/* =========================================
   SAC Conference Page — Redesigned
   ========================================= */
:root {
    --sac-primary: #1a3a69;
    --sac-primary-dark: #0f2544;
    --sac-accent: #3b82f6;
    --sac-accent-light: #eff6ff;
    --sac-warning: #f59e0b;
    --sac-warning-bg: #fef3c7;
    --sac-danger: #dc2626;
    --sac-bg: #f7f9fc;
    --sac-card: #ffffff;
    --sac-border: #e5e7eb;
    --sac-text: #1e293b;
    --sac-text-soft: #475569;
    --sac-text-muted: #94a3b8;
    --sac-shadow-sm: 0 1px 3px rgba(0,0,0,.05);
    --sac-shadow-md: 0 4px 12px rgba(0,0,0,.08);
    --sac-shadow-lg: 0 10px 30px rgba(0,0,0,.12);
    --sac-radius: 14px;
    --sac-radius-sm: 8px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body.sacse-page {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--sac-bg);
    color: var(--sac-text);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--sac-accent); text-decoration: none; transition: color .2s; }
a:hover { color: var(--sac-primary); }

.sac-container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* =========================================
   Header (sticky navigation)
   ========================================= */
.sac-header {
    position: sticky; top: 0; z-index: 100;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition: box-shadow .2s, border-color .2s;
}
.sac-header.is-scrolled {
    border-bottom-color: var(--sac-border);
    box-shadow: var(--sac-shadow-sm);
}
.sac-header__inner {
    max-width: 1120px; margin: 0 auto; padding: 14px 24px;
    display: flex; align-items: center; gap: 24px;
}
.sac-logo {
    display: flex; align-items: center; gap: 12px;
    color: var(--sac-primary); font-weight: 800; font-size: 1.1rem;
}
.sac-logo img { height: 36px; border-radius: 6px; }
.sac-nav {
    flex: 1; display: flex; justify-content: center; gap: 28px;
}
.sac-nav a {
    color: var(--sac-text-soft); font-weight: 600; font-size: .9rem;
    padding: 8px 4px; border-bottom: 2px solid transparent;
    transition: all .2s;
}
.sac-nav a:hover,
.sac-nav a.is-active {
    color: var(--sac-primary);
    border-bottom-color: var(--sac-accent);
}
.sac-cta {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 9px 16px; background: var(--sac-primary); color: #fff;
    border-radius: 8px; font-weight: 700; font-size: .88rem;
    transition: all .2s;
}
.sac-cta:hover { background: var(--sac-primary-dark); color: #fff; transform: translateY(-1px); }

/* =========================================
   Hero
   ========================================= */
.sac-hero {
    position: relative; padding: 80px 24px 72px; overflow: hidden;
    background: linear-gradient(135deg, var(--sac-primary) 0%, #2d5a9e 100%);
    color: #fff;
}
.sac-hero__bg {
    position: absolute; inset: 0; opacity: .15; pointer-events: none;
    background:
        radial-gradient(circle at 15% 20%, rgba(255,255,255,.4), transparent 40%),
        radial-gradient(circle at 85% 80%, rgba(255,255,255,.3), transparent 40%);
}
.sac-hero__inner {
    position: relative; max-width: 900px; margin: 0 auto; text-align: center;
}
.sac-hero__badge {
    display: inline-block; padding: 6px 14px;
    background: rgba(255,255,255,.15); backdrop-filter: blur(8px);
    border: 1px solid rgba(255,255,255,.25);
    border-radius: 999px; font-size: .82rem; font-weight: 700;
    letter-spacing: .02em; text-transform: uppercase; margin-bottom: 20px;
}
.sac-hero__title {
    font-size: clamp(1.6rem, 3.5vw, 2.5rem); font-weight: 900;
    line-height: 1.25; letter-spacing: -0.02em; margin-bottom: 24px;
}
.sac-hero__meta {
    display: flex; justify-content: center; flex-wrap: wrap; gap: 24px;
    margin-bottom: 32px; font-size: 1rem; opacity: .95;
}
.sac-hero__meta span { display: inline-flex; align-items: center; gap: 8px; }
.sac-hero__meta i { font-size: 1.1em; }
.sac-hero__actions { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }
.sac-btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: 10px; font-weight: 700;
    font-size: .92rem; transition: all .2s; border: 2px solid transparent;
}
.sac-btn--primary {
    background: #fff; color: var(--sac-primary);
}
.sac-btn--primary:hover { transform: translateY(-2px); box-shadow: var(--sac-shadow-lg); color: var(--sac-primary); }
.sac-btn--outline {
    background: transparent; color: #fff; border-color: rgba(255,255,255,.4);
}
.sac-btn--outline:hover { background: rgba(255,255,255,.1); border-color: #fff; color: #fff; }

