:root {
    --sky-navy: #112544;
    --sky-blue: #2f6fed;
    --sky-blue-dark: #245bc8;
    --sky-ivory: #f6f3ed;
    --sky-ink: #17263d;
    --sky-muted: #718096;
    --sky-line: #d9dee8;
    --sky-danger-bg: #fff1f1;
    --sky-danger: #b42318;
}

*, *::before, *::after { box-sizing: border-box; }
html, body { min-height: 100%; }
body.sky-auth-page {
    min-width: 320px;
    margin: 0;
    color: var(--sky-ink);
    background: var(--sky-ivory);
    font-family: "Pretendard", "Noto Sans KR", "Apple SD Gothic Neo", Arial, sans-serif;
}

.auth-shell { display: grid; grid-template-columns: minmax(0, 55fr) minmax(420px, 45fr); min-height: 100vh; }
.brand-panel { display: flex; align-items: center; padding: clamp(48px, 8vw, 120px); color: #fff; background: var(--sky-navy); }
.brand-content { width: min(560px, 100%); margin-inline: auto; }
.brand-name { margin: 0 0 22px; color: #fff; font: 700 clamp(22px, 2.2vw, 30px)/1 Georgia, "Times New Roman", serif; letter-spacing: .18em; }
.brand-kicker { margin: 0 0 26px; color: #aebdd5; font-size: 12px; font-weight: 800; letter-spacing: .16em; }
.brand-headline { max-width: 540px; margin: 0; color: #fff; font: 700 clamp(44px, 5.2vw, 78px)/1.04 Georgia, "Times New Roman", serif; letter-spacing: -.035em; }
.brand-copy { max-width: 430px; margin: 32px 0 0; color: #c8d2e3; font-size: clamp(14px, 1.3vw, 17px); line-height: 1.75; }
.form-panel { display: grid; place-items: center; padding: 48px 32px; background: var(--sky-ivory); }
.login-card { width: min(460px, 100%); padding: clamp(30px, 4vw, 46px); border: 1px solid rgba(17,37,68,.08); border-radius: 18px; background: #fff; box-shadow: 0 14px 38px rgba(17,37,68,.08); }
.kicker { margin: 0 0 10px; color: var(--sky-blue); font-size: 12px; font-weight: 900; letter-spacing: .13em; }
.title { margin: 0; color: var(--sky-ink); font: 700 clamp(32px, 4vw, 42px)/1.12 Georgia, "Times New Roman", serif; letter-spacing: -.035em; }
.subtitle { margin: 12px 0 28px; color: var(--sky-muted); font-size: 14px; line-height: 1.6; }
.login-tabs { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; margin-bottom: 26px; padding: 4px; border: 1px solid #e4e8ef; border-radius: 10px; background: #f8f9fb; }
.login-tab { min-height: 40px; padding: 0 12px; border: 0; border-radius: 7px; color: var(--sky-muted); background: transparent; font: inherit; font-size: 13px; font-weight: 800; cursor: pointer; }
.login-tab.active { color: #fff; background: var(--sky-navy); }
#loginForm { display: grid; gap: 16px; }
.field { display: grid; gap: 7px; }
.field label { color: var(--sky-ink); font-size: 13px; font-weight: 800; }
.field input { width: 100%; min-height: 50px; padding: 0 14px; border: 1px solid var(--sky-line); border-radius: 9px; color: var(--sky-ink); background: #fff; font: inherit; font-size: 15px; outline: none; transition: border-color .15s ease, box-shadow .15s ease; }
.field input::placeholder { color: #a3adbb; }
.field input:focus { border-color: var(--sky-blue); box-shadow: 0 0 0 3px rgba(47,111,237,.14); }
.btn-login, .btn-sso, .btn-signup { display: inline-flex; width: 100%; min-height: 48px; align-items: center; justify-content: center; border-radius: 9px; font: inherit; font-size: 14px; font-weight: 800; text-decoration: none; cursor: pointer; transition: background .15s ease, border-color .15s ease, transform .15s ease; }
.btn-login { margin-top: 2px; border: 0; color: #fff; background: var(--sky-blue); }
.btn-login:hover { background: var(--sky-blue-dark); }
.btn-login:active, .btn-sso:active, .btn-signup:active { transform: translateY(1px); }
.divider { display: flex; align-items: center; gap: 12px; margin: 24px 0 16px; color: #9aa5b5; font-size: 11px; font-weight: 700; }
.divider::before, .divider::after { content: ""; height: 1px; flex: 1; background: #edf0f4; }
.btn-sso { border: 1px solid #b8c7e3; color: var(--sky-navy); background: #fff; }
.btn-sso:hover { border-color: var(--sky-blue); color: var(--sky-blue-dark); background: #f7faff; }
.btn-signup { margin-top: 10px; border: 1px solid #e1e5ec; color: var(--sky-ink); background: #fff; }
.btn-signup:hover { border-color: #c8d1df; background: #fafbfc; }
.support-links { display: flex; justify-content: center; gap: 12px; margin-top: 20px; padding-top: 18px; border-top: 1px solid #edf0f4; font-size: 12px; }
.support-links a { color: var(--sky-muted); text-decoration: none; }
.support-links a:hover { color: var(--sky-blue-dark); text-decoration: underline; }
.admin-login-link { display: inline-flex; width: 100%; min-height: 44px; align-items: center; justify-content: center; margin-top: 18px; border: 1px solid #d9dee8; border-radius: 9px; color: var(--sky-ink); background: #fff; font-size: 13px; font-weight: 800; text-decoration: none; transition: border-color .15s ease, background .15s ease; }
.admin-login-link:hover { border-color: var(--sky-blue); background: #f7faff; }
.error-message { margin-top: 16px; padding: 11px 12px; border-radius: 8px; color: var(--sky-danger); background: var(--sky-danger-bg); font-size: 13px; line-height: 1.5; }
.error-message[hidden] { display: none; }
.sso-note { margin: 16px 0 0; color: var(--sky-muted); font-size: 12px; line-height: 1.55; }

@media (max-width: 900px) {
    .auth-shell { grid-template-columns: minmax(0, 48fr) minmax(360px, 52fr); }
    .brand-panel { padding: 52px 42px; }
    .brand-headline { font-size: clamp(40px, 5.5vw, 62px); }
    .form-panel { padding: 36px 24px; }
}
@media (max-width: 720px) {
    .auth-shell { display: block; }
    .brand-panel { min-height: 260px; padding: 42px 28px 48px; }
    .brand-name { margin-bottom: 16px; font-size: 22px; }
    .brand-kicker { margin-bottom: 18px; font-size: 10px; }
    .brand-headline { max-width: 360px; font-size: clamp(36px, 11vw, 54px); }
    .brand-copy { margin-top: 20px; font-size: 14px; }
    .form-panel { min-height: calc(100vh - 260px); padding: 24px 16px 36px; }
    .login-card { width: 100%; padding: 28px 22px; border-radius: 14px; }
}
@media (max-width: 380px) {
    .brand-panel { min-height: 238px; padding: 34px 24px 38px; }
    .form-panel { min-height: calc(100vh - 238px); }
    .brand-headline { font-size: 34px; }
    .login-card { padding-inline: 18px; }
    .support-links { gap: 8px; font-size: 11px; }
}