:root {
    --primary: #1A237E; /* Original Deep Blue */
    --primary-light: #E0E7FA;
    --secondary: #3949AB;
    --accent: #FFD700; /* Gold */
    --success: #10B981;
    --danger: #EF4444;
    --warning: #E65100;
    --bg-body: #F3F6F9;
    --bg-card: #ffffff;
    --text-main: #1E293B;
    --text-muted: #64748B;
    --sidebar-width: 260px;
    --right-panel-width: 320px;
    --border: #E2E8F0;
}

html, body {
    overflow: hidden;
    width: 100%;
    margin: 0;
    padding: 0;
    height: 100vh;
    background-color: var(--bg-body);
}

body {
    font-family: 'Plus Jakarta Sans', sans-serif;
    color: var(--text-main);
}

.app-container {
    display: flex;
    height: 100vh;
    width: 100%;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, var(--primary) 0%, var(--secondary) 100%); /* Premium gradient */
    border-right: none; /* Remove border, use shadow for depth */
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    z-index: 1000;
    box-shadow: 2px 0 15px rgba(0,0,0,0.1); /* Subtle shadow */
    color: white; /* Ensure text is visible */
}

.sidebar-header { padding: 30px 25px; display: flex; align-items: center; gap: 12px; }
.logo-img { height: 42px; width: 42px; border-radius: 50%; filter: brightness(1.2); }
.logo-text { font-size: 1.5rem; font-weight: 800; color: white; letter-spacing: -0.5px; }
.logo-text span { color: var(--accent); /* Accent for span */ }

.sidebar-nav { flex: 1; overflow-y: auto; padding: 0 15px 30px; }
.nav-group-label { padding: 25px 12px 8px; font-size: 0.65rem; text-transform: uppercase; color: rgba(255,255,255,0.6); /* Lighter label */ font-weight: 800; letter-spacing: 1.5px; }

.nav-link { padding: 12px 15px; border-radius: 14px; text-decoration: none; color: rgba(255,255,255,0.8); /* Lighter link text */ display: flex; align-items: center; gap: 12px; font-weight: 700; font-size: 0.9rem; transition: 0.2s; margin-bottom: 2px; cursor: pointer; }
.nav-link i { font-size: 1.1rem; width: 22px; text-align: center; color: rgba(255,255,255,0.7); } /* Icon color */
.nav-link:hover { background: rgba(255,255,255,0.1); color: white; } /* Light hover effect */
.nav-link.active { background: var(--accent); color: var(--primary); /* Gold background for active */ box-shadow: 0 5px 15px rgba(255, 215, 0, 0.3); } /* Gold shadow */
.nav-link.active i { color: var(--primary); } /* Dark icon for active */

.premium-promo { background: linear-gradient(135deg, #FFD700 0%, #E65100 100%); /* Gold gradient */ margin: 20px 15px; padding: 22px; border-radius: 24px; color: white; position: relative; overflow: hidden; box-shadow: 0 10px 25px rgba(230, 81, 0, 0.2); }
.premium-promo h4 { font-weight: 900; font-size: 1.1rem; margin-bottom: 5px; color: #1A237E; } /* Darker text for promo header */
.premium-promo p { font-size: 0.8rem; opacity: 0.9; margin-bottom: 15px; line-height: 1.4; color: rgba(26,35,126,0.8); } /* Darker text for promo paragraph */
.btn-upgrade-nav {
    background: linear-gradient(135deg, #1A237E 0%, #3949AB 100%);
    color: white;
    padding: 12px;
    border-radius: 16px;
    font-weight: 900;
    font-size: 0.85rem;
    border: none;
    width: 100%;
    cursor: pointer;
    box-shadow: 0 8px 15px rgba(26, 35, 126, 0.3);
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.btn-upgrade-nav:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 12px 20px rgba(26, 35, 126, 0.4);
    filter: brightness(1.15);
}

/* Main Area */
.main-layout {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg-body);
    min-width: 0;
}

.top-header {
    height: 70px;
    background: white;
    padding: 0 15px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-shrink: 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 900;
}

