/* ==========================================================================
   octave Ltd. — corporate site
   White-based, hairline-ruled editorial layout.
   ========================================================================== */

:root {
    /* ink & text */
    --ink: #0b1220;
    --ink-soft: #1e293b;
    --body: #4a5568;
    --muted: #8892a6;

    /* surfaces */
    --bg: #ffffff;
    --bg-soft: #f7f8fb;
    --bg-invert: #0b1220;

    /* lines */
    --line: #e4e8ef;
    --line-strong: #cfd6e2;

    /* accent */
    --accent: #1b4dd8;
    --accent-soft: #eef3ff;

    /* metrics */
    --shell: 1180px;
    --gutter: 24px;
    --header-h: 72px;
    --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

html {
    color-scheme: light;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.75;
    letter-spacing: -0.01em;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;

    /* 한글이 낱말 중간에서 끊기지 않도록 한다. */
    word-break: keep-all;
    overflow-wrap: anywhere;
}

h1,
h2,
h3,
h4 {
    margin: 0;
    font-weight: 700;
    letter-spacing: -0.035em;
    line-height: 1.25;
    color: var(--ink);
}

p {
    margin: 0;
}

ul,
ol,
dl,
dd {
    margin: 0;
    padding: 0;
}

li {
    list-style: none;
}

a {
    color: inherit;
    text-decoration: none;
}

svg {
    display: block;
}

::selection {
    background: var(--ink);
    color: #fff;
}

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
    border-radius: 2px;
}

.shell {
    width: 100%;
    max-width: var(--shell);
    margin: 0 auto;
    padding: 0 var(--gutter);
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    z-index: 200;
    padding: 12px 20px;
    background: var(--ink);
    color: #fff;
    font-size: 0.875rem;
}

.skip-link:focus {
    left: 16px;
    top: 16px;
}

/* --------------------------------------------------------------------------
   Shared type
   -------------------------------------------------------------------------- */

.eyebrow {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--muted);
}

.eyebrow .num {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
}

.eyebrow .num::after {
    content: '';
    width: 22px;
    height: 1px;
    background: var(--line-strong);
}

.eyebrow .dot {
    color: var(--line-strong);
    letter-spacing: 0;
}

.section-title {
    margin-top: 18px;
    font-size: clamp(1.75rem, 4vw, 2.75rem);
}

.section-desc {
    margin-top: 20px;
    max-width: 46ch;
    color: var(--body);
    font-size: 1.0625rem;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 52px;
    padding: 0 28px;
    border: 1px solid transparent;
    border-radius: 2px;
    font-size: 0.9375rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    transition: background-color 0.2s var(--ease), color 0.2s var(--ease),
        border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.btn:active {
    transform: translateY(1px);
}

.btn-solid {
    background: var(--ink);
    color: #fff;
}

.btn-solid:hover {
    background: var(--accent);
}

.btn-ghost {
    border-color: var(--line-strong);
    color: var(--ink);
}

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

.btn-invert {
    background: #fff;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
}

.btn-invert:hover {
    background: var(--accent);
    color: #fff;
}

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */

.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    z-index: 100;
    height: var(--header-h);
    background: rgba(255, 255, 255, 0);
    border-bottom: 1px solid transparent;
    transition: background-color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.site-header.is-stuck {
    background: rgba(255, 255, 255, 0.88);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom-color: var(--line);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-h);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--ink);
}

.brand-mark {
    width: 26px;
    height: 26px;
    flex: none;
}

.brand-text {
    display: inline-flex;
    align-items: baseline;
    gap: 6px;
}

.brand-name {
    font-size: 1.0625rem;
    font-weight: 800;
    letter-spacing: 0.06em;
}

.brand-suffix {
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--muted);
    letter-spacing: 0.02em;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 36px;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 30px;
}

.nav-list a {
    position: relative;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--ink-soft);
    transition: color 0.2s var(--ease);
}

.nav-list a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 100%;
    height: 1px;
    background: currentColor;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.25s var(--ease);
}

.nav-list a:hover,
.nav-list a.is-active {
    color: var(--accent);
}

.nav-list a:hover::after,
.nav-list a.is-active::after {
    transform: scaleX(1);
}

.nav-toggle {
    display: none;
    width: 44px;
    height: 44px;
    margin-right: -10px;
    padding: 0;
    border: 0;
    background: none;
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 1.5px;
    margin: 5px auto;
    background: var(--ink);
    transition: transform 0.25s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle[aria-expanded='true'] span:first-child {
    transform: translateY(3.25px) rotate(45deg);
}

.nav-toggle[aria-expanded='true'] span:last-child {
    transform: translateY(-3.25px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */

.hero {
    position: relative;
    padding: calc(var(--header-h) + 96px) 0 0;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(60% 55% at 78% 8%, rgba(27, 77, 216, 0.07), transparent 70%),
        radial-gradient(50% 50% at 4% 40%, rgba(11, 18, 32, 0.045), transparent 72%);
    pointer-events: none;
}

.hero-rules {
    position: absolute;
    inset: 0;
    max-width: var(--shell);
    margin: 0 auto;
    padding: 0 var(--gutter);
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    pointer-events: none;
}

