/* ===== থিওরিটিক্যাল ফিজিক্স থিম ===== */
:root {
    --quantum-blue: #00d4ff;
    --relativity-purple: #9d4edd;
    --string-green: #4ade80;
    --dark-matter: #0f172a;
    --neutron-star: #1e293b;
    --light-particle: #f8fafc;
    --energy-yellow: #fbbf24;
}

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

body {
    font-family: 'Segoe UI', 'JetBrains Mono', system-ui, sans-serif;
    background-color: var(--dark-matter);
    color: var(--light-particle);
    line-height: 1.8;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* ===== মোবাইল টোগল বাটন ===== */
.mobile-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.toggle-btn {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--quantum-blue), var(--relativity-purple));
    border: none;
    color: white;
    font-size: 24px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.toggle-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(0, 212, 255, 0.4);
}

.toggle-label {
    font-size: 12px;
    background: rgba(0, 0, 0, 0.7);
    padding: 4px 8px;
    border-radius: 10px;
    color: white;
}

/* ===== ব্যাকগ্রাউন্ড ফিজিক্স এনিমেশন ===== */
.physics-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}

.particle {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle, var(--quantum-blue), transparent);
    animation: particle-float 15s infinite linear;
    opacity: 0.3;
}

.wave {
    position: absolute;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--relativity-purple), transparent);
    animation: wave-move 20s infinite linear;
    opacity: 0.1;
}

.gravity-well {
    position: absolute;
    border-radius: 50%;
    border: 1px solid rgba(251, 191, 36, 0.1);
    animation: gravity-pulse 10s infinite alternate;
}

@keyframes particle-float {
    0% { transform: translate(0, 0) rotate(0deg); }
    100% { transform: translate(100px, 100px) rotate(360deg); }
}

@keyframes wave-move {
    0% { transform: translateX(-100%) skewX(20deg); }
    100% { transform: translateX(100vw) skewX(20deg); }
}

@keyframes gravity-pulse {
    0% { transform: scale(1); opacity: 0.05; }
    100% { transform: scale(1.5); opacity: 0.15; }
}

/* ===== হেডার ও নেভিগেশন ===== */
.physics-header {
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.9), rgba(30, 41, 59, 0.9));
    backdrop-filter: blur(10px);
    padding: 1.5rem 5%;
    border-bottom: 2px solid var(--quantum-blue);
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.physics-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(90deg, var(--quantum-blue), var(--relativity-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.physics-nav {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.physics-nav a {
    color: var(--light-particle);
    text-decoration: none;
    padding: 0px;
    border-radius: 25px;
    transition: all 0.3s;
    border: 1px solid transparent;
    font-weight: 500;
    font-size: 0.9rem;
}

.physics-nav a:hover {
    border-color: var(--quantum-blue);
    background: rgba(0, 212, 255, 0.1);
}

/* ===== মেইন কন্টেইনার ===== */
.physics-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 5%;
}

/* ===== ব্লগ হেডার ===== */
.blog-hero {
    text-align: center;
    padding: 3rem 1.5rem;
    margin-bottom: 2rem;
    background: linear-gradient(135deg, rgba(30, 41, 59, 0.8), rgba(15, 23, 42, 0.8));
    border-radius: 15px;
    border: 2px solid var(--relativity-purple);
    position: relative;
    overflow: hidden;
}

.blog-hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(157, 78, 221, 0.1) 0%, transparent 50%);
    animation: rotate 30s infinite linear;
    z-index: -1;
}

@keyframes rotate {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.physics-category {
    display: inline-block;
    background: linear-gradient(90deg, var(--quantum-blue), var(--string-green));
    color: white;
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    font-weight: 600;
    letter-spacing: 1px;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.physics-title {
    font-size: 2.2rem;
    margin-bottom: 1rem;
    background: linear-gradient(90deg, var(--quantum-blue), var(--energy-yellow), var(--relativity-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1.2;
}

.physics-subtitle {
    font-size: 1.1rem;
    color: #cbd5e1;
    max-width: 100%;
    margin: 0 auto 1.5rem;
}

.physics-meta {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
    color: #94a3b8;
    font-size: 0.9rem;
}

/* ===== কন্টেন্ট সেকশন ===== */
.content-section {
    background: rgba(30, 41, 59, 0.7);
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid rgba(0, 212, 255, 0.2);
    backdrop-filter: blur(5px);
}

.section-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--quantum-blue);
}

.section-icon {
    font-size: 1.5rem;
    color: var(--quantum-blue);
}

.section-title {
    font-size: 1.6rem;
    color: var(--light-particle);
}

.physics-content {
    font-size: 1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.physics-content p {
    margin-bottom: 1.2rem;
    text-align: justify;
}

