:root {
    --yi-ink: #10241f;
    --yi-ink-soft: #2a433b;
    --yi-muted: #5c7168;
    --yi-paper: #f3f7f4;
    --yi-paper-deep: #e4efe8;
    --yi-accent: #0d7a5f;
    --yi-accent-deep: #085c47;
    --yi-accent-soft: #b8e0d2;
    --yi-line: rgba(16, 36, 31, 0.12);
    --yi-shadow: 0 18px 40px rgba(16, 36, 31, 0.08);
    --yi-font-display: "Bricolage Grotesque", Georgia, serif;
    --yi-font-body: "Source Sans 3", system-ui, sans-serif;
    --yi-ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--yi-ink);
    background:
        radial-gradient(1200px 600px at 12% -10%, rgba(13, 122, 95, 0.12), transparent 55%),
        radial-gradient(900px 500px at 100% 8%, rgba(184, 224, 210, 0.55), transparent 50%),
        linear-gradient(180deg, #f7faf8 0%, var(--yi-paper) 40%, #eef4f0 100%);
    font-family: var(--yi-font-body);
    font-size: 1.05rem;
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--yi-accent-deep);
    text-decoration-thickness: 1px;
    text-underline-offset: 0.18em;
}

a:hover {
    color: var(--yi-ink);
}

.yi-wrap {
    width: min(1120px, calc(100% - 2.5rem));
    margin-inline: auto;
}

.yi-top {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.9rem 1.25rem;
    background: #f3f7f4;
    border-bottom: 1px solid var(--yi-line);
}

.yi-top-brand {
    font-family: var(--yi-font-display);
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: -0.02em;
    color: var(--yi-ink);
    text-decoration: none;
}

.yi-top-cta {
    display: inline-flex;
    align-items: center;
    padding: 0.55rem 1rem;
    border-radius: 999px;
    background: var(--yi-ink);
    color: #f7faf8;
    font-weight: 600;
    font-size: 0.92rem;
    text-decoration: none;
    transition: transform 0.35s var(--yi-ease), background 0.25s ease;
}

.yi-top-cta:hover {
    background: var(--yi-accent-deep);
    color: #fff;
    transform: translateY(-1px);
}

.yi-hero {
    position: relative;
    min-height: min(100vh, 920px);
    display: grid;
    align-items: end;
    overflow: hidden;
    isolation: isolate;
}

.yi-hero-plane {
    position: absolute;
    inset: 0;
    z-index: -1;
    background:
        linear-gradient(180deg, rgba(243, 247, 244, 0.15) 0%, rgba(16, 36, 31, 0.55) 72%, rgba(16, 36, 31, 0.82) 100%),
        radial-gradient(ellipse 80% 55% at 70% 35%, rgba(13, 122, 95, 0.45), transparent 60%),
        linear-gradient(135deg, #1a4a3d 0%, #0d2a24 42%, #163a32 100%);
}

.yi-hero-plane::after {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
    background-size: 72px 72px;
    mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 85%);
    opacity: 0.85;
}

.yi-hero-inner {
    width: min(1120px, calc(100% - 2.5rem));
    margin: 0 auto;
    padding: 7rem 0 4.5rem;
    color: #f4faf7;
}

.yi-brand {
    margin: 0 0 1rem;
    font-family: var(--yi-font-display);
    font-size: clamp(2.4rem, 7vw, 4.6rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 0.95;
}

.yi-headline {
    margin: 0 0 1rem;
    max-width: 14ch;
    font-family: var(--yi-font-display);
    font-size: clamp(1.65rem, 3.8vw, 2.6rem);
    font-weight: 600;
    letter-spacing: -0.03em;
    line-height: 1.15;
}

.yi-lede {
    margin: 0 0 1.75rem;
    max-width: 34rem;
    font-size: 1.12rem;
    color: rgba(244, 250, 247, 0.86);
}

.yi-hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.yi-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 3rem;
    padding: 0.7rem 1.25rem;
    border: 1px solid transparent;
    border-radius: 0.55rem;
    font-family: var(--yi-font-body);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    cursor: pointer;
    transition: transform 0.3s var(--yi-ease), background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.yi-btn:hover {
    transform: translateY(-2px);
}

.yi-btn-primary {
    background: #f4faf7;
    color: var(--yi-ink);
}

.yi-btn-primary:hover {
    background: #fff;
    color: var(--yi-ink);
}

.yi-btn-primary:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    transform: none;
}

.yi-btn-ghost {
    background: transparent;
    border-color: rgba(244, 250, 247, 0.35);
    color: #f4faf7;
}

.yi-btn-ghost:hover {
    border-color: #f4faf7;
    color: #fff;
}

.yi-btn-block {
    width: 100%;
}

.yi-section {
    padding: 5rem 0;
}

.yi-section-title {
    margin: 0 0 0.65rem;
    font-family: var(--yi-font-display);
    font-size: clamp(1.8rem, 3.5vw, 2.5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.15;
}

