:root {
    --primary: #0ea5e9;
    --primary-dark: #0284c7;
    --primary-light: #e0f2fe;
    --secondary: #64748b;
    
    --bg-body: #0f172a;
    --bg-card: #1e293b;
    --bg-elevated: #334155;
    --bg-nav: rgba(15, 23, 42, 0.95);
    
    --text-main: #f8fafc;
    --text-secondary: #94a3b8;
    --text-inverse: #ffffff;
    
    --border: #334155;
    
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --purple: #8b5cf6;
    
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-glow: 0 0 15px rgba(14, 165, 233, 0.3);
    
    --radius-lg: 1.25rem;
    --radius-md: 0.75rem;
    --radius-sm: 0.5rem;
}

[data-theme="light"] {
    --bg-body: #f8fafc;
    --bg-card: #ffffff;
    --bg-elevated: #f1f5f9;
    --bg-nav: rgba(255, 255, 255, 0.95);
    
    --text-main: #0f172a;
    --text-secondary: #64748b;
    --text-inverse: #ffffff;
    
    --border: #e2e8f0;
    --shadow-glow: 0 4px 15px rgba(14, 165, 233, 0.15);
}

* { 
    margin: 0; 
    padding: 0; 
    box-sizing: border-box; 
    outline: none; 
    -webkit-tap-highlight-color: transparent; 
}

body { 
    background: var(--bg-body); 
    color: var(--text-main); 
    font-family: 'Inter', system-ui, -apple-system, sans-serif; 
    overflow-x: hidden; 
    padding-bottom: 90px; 
    transition: background 0.3s ease, color 0.3s ease;
    line-height: 1.6;
    min-height: 100vh;
}

html[lang="ar"] body { font-family: 'Cairo', sans-serif; }

h1, h2, h3 { font-weight: 800; letter-spacing: -0.025em; line-height: 1.2; margin-bottom: 1rem; }
h1 { font-size: clamp(1.75rem, 5vw, 2.5rem); }
h2 { font-size: clamp(1.5rem, 4vw, 1.75rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.5rem); }
p { color: var(--text-secondary); margin-bottom: 1.5rem; }

.container { 
    max-width: 1200px; 
    margin: 0 auto; 
    padding: 2rem clamp(1rem, 5vw, 1.5rem); 
    width: 100%; 
}

.flex { display: flex; align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: 0.5rem; }
.gap-4 { gap: 1rem; }
.hidden { display: none !important; }
.w-full { width: 100%; }
.text-center { text-align: center; }
.text-mute { color: var(--text-secondary); }
.mt-4 { margin-top: 1.5rem; }
.mb-4 { margin-bottom: 1.5rem; }
.p-4 { padding: 1.5rem; }

/* Navigation */
nav.top-nav {
    background: var(--bg-nav);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem clamp(1rem, 3vw, 1.5rem);
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.logo { 
    font-size: clamp(1.1rem, 3vw, 1.3rem); 
    font-weight: 800; 
    color: var(--text-main); 
    display: flex; 
    align-items: center; 
    gap: 0.5rem; 
    cursor: pointer;
    flex-shrink: 0;
}

.nav-links {
    display: none;
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .nav-links { display: flex; }
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 600;
    cursor: pointer;
    transition: 0.2s;
    font-size: 0.95rem;
    white-space: nowrap;
}
.nav-link:hover, .nav-link.active { color: var(--primary); }

.nav-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

/* Buttons */
.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white; 
    border: none; 
    padding: clamp(0.6rem, 2vw, 0.8rem) clamp(1.2rem, 3vw, 1.8rem);
    border-radius: var(--radius-md); 
    font-weight: 700; 
    cursor: pointer; 
    transition: all 0.2s;
    box-shadow: 0 4px 12px rgba(14, 165, 233, 0.3);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: clamp(0.85rem, 2vw, 0.95rem);
    white-space: nowrap;
}
.btn-primary:hover { transform: translateY(-2px); filter: brightness(1.1); }
.btn-primary:active { transform: scale(0.98); }

