/* =============================================
   Grammar Portal — Modern Bangla Design
   ============================================= */
:root {
    --primary:       #1a6b3c;
    --primary-dark:  #0f3d22;
    --primary-light: #e8f5ee;
    --accent:        #f4a208;
    --text:          #1a1a2e;
    --text-muted:    #64748b;
    --border:        #e2e8f0;
    --bg:            #f7faf8;
    --card:          #ffffff;
    --shadow:        0 2px 12px rgba(26,107,60,.07);
    --shadow-lg:     0 8px 32px rgba(26,107,60,.13);
    --radius:        14px;
    --radius-sm:     9px;
    --font:          'Hind Siliguri', 'Noto Serif Bengali', sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{font-family:var(--font);background:var(--bg);color:var(--text);font-size:16px;line-height:1.75;min-height:100vh;display:flex;flex-direction:column;-webkit-font-smoothing:antialiased;}
.main-content{flex:1;}
.container{max-width:1160px;margin:0 auto;padding:0 18px;}
img{max-width:100%;}

/* ── HEADER ── */
.site-header{background:linear-gradient(135deg,var(--primary-dark),var(--primary));box-shadow:0 2px 18px rgba(0,0,0,.13);position:sticky;top:0;z-index:100;}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:13px 0;gap:16px;}
.logo{display:flex;align-items:center;gap:11px;text-decoration:none;color:white;}
.logo-icon{font-size:1.9rem;}
.logo-text{display:block;font-size:1.18rem;font-weight:700;line-height:1.2;letter-spacing:-.2px;}
.logo-sub{display:block;font-size:.68rem;opacity:.7;font-weight:300;letter-spacing:.3px;}
.main-nav{display:flex;align-items:center;gap:4px;}
.main-nav a{color:rgba(255,255,255,.85);text-decoration:none;padding:7px 13px;border-radius:8px;font-size:.88rem;font-weight:500;transition:all .2s;}
.main-nav a:hover,.main-nav a.active{background:rgba(255,255,255,.16);color:white;}
.main-nav .nav-btn{background:var(--accent);color:#1a1a2e!important;font-weight:700;padding:7px 16px;}
.main-nav .nav-btn:hover{background:#d48900;}
.burger{display:none;flex-direction:column;gap:5px;background:none;border:2px solid rgba(255,255,255,.35);padding:7px 9px;border-radius:7px;cursor:pointer;}
.burger span{display:block;width:18px;height:2px;background:white;border-radius:2px;transition:all .3s;}

/* Mobile nav */
@media(max-width:680px){
    .burger{display:flex;}
    .main-nav{display:none;flex-direction:column;gap:0;position:absolute;top:100%;left:0;right:0;background:var(--primary-dark);padding:10px 18px 16px;box-shadow:0 8px 24px rgba(0,0,0,.2);}
    .main-nav.open{display:flex;}
    .main-nav a{padding:11px 14px;width:100%;}
    .site-header{position:relative;}
    .header-inner{position:relative;}
}

/* ── FLASH ── */
.flash{padding:13px 18px;display:flex;justify-content:space-between;align-items:center;font-weight:500;font-size:.9rem;border-bottom:3px solid;}
.flash-success{background:#dcfce7;color:#15803d;border-color:#15803d;}
.flash-error{background:#fee2e2;color:#dc2626;border-color:#dc2626;}
.flash-info{background:#dbeafe;color:#1d4ed8;border-color:#1d4ed8;}
.flash button{background:none;border:none;cursor:pointer;font-size:1rem;color:inherit;opacity:.5;padding:0 4px;}

/* ── HERO ── */
.hero{background:linear-gradient(135deg,var(--primary-dark) 0%,var(--primary) 65%,#2d9b5f 100%);color:white;padding:72px 0 56px;text-align:center;position:relative;overflow:hidden;}
.hero::before{content:'';position:absolute;inset:0;background:radial-gradient(ellipse at 70% 50%,rgba(255,255,255,.05) 0%,transparent 60%);}
.hero-content{position:relative;z-index:1;}
.hero h1{font-size:clamp(1.7rem,4vw,2.8rem);font-weight:700;margin-bottom:14px;line-height:1.3;letter-spacing:-.3px;}
.hero p{font-size:1.08rem;opacity:.87;max-width:520px;margin:0 auto 28px;font-weight:300;}
.hero-actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;}
.hero-stats{display:flex;justify-content:center;gap:36px;margin-top:44px;flex-wrap:wrap;}
.hero-stat .num{font-size:1.9rem;font-weight:700;display:block;color:var(--accent);}
.hero-stat .lbl{font-size:.8rem;opacity:.72;}