.search-wrapper { position: relative; width: 400px; }
.search-wrapper input { width: 100%; padding: 12px 20px 12px 55px; border-radius: 14px; border: 1px solid var(--border); background: var(--bg-body); outline: none; font-weight: 600; transition: 0.3s; }
.search-wrapper input:focus { border-color: var(--primary); background: white; box-shadow: 0 0 0 4px var(--primary-light); }
.search-wrapper i { position: absolute; left: 20px; top: 50%; transform: translateY(-50%); color: var(--text-muted); font-size: 1.1rem; }

.header-actions { display: flex; align-items: center; gap: 12px; }
.points-badge { background: var(--primary); padding: 6px 12px; border-radius: 10px; display: flex; align-items: center; gap: 6px; font-weight: 800; color: white; box-shadow: 0 4px 10px rgba(26, 35, 126, 0.15); font-size: 0.85rem; }
.points-badge i { color: var(--accent); } /* Gold star */

.icon-btn { position: relative; font-size: 1.3rem; color: var(--text-muted); cursor: pointer; transition: 0.2s; background: var(--primary-light); /* Light background */ width: 40px; height: 40px; border-radius: 12px; display: flex; align-items: center; justify-content: center; }
.icon-btn:hover { color: var(--primary); background: var(--primary-light); }
.badge-dot { position: absolute; top: -1px; right: -1px; width: 12px; height: 12px; background: var(--danger); border: 2.5px solid white; border-radius: 50%; }

.profile-trigger { display: flex; align-items: center; gap: 8px; cursor: pointer; padding: 4px 8px; border-radius: 12px; transition: 0.2s; background: var(--bg-body); }
.profile-trigger:hover { background: var(--primary-light); }
.profile-trigger img { width: 38px; height: 38px; border-radius: 10px; object-fit: cover; border: 1.5px solid var(--border); }
.menu-btn {
    display: none;
    width: 44px;
    height: 44px;
    background: var(--bg-body);
    border-radius: 12px;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--primary);
    transition: 0.2s;
}

.menu-btn:hover { background: var(--primary-light); }
.profile-info-text { text-align: right; }
.profile-info-text .name { font-weight: 800; font-size: 0.95rem; color: var(--text-main); }
.profile-info-text .role { font-size: 0.75rem; color: var(--text-muted); font-weight: 700; }

.scroll-content { flex: 1; display: flex; overflow: hidden; background: var(--bg-body); }
.dashboard-body {
    flex: 1;
    padding: 30px;
    overflow-y: auto;
    overflow-x: hidden;
    scroll-behavior: smooth;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: block;
}

.content-section {
    width: 100%;
}

/* Welcome Card */
.welcome-hero {
    background: linear-gradient(135deg, var(--primary-light) 0%, #CCD6ED 100%);
    border-radius: 35px;
    padding: 35px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 35px;
    border: 1px solid var(--border);
    position: relative;
    min-height: 220px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}
.hero-text h1 { font-size: 2.2rem; font-weight: 950; color: var(--text-main); margin-bottom: 8px; }
.hero-text p { font-weight: 600; color: var(--text-muted); opacity: 0.9; margin-bottom: 30px; font-size: 0.95rem; }

.stat-row { display: flex; gap: 24px; align-items: center; flex-wrap: nowrap; }
.stat-box { display: flex; align-items: center; gap: 12px; min-width: 0; }
.stat-icon-wrap { width: 42px; height: 42px; background: white; border-radius: 12px; display: flex; align-items: center; justify-content: center; color: var(--primary); font-size: 1rem; flex-shrink: 0; }
.stat-label { font-size: 0.65rem; font-weight: 800; color: var(--text-muted); text-transform: uppercase; margin-bottom: 2px; }
.stat-value { font-size: 1.1rem; font-weight: 900; color: var(--text-main); }

/* Dashboard Layout & Grids */
.tile-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
    margin-bottom: 40px;
    width: 100%;
}

.tile {
    background: white;
    padding: 22px 20px;
    border-radius: 24px;
    border: 1.5px solid var(--border);
    cursor: pointer;
    transition: 0.3s;
    position: relative;
    box-shadow: 0 4px 10px rgba(0,0,0,0.02);
    display: flex;
    flex-direction: column;
}

