* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    display: flex; min-height: 100vh;
}

/* ── Panel izquierdo — brand ── */
.split-brand {
    flex: 0 0 52%;
    background: linear-gradient(145deg, #0f172a 0%, #1e3a5f 50%, #0f2744 100%);
    display: flex; flex-direction: column;
    justify-content: space-between;
    padding: 3rem 3.5rem;
    position: relative;
    overflow: hidden;
}
.split-brand::before {
    content: '';
    position: absolute; inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 20% 60%, rgba(37,99,235,0.18) 0%, transparent 70%),
        radial-gradient(ellipse 50% 40% at 80% 20%, rgba(99,102,241,0.12) 0%, transparent 60%);
    pointer-events: none;
}
.split-brand::after {
    content: '';
    position: absolute; inset: 0;
    background-image: radial-gradient(rgba(255,255,255,0.04) 1px, transparent 1px);
    background-size: 32px 32px;
    pointer-events: none;
}

.brand-top {
    position: relative; z-index: 1;
    display: flex; align-items: center; gap: 16px;
}
.brand-logo-wrap {
    width: 100px; height: 100px;
    border-radius: 18px; overflow: hidden;
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
}
.brand-logo-wrap img { width: 90px; height: 90px; object-fit: contain; }
.brand-name-top {
    font-size: 2.4rem; font-weight: 800;
    letter-spacing: -0.8px; line-height: 1;
}
.brand-name-top .t-arena { color: rgba(255,255,255,0.9); }
.brand-name-top .t-ops   { color: rgba(255,255,255,0.55); }

.brand-main { position: relative; z-index: 1; }
.brand-headline {
    font-size: 2.6rem; font-weight: 800;
    color: white; line-height: 1.15;
    letter-spacing: -1px; margin-bottom: 1.2rem;
}
.brand-headline span {
    background: linear-gradient(135deg, #60a5fa, #a78bfa);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.brand-sub {
    font-size: 1rem; color: rgba(255,255,255,0.5);
    line-height: 1.6; max-width: 340px;
}

.brand-features {
    position: relative; z-index: 1;
    display: flex; flex-direction: column; gap: 12px;
}
.brand-feat {
    display: flex; align-items: center; gap: 10px;
    color: rgba(255,255,255,0.45); font-size: 0.82rem;
}
.brand-feat-dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: linear-gradient(135deg, #60a5fa, #818cf8);
    flex-shrink: 0;
}

.brand-help {
    position: relative; z-index: 1;
    font-size: 0.75rem; color: rgba(255,255,255,0.3);
    line-height: 1.5;
}
.brand-help strong { color: rgba(255,255,255,0.5); font-weight: 600; }

/* ── Panel derecho — formulario ── */
.split-form-panel {
    flex: 1;
    background: #f8fafc;
    display: flex; align-items: center; justify-content: center;
    padding: 2rem;
}
.split-form-inner { width: 100%; max-width: 380px; }

.form-header { margin-bottom: 2.2rem; }
.form-greeting {
    font-size: 1.75rem; font-weight: 800;
    color: #0f172a; letter-spacing: -0.5px; margin-bottom: 0.4rem;
}
.form-sub { font-size: 0.88rem; color: #64748b; }

/* Error */
.form-error {
    background: #fef2f2; border: 1px solid #fecaca;
    color: #dc2626; border-radius: 8px;
    padding: 0.7rem 1rem; font-size: 0.85rem;
    margin-bottom: 1.2rem;
    display: flex; align-items: center; gap: 0.5rem;
}

.field-group { margin-bottom: 1.2rem; }
.field-label {
    display: block; font-size: 0.78rem; font-weight: 600;
    color: #374151; margin-bottom: 6px;
    letter-spacing: 0.3px; text-transform: uppercase;
}
.field-input {
    width: 100%; padding: 0.75rem 1rem;
    border: 1.5px solid #e2e8f0;
    border-radius: 10px; font-size: 0.92rem;
    color: #0f172a; background: white;
    transition: border-color 0.15s, box-shadow 0.15s;
    outline: none;
}
.field-input:focus {
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}
.field-input::placeholder { color: #cbd5e1; }

.btn-submit {
    width: 100%; padding: 0.85rem;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: white; font-size: 0.92rem; font-weight: 700;
    border: none; border-radius: 10px; cursor: pointer;
    transition: all 0.15s; margin-top: 0.4rem;
    box-shadow: 0 4px 14px rgba(37,99,235,0.35);
    letter-spacing: 0.2px;
}
.btn-submit:hover {
    background: linear-gradient(135deg, #1d4ed8, #1e40af);
    box-shadow: 0 6px 20px rgba(37,99,235,0.45);
    transform: translateY(-1px);
}

.form-footer {
    margin-top: 2rem; padding-top: 1.5rem;
    border-top: 1px solid #e2e8f0;
    text-align: center; font-size: 0.75rem; color: #94a3b8;
}

/* ── Responsive ── */
@media (max-width: 768px) {
body { flex-direction: column; }
.split-brand {
    flex: none; min-height: 220px;
    padding: 2rem;
    justify-content: flex-start; gap: 1.5rem;
}
.brand-main, .brand-features, .brand-help { display: none; }
.split-form-panel { padding: 2rem 1.5rem; }
}