*{box-sizing:border-box}
:root{--bg:#f4f6f8;--card:#fff;--text:#111;--muted:#667085;--border:#e4e7ec;--dark:#111;--soft:#f8f9fb;--success:#087443;--danger:#b42318;--shadow:0 12px 35px rgba(17,17,17,.06)}
html{scroll-behavior:smooth}body{margin:0;font-family:Inter,Arial,sans-serif;background:var(--bg);color:var(--text)}a{color:inherit}
.nav{min-height:76px;display:flex;align-items:center;justify-content:space-between;padding:0 5.5%;background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:20}.brand{font-weight:900;letter-spacing:.06em}.nav-actions{display:flex;gap:10px;align-items:center}
.btn{display:inline-flex;align-items:center;justify-content:center;border:1px solid #111;background:#fff;color:#111;padding:11px 17px;border-radius:10px;text-decoration:none;cursor:pointer;font-weight:750;font-size:14px;transition:.15s}.btn:hover{transform:translateY(-1px)}.btn.primary{background:#111;color:#fff}.btn.danger{border-color:#b42318;color:#b42318}.btn.small{padding:8px 11px;font-size:13px}
.hero{max-width:950px;margin:120px auto;padding:0 24px;text-align:center}.hero h1{font-size:clamp(42px,7vw,76px);margin:10px 0}.hero p{font-size:20px;line-height:1.6;color:var(--muted)}.hero-actions{display:flex;justify-content:center;gap:12px;margin-top:30px}
.auth-card{max-width:520px;margin:70px auto;padding:36px;background:var(--card);border:1px solid var(--border);border-radius:18px;box-shadow:var(--shadow)}.auth-card h1{margin:14px 0 8px}.auth-card form{display:grid;gap:10px;margin-top:24px}.auth-card input{padding:14px;border:1px solid #cfd4dc;border-radius:9px;font-size:16px}.auth-links{display:flex;justify-content:flex-end;margin-top:4px}.auth-links button{border:0;background:none;padding:0;color:#111;text-decoration:underline;cursor:pointer;font-weight:650}
.container{max-width:1120px;margin:50px auto;padding:0 24px}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:20px;margin-top:28px}.card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:24px;margin-bottom:20px;box-shadow:0 4px 18px rgba(17,17,17,.025)}.card h1{font-size:42px;margin:8px 0 14px}.card h2{margin-top:8px}.eyebrow{font-size:12px;font-weight:850;letter-spacing:.12em}.course-badge,.label{font-size:12px;font-weight:800;letter-spacing:.08em;text-transform:uppercase}.course-header{padding:36px}.course-header p:last-child{font-size:18px;line-height:1.6}.message{margin-top:12px;min-height:22px;color:var(--danger)}.message.success{color:var(--success)}.muted{color:var(--muted)}.empty-state{padding:22px;background:#f7f7f7;border-radius:12px}.notice{margin-top:24px;padding:20px;border-radius:12px;background:#f1f1f1}
label{font-weight:700}button{font:inherit}.admin-layout{display:grid;grid-template-columns:220px 1fr;gap:28px;max-width:1250px;margin:35px auto;padding:0 24px}.sidebar{position:sticky;top:105px;align-self:start;background:#fff;border:1px solid var(--border);border-radius:16px;padding:12px}.side-btn{width:100%;text-align:left;border:0;background:#fff;padding:12px 14px;border-radius:9px;cursor:pointer;font-weight:700}.side-btn:hover,.side-btn.active{background:#111;color:#fff}.admin-main{min-width:0}.admin-head{margin-bottom:28px}.admin-head h1{margin:6px 0 8px;font-size:44px}.admin-stats{grid-template-columns:repeat(4,minmax(0,1fr));margin-top:0}.stat-label{font-size:12px;color:var(--muted);font-weight:800;text-transform:uppercase;letter-spacing:.08em}.stat{font-size:34px;font-weight:900;margin-top:7px}
.admin-form{display:grid;grid-template-columns:1fr 1fr;gap:20px 24px}.form-field{display:flex;flex-direction:column;gap:8px}.form-field.full{grid-column:1/-1}.form-field input,.form-field select,.form-field textarea{width:100%;padding:13px;border:1px solid #cfd4dc;border-radius:10px;background:#fff;font-size:15px}.form-field textarea{min-height:110px;resize:vertical}.form-field input:focus,.form-field select:focus,.form-field textarea:focus{outline:2px solid #111;outline-offset:1px}.field-help{color:var(--muted);font-size:12px;line-height:1.4}.form-submit{grid-column:1/-1;justify-self:start}