.tile:hover { transform: translateY(-5px); border-color: var(--primary); box-shadow: 0 15px 30px rgba(0,0,0,0.04); }
.tile-icon-bg { width: 44px; height: 44px; border-radius: 12px; display: flex; align-items: center; justify-content: center; margin-bottom: 18px; font-size: 1.2rem; background: var(--primary-light); color: var(--primary); }
.tile h5 { font-size: 0.9rem; font-weight: 900; margin-bottom: 5px; color: var(--text-main); }
.tile p { font-size: 0.7rem; color: var(--text-muted); font-weight: 700; }
.tile .fa-arrow-right { position: absolute; right: 20px; bottom: 20px; font-size: 0.7rem; color: var(--text-muted); }

.dashboard-stack {
    display: flex;
    flex-direction: column;
    gap: 25px;
    width: 100%;
    margin-bottom: 40px;
}

.panel-box, .chart-panel {
    background: white;
    padding: 28px;
    border-radius: 28px;
    border: 1px solid var(--border);
    box-shadow: 0 8px 24px rgba(0,0,0,0.06);
    display: flex;
    flex-direction: column;
    width: 100%;
    height: auto;
}

.panel-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 25px; }
.panel-head h3 { font-size: 1.2rem; font-weight: 900; color: var(--text-main); }
.panel-link { font-size: 0.8rem; color: var(--primary); font-weight: 900; text-decoration: none; }

.list-row { display: flex; align-items: center; gap: 16px; padding: 16px 0; border-bottom: 1.5px solid var(--bg-body); transition: 0.3s; }
.list-row:last-child { border-bottom: none; }
.list-row:hover { transform: translateY(-5px); box-shadow: 0 15px 30px rgba(0,0,0,0.03); border-color: var(--primary); }
.list-icon-box { width: 44px; height: 44px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 1.2rem; flex-shrink: 0; background: var(--primary-light); color: var(--primary); }
.list-info { flex: 1; }
.list-title { font-size: 0.85rem; font-weight: 800; color: var(--text-main); margin-bottom: 3px; }
.list-subtitle { font-size: 0.7rem; color: var(--text-muted); font-weight: 700; }
.list-action { text-align: right; }
.list-status { font-size: 0.8rem; font-weight: 900; }

/* App Subject Grid */
.app-subject-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 25px; }
.app-subject-item { background: white; padding: 40px 25px; border-radius: 30px; border: 1.5px solid var(--border); cursor: pointer; transition: 0.3s; text-align: center; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 20px; box-shadow: 0 8px 24px rgba(0,0,0,0.05); } /* Enhanced shadow */
.app-subject-item:hover { transform: translateY(-10px); border-color: var(--primary); box-shadow: 0 20px 40px rgba(0,0,0,0.08); }
.app-subject-icon { width: 80px; height: 80px; background: var(--primary-light); color: var(--primary); border-radius: 24px; display: flex; align-items: center; justify-content: center; font-size: 2.2rem; transition: 0.3s; }
.app-subject-item:hover .app-subject-icon { transform: scale(1.1) rotate(5deg); background: var(--primary); color: white; }
.app-subject-name { font-size: 1.2rem; font-weight: 900; color: var(--text-main); font-family: 'Hind Siliguri', sans-serif; margin-top: 10px; } /* Ensure Hind Siliguri for Bengali */

/* Learning Path UI */
.learning-path { position: relative; padding-left: 50px; margin-top: 30px; }
.learning-path::before { content: ''; position: absolute; left: 21px; top: 0; bottom: 0; width: 3px; background: var(--border); z-index: 0; }
.path-item { position: relative; margin-bottom: 35px; background: white; padding: 25px 30px; border-radius: 24px; border: 1.5px solid var(--border); cursor: pointer; transition: 0.3s; display: flex; align-items: center; gap: 20px; box-shadow: 0 4px 10px rgba(0,0,0,0.02); }
.path-item:hover { transform: translateX(10px); border-color: var(--primary); box-shadow: 0 10px 25px rgba(0,0,0,0.05); }
.path-dot { position: absolute; left: -36px; top: 50%; transform: translateY(-50%); width: 14px; height: 14px; background: white; border: 3px solid var(--text-muted); border-radius: 50%; z-index: 1; transition: 0.3s; }
.path-item:hover .path-dot { border-color: var(--primary); transform: translateY(-50%) scale(1.4); }
.path-index { width: 44px; height: 44px; background: var(--primary-light); border-radius: 12px; display: flex; align-items: center; justify-content: center; font-weight: 900; color: var(--primary); font-size: 1rem; flex-shrink: 0; }
.path-content { flex: 1; }
.path-title { font-size: 1.05rem; font-weight: 850; color: var(--text-main); font-family: 'Hind Siliguri', sans-serif; }
.path-subtitle { font-size: 0.75rem; color: var(--text-muted); font-weight: 700; margin-top: 2px; }

