/* ===== CSS Variables ===== */
:root {
    /* Iranian Flag Colors */
    --iran-green: #239F40;
    --iran-white: #FFFFFF;
    --iran-red: #DA0000;
    
    /* Professional Engineering Colors */
    --steel-blue: #2C5F8D;
    --deep-navy: #1A3A52;
    --slate-gray: #4A5568;
    --concrete-gray: #718096;
    --light-gray: #E2E8F0;
    --off-white: #F7FAFC;
    
    /* Accent Colors */
    --accent-green: var(--iran-green);
    --accent-red: var(--iran-red);
    --primary: var(--steel-blue);
    --secondary: var(--deep-navy);
    
    /* Typography */
    --font-display: 'Archivo', sans-serif;
    --font-body: 'IBM Plex Serif', serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.2);
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--secondary);
    line-height: 1.7;
    background-color: var(--off-white);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
    color: var(--deep-navy);
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 3px solid transparent;
    border-image: linear-gradient(90deg, var(--iran-green) 0%, var(--iran-white) 33%, var(--iran-white) 66%, var(--iran-red) 100%) 1;
    z-index: 1000;
    padding: 1rem 0;
    animation: slideDown 0.5s ease;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    flex-direction: column;
}

.logo-name {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--deep-navy);
    letter-spacing: -0.5px;
}

.logo-subtitle {
    font-family: var(--font-body);
    font-size: 0.75rem;
    color: var(--concrete-gray);
    font-weight: 400;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-link {
    font-family: var(--font-display);
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--slate-gray);
    position: relative;
    padding: 0.5rem 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--iran-green), var(--iran-red));
    transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl) var(--spacing-md);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        linear-gradient(135deg, rgba(35, 159, 64, 0.03) 0%, transparent 50%),
        linear-gradient(225deg, rgba(218, 0, 0, 0.03) 0%, transparent 50%),
        linear-gradient(180deg, var(--off-white) 0%, #ffffff 100%);
    z-index: -1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(44, 95, 141, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 20s ease-in-out infinite;
}

.hero-background::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(35, 159, 64, 0.06) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 15s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    50% {
        transform: translate(50px, 50px) scale(1.1);
    }
}

.hero-content {
    text-align: center;
    max-width: 900px;
    animation: fadeInUp 0.8s ease 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-badge {
    display: inline-block;
    font-family: var(--font-display);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--primary);
    background: linear-gradient(135deg, rgba(35, 159, 64, 0.1), rgba(44, 95, 141, 0.1));
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    border: 2px solid rgba(44, 95, 141, 0.2);
    margin-bottom: var(--spacing-md);
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
}

.title-line {
    display: block;
    background: linear-gradient(135deg, var(--deep-navy) 0%, var(--primary) 50%, var(--iran-green) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.8s ease calc(0.4s + var(--line-delay, 0s)) both;
}

.title-line:nth-child(2) {
    --line-delay: 0.1s;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--slate-gray);
    margin-bottom: var(--spacing-lg);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    animation: fadeInUp 0.8s ease 0.6s both;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.8s both;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--concrete-gray);
    font-family: var(--font-display);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    animation: fadeInUp 0.8s ease 1s both;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid var(--primary);
    border-bottom: 2px solid var(--primary);
    transform: rotate(45deg);
    animation: bounce 2s ease infinite;
}

@keyframes bounce {
    0%, 100% {
        transform: rotate(45deg) translateY(0);
    }
    50% {
        transform: rotate(45deg) translateY(10px);
    }
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 600;
    padding: 1rem 2.5rem;
    border-radius: 4px;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--steel-blue));
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--steel-blue), var(--deep-navy));
}

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

.btn-secondary:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--slate-gray);
    border-color: var(--concrete-gray);
}

.btn-outline:hover {
    background: var(--slate-gray);
    color: white;
    border-color: var(--slate-gray);
}

.btn-full {
    width: 100%;
}

/* ===== Section Styles ===== */
section {
    padding: var(--spacing-xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--deep-navy);
}

.title-underline {
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--iran-green), var(--iran-red));
    margin: 0 auto;
    border-radius: 2px;
}

/* ===== Book Section ===== */
.book-section {
    background: white;
}

.book-showcase {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.book-cover-container {
    position: relative;
    perspective: 1500px;
}

.book-cover {
    position: relative;
    aspect-ratio: 2/3;
    transform-style: preserve-3d;
    transition: transform 0.6s ease;
    cursor: pointer;
}

.book-cover:hover {
    transform: rotateY(-15deg) rotateX(5deg);
}

.cover-design {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, var(--deep-navy) 0%, var(--primary) 100%);
    border-radius: 8px;
    box-shadow: var(--shadow-xl);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
}

.cover-top {
    height: 120px;
    background: linear-gradient(135deg, var(--iran-green) 0%, rgba(35, 159, 64, 0.8) 100%);
    position: relative;
    overflow: hidden;
}

.cover-pattern {
    position: absolute;
    inset: 0;
    background-image: 
        repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(255,255,255,0.05) 10px, rgba(255,255,255,0.05) 20px),
        repeating-linear-gradient(-45deg, transparent, transparent 10px, rgba(255,255,255,0.05) 10px, rgba(255,255,255,0.05) 20px);
}

.cover-content {
    flex: 1;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
}

.cover-title {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    color: white;
    line-height: 1.2;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.cover-divider {
    width: 60px;
    height: 3px;
    background: var(--iran-red);
    margin: 1rem 0;
}

