:root {
    --edu-ink: #172033;
    --edu-muted: #637083;
    --edu-brand: #2563eb;
    --edu-brand-dark: #1d4ed8;
    --edu-line: #dbe3ee;
    --edu-soft: #f8fafc;
    --edu-card: #ffffff;
    --edu-alert: #ef4444;
    --edu-warm: #f97316;
    --edu-radius: 22px;
    --mini-green: #163b32;
}

body {
    color: var(--edu-ink);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans Thai", Tahoma, sans-serif;
}

.site-header {
    background: rgba(255, 255, 255, .96);
    border-bottom: 1px solid var(--edu-line);
    box-shadow: 0 12px 30px rgba(23, 32, 51, .05);
}

.brand span {
    color: var(--edu-warm);
}

button,
.button,
.nav-cta,
.nav-form button {
    border-radius: 999px;
    font-weight: 800;
    letter-spacing: .01em;
    transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}

button:hover,
.button:hover,
.nav-cta:hover,
.nav-form button:hover {
    transform: translateY(-1px);
}

.button.primary,
button.primary,
.buy-box .primary {
    background: var(--edu-brand);
    border-color: var(--edu-brand);
    color: #fff;
    box-shadow: 0 12px 24px rgba(37, 99, 235, .18);
}

.button.primary:hover,
button.primary:hover,
.buy-box .primary:hover {
    background: var(--edu-brand-dark);
}

.button.secondary,
.product-shop-button,
.chat-button {
    background: #fff;
    border: 1px solid var(--edu-line);
    color: var(--edu-ink);
}

.chat-button {
    border-color: #bfdbfe;
    color: var(--edu-brand-dark);
}

.product-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 14px;
}

.product-chat-form {
    margin: 0;
}

.product-chat-form button,
.product-actions .button {
    min-height: 46px;
    padding-inline: 22px;
}

.message-nav {
    position: relative;
}

.message-nav span,
.site-header nav a span {
    background: var(--edu-alert);
    border-radius: 999px;
    color: #fff;
    display: inline-flex;
    font-size: 11px;
    font-weight: 800;
    line-height: 1;
    margin-left: 6px;
    min-width: 20px;
    padding: 5px 7px;
    place-content: center;
}

.messages-page,
.thread-page {
    background: var(--edu-soft);
    border-radius: var(--edu-radius);
    margin: clamp(28px, 5vw, 64px) auto;
    max-width: 1120px;
    padding: clamp(22px, 4vw, 44px);
}

.message-hero,
.thread-head {
    align-items: flex-end;
    display: flex;
    gap: 20px;
    justify-content: space-between;
    margin-bottom: 24px;
}

.message-hero h1,
.thread-head h1 {
    color: var(--edu-ink);
    margin-bottom: 8px;
}

.message-hero p:not(.eyebrow),
.thread-head p:not(.eyebrow) {
    color: var(--edu-muted);
    margin: 0;
}

.conversation-list {
    display: grid;
    gap: 14px;
}

.conversation-list a {
    align-items: center;
    background: var(--edu-card);
    border: 1px solid var(--edu-line);
    border-radius: 20px;
    box-shadow: 0 16px 35px rgba(23, 32, 51, .06);
    color: inherit;
    display: grid;
    gap: 16px;
    grid-template-columns: auto 1fr auto;
    padding: 16px;
    text-decoration: none;
}

.conversation-list a:hover {
    border-color: #bfdbfe;
}

.conversation-thumb,
.thread-product-card img {
    aspect-ratio: 1;
    border-radius: 16px;
    height: 72px;
    object-fit: cover;
    width: 72px;
}

.conversation-list strong {
    display: block;
    font-size: 17px;
    margin-bottom: 4px;
}

.conversation-list em {
    color: var(--edu-brand-dark);
    display: block;
    font-style: normal;
    font-weight: 800;
    margin-bottom: 4px;
}

.conversation-list p {
    color: var(--edu-muted);
    margin: 0;
}

.unread-badge {
    background: var(--edu-alert);
    border-radius: 999px;
    color: #fff;
    font-size: 12px;
    font-weight: 800;
    padding: 7px 10px;
}

.thread-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: flex-end;
}

.thread-product-card {
    align-items: center;
    background: #fff;
    border: 1px solid var(--edu-line);
    border-radius: 20px;
    display: flex;
    gap: 16px;
    margin-bottom: 18px;
    padding: 14px;
}

.thread-product-card span {
    color: var(--edu-muted);
    display: block;
    font-size: 13px;
    margin-bottom: 4px;
}

.thread-product-card strong {
    color: var(--edu-ink);
}

.message-stream {
    background: #fff;
    border: 1px solid var(--edu-line);
    border-radius: 22px;
    display: grid;
    gap: 12px;
    margin-bottom: 16px;
    padding: clamp(16px, 3vw, 28px);
}

.message-bubble {
    border: 1px solid var(--edu-line);
    border-radius: 18px;
    max-width: min(78%, 720px);
    padding: 14px 16px;
}

.message-bubble.mine {
    background: #eff6ff;
    border-color: #bfdbfe;
    justify-self: end;
}

.message-bubble.theirs {
    background: #fff7ed;
    border-color: #fed7aa;
    justify-self: start;
}

.message-bubble strong {
    display: block;
    margin-bottom: 6px;
}

.message-bubble p {
    margin: 0 0 8px;
}

.message-bubble time {
    color: var(--edu-muted);
    font-size: 12px;
}

.message-compose {
    background: #fff;
    border: 1px solid var(--edu-line);
    border-radius: 22px;
    display: grid;
    gap: 12px;
    padding: 14px;
}

.message-compose textarea {
    border: 1px solid var(--edu-line);
    border-radius: 16px;
    min-height: 110px;
    padding: 14px;
    resize: vertical;
}

.message-compose button {
    justify-self: end;
    min-width: 150px;
}

@media (max-width: 760px) {
    .message-hero,
    .thread-head {
        align-items: flex-start;
        flex-direction: column;
    }

    .conversation-list a {
        grid-template-columns: auto 1fr;
    }

    .unread-badge {
        grid-column: 2;
        justify-self: start;
    }

    .message-bubble {
        max-width: 100%;
    }
}