:root {
    --bg: #eef1f6;
    --text: #0f172a;
    --muted: #64748b;
    --card: #ffffff;
    --line: #d8dee8;
    --primary: #5b5cf6;
    --primary-2: #ad46ff;
    --btn-dark: #0f1b38;
    --footer-bg: #ffffff;
}
body[data-theme="dark"] {
    --bg: #0b1220;
    --text: #e5e7eb;
    --muted: #94a3b8;
    --card: #111827;
    --line: #1f2937;
    --btn-dark: #0f172a;
    --footer-bg: #0f172a;
}
* { box-sizing: border-box; }
body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: "Segoe UI", "PingFang SC", "Noto Sans SC", sans-serif;
}
a { color: inherit; text-decoration: none; }
.container { width: min(1080px, calc(100% - 32px)); margin: 0 auto; }
.topbar {
    height: 78px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 28px; }
.beta { font-size: 11px; color: #4f46e5; border: 1px solid #c7d2fe; border-radius: 999px; padding: 2px 8px; font-weight: 700; }
.nav { display: flex; align-items: center; gap: 14px; color: #334155; font-size: 14px; }
body[data-theme="dark"] .nav { color: #cbd5e1; }
.lang-select {
    height: 36px;
    border: 1px solid #d1d5db;
    border-radius: 10px;
    background: #fff;
    color: #334155;
    padding: 0 10px;
    font-weight: 600;
}
.theme-toggle {
    width: 36px;
    height: 36px;
    border: 1px solid #d1d5db;
    border-radius: 999px;
    background: #fff;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    line-height: 0;
}
.theme-toggle svg { width: 18px; height: 18px; }
body[data-theme="dark"] .lang-select,
body[data-theme="dark"] .theme-toggle {
    background: #111827;
    border-color: #334155;
    color: #e5e7eb;
}
.hero { text-align: center; padding: 28px 0 10px; }
.hero h1 {
    margin: 0;
    font-size: clamp(34px, 6vw, 56px);
    line-height: 1.1;
    letter-spacing: -0.02em;
}
.hero p {
    margin: 16px auto 0;
    color: var(--muted);
    max-width: 760px;
    font-size: 18px;
    line-height: 1.6;
}
.cards {
    margin-top: 26px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
}
.card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 16px;
    box-shadow: 0 8px 22px rgba(15, 23, 42, .08);
}
.card h3 { margin: 0; font-size: 18px; }
.card p { margin: 10px 0 0; color: var(--muted); line-height: 1.6; font-size: 14px; }
.layout {
    margin: 20px 0 50px;
    display: grid;
    grid-template-columns: 1.2fr .8fr;
    gap: 14px;
}
.form-grid {
    display: grid;
    gap: 12px;
    margin-top: 12px;
}
.field label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--muted);
}
.field input,
.field select,
.field textarea {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: var(--card);
    color: var(--text);
    padding: 10px 12px;
    font-size: 14px;
}
.field textarea { min-height: 130px; resize: vertical; }
.actions { display: flex; gap: 10px; align-items: center; }
.btn {
    border: 1px solid transparent;
    border-radius: 10px;
    height: 42px;
    padding: 0 18px;
    font-weight: 700;
    font-size: 14px;
    cursor: pointer;
}
.btn-primary {
    color: #fff;
    background: linear-gradient(90deg, var(--primary) 0%, var(--primary-2) 100%);
    box-shadow: 0 10px 24px rgba(99, 102, 241, .25);
}
.btn-ghost { background: #f2f5fa; border-color: #d7dfea; color: #0f172a; }
body[data-theme="dark"] .btn-ghost { background: #111827; border-color: #334155; color: #e5e7eb; }
.note { margin: 8px 0 0; color: var(--muted); font-size: 12px; }
.note.success { color: #16a34a; }
.note.error { color: #dc2626; }
.info-list { margin: 10px 0 0; padding: 0; list-style: none; }
.info-list li { padding: 8px 0; border-bottom: 1px dashed var(--line); color: var(--muted); font-size: 14px; }
.info-list li:last-child { border-bottom: none; }
footer {
    border-top: 1px solid var(--line);
    background: var(--footer-bg);
    padding: 22px 0 32px;
    color: #64748b;
    text-align: center;
    font-size: 14px;
}
@media (max-width: 900px) {
    .cards { grid-template-columns: 1fr; }
    .layout { grid-template-columns: 1fr; }
    .topbar { height: 70px; }
    .brand { font-size: 24px; }
}