/* Content Cards & Explanation */
.question-text { font-size: 1.15rem; font-weight: 800; color: var(--text-main); line-height: 1.6; font-family: 'Hind Siliguri', sans-serif; margin-bottom: 25px; }
.explanation-box { background: #FFFBEB; border: 1.5px solid #FDF6E3; padding: 25px; border-radius: 20px; margin-top: 20px; animation: slideDown 0.4s ease; box-shadow: 0 4px 10px rgba(0,0,0,0.02); }
.explanation-head { display: flex; align-items: center; gap: 10px; color: #D97706; font-weight: 900; font-size: 0.75rem; text-transform: uppercase; margin-bottom: 12px; letter-spacing: 1px; }
.explanation-text { color: #92400E; font-weight: 700; line-height: 1.6; font-size: 0.95rem; font-family: 'Hind Siliguri', sans-serif; }
@keyframes slideDown { from { opacity: 0; transform: translateY(-10px); } to { opacity: 1; transform: translateY(0); } }

/* Right Panel */
.right-info-panel {
    width: var(--right-panel-width);
    background: var(--bg-card); /* White background for right panel */
    border-left: 1px solid var(--border);
    flex-shrink: 0;
    padding: 40px 25px;
    display: flex;
    flex-direction: column;
    gap: 40px;
    overflow-y: auto;
    box-shadow: -2px 0 15px rgba(0,0,0,0.05); /* Subtle shadow */
}

.side-profile-header { text-align: center; }
.avatar-box { position: relative; display: inline-block; margin-bottom: 20px; }
.avatar-box img { width: 100px; height: 100px; border-radius: 30px; object-fit: cover; border: 5px solid var(--bg-body); box-shadow: 0 10px 25px rgba(0,0,0,0.05); }
.side-profile-header h4 { font-weight: 950; font-size: 1.3rem; color: var(--text-main); margin: 0; }
.side-profile-header p { font-size: 0.85rem; color: var(--text-muted); font-weight: 700; margin-top: 5px; }
.status-badge { display: inline-block; padding: 6px 15px; background: #ECFDF5; color: #10B981; border-radius: 50px; font-size: 0.7rem; font-weight: 800; margin-top: 15px; }

/* Progress Section in Right Panel */
.progress-section {
    /* Existing styles */
}

.stat-summary-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-top: 30px;
}

.stat-item-row {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: #F8FAFC;
    padding: 15px 10px;
    border-radius: 16px;
    font-size: 0.8rem;
    font-weight: 800;
    font-family: 'Hind Siliguri', sans-serif;
    border: 1px solid #E2E8F0;
}

.stat-item-row span:first-child {
    color: var(--text-main);
}

.stat-item-row span:last-child {
    color: var(--success); /* Default to success for correct, can be overridden */
}

#wrong-stat-val {
    color: var(--danger); /* Specific color for wrong stats */
}

.progress-donut-container { position: relative; width: 180px; height: 180px; margin: 20px auto; }
.donut-inner-text { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); text-align: center; pointer-events: none; }
.donut-inner-text h2 { font-size: 1.8rem; font-weight: 900; color: var(--text-main); margin: 0; line-height: 1; }
.donut-inner-text p { font-size: 0.7rem; color: var(--text-muted); font-weight: 700; text-transform: uppercase; margin: 0; }

.achievements-box .badges-row { display: flex; gap: 12px; margin-top: 20px; }
.badge-tile { background: var(--bg-body); width: 60px; height: 60px; border-radius: 18px; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; transition: 0.3s; }
.badge-tile:hover { transform: scale(1.1); background: white; box-shadow: 0 10px 20px rgba(0,0,0,0.05); }