.hero-rules span {
    border-left: 1px solid var(--line);
    opacity: 0.7;
}

.hero-rules span:first-child {
    border-left-color: transparent;
}

.hero .shell {
    position: relative;
}

.hero-title {
    margin-top: 26px;
    font-size: clamp(2.375rem, 6.4vw, 4.5rem);
    font-weight: 800;
    letter-spacing: -0.045em;
    line-height: 1.16;
}

.hero-lead {
    margin-top: 28px;
    max-width: 54ch;
    color: var(--body);
    font-size: clamp(1rem, 1.6vw, 1.1875rem);
    line-height: 1.85;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 40px;
}

.factstrip {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    margin-top: 96px;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.fact {
    padding: 28px 28px 28px 0;
    border-left: 1px solid var(--line);
    padding-left: 28px;
}

.fact:first-child {
    border-left: 0;
    padding-left: 0;
}

.fact dt {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
}

.fact dd {
    margin-top: 8px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--ink);
    word-break: break-word;
}

.fact dd a:hover {
    color: var(--accent);
}

/* --------------------------------------------------------------------------
   Sections
   -------------------------------------------------------------------------- */

.section {
    padding: clamp(80px, 11vw, 140px) 0;
}

.section-soft {
    background: var(--bg-soft);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.section-head {
    max-width: 780px;
    margin-bottom: clamp(48px, 6vw, 76px);
}

/* About */

.about-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: clamp(40px, 6vw, 88px);
    align-items: start;
}

.about-body p {
    color: var(--body);
    font-size: 1.0625rem;
    line-height: 1.95;
}

.about-body p + p {
    margin-top: 22px;
}

.principles {
    border-top: 1px solid var(--line);
}

.principles li {
    padding: 26px 0;
    border-bottom: 1px solid var(--line);
}

.principles h3 {
    font-size: 1.0625rem;
    letter-spacing: -0.02em;
}

.principles p {
    margin-top: 8px;
    color: var(--body);
    font-size: 0.9375rem;
    line-height: 1.8;
}

/* Business */

.biz-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    border-top: 1px solid var(--line-strong);
}

.biz-item {
    padding: 44px 36px 48px;
    border-left: 1px solid var(--line);
    background: transparent;
    transition: background-color 0.3s var(--ease);
}

.biz-item:first-child {
    border-left: 0;
    padding-left: 0;
}

.biz-item:last-child {
    padding-right: 0;
}

.biz-item:hover {
    background: rgba(255, 255, 255, 0.75);
}

.biz-num {
    display: block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.16em;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
}

.biz-item h3 {
    margin-top: 20px;
    font-size: 1.25rem;
    letter-spacing: -0.03em;
}

.biz-item > p {
    margin-top: 14px;
    color: var(--body);
    font-size: 0.9688rem;
    line-height: 1.85;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 24px;
}

.tags li {
    padding: 5px 12px;
    border: 1px solid var(--line-strong);
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--ink-soft);
    background: #fff;
}

/* Values */

.values-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    border-top: 1px solid var(--line-strong);
    border-left: 1px solid var(--line);
}

.value {
    grid-column: span 2;
    padding: 40px 34px 44px;
    border-right: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.value:nth-child(4),
.value:nth-child(5) {
    grid-column: span 3;
}

.value-en {
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--accent);
}

.value h3 {
    margin-top: 16px;
    font-size: 1.3125rem;
}

.value-desc {
    margin-top: 12px;
    color: var(--body);
    font-size: 0.9375rem;
    line-height: 1.85;
}

/* Company */

.company-grid {
    max-width: 840px;
}

.profile {
    border-top: 1px solid var(--line-strong);
}

.profile-row {
    display: grid;
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 20px;
    padding: 20px 0;
    border-bottom: 1px solid var(--line);
}

.profile-row dt {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--muted);
}

.profile-row dd {
    font-size: 0.9688rem;
    font-weight: 500;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
    word-break: keep-all;
}

.profile-row dd .sub {
    margin-left: 8px;
    color: var(--muted);
    font-weight: 400;
}

.profile-row dd a {
    border-bottom: 1px solid var(--line-strong);
    transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.profile-row dd a:hover {
    color: var(--accent);
    border-color: var(--accent);
}

/* --------------------------------------------------------------------------
   Contact
   -------------------------------------------------------------------------- */

.contact {
    padding: clamp(80px, 10vw, 128px) 0;
    background: var(--bg-invert);
    color: #fff;
}

.contact .eyebrow {
    color: rgba(255, 255, 255, 0.55);
}

.contact .eyebrow .num {
    color: #fff;
}

.contact .eyebrow .num::after {
    background: rgba(255, 255, 255, 0.3);
}

.contact-inner {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    gap: clamp(40px, 6vw, 80px);
    align-items: start;
}

.contact-title {
    margin: 20px 0 36px;
    color: #fff;
    font-size: clamp(1.625rem, 3.4vw, 2.375rem);
    line-height: 1.35;
}