.highlight {
    background: linear-gradient(90deg, rgba(0, 212, 255, 0.1), rgba(157, 78, 221, 0.1));
    border-left: 4px solid var(--quantum-blue);
    padding: 1.2rem;
    margin: 1.5rem 0;
    border-radius: 0 8px 8px 0;
    font-size: 0.95rem;
}

.equation {
    font-family: 'Cambria Math', 'Times New Roman', serif;
    font-size: 1.1rem;
    background: rgba(0, 0, 0, 0.3);
    padding: 1rem;
    border-radius: 8px;
    margin: 1.2rem 0;
    text-align: center;
    border: 1px solid var(--relativity-purple);
    overflow-x: auto;
}

/* ===== ফিজিক্স প্রজেক্ট গ্রিড (collapsible) ===== */
.projects-section {
    transition: all 0.3s ease;
}

.projects-collapsed {
    max-height: 300px;
    overflow: hidden;
    position: relative;
}

.projects-collapsed::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100px;
    background: linear-gradient(to bottom, transparent, rgba(15, 23, 42, 0.9));
    pointer-events: none;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.physics-project {
    background: linear-gradient(135deg, rgba(30, 41, 59, 0.9), rgba(15, 23, 42, 0.9));
    border-radius: 12px;
    padding: 1.5rem;
    border: 1px solid var(--string-green);
    transition: transform 0.3s, box-shadow 0.3s;
}

.physics-project:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(74, 222, 128, 0.2);
}

.project-title {
    font-size: 1.3rem;
    color: var(--string-green);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.project-canvas {
    width: 100%;
    height: 180px;
    background: rgba(0, 0, 0, 0.3);
    border-radius: 8px;
    margin: 1rem 0;
    border: 1px solid rgba(0, 212, 255, 0.3);
}

.project-controls {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 1rem;
}

.physics-btn {
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: 20px;
    background: linear-gradient(90deg, var(--quantum-blue), var(--relativity-purple));
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.9rem;
}

.physics-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 212, 255, 0.3);
}

/* ===== কোয়ান্টাম চার্ট ===== */
.quantum-chart-container {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 2rem 0;
    border: 1px solid var(--quantum-blue);
}

/* ===== ফুটার ===== */
.physics-footer {
    text-align: center;
    padding: 2rem 5%;
    margin-top: 3rem;
    border-top: 2px solid var(--relativity-purple);
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.9), rgba(30, 41, 59, 0.9));
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

/* ===== মোবাইল রেস্পন্সিভ ===== */
@media (max-width: 768px) {
    .physics-header {
flex-direction: column;
gap: 1rem;
padding: 1rem 5%;
    }
    
    .physics-title {
font-size: 1.8rem;
    }
    
    .physics-subtitle {
font-size: 1rem;
    }
    
    .content-section {
padding: 1.5rem;
    }
    
    .section-title {
font-size: 1.4rem;
    }
    
    .projects-grid {
grid-template-columns: 1fr;
gap: 1rem;
    }
    
    .physics-container {
padding: 1rem 4%;
    }
    
    .blog-hero {
padding: 2rem 1rem;
margin-bottom: 1.5rem;
    }
    
    .physics-nav {
justify-content: center;
    }
    
    .physics-btn {
padding: 0.5rem 1rem;
font-size: 0.85rem;
    }
    
    .project-canvas {
height: 150px;
    }
    
    /* টোগল বাটন শো করি মোবাইলে */
    .mobile-toggle {
display: flex;
    }
    
    /* প্রজেক্ট সেকশন কোলাপ্সড স্টাইল */
    .projects-collapsed .projects-grid {
max-height: 200px;
overflow: hidden;
    }
}

@media (max-width: 480px) {
    .physics-title {
font-size: 1.5rem;
    }
    
    .section-title {
font-size: 1.2rem;
    }
    
    .physics-content {
font-size: 0.95rem;
    }
    
    .project-controls {
flex-direction: column;
    }
    
    .physics-btn {
width: 100%;
justify-content: center;
    }
    
    .mobile-toggle {
bottom: 15px;
right: 15px;
    }
    
    .toggle-btn {
width: 50px;
height: 50px;
font-size: 20px;
    }
}

/* ডার্ক/লাইট মোড সুপোর্ট */
@media (prefers-color-scheme: light) {
    :root {
--dark-matter: #f1f5f9;
--neutron-star: #e2e8f0;
--light-particle: #1e293b;
    }
    
    body {
color: #1e293b;
    }
    
    .physics-project {
background: white;
    }
}