.study-alert { background: var(--primary-light); padding: 20px; border-radius: 24px; display: flex; gap: 15px; border: 1px solid #CCD6ED; /* Lighter primary border */ box-shadow: 0 4px 10px rgba(0,0,0,0.02); }
.alert-icon-box { width: 40px; height: 40px; background: white; border-radius: 12px; display: flex; align-items: center; justify-content: center; color: var(--primary); font-size: 1.1rem; flex-shrink: 0; }
.alert-info h5 { font-size: 0.9rem; font-weight: 800; color: var(--text-main); margin-bottom: 4px; }
.alert-info p { font-size: 0.75rem; color: var(--primary); font-weight: 600; line-height: 1.4; }

.btn-action-sm {
    background: linear-gradient(135deg, #4361ee 0%, #3a0ca3 100%);
    color: white;
    border: none;
    padding: 10px 22px;
    border-radius: 14px;
    font-weight: 900;
    font-size: 0.8rem;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 6px 12px rgba(67, 97, 238, 0.25);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}
.btn-action-sm:hover {
    background: linear-gradient(135deg, #4895ef 0%, #4361ee 100%);
    transform: translateY(-3px);
    box-shadow: 0 10px 18px rgba(67, 97, 238, 0.35);
}
.btn-action-sm:active { transform: translateY(-1px); }

/* Added Start Small Button Style */
.btn-start-small {
    background: linear-gradient(135deg, #10B981 0%, #059669 100%);
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 12px;
    font-weight: 900;
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 10px rgba(16, 185, 129, 0.2);
    text-transform: uppercase;
}
.btn-start-small:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 15px rgba(16, 185, 129, 0.3);
    filter: brightness(1.1);
}

/* Authentication Overlay */
.auth-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-body);
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    overflow-y: auto;
}
.auth-form-card {
    background: white;
    width: 100%;
    max-width: 500px;
    padding: 50px;
    border-radius: 40px;
    box-shadow: 0 40px 100px rgba(0,0,0,0.08);
    border: 1.5px solid #F1F5F9;
    transition: all 0.3s ease;
    margin: auto;
}
.auth-form-card:hover { transform: translateY(-5px); box-shadow: 0 50px 120px rgba(0,0,0,0.12); }
#auth-title { font-size: 2.2rem; font-weight: 950; color: var(--text-main); letter-spacing: -1px; }

/* Profile & Auth Forms */
.auth-form-group { margin-bottom: 20px; }
.auth-form-group label { display: block; font-size: 0.75rem; font-weight: 800; color: var(--text-muted); text-transform: uppercase; margin-bottom: 8px; letter-spacing: 0.5px; }
.auth-control {
    width: 100%;
    padding: 16px 24px;
    border-radius: 18px;
    border: 2px solid #F1F5F9;
    background: #F8FAFC;
    outline: none;
    font-weight: 700;
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    color: var(--text-main);
}
.auth-control:focus {
    border-color: #4361ee;
    background: white;
    box-shadow: 0 0 0 5px rgba(67, 97, 238, 0.1);
    transform: scale(1.01);
}

.promo-group .auth-control {
    background: #f8fafc;
    border: 2px dashed #cbd5e1;
}
.promo-group .auth-control:focus {
    border-style: solid;
    border-color: var(--primary);
}

.chip-box { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 10px; }
.chip-item { padding: 10px 22px; background: white; border: 1.5px solid var(--border); border-radius: 14px; font-size: 0.85rem; font-weight: 700; color: var(--text-muted); cursor: pointer; transition: 0.2s; }
.chip-item:hover { background: var(--bg-body); border-color: var(--primary); color: var(--primary); }
.chip-item.selected { background: var(--primary); border-color: var(--primary); color: white; box-shadow: 0 8px 15px rgba(26, 35, 126, 0.3); }

