/* Synexel UI */
:root {
    --synexel-primary: #4338ca;
    --synexel-primary-dark: #3730a3;
    --synexel-primary-light: #6366f1;
    --synexel-bg: #f8fafc;
    --synexel-text: #0f172a;
    --synexel-muted: #64748b;
}

*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; font-family: 'Segoe UI', system-ui, sans-serif; background: var(--synexel-bg); color: var(--synexel-text); }
a { color: var(--synexel-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
button, input { font: inherit; }
.hidden { display: none !important; }

.brand-logo {
    width: 3.5rem; height: 3.5rem; border-radius: 0.875rem;
    background: linear-gradient(135deg, var(--synexel-primary) 0%, var(--synexel-primary-light) 100%);
    color: #fff; display: flex; align-items: center; justify-content: center;
    font-size: 1.75rem; font-weight: 800; margin: 0 auto 1rem;
    box-shadow: 0 8px 24px rgba(67, 56, 202, .25);
}
.brand-logo-sm { width: 2.5rem; height: 2.5rem; font-size: 1.125rem; margin: 0; border-radius: 0.625rem; }
.brand-title { text-align: center; font-size: 1.75rem; font-weight: 700; margin: 0 0 .25rem; letter-spacing: -.02em; }
.brand-tagline { text-align: center; color: var(--synexel-muted); font-size: .875rem; margin: 0 0 2rem; }

.btn { border-radius: 0.5rem; padding: 0.5rem 1rem; font-size: 0.875rem; font-weight: 600; cursor: pointer; border: none; }
.btn-primary { background: var(--synexel-primary); color: #fff; }
.btn-primary:hover { background: var(--synexel-primary-dark); }
.btn-secondary { background: #fff; border: 1px solid #cbd5e1; color: #475569; }
.btn-secondary:hover { background: #f8fafc; }

.login-wrap { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 1rem; background: linear-gradient(160deg, #eef2ff 0%, #f8fafc 50%, #faf5ff 100%); }
.login-card { width: 100%; max-width: 28rem; background: #fff; border: 1px solid #e2e8f0; border-radius: 1rem; padding: 2rem; box-shadow: 0 24px 48px rgba(67, 56, 202, .08); }
.login-form { display: flex; flex-direction: column; gap: 1rem; }
.login-form label { display: block; font-size: .875rem; font-weight: 500; margin-bottom: .25rem; }
.remember-row { display: flex; align-items: center; gap: .5rem; font-size: .875rem; color: var(--synexel-muted); }
.login-footer { text-align: center; margin: 1.25rem 0 0; font-size: .75rem; color: #94a3b8; }
.field { width: 100%; border: 1px solid #cbd5e1; border-radius: 0.5rem; padding: 0.5rem 0.75rem; font-size: 0.875rem; }
.field:focus { outline: 2px solid #c7d2fe; border-color: var(--synexel-primary); }
.error-box { background: #fef2f2; border: 1px solid #fecaca; color: #b91c1c; border-radius: 0.5rem; padding: 0.75rem 1rem; font-size: 0.875rem; margin-bottom: 1rem; }

.page-header { background: #fff; border-bottom: 1px solid #e2e8f0; padding: 1rem 1.5rem; display: flex; align-items: center; justify-content: space-between; }
.header-brand { display: flex; align-items: center; gap: .75rem; }
.header-brand h1 { margin: 0; font-size: 1.125rem; font-weight: 700; }
.header-sub { font-weight: 400; color: var(--synexel-muted); }
.header-brand p { margin: 0; font-size: .875rem; color: var(--synexel-muted); }
.page-main { max-width: 72rem; margin: 0 auto; padding: 2rem 1.5rem; }
.toolbar-row { display: flex; flex-wrap: wrap; gap: .75rem; margin-bottom: 1.5rem; align-items: center; }
.upload-btn { cursor: pointer; }
.link-muted { font-size: .875rem; color: var(--synexel-muted); }

.workbook-grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
.workbook-card { background: #fff; border: 1px solid #e2e8f0; border-radius: 0.75rem; padding: 1.25rem; transition: .15s; }
.workbook-card:hover { border-color: #c7d2fe; box-shadow: 0 8px 24px rgba(67, 56, 202, .1); }
.workbook-card h2 { margin: 0; font-size: 1rem; }
.workbook-card p { margin: .25rem 0 0; font-size: .75rem; color: var(--synexel-muted); }
.workbook-thumb { height: 6rem; border-radius: 0.5rem; background: #eef2ff; display: flex; align-items: center; justify-content: center; font-size: 2.5rem; margin-bottom: 0.75rem; }
.workbook-actions { display: flex; gap: 0.5rem; margin-top: 1rem; }
.workbook-actions button { flex: 1; font-size: 0.75rem; padding: 0.35rem; border-radius: 0.5rem; border: 1px solid #e2e8f0; background: #fff; cursor: pointer; }
.workbook-actions .danger { color: #dc2626; border-color: #fecaca; }
.empty-state { grid-column: 1 / -1; text-align: center; padding: 3rem; background: #fff; border: 2px dashed #cbd5e1; border-radius: .75rem; }
.empty-title { font-size: 1.125rem; font-weight: 500; margin: 0; }
.empty-text { color: var(--synexel-muted); font-size: .875rem; margin: .5rem 0 0; }