:root {
    --background: #071425;
    --foreground: #f5fbff;
    --card: #10243a;
    --primary: #4ee7c5;
    --secondary: #18324c;
    --muted: #173049;
    --muted-foreground: #a8bdd0;
    --border: #2b4762;
    --input: #31506b;
    --light: #f3f8fb;
    --ink: #10243a;
    --danger: #ffb3ad;
    --warning: #ffe39a;
    --radius: .9rem;
    --content: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--background); color: var(--foreground); font-family: Arial, "Noto Sans KR", sans-serif; line-height: 1.65; }
a { color: inherit; }
button, input, select { font: inherit; }
.skip-link { position: fixed; z-index: 100; top: .75rem; left: .75rem; padding: .7rem 1rem; color: #071425; background: var(--primary); transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
:focus-visible { outline: 3px solid var(--primary); outline-offset: 3px; }

.site-header { position: sticky; z-index: 20; top: 0; height: 76px; display: flex; align-items: center; justify-content: space-between; padding: 0 max(24px, calc((100vw - var(--content)) / 2)); border-bottom: 1px solid rgba(78, 231, 197, .16); background: rgba(7, 20, 37, .88); backdrop-filter: blur(18px); }
.brand { font-size: 1.05rem; font-weight: 800; letter-spacing: .08em; text-decoration: none; }
.brand span { color: var(--primary); }
nav { display: flex; align-items: center; gap: 1.6rem; }
nav a { color: var(--muted-foreground); font-size: .92rem; text-decoration: none; }
nav a:hover { color: var(--foreground); }
nav .nav-cta { padding: .55rem .9rem; border: 1px solid var(--primary); border-radius: 999px; color: var(--primary); }

.hero { position: relative; min-height: 720px; display: grid; grid-template-columns: 1.05fr .95fr; align-items: center; gap: 3rem; max-width: var(--content); margin: 0 auto; padding: 6rem 24px 7rem; overflow: hidden; }
.hero-grid { position: absolute; inset: 0 45% 0 auto; width: 58%; opacity: .16; background-image: linear-gradient(var(--border) 1px, transparent 1px), linear-gradient(90deg, var(--border) 1px, transparent 1px); background-size: 52px 52px; mask-image: linear-gradient(to right, transparent, #000); }
.hero-copy { position: relative; z-index: 1; }
.hero-kicker, .section-heading > p, .session-list article > p { color: var(--primary); font-weight: 700; letter-spacing: .04em; }
h1 { max-width: 850px; margin: .3rem 0 1.3rem; font-size: clamp(3.2rem, 5.5vw, 5.8rem); line-height: .98; letter-spacing: -.065em; }
.hero-title-line { display: block; white-space: nowrap; }
.hero-title-line + .hero-title-line { margin-top: .08em; }
.hero-lead { max-width: 660px; margin: 0 0 2rem; color: #ccdae6; font-size: clamp(1.08rem, 2vw, 1.35rem); }
.event-meta { display: flex; flex-wrap: wrap; gap: .7rem 1.7rem; margin-bottom: 2.2rem; color: var(--muted-foreground); }
.event-meta span::before { content: ""; display: inline-block; width: .5rem; height: .5rem; margin-right: .6rem; border-radius: 50%; background: var(--primary); }
.hero-mark { position: relative; z-index: 1; display: grid; grid-template-columns: repeat(2, 1fr); aspect-ratio: 1; max-width: 460px; justify-self: end; border: 1px solid var(--border); border-radius: 50%; overflow: hidden; transform: rotate(-5deg); }
.hero-mark span { display: grid; place-items: center; border: 1px solid rgba(78, 231, 197, .22); color: var(--primary); font-size: clamp(4rem, 8vw, 7rem); font-weight: 800; line-height: 1; }

.button { display: inline-flex; align-items: center; justify-content: center; min-height: 52px; padding: .75rem 1.35rem; border: 0; border-radius: var(--radius); cursor: pointer; font-weight: 700; text-decoration: none; }
.button-primary { background: var(--primary); color: #071425; box-shadow: 0 10px 30px rgba(78, 231, 197, .13); }
.button-primary:hover { background: #7cefd7; }
.button:disabled { cursor: wait; opacity: .7; }

.section { padding: 7rem max(24px, calc((100vw - var(--content)) / 2)); }
.section-heading { max-width: 610px; margin-bottom: 3rem; }
.section-heading > p { margin: 0 0 .75rem; }
.section-heading h2 { margin: 0; font-size: clamp(2.25rem, 4.6vw, 4.4rem); line-height: 1.08; letter-spacing: -.045em; }
.about { background: var(--light); color: var(--ink); }
.feature-list { border-top: 1px solid #bfd0dc; }
.feature-list article { display: grid; grid-template-columns: 90px minmax(220px, .8fr) 1.2fr; gap: 1.5rem; align-items: baseline; padding: 2rem 0; border-bottom: 1px solid #bfd0dc; }
.feature-list article > span { color: #3d6b77; font-weight: 700; }
.feature-list h3 { margin: 0; font-size: 1.45rem; }
.feature-list p { margin: 0; color: #496377; }

