:root {
  --blue:#1f5f99;
  --blue2:#2f7dc4;
  --soft:#edf5ff;
  --yellow:#ffd65a;
  --red:#d94b4b;
  --text:#1d2530;
  --muted:#697386;
  --card:#ffffff;
  --bg:#f5f8fc;
  --shadow:0 12px 30px rgba(20,40,80,.12);
}
*{box-sizing:border-box} body{margin:0;font-family:Arial,Helvetica,sans-serif;background:linear-gradient(135deg,#f9fbff,#edf5ff);color:var(--text)}
a{color:inherit}.login-body{min-height:100vh;display:grid;place-items:center;padding:20px}.login-card{width:min(440px,100%);background:var(--card);border-radius:24px;box-shadow:var(--shadow);padding:30px}.brand{display:flex;align-items:center;gap:12px;margin-bottom:20px}.brand-logo{width:52px;height:52px;border-radius:16px;background:linear-gradient(135deg,var(--blue),var(--blue2));color:white;display:grid;place-items:center;font-weight:900;font-size:28px}.brand h1{margin:0;color:var(--blue)}.muted{color:var(--muted)}
.form{display:grid;gap:14px}.form label{display:grid;gap:6px;font-weight:700}.form input,.form textarea{width:100%;padding:12px 14px;border:1px solid #d8e2ef;border-radius:12px;font:inherit}.form textarea{min-height:130px}.btn{border:0;border-radius:12px;padding:12px 16px;background:var(--blue);color:white;font-weight:800;cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;gap:8px}.btn:hover{background:#164b7d}.btn.secondary{background:#e8eef8;color:var(--blue)}.btn.danger{background:var(--red)}.message{padding:12px 14px;border-radius:12px;background:#eef7ee;color:#1d6b38;display:none}.message.error{background:#fff0f0;color:#9d1f1f}.app-header{position:sticky;top:0;z-index:10;background:rgba(255,255,255,.9);backdrop-filter:blur(12px);border-bottom:1px solid #dce7f5}.header-inner{max-width:1200px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:12px 18px}.small-logo{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:900;color:var(--blue)}.small-logo span:first-child{width:38px;height:38px;border-radius:12px;background:linear-gradient(135deg,var(--blue),var(--blue2));display:grid;place-items:center;color:white}.menu-btn{display:none;background:var(--blue);color:#fff;border:0;border-radius:10px;padding:10px 12px}.main-nav{display:flex;gap:8px;align-items:center}.main-nav a,.main-nav button{border:0;background:transparent;text-decoration:none;color:var(--text);font-weight:700;padding:9px 11px;border-radius:10px;cursor:pointer}.main-nav a:hover,.main-nav a.active,.main-nav button:hover{background:var(--soft);color:var(--blue)}.container{max-width:1200px;margin:0 auto;padding:24px 18px}.hero{display:grid;grid-template-columns:1.3fr .7fr;gap:20px;align-items:stretch}.card,.hero-card{background:var(--card);border-radius:22px;box-shadow:var(--shadow);padding:22px}.hero-card{background:linear-gradient(135deg,var(--blue),var(--blue2));color:white}.hero-card h1{font-size:clamp(28px,5vw,48px);margin:0 0 10px}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.course-card{background:var(--card);border-radius:20px;box-shadow:var(--shadow);padding:20px;border-top:5px solid var(--blue2)}.course-card h3{margin-top:0}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.stat{background:white;border-radius:18px;padding:18px;box-shadow:var(--shadow)}.stat strong{display:block;font-size:30px;color:var(--blue)}.table-wrap{overflow:auto}.table{width:100%;border-collapse:collapse;background:white;border-radius:18px;overflow:hidden}.table th,.table td{text-align:left;padding:12px;border-bottom:1px solid #edf1f7}.table th{background:var(--soft);color:var(--blue)}.progress-list{display:grid;gap:10px}.progress-item{background:#f8fbff;border:1px solid #e1ebf7;border-radius:14px;padding:12px}.bar{height:10px;background:#e6eef8;border-radius:99px;overflow:hidden}.bar span{display:block;height:100%;background:var(--blue2);width:0}.editor-layout{display:grid;grid-template-columns:340px 1fr;gap:18px}.editor-panel{display:grid;grid-template-rows:auto 1fr;gap:12px}.tabs{display:flex;gap:8px;flex-wrap:wrap}.tab{border:0;border-radius:10px;padding:10px 12px;background:#e8eef8;color:var(--blue);font-weight:800;cursor:pointer}.tab.active{background:var(--blue);color:white}.codebox{width:100%;min-height:360px;font-family:Consolas,Monaco,monospace;font-size:14px;line-height:1.5;border:1px solid #d8e2ef;border-radius:16px;padding:14px;resize:vertical;background:#101827;color:#e8f1ff}.preview{width:100%;min-height:420px;border:1px solid #d8e2ef;border-radius:16px;background:white}.split{display:grid;grid-template-columns:1fr 1fr;gap:18px}.check-list{display:grid;gap:8px}.check{padding:10px;border-radius:12px;background:#fff0f0}.check.ok{background:#eef7ee}.footer{padding:30px;text-align:center;color:var(--muted)}
@media(max-width:900px){.hero,.editor-layout,.split{grid-template-columns:1fr}.grid{grid-template-columns:1fr 1fr}.stats{grid-template-columns:1fr 1fr}.menu-btn{display:block}.main-nav{display:none;position:absolute;left:12px;right:12px;top:66px;background:white;box-shadow:var(--shadow);border-radius:16px;padding:10px;flex-direction:column;align-items:stretch}.main-nav.open{display:flex}.main-nav a,.main-nav button{text-align:left}}
@media(max-width:560px){.grid,.stats{grid-template-columns:1fr}.container{padding:18px 12px}.card,.hero-card{padding:18px}.login-card{padding:22px}}