/* ===== ระบบการจัดการเรียนการสอน (โซนครู) ===== */
:root {
    --tp: #2563eb;
    --tp-d: #1e40af;
    --tp-l: #eff6ff;
    --tg: #10b981;
    --tw: #f59e0b;
    --tr: #ef4444;
    --tpurple: #8b5cf6;
}

* { box-sizing: border-box; }

body.teacher-body {
    font-family: 'Sarabun', sans-serif;
    margin: 0;
    background: #f1f5f9;
    color: #1f2937;
}

/* ---------- Login ---------- */
.login-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--tp) 0%, var(--tp-d) 100%);
    padding: 20px;
}
.login-card {
    background: #fff;
    width: 100%;
    max-width: 420px;
    border-radius: 18px;
    padding: 36px 32px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, .25);
}
.login-head { text-align: center; margin-bottom: 24px; }
.login-icon {
    width: 70px; height: 70px; margin: 0 auto 14px;
    background: var(--tp-l); color: var(--tp);
    border-radius: 50%; display: flex; align-items: center; justify-content: center;
    font-size: 30px;
}
.login-head h1 { font-size: 22px; margin: 0 0 6px; color: var(--tp-d); }
.login-head p { font-size: 13px; color: #6b7280; margin: 0; }

.login-form .form-group, .t-form .form-group { margin-bottom: 16px; }
.login-form label, .t-form label {
    display: block; font-weight: 600; font-size: 14px; margin-bottom: 6px; color: #374151;
}
.login-form input, .login-form select,
.t-form input, .t-form select, .t-form textarea {
    width: 100%; padding: 11px 13px; border: 1px solid #d1d5db;
    border-radius: 10px; font-family: inherit; font-size: 15px; background: #fff;
}
.login-form input:focus, .login-form select:focus,
.t-form input:focus, .t-form select:focus, .t-form textarea:focus {
    outline: none; border-color: var(--tp); box-shadow: 0 0 0 3px rgba(37, 99, 235, .15);
}
.btn-login {
    width: 100%; padding: 13px; border: none; border-radius: 10px;
    background: var(--tp); color: #fff; font-size: 16px; font-weight: 600;
    font-family: inherit; cursor: pointer; transition: .2s;
}
.btn-login:hover { background: var(--tp-d); }
.back-link { display: block; text-align: center; margin-top: 18px; color: #6b7280; text-decoration: none; font-size: 14px; }
.back-link:hover { color: var(--tp); }

.alert { padding: 12px 15px; border-radius: 10px; margin-bottom: 16px; font-size: 14px; }
.alert-error { background: #fef2f2; color: #b91c1c; border: 1px solid #fecaca; }

/* ---------- Topbar ---------- */
.t-topbar { background: #fff; box-shadow: 0 1px 4px rgba(0, 0, 0, .08); position: sticky; top: 0; z-index: 50; }
.t-topbar-inner {
    max-width: 1100px; margin: 0 auto; padding: 12px 20px;
    display: flex; align-items: center; justify-content: space-between;
}
.t-brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--tp-d); font-weight: 700; font-size: 18px; }
.t-brand i { color: var(--tp); }
.t-user { display: flex; align-items: center; gap: 14px; }
.t-user-info { text-align: right; line-height: 1.3; }
.t-user-info strong { display: block; font-size: 14px; }
.t-user-info small { color: #6b7280; font-size: 12px; }
.t-logout {
    width: 38px; height: 38px; border-radius: 9px; background: #fef2f2; color: var(--tr);
    display: flex; align-items: center; justify-content: center; text-decoration: none;
}
.t-logout:hover { background: var(--tr); color: #fff; }

/* ---------- Layout ---------- */
.t-main { min-height: calc(100vh - 130px); }
.t-container { max-width: 1100px; margin: 0 auto; padding: 28px 20px; }
.t-narrow { max-width: 760px; }

.t-welcome { margin-bottom: 24px; }
.t-welcome h1 { font-size: 26px; margin: 0 0 6px; color: var(--tp-d); }
.t-welcome p { color: #6b7280; margin: 0; }

/* ---------- Category cards ---------- */
.cat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 18px; margin-bottom: 32px; }
.cat-card {
    background: #fff; border-radius: 16px; padding: 24px; text-decoration: none; color: inherit;
    box-shadow: 0 2px 8px rgba(0, 0, 0, .06); transition: .2s; border-top: 4px solid var(--tp);
}
.cat-card:hover { transform: translateY(-4px); box-shadow: 0 10px 24px rgba(0, 0, 0, .12); }
.cat-icon { font-size: 30px; margin-bottom: 12px; }
.cat-card h3 { margin: 0 0 6px; font-size: 18px; }
.cat-count { color: #6b7280; font-size: 13px; }
.cat-plan { border-top-color: var(--tp); } .cat-plan .cat-icon { color: var(--tp); }
.cat-worksheet { border-top-color: var(--tg); } .cat-worksheet .cat-icon { color: var(--tg); }
.cat-knowledge { border-top-color: var(--tw); } .cat-knowledge .cat-icon { color: var(--tw); }
.cat-forum { border-top-color: var(--tpurple); } .cat-forum .cat-icon { color: var(--tpurple); }