.btn-secondary {
    background: var(--bg-elevated); 
    border: 1px solid var(--border); 
    color: var(--text-main);
    padding: clamp(0.6rem, 2vw, 0.8rem) clamp(1.2rem, 3vw, 1.8rem); 
    border-radius: var(--radius-md); 
    cursor: pointer; 
    font-weight: 600;
    transition: 0.2s;
    font-size: clamp(0.85rem, 2vw, 0.95rem);
    white-space: nowrap;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}
.btn-secondary:hover { border-color: var(--primary); }

.btn-small {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 6px 16px;
    border-radius: 20px;
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    transition: 0.2s;
    white-space: nowrap;
}
.btn-small.active-filter { background: var(--primary); color: white; border-color: var(--primary); }

.icon-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    width: 40px; 
    height: 40px;
    border-radius: 10px;
    cursor: pointer;
    display: flex; 
    align-items: center; 
    justify-content: center;
    transition: 0.2s;
    flex-shrink: 0;
}
.icon-btn:hover { background: var(--bg-elevated); color: var(--primary); border-color: var(--primary); }

/* User Badge */
.user-xp-badge {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
    padding: 5px 12px;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 6px;
    border: 1px solid rgba(245, 158, 11, 0.2);
}

/* Inputs */
.input-field {
    width: 100%; 
    padding: 1rem; 
    background: var(--bg-elevated); 
    border: 1px solid var(--border);
    border-radius: var(--radius-md); 
    color: var(--text-main); 
    margin-bottom: 1rem;
    transition: 0.2s;
    font-size: 1rem;
}
.input-field:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.1); }

/* Module Grid */
.module-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fill, minmax(clamp(140px, 30vw, 160px), 1fr)); 
    gap: clamp(1rem, 2vw, 1.25rem); 
    margin-top: 2rem;
}

.module-card {
    background: var(--bg-card); 
    border: 1px solid var(--border); 
    border-radius: 20px; 
    padding: clamp(1rem, 3vw, 1.5rem); 
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); 
    cursor: pointer;
    display: flex; 
    flex-direction: column; 
    align-items: center;
    text-align: center;
    aspect-ratio: 1 / 1;
    min-height: 140px;
}
.module-card:hover { 
    transform: translateY(-8px); 
    border-color: var(--primary); 
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.module-icon { 
    background: rgba(14, 165, 233, 0.1); 
    color: var(--primary); 
    width: clamp(48px, 15vw, 64px); 
    height: clamp(48px, 15vw, 64px);
    border-radius: 20px; 
    display: flex; 
    align-items: center; 
    justify-content: center;
    margin-bottom: 0.75rem;
    transition: 0.3s;
}
.module-card:hover .module-icon { background: var(--primary); color: white; transform: scale(1.1); }

.module-title { 
    font-weight: 700; 
    font-size: clamp(0.85rem, 2.5vw, 1rem); 
    margin-top: auto;
    line-height: 1.3;
}
.module-phase { 
    font-size: clamp(0.65rem, 2vw, 0.7rem); 
    color: var(--text-secondary); 
    text-transform: uppercase; 
    margin-top: 5px; 
    opacity: 0.7; 
}

/* Profile */
.profile-header { text-align: center; padding: 2rem 0; }
.avatar { 
    width: clamp(80px, 20vw, 100px); 
    height: clamp(80px, 20vw, 100px); 
    background: var(--bg-card); 
    border-radius: 50%; 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    margin: 0 auto 1.5rem;
    border: 3px solid var(--primary);
    box-shadow: var(--shadow-lg);
}

.stat-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 1rem;
    border-radius: 15px;
    text-align: center;
    flex: 1;
    min-width: 120px;
}

.menu-list { display: flex; flex-direction: column; gap: 10px; margin-top: 2rem; }
.menu-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 1.2rem;
    border-radius: 15px;
    color: var(--text-main);
    display: flex; 
    align-items: center; 
    gap: 15px;
    cursor: pointer;
    transition: 0.2s;
    font-weight: 600;
}
.menu-item:hover { transform: translateX(5px); border-color: var(--primary); }
html[dir="rtl"] .menu-item:hover { transform: translateX(-5px); }
.menu-item.text-danger { color: var(--danger); }

