/* --- 1. THEME VARIABLES --- */
:root {
    --bg-color: #ffffff;
    --card-bg: #ffffff;
    --primary-text: #111827;
    --secondary-text: #4b5563;
    --accent-color: #2563eb; /* Royal Blue */
    --code-bg: #f3f4f6;
    --border-color: #e5e7eb;
    --warning-bg: #fff7ed;
    --warning-border: #fdba74;
    --warning-text: #9a3412;
    --success-text: #059669;
    --success-bg: #ecfdf5;
    --radius: 12px;
    --shadow: 0 4px 20px rgba(0,0,0,0.05);
}

/* Home Page Specific Overrides */
body.home-page {
    background-color: #f8f9fa; /* Slightly darker bg for home */
    color: #1f2937;
}

/* --- 2. RESET & BASE --- */
* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--primary-text);
    line-height: 1.8;
    padding: 0 20px;
}

.container {
    max-width: 800px;
    margin: 60px auto;
}

/* Home container is slightly wider */
body.home-page .container {
    max-width: 900px;
    padding-top: 60px; /* Adjusting for missing body padding if needed */
}

/* --- 3. HEADERS --- */

/* Standard Project Header (Flexbox) */
header.project-header {
    margin-bottom: 60px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Home Page Header (Hero Style) */
header.home-header {
    margin-bottom: 60px;
    text-align: left;
    position: relative;
    border-bottom: none;
    display: block; /* Overrides flex */
}

/* --- 4. NAVIGATION & BUTTONS --- */
.nav-btn, .action-btn {
    background: none;
    border: 1px solid #e5e7eb;
    padding: 6px 14px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--secondary-text);
    font-family: inherit;
    transition: all 0.2s;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
}
.action-btn { background: white; border-radius: 20px; } /* Pill shape for home */

.nav-btn:hover, .action-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background-color: #f8fafc;
}

.back-link {
    text-decoration: none;
    color: var(--secondary-text);
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: color 0.2s;
}
.back-link:hover { color: var(--accent-color); }

.header-actions {
    position: absolute;
    top: 10px;
    right: 0;
    display: flex;
    gap: 10px;
}

/* --- 5. TYPOGRAPHY --- */
h1, h2, h3, .project-title, .section-title {
    font-family: 'Playfair Display', serif;
    color: #000;
}

.project-title {
    font-size: 2.5rem;
    line-height: 1.3;
    margin-bottom: 20px;
}

/* Home Page Main Title */
header.home-header h1 {
    font-size: 3rem;
    color: var(--primary-text);
    margin-bottom: 10px;
    line-height: 1.2;
}

.project-meta {
    color: var(--secondary-text);
    font-size: 1rem;
    margin-bottom: 50px;
    font-style: italic;
    border-left: 3px solid var(--accent-color);
    padding-left: 15px;
}

.role-title {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 20px;
    display: inline-block;
    font-family: 'Inter', sans-serif;
}

.bio-text {
    font-size: 1.1rem;
    color: var(--secondary-text);
    max-width: 800px;
}

h2 {
    font-size: 1.8rem;
    margin-top: 60px;
    margin-bottom: 25px;
    border-bottom: 1px solid #f0f0f0;
    padding-bottom: 10px;
}

.section-title {
    font-size: 1.8rem;
    margin-bottom: 30px;
    border-bottom: 2px solid #e5e7eb;
    padding-bottom: 10px;
    display: inline-block;
}

h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-top: 30px;
    margin-bottom: 15px;
    color: var(--primary-text);
    font-family: 'Inter', sans-serif; /* Reset h3 to sans for better readability in body */
}

/* Re-apply Serif to Project Cards and Section headers */
.project-card h3, .limitations-box h3 { font-family: 'Inter', sans-serif; } 

p { margin-bottom: 20px; font-size: 1.05rem; color: #374151; }
ul { margin-bottom: 20px; padding-left: 20px; color: #374151; }
li { margin-bottom: 10px; }

/* --- 6. COMPONENTS (PROJECT PAGES) --- */
.chart-container {
    margin: 40px 0;
    text-align: center;
    background: #fafafa;
    padding: 10px;
    border-radius: 8px;
    border: 1px solid #eee;
}
.chart-container img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
}
.chart-caption {
    margin-top: 10px;
    font-size: 0.9rem;
    color: var(--secondary-text);
    font-style: italic;
}

.highlight-box {
    background-color: #eff6ff;
    border-left: 4px solid var(--accent-color);
    padding: 20px;
    margin: 30px 0;
    color: #1e3a8a;
}

.equation-box {
    background-color: #fafafa;
    border: 1px solid var(--border-color);
    padding: 15px;
    text-align: center;
    margin: 20px 0;
    border-radius: 6px;
}

.limitations-box {
    background-color: var(--warning-bg);
    border: 1px solid var(--warning-border);
    color: var(--warning-text);
    padding: 20px;
    margin: 50px 0;
    border-radius: 6px;
}
.limitations-box h3 { margin-top: 0; color: #7c2d12; }