.btn-auth-submit {
    background: linear-gradient(135deg, #4361ee 0%, #3a0ca3 100%);
    color: white;
    border: none;
    padding: 18px;
    border-radius: 20px;
    font-weight: 900;
    font-size: 1.1rem;
    width: 100%;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    box-shadow: 0 10px 20px rgba(67, 97, 238, 0.2);
    letter-spacing: 0.5px;
}
.btn-auth-submit:hover {
    transform: translateY(-5px) scale(1.01);
    box-shadow: 0 15px 30px rgba(67, 97, 238, 0.3);
    filter: brightness(1.1);
}
.btn-auth-submit:active { transform: translateY(-2px) scale(0.98); }

.otp-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; margin-bottom: 30px; }
.otp-box { height: 60px; border-radius: 14px; border: 2px solid var(--border); background: var(--bg-body); text-align: center; font-size: 1.5rem; font-weight: 800; color: var(--primary); outline: none; transition: 0.3s; }
.otp-box:focus { border-color: var(--primary); background: white; box-shadow: 0 0 0 4px var(--primary-light); }

/* Utility */
#page-loader { display: none; position: fixed; inset: 0; background: rgba(255,255,255,0.98); z-index: 15000; align-items: center; justify-content: center; flex-direction: column; backdrop-filter: blur(15px); }

/* PDF Viewer Enhancements */
.pdf-viewer-modal { user-select: none !important; -webkit-user-select: none !important; }
.pdf-page-wrapper { margin-bottom: 25px; border-radius: 16px; overflow: hidden; }
.pdf-protection-overlay { pointer-events: all; }

.spin-wheel { width: 65px; height: 65px; border: 7px solid #f3f3f3; border-top: 7px solid var(--secondary); border-radius: 50%; animation: spinRound 1.2s cubic-bezier(0.4, 0, 0.2, 1) infinite; } /* Spin wheel color */
@keyframes spinRound { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

/* Quiz & Content */
.option-btn {
    background: white;
    padding: 22px 25px;
    border-radius: 20px;
    border: 2px solid #F1F5F9;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-weight: 800;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 15px;
    color: var(--text-main);
    box-shadow: 0 4px 6px rgba(0,0,0,0.02);
}
.option-btn:hover {
    border-color: #4361ee;
    background: #F8FAFF;
    transform: translateX(8px);
    box-shadow: 0 8px 15px rgba(67, 97, 238, 0.08);
}
.option-btn.correct {
    background: linear-gradient(90deg, #ECFDF5 0%, #D1FAE5 100%);
    border-color: #10B981;
    color: #065F46;
    box-shadow: 0 8px 20px rgba(16, 185, 129, 0.15);
}
.option-btn.wrong {
    background: linear-gradient(90deg, #FEF2F2 0%, #FEE2E2 100%);
    border-color: #EF4444;
    color: #991B1B;
    box-shadow: 0 8px 20px rgba(239, 68, 68, 0.15);
}

.tab-btn {
    padding: 18px 35px;
    font-weight: 900;
    color: #94A3B8;
    cursor: pointer;
    border-bottom: 4px solid transparent;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.tab-btn.active {
    color: #4361ee;
    border-bottom-color: #4361ee;
    background: rgba(67, 97, 238, 0.04);
}
.tab-btn:hover:not(.active) {
    color: #64748B;
    background: rgba(0,0,0,0.02);
}

.locked-card { opacity: 0.6; position: relative; overflow: hidden; pointer-events: none; }
.overlay-lock { position: absolute; inset: 0; background: rgba(255,255,255,0.85); display: flex; flex-direction: column; align-items: center; justify-content: center; z-index: 5; backdrop-filter: blur(5px); }

/* Exam Interface */
.exam-container { max-width: 900px; margin: 0 auto; }
.exam-header { background: white; padding: 25px 40px; border-radius: 30px; margin-bottom: 25px; display: flex; justify-content: space-between; align-items: center; border: 1.5px solid var(--border); position: sticky; top: 0; z-index: 100; box-shadow: 0 10px 30px rgba(0,0,0,0.02); }
.exam-timer { background: #FEF2F2; color: #EF4444; padding: 12px 25px; border-radius: 15px; font-weight: 900; font-size: 1.2rem; display: flex; align-items: center; gap: 10px; border: 1.5px solid #FEE2E2; }
.exam-timer.warning { animation: pulseWarning 1s infinite; }
@keyframes pulseWarning { 0% { transform: scale(1); } 50% { transform: scale(1.05); } 100% { transform: scale(1); } }
/* Digital Note Viewer */
.dn-card {
    background: white;
    padding: 40px;
    border-radius: 30px;
    border: 1.5px solid #f1f5f9;
    box-shadow: 0 10px 30px rgba(0,0,0,0.02);
    transition: 0.3s;
}

