/* ==========================================================================
   منصة إلكترونيات للجميع | Simple Electronics For All
   Subdomain: electronics.hibat-soft.com
   Theme: Dark PCB Mode (Default) & Light Lab Mode | RTL First
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Cairo:wght@400;500;600;700;800;900&family=JetBrains+Mono:wght@400;600;700&display=swap');

:root {
    /* المظهر الداكن الافتراضي - مستوحى من لوحات الدوائر المطبوعة وأجهزة الأوسيلوسكوب */
    --bg-primary: #070b14;
    --bg-secondary: #0f172a;
    --bg-card: #131c31;
    --bg-card-hover: #1a2642;
    --bg-glass: rgba(15, 23, 42, 0.85);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: rgba(56, 189, 248, 0.16);
    --border-strong: rgba(16, 185, 129, 0.35);

    /* ألوان العناصر الإلكترونية (PCB Emerald, Oscilloscope Cyan, Voltage Amber, Signal Red) */
    --accent-emerald: #10b981;
    --accent-emerald-glow: rgba(16, 185, 129, 0.25);
    --accent-cyan: #06b6d4;
    --accent-cyan-glow: rgba(6, 182, 212, 0.25);
    --accent-amber: #f59e0b;
    --accent-purple: #8b5cf6;
    --accent-red: #ef4444;
    --youtube-red: #ff0033;

    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.5);
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
    /* المظهر النهاري (Light Lab Mode) */
    --bg-primary: #f1f5f9;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f8fafc;
    --bg-glass: rgba(255, 255, 255, 0.9);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --border-strong: rgba(16, 185, 129, 0.45);
    --shadow-sm: 0 4px 15px rgba(15, 23, 42, 0.06);
    --shadow-lg: 0 16px 35px rgba(15, 23, 42, 0.1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-family: 'Cairo', system-ui, -apple-system, sans-serif;
    direction: rtl;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.75;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    background-image: 
        radial-gradient(circle at 15% 15%, rgba(16, 185, 129, 0.06) 0%, transparent 35%),
        radial-gradient(circle at 85% 80%, rgba(6, 182, 212, 0.06) 0%, transparent 35%);
}

/* خلفية شبكية هندسية تحاكي ورق الرسم الهندسي وخطوط PCB */
.pcb-grid-bg {
    background-size: 32px 32px;
    background-image: 
        linear-gradient(to right, rgba(56, 189, 248, 0.04) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(56, 189, 248, 0.04) 1px, transparent 1px);
}

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition);
}

ul, ol {
    padding-right: 1.4rem;
}

code, pre, .mono {
    font-family: 'JetBrains Mono', monospace;
    direction: ltr;
    display: inline-block;
}

.container {
    width: 100%;
    max-width: 1320px;
    margin: 0 auto;
    padding: 0 1.25rem;
}

/* ==========================================================================
   الشريط العلوي والترويسة (Navbar & Top Banner)
   ========================================================================== */
.top-subdomain-bar {
    background: linear-gradient(90deg, #064e3b, #0f172a, #1e1b4b);
    color: #e2e8f0;
    font-size: 0.85rem;
    padding: 0.45rem 0;
    border-bottom: 1px solid rgba(16, 185, 129, 0.25);
}

.top-subdomain-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.subdomain-pill {
    background: rgba(16, 185, 129, 0.15);
    border: 1px solid rgba(16, 185, 129, 0.4);
    color: #34d399;
    padding: 0.1rem 0.65rem;
    border-radius: 99px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.78rem;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border-color);
}

.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 76px;
    gap: 1rem;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 0.85rem;
}

.brand-icon {
    width: 46px;
    height: 46px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--accent-emerald), var(--accent-cyan));
    display: flex;
    align-items: center;
    justify-content: center;
    color: #06131f;
    font-weight: 900;
    box-shadow: 0 0 20px var(--accent-emerald-glow);
    flex-shrink: 0;
}

.brand-text h1 {
    font-size: 1.25rem;
    font-weight: 800;
    line-height: 1.2;
    background: linear-gradient(90deg, var(--text-primary), var(--accent-emerald));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.brand-text span {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: block;
    font-family: 'JetBrains Mono', monospace;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    list-style: none;
    padding: 0;
}

.nav-link {
    padding: 0.55rem 1rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.45rem;
}

.nav-link:hover, .nav-link.active {
    color: var(--accent-emerald);
    background: rgba(16, 185, 129, 0.1);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 0.65rem;
}