/* ---------- Sections / buttons ---------- */
.t-section { background: #fff; border-radius: 16px; padding: 22px; box-shadow: 0 2px 8px rgba(0, 0, 0, .06); }
.t-section-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; flex-wrap: wrap; gap: 12px; }
.t-section-head h2 { font-size: 20px; margin: 0; color: var(--tp-d); }

.btn-primary {
    display: inline-flex; align-items: center; gap: 8px; background: var(--tp); color: #fff;
    border: none; padding: 10px 18px; border-radius: 10px; font-family: inherit; font-size: 14px;
    font-weight: 600; text-decoration: none; cursor: pointer;
}
.btn-primary:hover { background: var(--tp-d); }
.btn-ghost {
    display: inline-flex; align-items: center; gap: 8px; color: var(--tp); text-decoration: none;
    font-weight: 600; font-size: 14px; margin-bottom: 16px;
}

/* ---------- Lists ---------- */
.post-list { display: flex; flex-direction: column; gap: 10px; }
.post-row {
    display: flex; align-items: center; gap: 12px; padding: 12px 14px; border: 1px solid #eef0f3;
    border-radius: 10px; text-decoration: none; color: inherit; transition: .15s; flex-wrap: wrap;
}
.post-row:hover { background: var(--tp-l); border-color: #c7d7fb; }
.post-row-title { flex: 1; font-weight: 600; min-width: 180px; }
.post-row-meta { color: #6b7280; font-size: 13px; }

.card-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
.info-card {
    background: #fff; border-radius: 14px; padding: 18px; text-decoration: none; color: inherit;
    box-shadow: 0 2px 8px rgba(0, 0, 0, .06); transition: .2s;
}
.info-card:hover { transform: translateY(-3px); box-shadow: 0 8px 20px rgba(0, 0, 0, .1); }
.info-card h3 { margin: 0 0 8px; font-size: 17px; color: var(--tp-d); }
.info-card-excerpt { color: #6b7280; font-size: 14px; min-height: 38px; margin: 0 0 12px; }
.info-card-foot { display: flex; flex-wrap: wrap; gap: 12px; font-size: 12px; color: #9ca3af; }

.badge { display: inline-block; padding: 3px 10px; border-radius: 999px; font-size: 12px; font-weight: 600; color: #fff; }
.badge-plan { background: var(--tp); } .badge-worksheet { background: var(--tg); }
.badge-knowledge { background: var(--tw); } .badge-forum { background: var(--tpurple); }

.empty-state { text-align: center; padding: 50px 20px; color: #9ca3af; }
.empty-state i { font-size: 44px; margin-bottom: 12px; display: block; }

/* ---------- Post detail ---------- */
.post-detail { background: #fff; border-radius: 16px; padding: 26px; box-shadow: 0 2px 8px rgba(0, 0, 0, .06); margin-bottom: 24px; }
.post-detail h1 { font-size: 24px; margin: 12px 0; color: #111827; }
.post-meta { display: flex; flex-wrap: wrap; gap: 16px; color: #6b7280; font-size: 13px; margin-bottom: 18px; }
.post-content { line-height: 1.8; font-size: 16px; color: #374151; white-space: normal; }
.file-download {
    display: inline-flex; align-items: center; gap: 10px; margin-top: 20px; padding: 12px 18px;
    background: var(--tp-l); color: var(--tp-d); border-radius: 10px; text-decoration: none; font-weight: 600;
}
.file-download:hover { background: #dbe6fe; }

/* ---------- Comments ---------- */
.comments { background: #fff; border-radius: 16px; padding: 24px; box-shadow: 0 2px 8px rgba(0, 0, 0, .06); }
.comments h2 { font-size: 18px; color: var(--tp-d); margin: 0 0 16px; }
.comment-form textarea { width: 100%; padding: 12px; border: 1px solid #d1d5db; border-radius: 10px; font-family: inherit; resize: vertical; }
.comment-form button { margin-top: 10px; }
.comment-list { list-style: none; padding: 0; margin: 22px 0 0; }
.comment-list li { padding: 14px 0; border-top: 1px solid #eef0f3; }
.comment-head { display: flex; align-items: baseline; gap: 10px; margin-bottom: 6px; flex-wrap: wrap; }
.comment-head small { color: #9ca3af; font-size: 12px; }
.comment-body { color: #374151; line-height: 1.6; }
.muted { color: #9ca3af; margin-top: 16px; }
.req { color: var(--tr); }
.t-form small { color: #9ca3af; font-size: 12px; }

/* ---------- Footer ---------- */
.t-footer { text-align: center; padding: 18px; color: #9ca3af; font-size: 13px; }

@media (max-width: 600px) {
    .t-user-info { display: none; }
}