.dn-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.04);
}

.dn-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.dn-card-num {
    font-weight: 900;
    color: #4361ee;
    font-size: 0.75rem;
    letter-spacing: 1.5px;
}

.dn-type-badge {
    background: #f1f5f9;
    color: #64748b;
    padding: 6px 14px;
    border-radius: 50px;
    font-size: 0.7rem;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.dn-question {
    font-size: 1.25rem;
    font-weight: 800;
    color: #1e293b;
    line-height: 1.6;
    font-family: 'Hind Siliguri', sans-serif;
}

.dn-options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: 25px;
}

.dn-option {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px 20px;
    background: #f8fafc;
    border: 1.5px solid #eef2ff;
    border-radius: 15px;
}

.dn-option .opt-label {
    width: 28px;
    height: 28px;
    background: white;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    color: #4361ee;
    font-size: 0.8rem;
    box-shadow: 0 4px 10px rgba(67, 97, 238, 0.05);
}

.dn-option .opt-text {
    font-weight: 700;
    color: #475569;
    font-size: 0.95rem;
}

@media (max-width: 600px) {
    .dn-options-grid { grid-template-columns: 1fr; }
}

.dn-answer-box {
    margin-top: 30px;
    padding: 30px;
    background: #f0fdf4;
    border-radius: 20px;
    border-left: 6px solid #10b981;
}

.dn-answer-label {
    font-weight: 950;
    color: #059669;
    font-size: 0.7rem;
    letter-spacing: 1px;
    margin-bottom: 12px;
}

.dn-answer {
    font-size: 1.05rem;
    font-weight: 700;
    color: #064e3b;
    line-height: 1.7;
    font-family: 'Hind Siliguri', sans-serif;
}

.dn-watermark {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) rotate(-45deg);
    font-size: 5rem;
    color: rgba(0,0,0,0.02);
    font-weight: 900;
    pointer-events: none;
    white-space: nowrap;
    text-align: center;
    z-index: 10;
}
@keyframes animateUp { from { opacity: 0; transform: translateY(30px); } to { opacity: 1; transform: translateY(0); } }

.question-card { background: white; padding: 45px; border-radius: 35px; border: 1.5px solid var(--border); margin-bottom: 30px; box-shadow: 0 20px 50px rgba(0,0,0,0.03); }
.exam-option { background: var(--bg-body); padding: 22px 30px; border-radius: 20px; border: 2px solid var(--border); cursor: pointer; transition: 0.3s; font-weight: 700; font-size: 1.05rem; display: flex; align-items: center; gap: 15px; margin-bottom: 15px; }
.exam-option:hover { border-color: var(--primary); background: var(--primary-light); color: var(--primary); }
.exam-option.selected { border-color: var(--primary); background: var(--primary); color: white; box-shadow: 0 10px 25px rgba(26, 35, 126, 0.3); }
.exam-option .opt-index { width: 32px; height: 32px; background: rgba(0,0,0,0.05); border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 0.9rem; }
.exam-option.selected .opt-index { background: rgba(255,255,255,0.2); }

.exam-nav { display: flex; justify-content: space-between; align-items: center; gap: 20px; margin-top: 40px; }
.btn-exam-nav {
    padding: 18px 36px;
    border-radius: 20px;
    font-weight: 900;
    font-size: 1rem;
    border: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    display: flex;
    align-items: center;
    gap: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 6px 15px rgba(0,0,0,0.1);
}

.btn-exam-nav:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 25px rgba(0,0,0,0.15);
}

.btn-prev { background: #F1F5F9; color: #64748B; border: 2px solid #E2E8F0; }
.btn-prev:hover { background: #E2E8F0; color: #1E293B; border-color: #CBD5E1; }

.btn-next { background: linear-gradient(135deg, #4361ee 0%, #3a0ca3 100%); color: white; }
.btn-next:hover { filter: brightness(1.15); }