.contact-meta {
    border-top: 1px solid rgba(255, 255, 255, 0.18);
}

.contact-meta > div {
    padding: 20px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.contact-meta dt {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    color: rgba(255, 255, 255, 0.5);
}

.contact-meta dd {
    margin-top: 6px;
    font-size: 0.9375rem;
    color: rgba(255, 255, 255, 0.92);
}

.contact-meta dd a {
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.contact-meta dd a:hover {
    border-color: #fff;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */

.site-footer {
    padding: 64px 0 56px;
    background: var(--bg);
    border-top: 1px solid var(--line);
}

.footer-inner {
    display: grid;
    gap: 28px;
}

.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--ink);
}

.footer-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
}

.footer-nav a {
    font-size: 0.9375rem;
    color: var(--body);
    transition: color 0.2s var(--ease);
}

.footer-nav a:hover {
    color: var(--accent);
}

.footer-legal {
    padding-top: 24px;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 0.8125rem;
    line-height: 2;
    font-variant-numeric: tabular-nums;
}

/* 항목은 통째로 줄바꿈되고, 구분자는 CSS가 넣는다. */
.footer-legal span {
    display: inline-block;
    white-space: nowrap;
}

.footer-legal span:not(:last-child)::after {
    content: '|';
    margin: 0 8px;
    color: var(--line-strong);
}

.copyright {
    color: var(--muted);
    font-size: 0.8125rem;
}

/* --------------------------------------------------------------------------
   Reveal
   -------------------------------------------------------------------------- */

.reveal {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
    transition-delay: var(--reveal-delay, 0s);
}

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

.no-js .reveal,
.reveal.is-static {
    opacity: 1;
    transform: none;
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */

/* 데스크톱 내비가 CTA와 붙기 시작하는 구간에서 살짝 줄인다. */
@media (max-width: 1080px) and (min-width: 841px) {
    .site-nav {
        gap: 24px;
    }

    .nav-list {
        gap: 22px;
    }

    .nav-list a {
        font-size: 0.875rem;
    }
}

@media (max-width: 1024px) {
    .about-grid,
    .contact-inner {
        grid-template-columns: minmax(0, 1fr);
    }

    .biz-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .biz-item:nth-child(odd) {
        border-left: 0;
        padding-left: 0;
    }

    .biz-item:nth-child(even) {
        padding-right: 0;
    }

    .biz-item:nth-child(n + 3) {
        border-top: 1px solid var(--line);
    }

    .values-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .value,
    .value:nth-child(4),
    .value:nth-child(5) {
        grid-column: span 1;
    }

    .factstrip {
        grid-template-columns: repeat(2, 1fr);
    }

    .fact {
        padding: 22px 22px 22px 22px;
        border-top: 1px solid var(--line);
    }

    .fact:nth-child(-n + 2) {
        border-top: 0;
    }

    .fact:nth-child(odd) {
        border-left: 0;
        padding-left: 0;
    }
}

@media (max-width: 840px) {
    :root {
        --gutter: 16px;
    }

    .nav-toggle {
        display: block;
    }

    .site-nav {
        position: fixed;
        inset: var(--header-h) 0 auto 0;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        padding: 8px var(--gutter) 28px;
        background: #fff;
        border-bottom: 1px solid var(--line);
        box-shadow: 0 24px 40px -28px rgba(11, 18, 32, 0.35);
        transform: translateY(-12px);
        opacity: 0;
        visibility: hidden;
        transition: opacity 0.22s var(--ease), transform 0.22s var(--ease), visibility 0.22s;
    }

    .site-nav.is-open {
        transform: none;
        opacity: 1;
        visibility: visible;
    }

    .nav-list {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }

    .nav-list a {
        display: block;
        padding: 16px 0;
        border-bottom: 1px solid var(--line);
        font-size: 1rem;
    }

    .nav-list a::after {
        display: none;
    }

    .site-header:not(.is-stuck).has-open-nav {
        background: #fff;
    }

    .hero {
        padding-top: calc(var(--header-h) + 56px);
    }

    .hero-rules {
        grid-template-columns: repeat(2, 1fr);
    }

    .factstrip {
        margin-top: 64px;
    }

    .btn {
        min-height: 50px;
        flex: 1 1 auto;
    }

    .profile-row {
        grid-template-columns: minmax(0, 1fr);
        gap: 4px;
    }

    .biz-grid {
        grid-template-columns: minmax(0, 1fr);
    }

    .biz-item {
        padding: 32px 0 36px;
        border-left: 0;
    }

    .biz-item:nth-child(n + 2) {
        border-top: 1px solid var(--line);
    }

    .values-grid {
        grid-template-columns: minmax(0, 1fr);
        border-left: 0;
    }

    .value {
        padding: 30px 0 34px;
        border-right: 0;
    }
}

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

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }

    .reveal {
        opacity: 1;
        transform: none;
    }
}

@media print {
    .site-header,
    .nav-toggle,
    .hero-rules,
    .hero-actions {
        display: none !important;
    }

    body {
        color: #000;
    }

    .contact {
        background: #fff;
        color: #000;
    }

    .contact-title,
    .contact-meta dd {
        color: #000;
    }
}