/* ── BUTTONS ── */
.btn{display:inline-flex;align-items:center;gap:7px;padding:11px 22px;border-radius:var(--radius-sm);font-size:.92rem;font-weight:600;font-family:var(--font);text-decoration:none;border:2px solid transparent;cursor:pointer;transition:all .2s;line-height:1.3;}
.btn-primary{background:var(--accent);color:#1a1a2e;border-color:var(--accent);}
.btn-primary:hover{background:#d48900;transform:translateY(-1px);box-shadow:0 4px 14px rgba(244,162,8,.3);}
.btn-outline{background:transparent;color:white;border-color:rgba(255,255,255,.45);}
.btn-outline:hover{background:rgba(255,255,255,.1);border-color:white;}
.btn-green{background:var(--primary);color:white;}
.btn-green:hover{background:var(--primary-dark);transform:translateY(-1px);}
.btn-gray{background:#f1f5f9;color:#475569;border:1px solid var(--border);}
.btn-gray:hover{background:#e2e8f0;}
.btn-sm{padding:7px 14px;font-size:.82rem;}
.btn-lg{padding:14px 30px;font-size:1rem;}
.btn-full{width:100%;justify-content:center;}

/* ── TOPIC CARDS ── */
.topics-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:20px;padding:36px 0;}
.topic-card{background:var(--card);border-radius:var(--radius);border:2px solid var(--border);padding:26px 20px;text-decoration:none;color:var(--text);display:flex;flex-direction:column;gap:10px;transition:all .25s;position:relative;overflow:hidden;}
.topic-card::after{content:'';position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--primary),var(--accent));transform:scaleX(0);transition:transform .25s;}
.topic-card:hover{border-color:var(--primary);box-shadow:var(--shadow-lg);transform:translateY(-3px);}
.topic-card:hover::after{transform:scaleX(1);}
.topic-icon{font-size:2.2rem;}
.topic-title{font-size:1.08rem;font-weight:700;color:var(--primary-dark);line-height:1.3;}
.topic-desc{font-size:.85rem;color:var(--text-muted);line-height:1.65;}
.topic-badge{display:inline-block;background:var(--primary-light);color:var(--primary-dark);padding:4px 11px;border-radius:20px;font-size:.76rem;font-weight:600;margin-top:auto;}

/* ── LESSON PAGE ── */
.page-hero{background:linear-gradient(135deg,var(--primary-dark),var(--primary));color:white;padding:36px 0;}
.page-hero h1{font-size:clamp(1.4rem,3vw,2rem);margin-bottom:7px;font-weight:700;}
.page-hero p{opacity:.82;font-size:.95rem;font-weight:300;}
.breadcrumb{display:flex;align-items:center;gap:7px;font-size:.82rem;margin-bottom:10px;color:rgba(255,255,255,.7);flex-wrap:wrap;}
.breadcrumb a{color:rgba(255,255,255,.8);text-decoration:none;}
.breadcrumb a:hover{color:var(--accent);}

.topic-layout{display:grid;grid-template-columns:265px 1fr;gap:24px;padding:28px 0 56px;align-items:start;}

