:root {
    --bg: #d6e0d2;
    --text: #1a1a1a;
    --muted: #5a6355;
    --accent: #2f4a35;
}

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

html, body {
    height: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
        "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ─── Navigation ─────────────────────────────────────── */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 2.5rem;
    background: transparent;
}

.nav-left {
    display: flex;
    align-items: baseline;
    gap: 2.5rem;
}

.brand {
    font-size: 1.15rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-decoration: none;
    color: var(--text);
}

.brand:hover {
    opacity: 0.6;
}

.nav-link {
    font-size: 0.95rem;
    text-decoration: none;
    color: var(--text);
    letter-spacing: 0.04em;
    transition: opacity 0.15s ease;
}

.nav-link:hover {
    opacity: 0.55;
}

.nav-right {
    display: flex;
    gap: 1rem;
}

.lang-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 0.85rem;
    font-family: inherit;
    color: var(--muted);
    letter-spacing: 0.03em;
    padding: 0.2rem 0.4rem;
    transition: color 0.15s ease;
}

.lang-btn:hover {
    color: var(--text);
}

.lang-btn.active {
    color: var(--text);
    font-weight: 600;
    border-bottom: 1.5px solid var(--text);
}

/* ─── Main content ───────────────────────────────────── */
main {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 6rem 2rem 4rem;
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 500;
    letter-spacing: -0.02em;
}

.hero-sub {
    margin-top: 1rem;
    font-size: 1rem;
    color: var(--muted);
    letter-spacing: 0.06em;
}

.placeholder {
    font-size: 1.4rem;
    color: var(--muted);
    letter-spacing: 0.08em;
}

/* ─── Mobile ─────────────────────────────────────────── */
@media (max-width: 640px) {
    nav {
        padding: 1rem 1.25rem;
    }
    .nav-left {
        gap: 1.25rem;
    }
    .brand {
        font-size: 1rem;
    }
    .nav-link {
        font-size: 0.85rem;
    }
    .lang-btn {
        font-size: 0.78rem;
    }
}