:root {
    --bg: #f6f7fb;
    --card: #ffffff;
    --text: #151821;
    --muted: #5d6475;
    --border: #e3e6ef;
    --accent: #2f6bff;
    --accent-2: #1f55d6;
    --accent-soft: #eaf0ff;
    --ok: #13854a;
    --ok-soft: #e7f6ee;
    --err: #c62828;
    --err-soft: #fdecec;
    --radius: 14px;
    color-scheme: light;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0f1218;
        --card: #171b23;
        --text: #eef1f7;
        --muted: #9aa3b5;
        --border: #262c38;
        --accent: #5b8cff;
        --accent-2: #7aa2ff;
        --accent-soft: #1b2440;
        --ok: #4cc584;
        --ok-soft: #12291e;
        --err: #ff7b7b;
        --err-soft: #2e1717;
        color-scheme: dark;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
}

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

.wrap { max-width: 860px; margin: 0 auto; padding: 0 16px; }

/* шапка */
.site-header { border-bottom: 1px solid var(--border); background: var(--card); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; height: 56px; }
.logo { font-weight: 800; font-size: 20px; color: var(--text); text-decoration: none; letter-spacing: -0.02em; }
.logo span { color: var(--accent); }
.nav { display: flex; gap: 14px; font-size: 14px; overflow-x: auto; white-space: nowrap; }
.nav a { color: var(--muted); text-decoration: none; }
.nav a:hover, .nav a[aria-current="page"] { color: var(--text); }

/* первый экран */
.hero { padding: 28px 0 8px; text-align: center; }
.hero h1 { font-size: clamp(26px, 5vw, 36px); line-height: 1.2; margin: 0 0 8px; letter-spacing: -0.02em; }
.hero .lead { color: var(--muted); margin: 0 auto 20px; max-width: 620px; }

/* инструмент */
.tool { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }

.drop {
    display: block;
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 32px 16px;
    text-align: center;
    cursor: pointer;
    transition: border-color .15s, background .15s;
}
.drop:hover, .drop.over { border-color: var(--accent); background: var(--accent-soft); }
.drop .icon { font-size: 34px; line-height: 1; }
.drop .title { font-weight: 600; margin: 10px 0 4px; }
.drop .hint { color: var(--muted); font-size: 14px; margin: 0; }
.drop input { display: none; }

.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    border: 0; border-radius: 10px; padding: 12px 20px;
    font: inherit; font-weight: 600; cursor: pointer;
    background: var(--accent); color: #fff; text-decoration: none;
}
.btn:hover { background: var(--accent-2); }
.btn[disabled] { opacity: .5; cursor: default; }
.btn.secondary { background: transparent; color: var(--text); border: 1px solid var(--border); }

.file-info { display: none; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.file-info .name { font-weight: 600; word-break: break-all; }
.file-info .meta { color: var(--muted); font-size: 14px; }

.options { display: none; margin-top: 16px; gap: 14px; flex-direction: column; }
.options fieldset { border: 0; padding: 0; margin: 0; }
.options legend { font-weight: 600; font-size: 14px; margin-bottom: 8px; }
.choices { display: flex; flex-wrap: wrap; gap: 8px; }
.choices label {
    border: 1px solid var(--border); border-radius: 10px; padding: 8px 12px; cursor: pointer; font-size: 14px;
}
.choices input { position: absolute; opacity: 0; pointer-events: none; }
.choices label:has(input:checked) { border-color: var(--accent); background: var(--accent-soft); }
.choices small { color: var(--muted); display: block; }
.num-row { display: flex; gap: 12px; flex-wrap: wrap; }
.num-row label { font-size: 14px; color: var(--muted); }
.num-row input { width: 90px; margin-left: 6px; padding: 6px 8px; border: 1px solid var(--border); border-radius: 8px; background: var(--card); color: var(--text); font: inherit; }

.actions { display: none; margin-top: 16px; gap: 10px; flex-wrap: wrap; }

.progress { display: none; margin-top: 16px; }
.bar { height: 10px; background: var(--border); border-radius: 99px; overflow: hidden; }
.bar > div { height: 100%; width: 0; background: var(--accent); transition: width .2s; }
.progress .label { display: flex; justify-content: space-between; color: var(--muted); font-size: 14px; margin-top: 6px; }

.result, .error { display: none; margin-top: 16px; border-radius: 12px; padding: 14px 16px; }
.result { background: var(--ok-soft); }
.result .head { font-weight: 600; color: var(--ok); margin: 0 0 8px; }
.result .sizes { margin: 0 0 12px; color: var(--muted); font-size: 14px; }
.error { background: var(--err-soft); color: var(--err); }

.bigfile-hint { display: none; margin-top: 14px; padding: 12px 14px; border-radius: 10px; background: var(--accent-soft); font-size: 14px; }
.bigfile-hint a { font-weight: 600; }

.unsupported { display: none; margin-bottom: 14px; padding: 12px 14px; border-radius: 10px; background: var(--err-soft); color: var(--err); font-size: 14px; }

.privacy-note { color: var(--muted); font-size: 13px; text-align: center; margin: 12px 0 0; }

/* контент */
section.content { margin: 40px 0; }
section.content h2 { font-size: 24px; line-height: 1.3; margin: 0 0 14px; letter-spacing: -0.01em; }
section.content p { margin: 0 0 12px; }

.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.steps li { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
.steps .n { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 700; font-size: 14px; }
.steps h3 { font-size: 16px; margin: 10px 0 4px; }
.steps p { color: var(--muted); font-size: 14px; margin: 0; }
@media (max-width: 640px) { .steps { grid-template-columns: 1fr; } }

.faq details { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 14px 16px; margin-bottom: 8px; }
.faq summary { font-weight: 600; cursor: pointer; }
.faq details p { margin: 10px 0 0; color: var(--muted); }

.tools-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px; }
.tools-grid a {
    display: block; background: var(--card); border: 1px solid var(--border); border-radius: 12px;
    padding: 14px 16px; text-decoration: none; color: var(--text);
}
.tools-grid a:hover { border-color: var(--accent); }
.tools-grid strong { display: block; }
.tools-grid span { color: var(--muted); font-size: 14px; }

/* подвал */
.site-footer { border-top: 1px solid var(--border); margin-top: 48px; padding: 24px 0 32px; color: var(--muted); font-size: 14px; }
.site-footer p { margin: 0 0 8px; }
.site-footer .links a { color: var(--muted); margin-right: 14px; }