* { box-sizing: border-box; }
body { overflow-x: hidden; }

/* ── Split layout ── */
.auth-layout {
    display: grid;
    grid-template-columns: 420px 1fr;
    min-height: 100vh;
}

/* ── Left panel ── */
.auth-left {
    background: linear-gradient(160deg, #091526 0%, #060a14 100%);
    display: flex;
    flex-direction: column;
    padding: 48px 44px;
    position: relative;
    overflow: hidden;
}
.auth-left::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(0,229,255,0.035) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,229,255,0.035) 1px, transparent 1px);
    background-size: 44px 44px;
    pointer-events: none;
}
.auth-left::after {
    content: '';
    position: absolute;
    bottom: -80px;
    left: 50%;
    transform: translateX(-50%);
    width: 440px;
    height: 440px;
    background: radial-gradient(circle, rgba(0,180,204,0.1) 0%, transparent 68%);
    pointer-events: none;
}
.auth-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    position: relative;
    z-index: 1;
}
.auth-brand-logo { width: 30px; height: 30px; object-fit: contain; }
.auth-brand-name {
    font-size: 1.05rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: 0.04em;
}
.auth-left-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
    z-index: 1;
    padding: 40px 0;
}
.auth-left-label {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--cyan);
    text-transform: uppercase;
    margin-bottom: 14px;
}
.auth-left-title {
    font-size: 1.9rem;
    font-weight: 800;
    color: #fff;
    line-height: 1.3;
    margin-bottom: 16px;
    letter-spacing: -0.01em;
}
.auth-left-desc {
    font-size: 0.875rem;
    color: #7a9cbc;
    line-height: 1.75;
    margin-bottom: 36px;
}
.auth-feature-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.auth-feature-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.875rem;
    color: #a0c0dc;
    font-weight: 500;
}
.auth-feature-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--cyan);
    flex-shrink: 0;
    box-shadow: 0 0 6px rgba(0,229,255,0.5);
}
.auth-left-footer {
    position: relative;
    z-index: 1;
    padding-top: 24px;
    border-top: 1px solid rgba(255,255,255,0.07);
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}
.auth-left-footer a {
    font-size: 0.75rem;
    color: #3a5a78;
    text-decoration: none;
    transition: color 0.2s;
}
.auth-left-footer a:hover { color: #7a9cbc; }

/* ── Right panel ── */
.auth-right {
    background: #060a14;
    border-left: 1px solid rgba(255,255,255,0.06);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 48px;
    overflow-y: auto;
    min-height: 100vh;
}
.auth-right-inner {
    width: 100%;
    max-width: 380px;
}
.auth-back-link { margin-bottom: 28px; }
.auth-back-link a {
    font-size: 0.8rem;
    color: #4a6a88;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: color 0.2s;
}
.auth-back-link a:hover { color: var(--cyan); }
.auth-right-header { margin-bottom: 32px; }
.auth-right-sub {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--cyan);
    text-transform: uppercase;
    margin-bottom: 6px;
}
.auth-right-title {
    font-size: 1.8rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: -0.01em;
}

/* ── Form elements ── */
.auth-form { display: flex; flex-direction: column; gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-label { font-size: 0.8rem; color: #a0b8cc; font-weight: 500; }
.form-input-wrap { position: relative; }
.form-input {
    width: 100%; background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1); border-radius: 10px;
    padding: 12px 16px; font-size: 0.95rem; color: #fff;
    font-family: 'Noto Sans KR', sans-serif; outline: none;
    transition: border-color 0.2s, box-shadow 0.2s; box-sizing: border-box;
}
.form-input::placeholder { color: #4a6070; }
.form-input:focus { border-color: var(--cyan); box-shadow: 0 0 0 3px rgba(0,229,255,0.12); }
.form-input.has-toggle { padding-right: 48px; }
.pw-toggle {
    position: absolute; right: 14px; top: 50%; transform: translateY(-50%);
    background: none; border: none; cursor: pointer; color: #6a8aaa;
    padding: 4px; display: flex; align-items: center; transition: color 0.2s;
}
.pw-toggle:hover { color: #a0b8cc; }
.auth-submit {
    width: 100%; padding: 14px;
    background: linear-gradient(135deg, #00b4cc, #0099aa);
    border: none; border-radius: 10px; color: #fff;
    font-size: 1rem; font-weight: 700;
    font-family: 'Noto Sans KR', sans-serif; cursor: pointer;
    margin-top: 4px; letter-spacing: 0.05em;
    transition: opacity 0.2s, transform 0.15s;
}
.auth-submit:hover { opacity: 0.9; transform: translateY(-1px); }
.auth-submit:active { transform: translateY(0); }
.auth-submit:disabled { opacity: 0.6; cursor: not-allowed; transform: none; }
.auth-divider { display: flex; align-items: center; gap: 12px; margin: 8px 0; }
.divider-line { flex: 1; height: 1px; background: rgba(255,255,255,0.1); }
.divider-text { font-size: 0.8rem; color: #6a8aaa; white-space: nowrap; }
.social-btn {
    width: 100%; padding: 13px; border: none; border-radius: 10px;
    font-size: 0.92rem; font-weight: 600;
    font-family: 'Noto Sans KR', sans-serif; cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    gap: 10px; transition: opacity 0.2s;
}
.social-btn:hover { opacity: 0.88; }
.social-btn.kakao { background: #FEE500; color: rgba(0,0,0,0.85); }
.social-btn.google { background: #fff; color: rgba(0,0,0,0.85); border: 1px solid #e0e0e0; }
.social-group { display: flex; flex-direction: column; gap: 10px; }
.auth-footer-text { text-align: center; font-size: 0.85rem; color: #6a8aaa; margin-top: 24px; }
.auth-footer-text a { color: var(--cyan); font-weight: 600; text-decoration: none; }
.auth-footer-text a:hover { text-decoration: underline; }
.form-error { font-size: 0.78rem; color: #fa5757; display: block; opacity: 0; line-height: 1.4; transition: opacity 0.15s; }
.form-error.show { opacity: 1; }
.auth-mobile-footer {
    display: none;
    text-align: center;
    margin-top: 36px;
    font-size: 0.72rem;
    color: #3a5a78;
    line-height: 2;
}
.auth-mobile-footer a { color: #3a5a78; text-decoration: none; }
.auth-mobile-footer a:hover { color: var(--cyan); }

/* ── Mobile ── */
.auth-mobile-header {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0;
    padding: 14px 20px;
    background: rgba(6,10,20,0.96);
    border-bottom: 1px solid rgba(255,255,255,0.07);
    z-index: 100;
    align-items: center;
    justify-content: space-between;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
.auth-mobile-home {
    font-size: 0.8rem;
    color: #6a8aaa;
    text-decoration: none;
    transition: color 0.2s;
}
.auth-mobile-home:hover { color: var(--cyan); }
@media (max-width: 820px) {
    .auth-layout { grid-template-columns: 1fr; }
    .auth-left { display: none; }
    .auth-mobile-header { display: flex; }
    .auth-right {
        border-left: none;
        padding: 80px 24px 48px;
    }
    .auth-back-link { display: none; }
    .auth-mobile-footer { display: block; }
}