.definition-list {
    margin-bottom: 30px;
    background: #fafafa;
    padding: 20px;
    border-radius: 8px;
    border: 1px solid #eee;
}
.definition-item { margin-bottom: 15px; }
.definition-title { font-weight: 700; color: #1f2937; display: block; margin-bottom: 4px; }
.definition-text { color: #4b5563; font-size: 0.95rem; }

.math-block { text-align: center; margin: 30px 0; font-size: 1.2rem; }

/* Tables */
.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    font-size: 0.95rem;
}
.comparison-table th {
    background-color: #f8fafc;
    text-align: left;
    padding: 12px;
    border-bottom: 2px solid var(--border-color);
    font-weight: 600;
}
.comparison-table td {
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
    vertical-align: top;
}
.badge {
    display: inline-block;
    padding: 4px 8px;
    border-radius: 4px;
    font-weight: bold;
    font-size: 0.8rem;
}
.badge-green { background: var(--success-bg); color: var(--success-text); }
.badge-red { background: var(--warning-bg); color: var(--warning-text); }

/* --- 7. COMPONENTS (HOME PAGE) --- */
.skills-wrapper { display: flex; flex-wrap: wrap; gap: 12px; }
.skill-pill {
    background: #ffffff;
    border: 1px solid #e5e7eb;
    padding: 8px 20px;
    border-radius: 30px;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--primary-text);
    box-shadow: 0 2px 5px rgba(0,0,0,0.02);
}

.projects-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
}

.project-card {
    background: var(--card-bg);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid transparent;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
    height: 100%; 
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.08);
    border-color: #e5e7eb;
}
.project-card h3 {
    font-size: 1.35rem;
    margin-bottom: 12px;
    color: var(--primary-text);
    line-height: 1.3;
}
.project-card p {
    color: var(--secondary-text);
    margin-bottom: 25px;
    font-size: 1rem;
    flex-grow: 1;
}
.project-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
}
.project-link span { margin-left: 6px; font-size: 1.1rem; }
.arrow-icon { display: inline-block; transition: transform 0.2s; }

/* --- 8. FOOTER --- */
footer {
    text-align: center;
    color: var(--secondary-text);
    font-size: 0.95rem;
    margin-top: 50px;
    border-top: 1px solid #e5e7eb;
    padding-top: 40px;
    padding-bottom: 40px;
}
.footer-links {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
}
.footer-links a {
    color: var(--secondary-text);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: 0.2s;
}
.footer-links a:hover {
    color: var(--accent-color);
    border-color: var(--accent-color);
}

/* --- 9. RTL SUPPORT --- */
.rtl-active {
    direction: rtl;
    font-family: 'Cairo', sans-serif;
    text-align: right;
}
.rtl-active h1, .rtl-active h2, .rtl-active h3, .rtl-active .project-title, .rtl-active .role-title { 
    font-family: 'Cairo', sans-serif; 
}

.rtl-active .header-actions { right: auto; left: 0; }
.rtl-active header.home-header { text-align: right; }

.rtl-active .back-link svg, .rtl-active .arrow-icon { transform: rotate(180deg); }
.rtl-active ul { padding-right: 20px; padding-left: 0; }
.rtl-active .project-meta { border-left: none; border-right: 3px solid var(--accent-color); padding-left: 0; padding-right: 15px; }
.rtl-active .highlight-box { border-left: none; border-right: 4px solid var(--accent-color); }
.rtl-active .comparison-table th, .rtl-active .comparison-table td { text-align: right; }
.rtl-active .project-link span { margin-left: 0; margin-right: 6px; }

/* Unified Language Toggle Logic */
span[lang="ar"], div[lang="ar"], p[lang="ar"], h1[lang="ar"], h2[lang="ar"], h3[lang="ar"], ul[lang="ar"], li[lang="ar"] { display: none; }

.rtl-active span[lang="en"], .rtl-active div[lang="en"], .rtl-active p[lang="en"], .rtl-active h1[lang="en"], .rtl-active h2[lang="en"], .rtl-active h3[lang="en"], .rtl-active ul[lang="en"], .rtl-active li[lang="en"] { display: none; }

.rtl-active span[lang="ar"], .rtl-active div[lang="ar"], .rtl-active p[lang="ar"], .rtl-active h1[lang="ar"], .rtl-active h2[lang="ar"], .rtl-active h3[lang="ar"], .rtl-active ul[lang="ar"], .rtl-active li[lang="ar"] { display: block; }

.rtl-active li[lang="ar"] { display: list-item; }
.rtl-active span[lang="ar"] { display: inline; }

/* --- 10. MEDIA QUERIES --- */
@media (max-width: 768px) {
    .project-title, header.home-header h1 { font-size: 2rem; }
    .comparison-table { display: block; overflow-x: auto; }
    
    /* Home Header Mobile */
    .header-actions { position: relative; margin-bottom: 20px; top: 0; justify-content: flex-start; }
    
    /* Grid */
    .projects-grid { grid-template-columns: 1fr; }
}