:root {
    --primary: #154d78;
    --primary-dark: #0c3454;
    --surface: #ffffff;
    --background: #eef3f7;
    --border: #dce4ea;
    --text: #1f2d38;
    --muted: #667784;
    --danger: #b42318;
}

* { box-sizing: border-box; }
body { margin: 0; color: var(--text); background: var(--background); font-family: system-ui, -apple-system, "Segoe UI", sans-serif; }
button, input, textarea { font: inherit; }
button, .button { border: 0; border-radius: 8px; padding: .65rem 1rem; background: var(--primary); color: #fff; cursor: pointer; text-decoration: none; }
button:hover, .button:hover { background: var(--primary-dark); }
button:disabled { opacity: .55; cursor: wait; }
.secondary { background: #607381; }
.danger { background: var(--danger); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

.chat-page { height: 100vh; display: grid; grid-template-rows: auto 1fr auto auto; }
.chat-header { display: flex; gap: .8rem; align-items: center; padding: .8rem max(1rem, calc((100vw - 900px) / 2)); background: var(--primary); color: #fff; }
.chat-header img { border-radius: 50%; object-fit: contain; background: #fff; }
.chat-header h1 { font-size: 1.1rem; margin: 0; }
.chat-header p { margin: .15rem 0 0; font-size: .82rem; opacity: .8; }
.chat-container { width: min(900px, 100%); margin: 0 auto; overflow-y: auto; padding: 1.2rem; display: flex; flex-direction: column; gap: .8rem; }
.message { max-width: min(78%, 680px); padding: .75rem 1rem; border-radius: 16px; line-height: 1.65; white-space: pre-wrap; overflow-wrap: anywhere; }
.message.user { align-self: flex-end; color: #fff; background: var(--primary); border-bottom-right-radius: 4px; }
.message.bot { align-self: flex-start; background: #fff; box-shadow: 0 2px 10px rgb(21 77 120 / 8%); border-bottom-left-radius: 4px; }
.message img { display: block; max-width: 100%; max-height: 520px; margin-top: .6rem; border-radius: 8px; object-fit: contain; }
.quick-actions { width: min(900px, 100%); margin: 0 auto; padding: .5rem 1rem; display: flex; gap: .5rem; overflow-x: auto; }
.quick-actions button { white-space: nowrap; padding: .45rem .7rem; color: var(--primary); background: #fff; border: 1px solid var(--border); }
.chat-footer { background: #fff; border-top: 1px solid var(--border); padding: .8rem max(1rem, calc((100vw - 900px) / 2)); }
.chat-footer form { display: flex; gap: .6rem; }
.chat-footer input { flex: 1; min-width: 0; border: 1px solid var(--border); border-radius: 10px; padding: .75rem; }
.chat-footer p { margin: .5rem 0 0; text-align: center; color: var(--muted); font-size: .75rem; }

.admin-header { display: flex; align-items: center; gap: 1rem; padding: .85rem max(1rem, calc((100vw - 1100px) / 2)); background: var(--primary); }
.admin-header a, .link-button { color: #fff; text-decoration: none; background: transparent; padding: 0; }
.admin-header form { margin-left: auto; }
.admin-main { width: min(1100px, calc(100% - 2rem)); margin: 1.5rem auto; padding: 1.5rem; background: #fff; border-radius: 12px; box-shadow: 0 4px 20px rgb(0 0 0 / 6%); }
.page-heading { display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.page-heading h1, .admin-main > h1 { margin-top: 0; }
.hint { color: var(--muted); }
.qa-list { display: grid; gap: 1rem; }
.qa-card { padding: 1rem; border: 1px solid var(--border); border-radius: 10px; }
.qa-card h2 { margin: 0 0 .7rem; font-size: 1rem; color: var(--primary); }
.answer-preview img { max-width: 320px; max-height: 200px; }
.actions { display: flex; align-items: center; gap: .6rem; margin-top: 1rem; }
.editor-form { display: grid; gap: 1rem; }
.editor-form label { display: grid; gap: .4rem; font-weight: 600; }
.editor-form input, .editor-form textarea, .login-card input { width: 100%; border: 1px solid var(--border); border-radius: 8px; padding: .7rem; }
.editor-form textarea { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; resize: vertical; }
.upload-row { display: flex; align-items: end; gap: .7rem; flex-wrap: wrap; }
.table-wrap { margin-top: 1rem; overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: .7rem; border: 1px solid var(--border); text-align: left; vertical-align: top; font-size: .85rem; }
th { background: #f6f8fa; }
.login-card { width: min(420px, calc(100% - 2rem)); margin: 12vh auto; padding: 2rem; background: #fff; border-radius: 12px; box-shadow: 0 8px 30px rgb(0 0 0 / 10%); }
.login-card h1 { margin-top: 0; }
.login-card form { display: grid; gap: 1rem; }
.login-card label { display: grid; gap: .4rem; }
.alert.error { color: var(--danger); }

@media (max-width: 640px) {
    .message { max-width: 90%; }
    .admin-main { padding: 1rem; }
    .admin-header { overflow-x: auto; }
    .page-heading { align-items: flex-start; }
}