/* Plan Cards */
.plan-card {
    background: var(--bg-card);
    padding: clamp(1.5rem, 4vw, 2.5rem);
    border-radius: 24px;
    border: 1px solid var(--border);
    margin-bottom: 1.5rem;
    position: relative;
    transition: 0.3s;
}
.plan-card.featured { 
    border: 2px solid var(--primary); 
    background: linear-gradient(180deg, var(--bg-card), rgba(14,165,233,0.05)); 
}
.plan-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.price { 
    font-size: clamp(2rem, 5vw, 2.5rem); 
    font-weight: 800; 
    color: var(--text-main); 
    margin: 10px 0; 
}
.badge { 
    background: var(--primary); 
    color: white; 
    padding: 4px 12px; 
    border-radius: 20px; 
    font-size: 0.75rem; 
    font-weight: 700; 
    position: absolute; 
    top: 20px; 
    right: 20px; 
}

/* Auth Box */
.auth-box {
    max-width: 420px;
    margin: 4rem auto;
    padding: clamp(2rem, 5vw, 3rem);
    background: var(--bg-card);
    border-radius: 32px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
    text-align: center;
}
.auth-icon {
    width: 80px; 
    height: 80px;
    background: rgba(14, 165, 233, 0.1);
    border-radius: 50%;
    margin: 0 auto 2rem;
    display: flex; 
    align-items: center; 
    justify-content: center;
    color: var(--primary);
}

/* Toast */
#toast {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%) translateY(30px);
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 12px clamp(16px, 4vw, 24px);
    border-radius: 100px;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    opacity: 0;
    transition: 0.3s cubic-bezier(0.18, 0.89, 0.32, 1.28);
    pointer-events: none;
    display: flex; 
    align-items: center; 
    gap: 10px;
    font-weight: 600;
    max-width: 90vw;
    font-size: clamp(0.85rem, 2.5vw, 0.95rem);
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* Bottom Nav */
.bottom-nav {
    position: fixed;
    bottom: 0;
    width: 100%;
    background: var(--bg-nav);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    justify-content: space-around;
    padding: 0.8rem clamp(0.5rem, 2vw, 1rem);
    border-top: 1px solid var(--border);
    z-index: 100;
}
.nav-item {
    background: none; 
    border: none;
    color: var(--text-secondary);
    display: flex; 
    flex-direction: column; 
    align-items: center; 
    gap: 4px;
    font-size: clamp(0.65rem, 2vw, 0.7rem); 
    font-weight: 600; 
    cursor: pointer;
    transition: 0.2s;
    padding: 0.5rem;
}
.nav-item.active { color: var(--primary); transform: translateY(-2px); }

/* Hero */
.hero { 
    text-align: center; 
    padding: clamp(2rem, 5vw, 4rem) clamp(1rem, 3vw, 1rem); 
}
.hero h1 { 
    max-width: 800px; 
    margin: 0 auto 1.5rem; 
}
.hero p { 
    max-width: 600px; 
    margin: 0 auto 2.5rem; 
    font-size: clamp(1rem, 2.5vw, 1.2rem); 
}

/* Responsive Utilities */
@media (max-width: 768px) {
    .container { padding: 1.5rem 1rem; }
    
    nav.top-nav { padding: 0.75rem 1rem; }
    
    .nav-controls { gap: 0.5rem; }
    
    .hero { padding: 2rem 1rem; }
    
    .module-grid { 
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); 
        gap: 1rem; 
    }
    
    .btn-primary, .btn-secondary {
        padding: 0.6rem 1rem;
        font-size: 0.85rem;
    }
    
    #authBtn {
        padding: 0.5rem 1rem !important;
        font-size: 0.85rem !important;
    }
    
    .flex.gap-4 {
        gap: 0.75rem;
    }
    
    .auth-box {
        margin: 2rem auto;
        padding: 2rem 1.5rem;
    }
}

@media (max-width: 480px) {
    .logo span { display: none; }
    
    .user-xp-badge { display: none; }
    
    .module-grid { 
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); 
    }
    
    .nav-controls { 
        flex-wrap: nowrap;
        gap: 0.25rem;
    }
    
    .icon-btn {
        width: 36px;
        height: 36px;
    }
}

/* Animations */
@keyframes fadeIn { 
    from { opacity: 0; transform: translateY(10px); } 
    to { opacity: 1; transform: translateY(0); } 
}
.view { animation: fadeIn 0.4s ease-out; }

/* Loader */
.loader {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 2rem auto;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}