/* Sidebar */
.sidebar{background:var(--card);border-radius:var(--radius);border:1px solid var(--border);box-shadow:var(--shadow);position:sticky;top:76px;overflow:hidden;}
.sidebar-header{background:var(--primary);color:white;padding:14px 18px;font-weight:700;font-size:.88rem;}
.sidebar-nav a{display:block;padding:10px 18px;color:var(--text);text-decoration:none;font-size:.85rem;border-bottom:1px solid var(--border);transition:background .15s;line-height:1.45;}
.sidebar-nav a:hover{background:var(--primary-light);color:var(--primary);}
.sidebar-nav a.active{background:var(--primary-light);color:var(--primary-dark);font-weight:600;border-left:3px solid var(--primary);}
.sidebar-section-label{padding:9px 18px 4px;font-size:.72rem;font-weight:700;color:var(--text-muted);text-transform:uppercase;letter-spacing:.5px;background:#f8fafc;border-bottom:1px solid var(--border);}
.sidebar-actions{padding:14px;border-top:1px solid var(--border);display:flex;flex-direction:column;gap:8px;}

/* Content */
.section-block{background:var(--card);border-radius:var(--radius);border:1px solid var(--border);margin-bottom:22px;overflow:hidden;box-shadow:var(--shadow);}
.section-title{background:linear-gradient(90deg,var(--primary-light),#f0faf5);padding:14px 22px;font-size:1rem;font-weight:700;color:var(--primary-dark);border-bottom:2px solid var(--primary);display:flex;align-items:center;gap:9px;}
.rule-block{padding:22px;border-bottom:1px solid var(--border);}
.rule-block:last-child{border-bottom:none;}
.rule-title{font-size:.96rem;font-weight:700;color:var(--primary-dark);margin-bottom:13px;padding-bottom:9px;border-bottom:1px dashed var(--border);display:flex;align-items:center;gap:7px;}
.rule-title::before{content:'▶';color:var(--accent);font-size:.65rem;}
.rule-body{font-size:.91rem;line-height:1.85;}
.rule-body p{margin-bottom:9px;}
.rule-body ul,.rule-body ol{padding-left:20px;margin-bottom:9px;}
.rule-body li{margin-bottom:4px;}

/* Colored boxes */
.rule-box,.box-green{background:#f0fdf4;border:1px solid #bbf7d0;border-left:4px solid var(--primary);border-radius:var(--radius-sm);padding:13px 16px;margin:10px 0;font-size:.9rem;line-height:1.8;}
.box-blue,.rule-box-blue{background:#eff6ff;border:1px solid #bfdbfe;border-left:4px solid #3b82f6;border-radius:var(--radius-sm);padding:13px 16px;margin:10px 0;font-size:.9rem;line-height:1.8;}
.box-yellow,.rule-tip{background:#fffbeb;border:1px solid #fde68a;border-left:4px solid var(--accent);border-radius:var(--radius-sm);padding:11px 15px;margin:10px 0;font-size:.87rem;color:#78350f;line-height:1.8;}
.box-purple,.rule-box-purple{background:#faf5ff;border:1px solid #e9d5ff;border-left:4px solid #a855f7;border-radius:var(--radius-sm);padding:13px 16px;margin:10px 0;font-size:.9rem;line-height:1.8;}
.box-orange,.rule-box-orange{background:#fff7ed;border:1px solid #fed7aa;border-left:4px solid #f97316;border-radius:var(--radius-sm);padding:13px 16px;margin:10px 0;font-size:.9rem;line-height:1.8;}
.box-red,.rule-box-red{background:#fef2f2;border:1px solid #fecaca;border-left:4px solid #ef4444;border-radius:var(--radius-sm);padding:13px 16px;margin:10px 0;font-size:.9rem;color:#7f1d1d;line-height:1.8;}
.tip-block{background:#fffbeb;border-left:4px solid var(--accent);padding:10px 14px;margin:8px 0;border-radius:0 8px 8px 0;font-size:.88rem;}
.rule-block-inner{background:#f0fdf4;border-left:4px solid var(--primary);padding:10px 14px;margin:8px 0;border-radius:0 8px 8px 0;font-size:.88rem;}
.exc-block{background:#fef2f2;border-left:4px solid #ef4444;padding:10px 14px;margin:8px 0;border-radius:0 8px 8px 0;font-size:.88rem;}