.btn-finish { background: linear-gradient(135deg, #10B981 0%, #059669 100%); color: white; }
.btn-finish:hover { filter: brightness(1.15); }

.question-status-grid { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; padding: 20px; background: white; border-radius: 20px; border: 1.5px solid var(--border); }
.q-dot { width: 35px; height: 35px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 0.8rem; font-weight: 800; background: var(--bg-body); color: var(--text-muted); border: 1.5px solid var(--border); cursor: pointer; }
.q-dot.active { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
.q-dot.answered { background: var(--primary); color: white; border-color: var(--primary); }

/* Responsive adjustments */
@media (max-width: 1250px) {
    .tile-grid { grid-template-columns: repeat(4, 1fr); }
    .stat-row { gap: 15px; }
}

@media (max-width: 1150px) {
    .sidebar { position: fixed; left: -110%; height: 100vh; transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1); background: linear-gradient(180deg, var(--primary) 0%, var(--secondary) 100%); z-index: 1500; }
    .sidebar.active { left: 0; box-shadow: 20px 0 60px rgba(0,0,0,0.3); }
    .right-info-panel { display: none; }
    .menu-btn { display: flex !important; }
    .main-layout { margin-left: 0; width: 100%; }
    .dashboard-body { width: 100%; max-width: none; padding: 20px; display: block; }
    .tile-grid { grid-template-columns: repeat(3, 1fr); gap: 15px; margin-bottom: 25px; }
    .dashboard-stack { gap: 20px; }
    .search-wrapper { display: none; }
}

@media (max-width: 900px) {
    .welcome-hero { flex-direction: column; text-align: center; padding: 30px 20px; min-height: auto; gap: 20px; }
    .hero-text h1 { font-size: 1.8rem; margin-bottom: 5px; }
    .stat-row { justify-content: center; flex-wrap: wrap; gap: 15px; }
    .hero-illustration { display: none; }
}

@media (max-width: 768px) {
    .dashboard-body { padding: 15px; width: 100%; }
    .top-header { padding: 0 15px; height: 65px; }
    .tile-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .dash-layout-grid { grid-template-columns: 1fr; gap: 15px; }

    .app-subject-grid { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 15px; }
    .app-subject-item { padding: 20px 10px; min-height: 160px; }
    .app-subject-icon { width: 55px; height: 55px; font-size: 1.4rem; border-radius: 16px; }
    .app-subject-name { font-size: 0.9rem; margin-top: 10px; }

    .auth-form-card { padding: 30px 20px; margin: 15px; border-radius: 20px; width: calc(100% - 30px); max-width: 450px; }
    #auth-title { font-size: 1.8rem; }

    .learning-path { padding-left: 35px; }
    .path-item { padding: 15px; gap: 12px; }
    .path-dot { left: -28px; }
    .path-index { width: 32px; height: 32px; font-size: 0.85rem; }
    .path-title { font-size: 0.9rem; }

    .question-card { padding: 25px 20px; border-radius: 18px; }
    .exam-header { padding: 15px; flex-direction: column; gap: 12px; align-items: stretch; text-align: center; }
    .exam-timer { width: 100%; justify-content: center; padding: 8px; font-size: 1.1rem; }

    .btn-exam-nav { padding: 12px 20px; font-size: 0.8rem; }
}

@media (max-width: 480px) {
    .top-header { height: 60px; }
    .points-badge { padding: 4px 10px; font-size: 0.75rem; }
    .profile-info-text { display: none; }
    .profile-trigger { padding: 0; background: none; border: none; }
    .profile-trigger img { width: 38px; height: 38px; }

    .welcome-hero h1 { font-size: 1.5rem; }
    .stat-box { flex-direction: column; gap: 4px; text-align: center; }
    .stat-icon-wrap { width: 38px; height: 38px; font-size: 1rem; }

    .tile-grid { grid-template-columns: 1fr 1fr; }
    .tile { padding: 15px; border-radius: 18px; }
    .tile h5 { font-size: 0.85rem; }

    .otp-grid { gap: 6px; }
    .otp-box { height: 45px; font-size: 1.1rem; }

    .tab-btn { padding: 10px 12px; font-size: 0.75rem; }
}