/* ==========================================================================
   الأزرار والعناصر التفاعلية (Buttons & Badges)
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.65rem 1.25rem;
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 0.93rem;
    cursor: pointer;
    border: 1px solid transparent;
    transition: var(--transition);
    font-family: inherit;
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-emerald), #059669);
    color: #ffffff;
    box-shadow: 0 4px 15px var(--accent-emerald-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--accent-emerald-glow);
}

.btn-cyan {
    background: linear-gradient(135deg, var(--accent-cyan), #0284c7);
    color: #ffffff;
    box-shadow: 0 4px 15px var(--accent-cyan-glow);
}

.btn-cyan:hover {
    transform: translateY(-2px);
}

.btn-youtube {
    background: linear-gradient(135deg, #ff0033, #cc0000);
    color: #ffffff;
    box-shadow: 0 4px 15px rgba(255, 0, 51, 0.28);
}

.btn-youtube:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 22px rgba(255, 0, 51, 0.4);
}

.btn-outline {
    background: transparent;
    border-color: var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--accent-emerald);
    color: var(--accent-emerald);
    background: rgba(16, 185, 129, 0.06);
}

.btn-icon {
    width: 42px;
    height: 42px;
    padding: 0;
    border-radius: var(--radius-sm);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-icon:hover {
    border-color: var(--accent-cyan);
    color: var(--accent-cyan);
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.25rem 0.75rem;
    border-radius: 99px;
    font-size: 0.78rem;
    font-weight: 700;
}

.badge-emerald {
    background: rgba(16, 185, 129, 0.15);
    color: #34d399;
    border: 1px solid rgba(16, 185, 129, 0.35);
}

.badge-cyan {
    background: rgba(6, 182, 212, 0.15);
    color: #22d3ee;
    border: 1px solid rgba(6, 182, 212, 0.35);
}

.badge-amber {
    background: rgba(245, 158, 11, 0.15);
    color: #fbbf24;
    border: 1px solid rgba(245, 158, 11, 0.35);
}

.badge-purple {
    background: rgba(139, 92, 246, 0.15);
    color: #c084fc;
    border: 1px solid rgba(139, 92, 246, 0.35);
}

/* ==========================================================================
   قسم الواجهة الترحيبية (Hero Section)
   ========================================================================== */
.hero-section {
    padding: 3.5rem 0 2.5rem;
    position: relative;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 2.5rem;
    align-items: center;
}

.hero-title {
    font-size: clamp(2rem, 4vw, 3.1rem);
    font-weight: 900;
    line-height: 1.25;
    margin: 1rem 0;
}

.hero-title .highlight {
    background: linear-gradient(90deg, var(--accent-emerald), var(--accent-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 1.8rem;
    max-width: 640px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    margin-top: 2.2rem;
}

.stat-box {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: var(--radius-md);
    text-align: center;
}

.stat-box strong {
    display: block;
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--accent-emerald);
    font-family: 'JetBrains Mono', monospace;
}

.stat-box span {
    font-size: 0.82rem;
    color: var(--text-secondary);
}

/* بطاقة المختبر التفاعلي في الواجهة الرئيسية */
.oscilloscope-card {
    background: var(--bg-card);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

.oscilloscope-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.led-dots {
    display: flex;
    gap: 6px;
}

.led-dot {
    width: 11px;
    height: 11px;
    border-radius: 50%;
}

/* ==========================================================================
   البطاقات والشبكات (Cards & Grids)
   ========================================================================== */
.section-block {
    padding: 3rem 0;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.section-title {
    font-size: 1.75rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 0.65rem;
}

.cards-grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 1.5rem;
}

.cards-grid-4 {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.35rem;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-emerald);
    box-shadow: var(--shadow-lg);
}

.card-thumb {
    position: relative;
    aspect-ratio: 16 / 9;
    background: #090d16;
    overflow: hidden;
}

.card-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

.card:hover .card-thumb img {
    transform: scale(1.05);
}

.play-overlay {
    position: absolute;
    inset: 0;
    background: rgba(7, 11, 20, 0.45);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.9;
    transition: var(--transition);
}

.play-btn-circle {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--youtube-red);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 25px rgba(255, 0, 51, 0.5);
    transition: var(--transition);
}

.card:hover .play-btn-circle {
    transform: scale(1.12);
}

.duration-badge {
    position: absolute;
    bottom: 10px;
    left: 10px;
    background: rgba(7, 11, 20, 0.85);
    color: #fff;
    padding: 0.2rem 0.6rem;
    border-radius: 6px;
    font-size: 0.78rem;
    font-family: 'JetBrains Mono', monospace;
}