.cover-subtitle {
    font-family: var(--font-body);
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.6;
}

.cover-bottom {
    padding: 1.5rem 2rem;
    background: rgba(0, 0, 0, 0.2);
    border-top: 2px solid var(--iran-red);
}

.cover-author {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    color: white;
    text-align: center;
}

.book-shadow {
    position: absolute;
    bottom: -30px;
    left: 50%;
    transform: translateX(-50%);
    width: 80%;
    height: 30px;
    background: radial-gradient(ellipse, rgba(0, 0, 0, 0.3), transparent);
    filter: blur(10px);
    z-index: -1;
}

.book-details {
    animation: fadeInRight 0.8s ease;
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.book-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--deep-navy);
    margin-bottom: 0.5rem;
}

.book-subtitle {
    font-size: 1.1rem;
    color: var(--slate-gray);
    margin-bottom: var(--spacing-md);
    font-style: italic;
}

.book-description {
    margin-bottom: var(--spacing-md);
}

.book-description p {
    margin-bottom: var(--spacing-sm);
    color: var(--slate-gray);
    font-size: 1.05rem;
}

.book-features {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--off-white);
    border-radius: 8px;
    border-left: 4px solid var(--iran-green);
}

.feature {
    display: flex;
    gap: var(--spacing-sm);
    align-items: flex-start;
}

.feature-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.feature-text h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--deep-navy);
    margin-bottom: 0.25rem;
}

.feature-text p {
    font-size: 0.9rem;
    color: var(--concrete-gray);
}

.book-cta {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

/* ===== About Section ===== */
.about-section {
    background: linear-gradient(180deg, white 0%, var(--off-white) 100%);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-xl);
    align-items: start;
}

.about-image {
    position: sticky;
    top: 120px;
}

.image-placeholder {
    aspect-ratio: 3/4;
    background: linear-gradient(135deg, var(--light-gray), var(--off-white));
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 3px solid var(--iran-green);
    box-shadow: var(--shadow-lg);
}

.placeholder-icon {
    width: 80px;
    height: 80px;
    color: var(--concrete-gray);
    opacity: 0.5;
}

.about-name {
    font-size: 2rem;
    font-weight: 700;
    color: var(--deep-navy);
    margin-bottom: 0.5rem;
}

.about-title {
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    font-family: var(--font-display);
}

.about-bio {
    margin-bottom: var(--spacing-md);
}

.bio-placeholder {
    color: var(--concrete-gray);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--off-white);
    border-left: 3px solid var(--iran-red);
    border-radius: 4px;
}

.credentials {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.credential-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    padding: var(--spacing-sm);
    background: white;
    border-radius: 6px;
    border-left: 4px solid var(--primary);
    box-shadow: var(--shadow-sm);
}

.credential-label {
    font-family: var(--font-display);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--concrete-gray);
}

.credential-value {
    font-size: 1rem;
    color: var(--deep-navy);
    font-weight: 500;
}

/* ===== Contact Section ===== */
.contact-section {
    background: white;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-xl);
}

.contact-info h3 {
    font-size: 1.8rem;
    margin-bottom: var(--spacing-sm);
    color: var(--deep-navy);
}

.contact-info > p {
    color: var(--slate-gray);
    margin-bottom: var(--spacing-md);
    font-size: 1.05rem;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.contact-method {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--off-white);
    border-radius: 8px;
    border-left: 4px solid var(--iran-green);
}

.method-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.method-details h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--deep-navy);
    margin-bottom: 0.25rem;
}

.method-details p {
    font-size: 0.9rem;
    color: var(--concrete-gray);
}

.form-wrapper h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--deep-navy);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--slate-gray);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group input,
.form-group textarea {
    font-family: var(--font-body);
    font-size: 1rem;
    padding: 0.75rem 1rem;
    border: 2px solid var(--light-gray);
    border-radius: 4px;
    background: var(--off-white);
    color: var(--secondary);
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: white;
    box-shadow: 0 0 0 3px rgba(44, 95, 141, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-note {
    font-size: 0.85rem;
    color: var(--concrete-gray);
    margin-top: var(--spacing-sm);
    font-style: italic;
}

/* ===== Footer ===== */
.footer {
    background: linear-gradient(180deg, var(--deep-navy) 0%, #0d1f2d 100%);
    color: white;
    padding: var(--spacing-lg) 0 var(--spacing-md);
    border-top: 4px solid transparent;
    border-image: linear-gradient(90deg, var(--iran-green), var(--iran-white), var(--iran-red)) 1;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
}

.footer-info h3 {
    font-size: 1.5rem;
    color: white;
    margin-bottom: 0.5rem;
}

.footer-info p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
}

.footer-links {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    font-family: var(--font-display);
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--iran-green);
}

.footer-bottom {
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.85rem;
}

/* ===== Responsive Design ===== */
@media (max-width: 968px) {
    .book-showcase,
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .book-cover-container {
        max-width: 400px;
        margin: 0 auto;
    }
    
    .about-image {
        position: static;
        max-width: 300px;
        margin: 0 auto;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .hero {
        min-height: 80vh;
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: stretch;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
    
    section {
        padding: var(--spacing-lg) 0;
    }
    
    .book-cta {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .hero-badge {
        font-size: 0.7rem;
        padding: 0.4rem 1rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .book-title {
        font-size: 1.8rem;
    }
}