arial, Helvetica, sans-serif;
    font-size: 16px;
    line-height: 1.6;
}

a { color: var(--accent); }
a:hover { color: var(--accent-hover); }

.wrap {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 16px;
}

/* ---------- Header ---------- */
.site-header {
    background: var(--panel);
    border-bottom: 2px solid var(--accent);
    position: sticky;
    top: 0;
    z-index: 100;
}
.header-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding-top: 10px;
    padding-bottom: 10px;
    position: relative;
}
.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 19px;
    font-weight: bold;
    color: var(--text);
    text-decoration: none;
    letter-spacing: 0.4px;
    white-space: nowrap;
}
.logo span { color: var(--accent); }
.logo-icon {
    width: 24px;
    height: 24px;
    flex: none;
    transition: transform 0.6s ease;
}
.logo:hover .logo-icon { transform: rotate(180deg); }

.nav-toggle { display: none; }
.burger {
    display: none;
    margin-left: auto;
    width: 40px;
    height: 40px;
    border: 1px solid var(--border);
    background: var(--panel-2);
    cursor: pointer;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
}
.burger span {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--accent);
    transition: transform 0.25s ease, opacity 0.2s ease;
}
.nav-toggle:checked ~ .burger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle:checked ~ .burger span:nth-child(2) { opacity: 0; }
.nav-toggle:checked ~ .burger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.site-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 2px 13px;
    margin-left: auto;
}
.site-nav a {
    color: var(--muted);
    text-decoration: none;
    font-size: 13px;
    padding: 4px 0;
    border-bottom: 2px solid transparent;
    transition: color 0.15s ease, border-color 0.15s ease;
}
.site-nav a:hover,
.site-nav a.active {
    color: var(--text);
    border-bottom-color: var(--accent);
}

@media (max-width: 920px) {
    .burger { display: flex; }
    .site-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        margin: 0 -16px;
        flex-direction: column;
        gap: 0;
        background: var(--panel);
        border-top: 1px solid var(--border);
        border-bottom: 2px solid var(--accent);
        z-index: 99;
    }
    .nav-toggle:checked ~ .site-nav { display: flex; animation: navDrop 0.22s ease; }
    .site-nav a {
        padding: 12px 16px;
        font-size: 15px;
        border-bottom: 1px solid var(--border);
    }
    .site-nav a:last-child { border-bottom: none; }
    .site-nav a.active { border-left: 3px solid var(--accent); padding-left: 13px; color: var(--text); }
    .site-nav a:hover { background: var(--panel-2); }
}
@keyframes navDrop {
    from { opacity: 0; transform: translateY(-6px); }
    to   { opacity: 1; transform: none; }
}

/* ---------- Footer ---------- */
.site-footer {
    background: var(--panel);
    border-top: 1px solid var(--border);
    margin-top: 40px;
    padding: 24px 0;
    font-size: 14px;
    color: var(--muted);
}
.site-footer .wrap {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.footer-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 4px 16px;
}
.footer-nav a { color: var(--muted); text-decoration: none; }
.footer-nav a:hover { color: var(--accent); }
.footer-note { font-size: 13px; }

/* ---------- Content / calculator ---------- */
.content-section {
    margin: 20px auto;
    padding: 20px 0;
    line-height: 1.6;
}
h1 {
    font-size: 26px;
    line-height: 1.3;
    margin: 24px 0 8px;
}
.content-section h2 { color: var(--accent); margin-top: 25px; }
.content-section h3 { color: var(--text); margin-top: 25px; }
.content-section p { color: var(--text); }
.content-section ul { padding-left: 20px; }
.content-section li { margin: 8px 0; }
.lead { color: var(--muted); margin-top: 0; }

.calculator-container {
    margin: 10px auto;
    padding: 14px;
    border: 1px solid var(--border);
    background: var(--panel);
}
.calculator-input { margin: 15px 0; }
.calculator-input label {
    display: block;
    margin-bottom: 10px;
    font-weight: bold;
}
.calculator-input input,
.calculator-input select {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    background: var(--panel-2);
    color: var(--text);
    font-size: 16px;
}
.calculator-input input:focus,
.calculator-input select:focus {
    outline: 2px solid var(--accent);
    outline-offset: -1px;
}
.input-hint {
    font-size: 13px;
    color: var(--muted);
    margin-top: 6px;
}
.size-row { display: flex; gap: 8px; }
.size-row select, .size-row input { flex: 1; min-width: 0; }

.who-toggle {
    display: flex;
    gap: 8px;
    margin-bottom: 8px;
    flex-wrap: wrap;
}
.who-toggle button {
    flex: 1;
    min-width: 120px;
    padding: 9px 8px;
    border: 2px solid var(--accent);
    background: transparent;
    color: var(--accent);
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
    transition: background 0.15s, color 0.15s;
}
.who-toggle button.active {
    background: var(--accent);
    color: #111;
}