.card-body {
    padding: 1.35rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-title {
    font-size: 1.15rem;
    font-weight: 800;
    margin: 0.6rem 0;
    line-height: 1.45;
}

.card-desc {
    color: var(--text-secondary);
    font-size: 0.92rem;
    margin-bottom: 1.2rem;
    flex: 1;
}

.card-footer {
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
}

/* ==========================================================================
   صفحة الدرس التفاعلي (4-in-1 Interactive Lesson Layout)
   ========================================================================== */
.lesson-workspace {
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 1.75rem;
    align-items: start;
}

.video-player-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    background: #000;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-strong);
    box-shadow: var(--shadow-lg);
}

.video-player-wrapper iframe {
    width: 100%;
    height: 100%;
    border: 0;
}

.lesson-tabs-bar {
    display: flex;
    gap: 0.5rem;
    background: var(--bg-secondary);
    padding: 0.5rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    margin: 1.5rem 0;
    overflow-x: auto;
}

.lesson-tab-btn {
    flex: 1;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: inherit;
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: var(--transition);
    white-space: nowrap;
}

.lesson-tab-btn.active {
    background: linear-gradient(135deg, var(--accent-emerald), #059669);
    color: #fff;
    box-shadow: 0 4px 12px var(--accent-emerald-glow);
}

.lesson-section-panel {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.75rem;
    margin-bottom: 1.75rem;
}

.lesson-content h3 {
    color: var(--accent-emerald);
    margin: 1.4rem 0 0.6rem;
    font-size: 1.25rem;
}

.lesson-content p, .lesson-content li {
    color: var(--text-primary);
    font-size: 1.02rem;
    margin-bottom: 0.75rem;
}

.formula-box {
    background: var(--bg-secondary);
    border-right: 4px solid var(--accent-cyan);
    padding: 1rem 1.25rem;
    border-radius: var(--radius-sm);
    margin: 1.2rem 0;
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--accent-cyan);
    text-align: center;
}

/* نافذة محاكي الدوائر المدمج (Embedded Simulator Frame) */
.simulator-frame-container {
    background: #050811;
    border: 2px solid var(--border-strong);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.simulator-toolbar {
    background: var(--bg-secondary);
    padding: 0.85rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.simulator-iframe {
    width: 100%;
    height: 560px;
    border: 0;
    display: block;
    background: #0a0f1d;
}

/* ==========================================================================
   محرك الاختبارات التفاعلي (Interactive Quiz UI)
   ========================================================================== */
.quiz-box {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.75rem;
}

.question-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    margin-bottom: 1.25rem;
    transition: var(--transition);
}

.options-list {
    display: grid;
    gap: 0.75rem;
    margin-top: 1rem;
}

.option-label {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    padding: 0.9rem 1.15rem;
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.option-label:hover {
    border-color: var(--accent-cyan);
    background: var(--bg-card-hover);
}

.option-label input[type="radio"] {
    accent-color: var(--accent-emerald);
    width: 18px;
    height: 18px;
}

.option-label.correct-choice {
    border-color: var(--accent-emerald) !important;
    background: rgba(16, 185, 129, 0.15) !important;
}

.option-label.wrong-choice {
    border-color: var(--accent-red) !important;
    background: rgba(239, 68, 68, 0.15) !important;
}

.explanation-box {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: var(--radius-sm);
    background: rgba(6, 182, 212, 0.1);
    border-right: 4px solid var(--accent-cyan);
    font-size: 0.95rem;
    display: none;
}

/* ==========================================================================
   التذييل (Footer) والتجاوب مع الشاشات (Responsive)
   ========================================================================== */
.site-footer {
    margin-top: auto;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 3.5rem 0 1.5rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.footer-links {
    list-style: none;
    padding: 0;
}

.footer-links li {
    margin-bottom: 0.6rem;
}

.footer-links a {
    color: var(--text-secondary);
}

.footer-links a:hover {
    color: var(--accent-emerald);
    padding-right: 4px;
}

.mobile-menu-btn {
    display: none;
}

@media (max-width: 1024px) {
    .hero-grid, .lesson-workspace {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        right: 0;
        left: 0;
        background: var(--bg-secondary);
        flex-direction: column;
        padding: 1rem;
        border-bottom: 1px solid var(--border-color);
    }
    .nav-links.show {
        display: flex;
    }
    .mobile-menu-btn {
        display: inline-flex;
    }
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .simulator-iframe {
        height: 430px;
    }
}