:root {
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #94a3b8;
    --surface: #ffffff;
    --glass-bg: rgba(255, 255, 255, 0.55);
    --glass-border: rgba(0, 0, 0, 0.06);
    --border-subtle: rgba(0, 0, 0, 0.06);
    --accent: #2563eb;
    --accent-muted: rgba(37, 99, 235, 0.10);
    --accent-border: rgba(37, 99, 235, 0.25);
    --radius-full: 9999px;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    color: var(--text-primary);
    background: var(--surface);
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

#particleCanvas {
    position: fixed;
    inset: 0;
    z-index: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.lp-nav {
    position: fixed;
    top: 16px;
    left: 50%;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 8px;
    width: max-content;
    max-width: calc(100% - 32px);
    padding: 6px 8px 6px 16px;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    background: var(--glass-bg);
    box-shadow: 0 2px 16px rgba(0, 0, 0, 0.04);
    backdrop-filter: saturate(180%) blur(16px);
    -webkit-backdrop-filter: saturate(180%) blur(16px);
    transform: translateX(-50%);
}
.lp-nav__logo { display: flex; align-items: center; flex-shrink: 0; margin-right: 8px; text-decoration: none; }
.lp-nav__logo img { height: 22px; }
.lp-nav__links { display: flex; align-items: center; gap: 4px; }
.lp-nav__links a,
.lp-nav__login {
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    text-decoration: none;
    transition: color 0.15s, background 0.15s;
}
.lp-nav__links a { padding: 6px 12px; }
.lp-nav__links a:hover { color: var(--text-primary); background: rgba(0, 0, 0, 0.04); }
.lp-nav__spacer { flex: 1; min-width: 12px; }
.lp-nav__login { flex-shrink: 0; padding: 6px 14px; }
.lp-nav button.lp-nav__login { border: 0; background: transparent; font-family: inherit; cursor: pointer; }
.lp-nav__login:hover { color: var(--text-primary); }
.lp-nav__cta {
    flex-shrink: 0;
    padding: 7px 18px;
    border-radius: var(--radius-full);
    color: #ffffff;
    background: var(--text-primary);
    font-size: 13px;
    font-weight: 600;
    text-decoration: none;
    transition: opacity 0.15s;
}
.lp-nav__cta:hover { color: #ffffff; opacity: 0.85; }
.lp-nav__burger {
    display: none;
    padding: 4px 8px;
    border: 0;
    color: var(--text-secondary);
    background: transparent;
    font-size: 20px;
    cursor: pointer;
}

.help-hero {
    position: relative;
    z-index: 2;
    min-height: 72vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 24px 64px;
    text-align: center;
}
.help-hero__inner { max-width: 640px; }
.help-hero__logo { height: 42px; margin-bottom: 24px; }
.help-hero__eyebrow {
    margin-bottom: 12px;
    color: var(--accent);
    font-size: 13px;
    font-weight: 600;
}
.help-hero__title {
    margin-bottom: 18px;
    font-size: 48px;
    font-weight: 300;
    line-height: 1.2;
}
.help-hero__sub {
    max-width: 540px;
    margin: 0 auto 32px;
    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1.8;
}
.help-hero__actions { display: flex; align-items: center; justify-content: center; gap: 12px; }

.lp-button {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 0 22px;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-full);
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: opacity 0.2s, background 0.2s, transform 0.2s;
}
.lp-button--primary { border-color: var(--text-primary); color: var(--surface); background: var(--text-primary); }
.lp-button--primary:hover { color: var(--surface); opacity: 0.85; transform: translateY(-1px); }
.lp-button--secondary { color: var(--text-secondary); background: var(--glass-bg); backdrop-filter: blur(8px); }
.lp-button--secondary:hover { color: var(--text-primary); background: rgba(0, 0, 0, 0.04); }

.lp-section {
    position: relative;
    z-index: 2;
    max-width: 960px;
    margin: 0 auto;
    padding: 72px 24px;
    scroll-margin-top: 76px;
}
.lp-section__header { margin-bottom: 36px; text-align: center; }
.lp-section__title { margin-bottom: 10px; font-size: 28px; font-weight: 600; line-height: 1.3; }
.lp-section__sub { max-width: 620px; margin: 0 auto; color: var(--text-tertiary); font-size: 15px; line-height: 1.7; }

.help-steps { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.help-step,
.help-template {
    border: 1px solid var(--border-subtle);
    border-radius: 16px;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}
.help-step { min-width: 0; padding: 28px; }
.help-step__number { display: block; margin-bottom: 14px; color: var(--accent); font-family: Georgia, serif; font-size: 12px; }
.help-step:nth-child(2) .help-step__number { color: #059669; }
.help-step:nth-child(3) .help-step__number { color: #d946ef; }
.help-step:nth-child(4) .help-step__number { color: #d97706; }
.help-step h3 { margin-bottom: 8px; font-size: 18px; font-weight: 600; }
.help-step p { color: var(--text-secondary); font-size: 14px; line-height: 1.7; }

.help-templates { display: grid; gap: 14px; }
.help-template {
    min-width: 0;
    display: grid;
    grid-template-columns: 48px minmax(0, 1fr) auto;
    align-items: center;
    gap: 20px;
    padding: 24px;
}
.help-template__icon {
    width: 48px;
    height: 48px;
    display: grid;
    place-items: center;
    border-radius: 12px;
    color: var(--accent);
    background: var(--accent-muted);
    font-size: 22px;
}
.help-template__icon--green { color: #059669; background: rgba(5, 150, 105, 0.10); }
.help-template__body h3 { margin-bottom: 7px; font-size: 18px; font-weight: 600; }
.help-template__body p { margin-bottom: 9px; color: var(--text-secondary); font-size: 14px; line-height: 1.65; }
.help-template__body span { color: var(--text-tertiary); font-size: 12px; }
.help-template__body span i { margin-right: 4px; color: #22c55e; }
.help-template__action { white-space: nowrap; }