.yi-section-lede {
    margin: 0 0 2.25rem;
    max-width: 36rem;
    color: var(--yi-muted);
    font-size: 1.08rem;
}

.yi-corners {
    background: linear-gradient(180deg, transparent, rgba(228, 239, 232, 0.65));
}

.yi-corner-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 1.5rem 2rem;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    counter-reset: none;
}

.yi-corner {
    padding-top: 1rem;
    border-top: 1px solid var(--yi-line);
}

.yi-corner-index {
    display: block;
    margin-bottom: 0.55rem;
    color: var(--yi-accent);
    font-family: var(--yi-font-display);
    font-weight: 700;
    font-size: 0.95rem;
    letter-spacing: 0.06em;
}

.yi-corner h3 {
    margin: 0 0 0.4rem;
    font-family: var(--yi-font-display);
    font-size: 1.45rem;
    letter-spacing: -0.02em;
}

.yi-corner p {
    margin: 0;
    color: var(--yi-ink-soft);
}

.yi-run-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 0;
    border-top: 1px solid var(--yi-line);
}

.yi-run-list li {
    padding: 1.05rem 0;
    border-bottom: 1px solid var(--yi-line);
    font-size: 1.2rem;
    font-weight: 500;
    letter-spacing: -0.01em;
}

.yi-plans {
    background:
        linear-gradient(180deg, rgba(13, 122, 95, 0.06), transparent 40%),
        var(--yi-paper-deep);
}

.yi-plan-row {
    display: grid;
    gap: 1.25rem;
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.yi-plan {
    padding: 1.5rem 0 0;
    border-top: 2px solid var(--yi-ink);
}

.yi-plan-featured {
    border-top-color: var(--yi-accent);
}

.yi-plan h3 {
    margin: 0 0 0.5rem;
    font-family: var(--yi-font-display);
    font-size: 1.35rem;
}

.yi-plan-price {
    margin: 0 0 0.85rem;
    font-family: var(--yi-font-display);
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
}

.yi-plan-price span {
    margin-left: 0.2rem;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--yi-muted);
}

.yi-plan p:last-child {
    margin: 0;
    color: var(--yi-ink-soft);
}

.yi-inquiry {
    padding-bottom: 6rem;
}

.yi-inquiry-wrap {
    display: grid;
    gap: 2.5rem;
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    align-items: start;
}

.yi-inquiry-contact {
    margin: 1.5rem 0 0;
    color: var(--yi-muted);
}

.yi-form {
    display: grid;
    gap: 1rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.72);
    border: 1px solid var(--yi-line);
    border-radius: 1rem;
    box-shadow: var(--yi-shadow);
}

.yi-field {
    display: grid;
    gap: 0.35rem;
}

.yi-field label {
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--yi-ink-soft);
}

.yi-optional {
    font-weight: 400;
    color: var(--yi-muted);
}

.yi-field input {
    width: 100%;
    min-height: 2.85rem;
    padding: 0.65rem 0.85rem;
    border: 1px solid var(--yi-line);
    border-radius: 0.55rem;
    background: #fff;
    color: var(--yi-ink);
    font: inherit;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.yi-field input:focus {
    outline: none;
    border-color: var(--yi-accent);
    box-shadow: 0 0 0 3px rgba(13, 122, 95, 0.15);
}

.yi-form .yi-btn-primary {
    background: var(--yi-accent);
    color: #fff;
    margin-top: 0.35rem;
}

.yi-form .yi-btn-primary:hover:not(:disabled) {
    background: var(--yi-accent-deep);
    color: #fff;
}

.yi-status {
    margin: 0.25rem 0 0;
    font-size: 0.95rem;
}

.yi-status-success {
    color: var(--yi-accent-deep);
}

.yi-status-error {
    color: #9b1c1c;
}

.yi-footer {
    border-top: 1px solid var(--yi-line);
    padding: 1.5rem 0 2rem;
    background: rgba(255, 255, 255, 0.35);
}

.yi-footer-inner {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem 1.5rem;
    justify-content: space-between;
    color: var(--yi-muted);
    font-size: 0.95rem;
}

.yi-footer a {
    color: inherit;
}

[data-reveal] {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.7s var(--yi-ease), transform 0.7s var(--yi-ease);
}

[data-reveal].is-visible {
    opacity: 1;
    transform: none;
}

@media (max-width: 900px) {
    .yi-plan-row,
    .yi-inquiry-wrap {
        grid-template-columns: 1fr;
    }

    .yi-hero-inner {
        padding-top: 6rem;
        padding-bottom: 3.5rem;
    }
}

@media (max-width: 640px) {
    .yi-corner-list {
        grid-template-columns: 1fr;
    }

    .yi-section {
        padding: 3.5rem 0;
    }

    .yi-run-list li {
        font-size: 1.05rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    [data-reveal] {
        transition: none !important;
        opacity: 1;
        transform: none;
    }
}