/* Tables */
.rule-table,.rule-body table{width:100%;border-collapse:collapse;margin:11px 0;border-radius:var(--radius-sm);overflow:hidden;border:1px solid var(--border);font-size:.86rem;}
.rule-table th,.rule-body table th{background:var(--primary);color:white;padding:9px 13px;text-align:left;font-weight:600;}
.rule-table td,.rule-body table td{padding:9px 13px;border-bottom:1px solid var(--border);}
.rule-table tr:nth-child(even) td,.rule-body table tr:nth-child(even) td{background:#f8fafc;}
.rule-table tr:last-child td,.rule-body table tr:last-child td{border-bottom:none;}

/* Example card */
.ex-block{background:#f0f9ff;border:1px solid #bae6fd;border-radius:var(--radius-sm);padding:13px 15px;margin:10px 0;}
.ex-block .ex-en{font-weight:700;color:#0369a1;margin-bottom:4px;font-size:.91rem;}
.ex-block .ex-bn{color:#64748b;font-size:.85rem;margin-bottom:4px;}
.ex-block .ex-exp{background:#e0f2fe;padding:3px 9px;border-radius:4px;font-size:.78rem;color:#0c4a6e;display:inline-block;}

/* Examples section */
.examples-section{background:#f8fffe;border-top:1px solid var(--border);padding:16px 22px;}
.examples-title{font-size:.78rem;font-weight:700;text-transform:uppercase;color:var(--text-muted);letter-spacing:.5px;margin-bottom:11px;}
.example-item{background:var(--card);border:1px solid var(--border);border-radius:var(--radius-sm);padding:13px 15px;margin-bottom:9px;position:relative;}
.example-num{position:absolute;top:-8px;left:13px;background:var(--primary);color:white;font-size:.67rem;font-weight:700;padding:1px 7px;border-radius:10px;}
.example-text{font-size:.91rem;color:var(--primary-dark);font-weight:500;margin-top:5px;margin-bottom:4px;}
.example-translation{font-size:.83rem;color:var(--text-muted);margin-bottom:4px;}
.example-explanation{font-size:.78rem;color:#92400e;background:#fffbeb;padding:3px 8px;border-radius:4px;display:inline-block;}

/* Topic actions bar */
.topic-actions{display:flex;align-items:center;gap:10px;padding:14px 22px;background:#f8fafc;border-bottom:1px solid var(--border);flex-wrap:wrap;}
.topic-actions span{font-size:.82rem;color:var(--text-muted);}

/* ── FORMS ── */
.auth-page{min-height:calc(100vh - 160px);display:flex;align-items:center;justify-content:center;padding:36px 18px;background:linear-gradient(135deg,#f0faf5,var(--bg));}
.auth-card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow-lg);border:1px solid var(--border);padding:36px;width:100%;max-width:420px;}
.auth-title{font-size:1.4rem;font-weight:700;color:var(--primary-dark);margin-bottom:5px;text-align:center;}
.auth-subtitle{text-align:center;color:var(--text-muted);font-size:.87rem;margin-bottom:24px;}
.form-group{margin-bottom:16px;}
.form-group label{display:block;font-size:.87rem;font-weight:600;color:var(--text);margin-bottom:6px;}
.form-group input,.form-group select,.form-group textarea{width:100%;padding:10px 13px;border:2px solid var(--border);border-radius:var(--radius-sm);font-size:.92rem;font-family:var(--font);color:var(--text);background:#fdfdfd;transition:border-color .2s,box-shadow .2s;}
.form-group input:focus,.form-group select:focus,.form-group textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(26,107,60,.09);background:white;}
.auth-link{text-align:center;margin-top:18px;font-size:.87rem;color:var(--text-muted);}
.auth-link a{color:var(--primary);font-weight:600;text-decoration:none;}
.auth-link a:hover{text-decoration:underline;}

/* ── DASHBOARD ── */
.dashboard-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:16px;margin-bottom:28px;}
.stat-card{background:var(--card);border-radius:var(--radius);padding:20px;border:1px solid var(--border);box-shadow:var(--shadow);display:flex;align-items:center;gap:13px;}
.stat-icon{font-size:2rem;background:var(--primary-light);padding:11px;border-radius:var(--radius-sm);line-height:1;}
.stat-num{font-size:1.5rem;font-weight:700;color:var(--primary-dark);}
.stat-lbl{font-size:.8rem;color:var(--text-muted);}
.progress-bar-wrap{background:var(--border);border-radius:20px;height:7px;overflow:hidden;margin-top:7px;}
.progress-bar{height:100%;background:linear-gradient(90deg,var(--primary),var(--accent));border-radius:20px;transition:width .4s ease;}