.calculate-btn {
    background: var(--accent);
    color: #111;
    padding: 12px 20px;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    width: 100%;
    margin-top: 10px;
}
.calculate-btn:hover { background: var(--accent-hover); }

.result {
    margin-top: 20px;
    padding: 15px;
    background: var(--panel-2);
    border-left: 4px solid var(--accent);
    display: none;
}
.result.active { display: block; }
.result h3 { margin-top: 0; color: var(--accent); }

.dose-highlight {
    font-size: 1.45rem;
    font-weight: bold;
    color: var(--accent);
}
.dose-row {
    background: var(--panel);
    border-left: 3px solid var(--border);
    padding: 8px 12px;
    margin: 8px 0;
}
.dose-row-primary {
    background: #241505;
    border-left: 3px solid var(--accent);
    padding: 8px 12px;
    margin: 8px 0;
}
.dose-row-primary .dose-highlight { font-size: 1.7rem; }

.info-note {
    background: var(--ok-bg);
    border-left: 4px solid var(--ok-border);
    padding: 10px;
    margin-top: 10px;
    font-size: 14px;
}
.warning {
    background: var(--warn-bg);
    border-left: 4px solid var(--warn-border);
    padding: 10px;
    margin-top: 15px;
    font-size: 14px;
}
.error-block {
    background: var(--err-bg);
    border-left: 4px solid var(--err-border);
    padding: 10px;
    margin-top: 15px;
    display: none;
    font-size: 14px;
}
.result-params {
    font-size: 14px;
    color: var(--muted);
    margin-bottom: 12px;
    padding: 8px 10px;
    background: var(--panel);
}
.result-params span { display: inline-block; margin-right: 16px; }
.result-params strong { color: var(--text); }

/* ---------- Tables ---------- */
.dose-table {
    width: 100%;
    border-collapse: collapse;
    margin: 10px 0;
    font-size: 14px;
}
.dose-table th,
.dose-table td {
    border: 1px solid var(--border);
    padding: 8px 10px;
    text-align: left;
}
.dose-table th {
    background: var(--panel-2);
    font-weight: bold;
    color: var(--accent);
}
.dose-table tr:nth-child(even) { background: var(--panel); }
.table-scroll { overflow-x: auto; }

/* ---------- FAQ ---------- */
.faq details {
    border: 1px solid var(--border);
    background: var(--panel);
    margin: 8px 0;
}
.faq summary {
    cursor: pointer;
    padding: 12px 14px;
    font-weight: bold;
    list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before {
    content: "+";
    color: var(--accent);
    font-weight: bold;
    display: inline-block;
    width: 20px;
}
.faq details[open] summary::before { content: "\2013"; }
.faq details p {
    margin: 0;
    padding: 0 14px 14px 34px;
    color: var(--muted);
}

/* ---------- 404 ---------- */
.err-page { text-align: center; padding: 60px 0; }
.err-page .code { font-size: 72px; font-weight: bold; color: var(--accent); }

@media (max-width: 600px) {
    h1 { font-size: 22px; }
}


/* ---------- Calculator cards (homepage) ---------- */
.calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(255px, 1fr));
    gap: 12px;
    margin: 16px 0;
}
.calc-card {
    display: flex;
    gap: 12px;
    align-items: flex-start;
    padding: 14px;
    border: 1px solid var(--border);
    background: var(--panel);
    text-decoration: none;
    color: var(--text);
    transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}
.calc-card:hover {
    transform: translateY(-3px);
    border-color: var(--accent);
    background: var(--panel-2);
    color: var(--text);
}
.calc-card .card-icon {
    width: 34px;
    height: 34px;
    flex: none;
    color: var(--accent);
}
.calc-card:hover .card-icon { animation: iconPop 0.3s ease; }
.calc-card b { display: block; margin-bottom: 3px; }
.calc-card small { color: var(--muted); font-size: 13px; line-height: 1.45; display: block; }
@keyframes iconPop {
    0% { transform: scale(1); }
    50% { transform: scale(1.12); }
    100% { transform: scale(1); }
}

/* ---------- Animations ---------- */
main .content-section { animation: fadeUp 0.45s ease both; }
.result.active { animation: fadeUp 0.3s ease; }
.calculate-btn { transition: background 0.15s ease, transform 0.12s ease; }
.calculate-btn:active { transform: scale(0.985); }
.faq details { transition: border-color 0.15s ease; }
.faq details[open] { border-color: var(--accent-dark); }
.dose-table tbody tr { transition: background 0.12s ease; }
.dose-table tbody tr:hover { background: var(--panel-2); }
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: none; }
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation: none !important; transition: none !important; }
    html { scroll-behavior: auto; }
}