.help-checklist {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-top: 1px solid var(--border-subtle);
    border-bottom: 1px solid var(--border-subtle);
    list-style: none;
}
.help-checklist li { min-width: 0; padding: 24px 18px; }
.help-checklist li + li { border-left: 1px solid var(--border-subtle); }
.help-checklist li > span {
    width: 24px;
    height: 24px;
    display: grid;
    place-items: center;
    margin-bottom: 14px;
    border-radius: 50%;
    color: var(--accent);
    background: var(--accent-muted);
    font-size: 12px;
    font-weight: 700;
}
.help-checklist h3 { margin-bottom: 6px; font-size: 15px; font-weight: 600; }
.help-checklist p { color: var(--text-secondary); font-size: 13px; line-height: 1.65; }

.help-support {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 40px;
    padding: 34px 36px;
    border: 1px solid var(--accent-border);
    border-radius: 16px;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
}
.help-support__eyebrow { margin-bottom: 10px; color: var(--accent); font-size: 12px; font-weight: 600; }
.help-support h2 { margin-bottom: 9px; font-size: 23px; font-weight: 600; }
.help-support__copy > p:last-child { max-width: 560px; color: var(--text-secondary); font-size: 14px; line-height: 1.7; }
.help-support__action { display: flex; flex-direction: column; align-items: flex-end; gap: 12px; }
.help-support__links { display: flex; gap: 16px; }
.help-support__links a { color: var(--text-tertiary); font-size: 12px; text-decoration: none; }
.help-support__links a:hover { color: var(--text-secondary); }
.help-notice { margin-bottom: 18px; padding: 10px 12px; border-radius: 6px; color: #92400e; background: rgba(245, 158, 11, 0.12); font-size: 13px; }

.lp-footer {
    position: relative;
    z-index: 2;
    max-width: 960px;
    margin: 0 auto;
    padding: 32px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--text-tertiary);
    font-size: 12px;
}
.lp-footer__links { display: flex; gap: 20px; }
.lp-footer a { color: var(--text-tertiary); text-decoration: none; transition: color 0.15s; }
.lp-footer a:hover { color: var(--text-secondary); }

.lp-reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}
.lp-reveal--visible { opacity: 1; transform: translateY(0); }

@media (prefers-color-scheme: dark) {
    html:not([data-theme]) {
        --text-primary: #e2e8f0;
        --text-secondary: #94a3b8;
        --text-tertiary: #64748b;
        --surface: #0c1222;
        --glass-bg: rgba(15, 23, 42, 0.6);
        --glass-border: rgba(255, 255, 255, 0.06);
        --border-subtle: rgba(255, 255, 255, 0.06);
        --accent-muted: rgba(37, 99, 235, 0.12);
        --accent-border: rgba(37, 99, 235, 0.3);
    }
    html:not([data-theme]) .lp-nav__cta,
    html:not([data-theme]) .lp-button--primary { color: #0f172a; background: #e2e8f0; border-color: #e2e8f0; }
}

@media (max-width: 768px) {
    .lp-nav__links { display: none; }
    .lp-nav__burger { display: block; }
    .lp-nav__links.open {
        position: absolute;
        top: 56px;
        left: 0;
        right: 0;
        display: flex;
        flex-direction: column;
        align-items: stretch;
        gap: 2px;
        padding: 8px;
        border: 1px solid var(--glass-border);
        border-radius: 12px;
        background: var(--surface);
        box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
        backdrop-filter: blur(16px);
    }
    .lp-nav__links.open a { text-align: center; }
    .help-hero { min-height: 68vh; padding: 112px 20px 52px; }
    .help-hero__title { font-size: 38px; }
    .help-hero__sub { font-size: 15px; }
    .lp-section { padding: 56px 20px; }
    .help-steps { grid-template-columns: 1fr; }
    .help-template { grid-template-columns: 44px minmax(0, 1fr); }
    .help-template__icon { width: 44px; height: 44px; }
    .help-template__action { grid-column: 1 / -1; width: 100%; }
    .help-checklist { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .help-checklist li:nth-child(3) { border-left: 0; border-top: 1px solid var(--border-subtle); }
    .help-checklist li:nth-child(4) { border-top: 1px solid var(--border-subtle); }
    .help-support { grid-template-columns: 1fr; gap: 24px; padding: 28px; }
    .help-support__action { align-items: flex-start; }
    .lp-footer { flex-direction: column; gap: 12px; text-align: center; }
}

@media (max-width: 480px) {
    .lp-nav { padding-left: 12px; }
    .lp-nav__logo { margin-right: 0; }
    .lp-nav__login { display: none; }
    .lp-nav__cta { padding: 7px 14px; }
    .help-hero__actions { flex-direction: column; }
    .help-hero__actions .lp-button { width: 100%; max-width: 240px; }
    .help-checklist { grid-template-columns: 1fr; }
    .help-checklist li + li { border-top: 1px solid var(--border-subtle); border-left: 0; }
    .help-support { padding: 24px 20px; }
    .help-support__action .lp-button { width: 100%; max-width: 100%; overflow-wrap: anywhere; }
    .lp-footer__links { flex-wrap: wrap; justify-content: center; gap: 12px 18px; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    .lp-reveal { opacity: 1; transform: none; transition: none; }
}