.program { background: var(--background); }
.session-list { border-top: 1px solid var(--border); }
.session-list article { display: grid; grid-template-columns: 145px minmax(220px, .8fr) 1.2fr; gap: 1.5rem; align-items: baseline; padding: 1.8rem 0; border-bottom: 1px solid var(--border); }
.session-list article > p, .session-list h3, .session-list span { margin: 0; }
.session-list h3 { font-size: 1.35rem; }
.session-list span { color: var(--muted-foreground); }

.guide { background: var(--muted); }
.guide-columns { display: grid; grid-template-columns: .85fr 1.15fr; gap: 7rem; }
.audience-list { margin: 0; padding: 0; list-style: none; counter-reset: audience; }
.audience-list li { position: relative; padding: 1rem 0 1rem 2rem; border-bottom: 1px solid var(--border); counter-increment: audience; }
.audience-list li::before { content: counter(audience); position: absolute; left: 0; color: var(--primary); font-weight: 700; }
.faq details { padding: 1.3rem 0; border-bottom: 1px solid var(--border); }
.faq summary { cursor: pointer; font-size: 1.08rem; font-weight: 700; }
.faq p { margin: .8rem 2rem 0 0; color: var(--muted-foreground); }

.registration { display: grid; grid-template-columns: .8fr 1.2fr; gap: 6rem; align-items: start; background: var(--light); color: var(--ink); }
.registration-copy { position: sticky; top: 110px; }
.registration-copy > p { max-width: 480px; color: #496377; }
.registration-copy .privacy-note { margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid #cbd9e3; font-size: .9rem; }
.form-panel { padding: clamp(1.4rem, 4vw, 3rem); border-radius: 30px; background: #fff; box-shadow: 0 26px 70px rgba(18, 47, 69, .12); }
.field { display: grid; gap: .45rem; margin-bottom: 1.35rem; }
.field label, legend { font-weight: 700; }
.field label span, legend span { color: #4d687a; font-size: .84rem; font-weight: 400; }
input, select { width: 100%; min-height: 50px; padding: .65rem .8rem; border: 1px solid #9eb3c2; border-radius: .7rem; color: var(--ink); background: #fff; }
input:hover, select:hover { border-color: #54768c; }
input:focus, select:focus { border-color: #0b806d; outline: 3px solid rgba(78, 231, 197, .28); }
fieldset { min-width: 0; margin: 0 0 .1rem; padding: 0; border: 0; }
legend { margin-bottom: .6rem; }
.field-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.check-field { display: flex; gap: .7rem; align-items: flex-start; width: 100%; margin: 1.5rem 0; color: #3c586a; cursor: pointer; }
.check-field input[type="checkbox"] { position: absolute; width: 1px; height: 1px; min-height: 1px; margin: -1px; padding: 0; opacity: 0; }
.check-field > span { display: flex; align-items: flex-start; flex: 1 1 auto; min-width: 0; white-space: normal; word-break: keep-all; }
.check-field > span::before { content: ""; display: block; flex: 0 0 20px; width: 20px; height: 20px; margin: .12rem .7rem 0 0; border: 2px solid #6d8797; border-radius: .25rem; background: #fff; box-sizing: border-box; }
.check-field input[type="checkbox"]:checked + span::before { border-color: #0b806d; background-color: #0b806d; background-image: linear-gradient(45deg, transparent 45%, #fff 45%, #fff 58%, transparent 58%), linear-gradient(-45deg, transparent 48%, #fff 48%, #fff 60%, transparent 60%); background-position: 3px 8px, 8px 5px; background-size: 8px 8px, 8px 10px; background-repeat: no-repeat; }
.check-field input[type="checkbox"]:focus-visible + span::before { outline: 3px solid rgba(78, 231, 197, .45); outline-offset: 2px; }
.check-field strong { color: #0b806d; }
.submit-button { width: 100%; }
.loading-label { display: none; }
.is-submitting .submit-button > span:first-child { display: none; }
.is-submitting .loading-label { display: inline; }
.notice { margin-bottom: 1.5rem; padding: 1rem 1.1rem; border-radius: var(--radius); }
.notice h3 { margin: 0 0 .3rem; }
.notice p { margin: 0; }
.notice .registration-code { margin-top: .8rem; }
.notice.error { border: 1px solid #dc554f; background: #fff0ef; color: #7c2622; }
.notice.warning { border: 1px solid #d49f24; background: #fff9e8; color: #704d00; }
.notice.success { border: 1px solid #11937d; background: #e8fff9; color: #075c4e; }
footer { display: flex; justify-content: space-between; align-items: center; max-width: var(--content); margin: 0 auto; padding: 2.5rem 24px; color: var(--muted-foreground); }
footer span { color: var(--foreground); font-weight: 800; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }

.admin-page { min-height: 100vh; background: var(--light); color: var(--ink); }
.admin-header { min-height: 76px; display: flex; align-items: center; justify-content: space-between; padding: 1rem max(24px, calc((100vw - 1440px) / 2)); background: var(--background); color: var(--foreground); }
.admin-header > div { display: flex; align-items: center; gap: 1.2rem; }
.admin-header p { margin: 0; color: var(--muted-foreground); }
.admin-user { overflow-wrap: anywhere; }
.admin-main { width: min(100% - 32px, 1800px); max-width: none; margin: 0 auto; padding: 3.5rem 0 6rem; }
.admin-title { display: flex; align-items: end; justify-content: space-between; gap: 2rem; margin-bottom: 2rem; }
.admin-title h1 { margin: 0; font-size: clamp(2.2rem, 5vw, 4rem); color: var(--ink); }
.admin-title p { margin: .5rem 0 0; color: #567082; }
.admin-title > strong { color: #0b806d; font-size: 1.7rem; white-space: nowrap; }
.admin-filters { display: grid; grid-template-columns: minmax(240px, 1fr) 180px auto auto; gap: 1rem; align-items: end; margin-bottom: 2rem; padding: 1.4rem; border: 1px solid #cbd9e3; border-radius: var(--radius); background: #fff; }
.admin-filters .field { margin: 0; }
.button-secondary { border: 1px solid #8ba3b4; background: #fff; color: var(--ink); }
.button-small { min-height: 42px; padding: .5rem .8rem; background: var(--secondary); color: #fff; }
.button-danger { background: #b42318; color: #fff; }
.result-summary { color: #567082; }
.table-scroll { overflow-x: auto; border: 1px solid #cbd9e3; border-radius: var(--radius); background: #fff; }
table { width: 100%; min-width: 1180px; border-collapse: collapse; font-size: .9rem; }
th, td { padding: 1rem; border-bottom: 1px solid #dce6ed; text-align: left; vertical-align: top; }
th { position: sticky; top: 0; z-index: 1; background: #eaf1f5; color: #3f5b6d; }
td span { color: #627b8c; }
.status-pill { display: inline-block; margin-top: .4rem; padding: .15rem .55rem; border-radius: 999px; font-size: .78rem; font-weight: 700; }
.status-new { background: #e1f2ff; color: #15577e; }
.status-confirmed { background: #dff9ef; color: #08634f; }
.status-cancelled { background: #f3e7e7; color: #7d3434; }
.status-actions { display: flex; flex-wrap: nowrap; align-items: center; gap: .5rem; min-width: 570px; }
.status-form { display: grid; grid-template-columns: 115px minmax(180px, 1fr) auto; gap: .5rem; align-items: center; min-width: 0; flex: 1 1 auto; }
.status-form input, .status-form select { min-height: 42px; padding: .45rem .55rem; }
.delete-form { display: inline-flex; min-width: 0; margin-top: 0; flex: 0 0 auto; }
.admin-empty { padding: 4rem 2rem; border: 1px dashed #a8bbc8; border-radius: var(--radius); text-align: center; background: #fff; }
.admin-empty h2 { margin: 0; }
.admin-empty p { margin: .5rem 0 0; color: #607889; }
.pagination { display: flex; justify-content: center; align-items: center; gap: 1rem; margin-top: 2rem; }

@media (max-width: 860px) {
    nav a:not(.nav-cta) { display: none; }
    .hero { min-height: auto; grid-template-columns: 1fr; padding-top: 5rem; }
    .hero-mark { max-width: 360px; justify-self: start; }
    .feature-list article, .session-list article { grid-template-columns: 70px 1fr; }
    .feature-list article p, .session-list article span { grid-column: 2; }
    .guide-columns, .registration { grid-template-columns: 1fr; gap: 4rem; }
    .registration-copy { position: static; }
    .admin-filters { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 560px) {
    .site-header { height: 68px; }
    .section { padding-top: 5rem; padding-bottom: 5rem; }
    h1 { font-size: clamp(2.5rem, 11vw, 3.8rem); }
    .hero-mark { width: 90%; }
    .feature-list article, .session-list article { grid-template-columns: 1fr; gap: .55rem; }
    .feature-list article p, .session-list article span { grid-column: 1; }
    .field-pair { grid-template-columns: 1fr; gap: 0; }
    .form-panel { margin: 0 -8px; border-radius: 20px; }
    footer { display: block; }
    .admin-header { align-items: flex-start; }
    .admin-header > div { display: block; }
    .admin-user { max-width: 45%; font-size: .8rem; text-align: right; }
    .admin-title { align-items: flex-start; }
    .admin-filters { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}