.table-wrap{overflow-x:auto}table{width:100%;border-collapse:collapse}th,td{text-align:left;padding:13px 10px;border-bottom:1px solid var(--border);vertical-align:top}th{font-size:12px;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}.row-actions{display:flex;flex-wrap:wrap;gap:7px}.list{display:grid;gap:12px}.list-item{padding:16px;border:1px solid var(--border);border-radius:12px;background:var(--soft)}.list-item-head{display:flex;justify-content:space-between;gap:15px;align-items:flex-start}
.video-frame{width:100%;aspect-ratio:16/9;border:0;border-radius:14px;background:#000}.progress-wrap{margin:16px 0}.progress-meta{display:flex;justify-content:space-between;font-size:13px;color:var(--muted);margin-bottom:7px}.progress-bar{height:10px;background:#e7e9ee;border-radius:999px;overflow:hidden}.progress-fill{height:100%;background:#111;border-radius:999px;transition:width .2s}.lesson{padding:22px 0;border-top:1px solid var(--border)}.lesson:first-child{border-top:0}.lesson-actions{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-top:14px}.complete-btn.completed{background:#e9f7ef;border-color:#087443;color:#087443}.resource-link{display:inline-flex;gap:7px;align-items:center}.cert-card{display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap}
.chat-shell{display:grid;grid-template-rows:auto 1fr auto;min-height:520px}.chat-box{height:390px;overflow:auto;padding:18px;background:#f7f8fa;border-radius:12px;border:1px solid var(--border)}.chat-message{max-width:78%;padding:10px 13px;border-radius:14px;margin:8px 0;white-space:pre-wrap;word-break:break-word}.chat-message.mine{margin-left:auto;background:#111;color:#fff;border-bottom-right-radius:4px}.chat-message.theirs{background:#fff;border:1px solid var(--border);border-bottom-left-radius:4px}.chat-message img{display:block;max-width:260px;max-height:260px;border-radius:10px;margin-top:7px}.chat-compose{display:grid;grid-template-columns:1fr auto auto;gap:9px;margin-top:12px}.chat-compose textarea{resize:none;padding:12px;border:1px solid #cfd4dc;border-radius:10px;min-height:46px}.chat-compose input[type=file]{display:none}.attach-label{display:inline-flex;align-items:center;justify-content:center;border:1px solid #111;border-radius:10px;padding:0 14px;cursor:pointer;font-weight:750;background:#fff}
.tabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:22px}.section{display:none}.section.active{display:block}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:20px}.badge{display:inline-block;padding:5px 8px;border-radius:999px;background:#eef1f5;font-size:12px;font-weight:800}
@media(max-width:900px){.admin-layout{grid-template-columns:1fr}.sidebar{position:static;display:flex;overflow:auto;gap:6px}.side-btn{white-space:nowrap;width:auto}.admin-stats{grid-template-columns:1fr 1fr}.two-col{grid-template-columns:1fr}}
@media(max-width:700px){.nav{padding:0 20px}.hero{margin:70px auto}.container{margin:30px auto}.card h1,.admin-head h1{font-size:32px}.admin-stats{grid-template-columns:1fr}.admin-form{grid-template-columns:1fr}.form-field.full,.form-submit{grid-column:auto}.form-submit{width:100%}.hero-actions{flex-direction:column}.chat-compose{grid-template-columns:1fr 1fr}.chat-compose textarea{grid-column:1/-1}}

.modal-backdrop{position:fixed;inset:0;background:rgba(0,0,0,.48);display:flex;align-items:center;justify-content:center;padding:20px;z-index:100}.modal-backdrop[hidden]{display:none}.modal-card{width:min(680px,100%);max-height:90vh;overflow:auto;background:#fff;border-radius:18px;padding:26px;box-shadow:0 25px 80px rgba(0,0,0,.25)}.modal-head{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-bottom:18px}.modal-head h2{margin:0}.content-actions{display:flex;flex-wrap:wrap;gap:7px;margin-top:12px}.content-item{display:block}.course-list-actions{display:flex;flex-wrap:wrap;gap:7px;margin-top:12px}.danger-text{color:#b42318}.success-text{color:#087443}

.brand-logo{display:flex;align-items:center;gap:10px}.brand-logo img{display:block;width:170px;height:54px;object-fit:contain}.admin-brand-logo span,.auth-brand-logo span{font-size:12px;letter-spacing:.1em;font-weight:900}.auth-brand-logo{justify-content:center;margin-bottom:8px}.auth-brand-logo img{width:250px;height:130px}.admin-brand-logo img{width:155px;height:54px}.nav .brand-logo{min-width:170px}@media(max-width:700px){.brand-logo img{width:145px;height:48px}.auth-brand-logo img{width:220px;height:115px}}