/* =========================================
   Important Dates
   ========================================= */
.sac-dates {
    position: relative;
    z-index: 5;
    scroll-margin-top: 90px;
    padding: 32px 24px 40px;
}
.sac-dates__grid {
    display: grid; gap: 16px;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}
.sac-date-card {
    background: var(--sac-card); border: 1px solid var(--sac-border);
    border-radius: var(--sac-radius); padding: 20px;
    box-shadow: var(--sac-shadow-md);
    transition: transform .2s, box-shadow .2s;
}
.sac-date-card:hover { transform: translateY(-3px); box-shadow: var(--sac-shadow-lg); }
.sac-date-card--warning { border-left: 4px solid var(--sac-warning); }
.sac-date-card__label {
    font-size: .78rem; font-weight: 700; letter-spacing: .05em;
    text-transform: uppercase; color: var(--sac-text-muted);
    margin-bottom: 10px;
}
.sac-date-card__dates { font-size: .95rem; }
.sac-date__original {
    color: var(--sac-text-muted); font-size: .88rem; margin-bottom: 6px;
}
.sac-date__extended {
    display: flex; align-items: center; gap: 6px;
    color: var(--sac-primary); font-weight: 800; font-size: 1rem;
}
.sac-date__current { color: var(--sac-text); font-weight: 700; font-size: 1rem; }
.sac-date-card__notice {
    margin-top: 14px; padding: 10px 12px;
    background: var(--sac-warning-bg); border-radius: 8px;
    display: flex; gap: 8px; align-items: flex-start;
    font-size: .82rem; color: #78350f; line-height: 1.5;
}
.sac-date-card__notice i { flex-shrink: 0; color: var(--sac-warning); font-size: 1em; margin-top: 2px; }

/* =========================================
   Sections
   ========================================= */
.sac-main { padding: 40px 24px 80px; }
.sac-section { margin-bottom: 48px; scroll-margin-top: 90px; }
.sac-section__title {
    display: flex; align-items: center; gap: 12px;
    font-size: clamp(1.3rem, 2.2vw, 1.6rem); font-weight: 800;
    color: var(--sac-primary); margin-bottom: 20px;
    letter-spacing: -0.01em;
}
.sac-section__title i { font-size: 1.1em; color: var(--sac-accent); }
.sac-badge {
    margin-left: auto; font-size: .75rem; font-weight: 700;
    padding: 4px 10px; border-radius: 999px;
    background: var(--sac-accent-light); color: var(--sac-accent);
}

/* Card */
.sac-card {
    background: var(--sac-card); border: 1px solid var(--sac-border);
    border-radius: var(--sac-radius); padding: 28px;
    box-shadow: var(--sac-shadow-sm);
    line-height: 1.75; color: var(--sac-text-soft);
}
.sac-card--compact { padding: 20px 28px; }
.sac-card__lead { font-size: 1rem; margin-bottom: 24px; color: var(--sac-text); }
.sac-card__lead > :last-child { margin-bottom: 0; }
.sac-card__subtitle {
    font-size: 1.05rem; font-weight: 700; color: var(--sac-text);
    margin: 24px 0 14px; padding-top: 20px; border-top: 1px solid var(--sac-border);
}
.sac-card p { margin-bottom: 14px; }
.sac-card p:last-child { margin-bottom: 0; }
.sac-card a { font-weight: 600; }
.sac-card strong { color: var(--sac-text); font-weight: 700; }
.sac-card ul { padding-left: 20px; margin: 14px 0; }
.sac-card ul li { margin-bottom: 8px; }

/* Topics grid */
.sac-topics-grid {
    display: grid; gap: 10px 24px;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}
.sac-topic {
    display: flex; align-items: flex-start; gap: 10px;
    padding: 8px 0; font-size: .92rem; color: var(--sac-text-soft);
}
.sac-topic i { color: var(--sac-accent); margin-top: 4px; flex-shrink: 0; font-size: .85em; }

/* Alert (OA notice etc.) */
.sac-alert {
    display: flex; gap: 16px; padding: 24px 28px;
    background: linear-gradient(135deg, #fffbeb 0%, #fef3c7 100%);
    border: 1px solid #fde68a; border-left: 4px solid var(--sac-warning);
    border-radius: var(--sac-radius);
}
.sac-alert__icon {
    width: 44px; height: 44px; flex-shrink: 0;
    background: var(--sac-warning); color: #fff;
    border-radius: 50%; display: flex; align-items: center; justify-content: center;
    font-size: 1.3rem;
}
.sac-alert__body { flex: 1; color: #78350f; }
.sac-alert__title {
    font-size: 1.1rem; font-weight: 800; color: #78350f;
    margin-bottom: 10px; letter-spacing: -0.01em;
}
.sac-alert__content { font-size: .92rem; line-height: 1.7; }
.sac-alert__content ul { padding-left: 20px; margin: 10px 0; }
.sac-alert__content strong { color: #78350f; font-weight: 800; }