/* ── SECTIONS ── */
.section-header{text-align:center;padding:46px 0 8px;}
.section-header h2{font-size:clamp(1.3rem,3vw,1.8rem);font-weight:700;color:var(--primary-dark);margin-bottom:9px;}
.section-header p{color:var(--text-muted);max-width:480px;margin:0 auto;font-size:.92rem;}

/* ── ALERTS ── */
.alert{padding:13px 16px;border-radius:var(--radius-sm);margin-bottom:14px;font-size:.88rem;border-left:4px solid;}
.alert-info{background:#eff6ff;color:#1e40af;border-color:#3b82f6;}
.alert-success{background:#f0fdf4;color:#15803d;border-color:#22c55e;}
.alert-warning{background:#fffbeb;color:#92400e;border-color:#f59e0b;}
.alert-danger{background:#fef2f2;color:#991b1b;border-color:#ef4444;}

/* ── FOOTER ── */
.site-footer{background:var(--primary-dark);color:rgba(255,255,255,.78);padding:44px 0 0;margin-top:auto;}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:36px;margin-bottom:36px;}
.footer-brand h3{color:white;font-size:1.05rem;margin:9px 0 7px;}
.footer-brand p{font-size:.83rem;line-height:1.7;opacity:.8;}
.footer-links h4{color:white;font-size:.86rem;margin-bottom:12px;font-weight:700;}
.footer-links a{display:block;color:rgba(255,255,255,.65);text-decoration:none;font-size:.83rem;padding:3px 0;transition:color .2s;}
.footer-links a:hover{color:var(--accent);}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:16px 0;text-align:center;font-size:.78rem;opacity:.55;}

/* ── SHARE / DOWNLOAD BAR ── */
.action-float{position:fixed;bottom:24px;right:24px;display:flex;flex-direction:column;gap:10px;z-index:80;}
.action-float button,.action-float a{width:48px;height:48px;border-radius:50%;border:none;cursor:pointer;font-size:1.2rem;display:flex;align-items:center;justify-content:center;box-shadow:0 4px 16px rgba(0,0,0,.15);transition:all .2s;text-decoration:none;}
.action-float .af-share{background:var(--primary);color:white;}
.action-float .af-pdf{background:var(--accent);color:#1a1a2e;}
.action-float button:hover,.action-float a:hover{transform:scale(1.1);}

/* ── RESPONSIVE ── */
@media(max-width:900px){
    .topic-layout{grid-template-columns:1fr;}
    .sidebar{position:static;}
    .footer-grid{grid-template-columns:1fr 1fr;}
}
@media(max-width:580px){
    .footer-grid{grid-template-columns:1fr;gap:20px;}
    .auth-card{padding:24px 18px;}
    .hero{padding:48px 0 36px;}
    .hero-stats{gap:20px;}
    .topics-grid{grid-template-columns:1fr;}
    .dashboard-grid{grid-template-columns:1fr 1fr;}
    .topic-actions{gap:7px;}
}
@media(max-width:360px){
    .dashboard-grid{grid-template-columns:1fr;}
}

/* ── PRINT / PDF ── */
@media print{
    .site-header,.site-footer,.sidebar,.topic-actions,.action-float,.btn{display:none!important;}
    .topic-layout{grid-template-columns:1fr;}
    body{font-size:13px;}
    .rule-box,.box-blue,.box-yellow,.box-purple,.box-orange,.box-red{break-inside:avoid;}
}

/* ── UTILITY ── */
.mt-1{margin-top:8px;}.mt-2{margin-top:16px;}.mt-3{margin-top:24px;}.mt-4{margin-top:32px;}
.mb-2{margin-bottom:16px;}.mb-4{margin-bottom:32px;}
.text-center{text-align:center;}.text-muted{color:var(--text-muted);}
.d-flex{display:flex;}.gap-2{gap:12px;}.align-center{align-items:center;}.justify-between{justify-content:space-between;}