/* Chairs grid */
.sac-chairs-grid {
    display: grid; gap: 20px;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}
.sac-chair-card {
    position: relative; background: var(--sac-card);
    border: 1px solid var(--sac-border); border-radius: var(--sac-radius);
    padding: 28px 24px 24px; text-align: center;
    box-shadow: var(--sac-shadow-sm);
    transition: transform .2s, box-shadow .2s, border-color .2s;
}
.sac-chair-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--sac-shadow-lg);
    border-color: var(--sac-accent);
}
.sac-chair-card--lead { border-top: 3px solid var(--sac-primary); }
.sac-chair-card__role {
    position: absolute; top: 12px; right: 12px;
    font-size: .68rem; font-weight: 800; letter-spacing: .05em;
    text-transform: uppercase;
    padding: 4px 10px; border-radius: 999px;
    background: var(--sac-primary); color: #fff;
}
.sac-chair-card__avatar {
    width: 72px; height: 72px; margin: 0 auto 14px;
    background: var(--sac-accent-light); color: var(--sac-accent);
    border-radius: 50%; display: flex; align-items: center; justify-content: center;
    font-size: 2.4rem;
}
.sac-chair-card__name {
    font-size: 1.1rem; font-weight: 800; color: var(--sac-text);
    margin-bottom: 6px;
}
.sac-chair-card__aff {
    font-size: .85rem; color: var(--sac-text-muted);
    margin-bottom: 14px; line-height: 1.5;
}
.sac-chair-card__email {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: .82rem; font-weight: 600;
    padding: 8px 14px; background: var(--sac-accent-light);
    border-radius: 8px; color: var(--sac-accent);
}
.sac-chair-card__email:hover { background: var(--sac-accent); color: #fff; }

/* PC grid */
.sac-pc-grid {
    display: grid; gap: 12px 20px;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}
.sac-pc-item {
    padding: 12px 0; border-bottom: 1px solid var(--sac-border);
    display: flex; flex-direction: column; gap: 4px;
}
.sac-pc-item:last-child, .sac-pc-item:nth-last-child(-n+3) { border-bottom: none; }
.sac-pc-item strong { font-size: .93rem; color: var(--sac-text); font-weight: 700; }
.sac-pc-item span { font-size: .82rem; color: var(--sac-text-muted); }

/* Inquiry */
.sac-inquiry {
    display: flex; gap: 16px; align-items: flex-start;
    padding: 24px 28px;
    background: var(--sac-accent-light); border: 1px solid #bfdbfe;
    border-radius: var(--sac-radius); color: var(--sac-text-soft);
    font-size: .92rem; line-height: 1.7;
}
.sac-inquiry > i { color: var(--sac-accent); font-size: 1.4rem; margin-top: 2px; flex-shrink: 0; }
.sac-inquiry a { font-weight: 700; }

/* =========================================
   Footer
   ========================================= */
.sac-footer {
    padding: 30px 24px; background: #fff; border-top: 1px solid var(--sac-border);
    text-align: center; font-size: .85rem; color: var(--sac-text-muted);
}
.sac-footer a { font-weight: 700; }

/* Scroll top */
.sac-scroll-top {
    position: fixed; right: 24px; bottom: 24px; z-index: 50;
    width: 48px; height: 48px; border-radius: 50%;
    background: var(--sac-primary); color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.3rem; box-shadow: var(--sac-shadow-lg);
    opacity: 0; visibility: hidden; transform: translateY(10px);
    transition: all .3s;
}
.sac-scroll-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.sac-scroll-top:hover { background: var(--sac-primary-dark); color: #fff; transform: scale(1.08); }

/* =========================================
   Responsive
   ========================================= */
@media (max-width: 900px) {
    .sac-nav { display: none; }
    .sac-hero { padding: 60px 24px 56px; }
    .sac-dates { padding: 24px 16px 32px; }
    .sac-main { padding: 32px 16px 64px; }
    .sac-card { padding: 22px; }
    .sac-chair-card { padding: 24px 20px; }
}
@media (max-width: 560px) {
    .sac-header__inner { padding: 12px 16px; gap: 12px; }
    .sac-logo span { display: none; }
    .sac-cta { padding: 8px 12px; font-size: .82rem; }
    .sac-hero__title { font-size: 1.4rem; }
    .sac-hero__meta { gap: 14px; font-size: .9rem; }
    .sac-hero__actions { flex-direction: column; width: 100%; }
    .sac-btn { width: 100%; justify-content: center; }
    .sac-alert { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
    * { scroll-behavior: auto !important; transition: none !important; }
}