:root {
    --bg-color: #0f1012;         /* Dark modern background */
    --surface-color: #181a1e;    /* Card background */
    --text-primary: #f3f4f6;     /* Off-white */
    --text-secondary: #9ca3af;   /* Muted gray */
    --accent-color: #3b82f6;     /* Premium Blue Accent */
    --border-color: #27272a;
    --font-main: 'Plus Jakarta Sans', sans-serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-main);
    line-height: 1.6;
    padding: 0 5%;
}

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
}

.logo span {
    color: var(--accent-color);
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    margin: 0 1.5rem;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--text-primary);
}

.btn-primary {
    background: var(--text-primary);
    color: var(--bg-color);
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: opacity 0.3s;
}

.btn-primary:hover {
    background: linear-gradient(47deg, #0f172a, #6366f1, #38bdf8);
    color: var(--text-primary);
    box-shadow: 0 4px 8px #9b8585;
    opacity: 0.9;
}

.btn-secondary {
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 500;
}

.btn-secondary:hover {
    background: linear-gradient(47deg, #0f172a, #6366f1, #38bdf8);
    color: var(--text-primary);
    box-shadow: 0 4px 8px #9b8585;
}
/* Hero Section */
.hero {
    padding: 6rem 0;
    max-width: 800px;
}

.hero-badge {
    display: inline-block;
    padding: 0.35rem 1rem;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* Projects Section */
.projects {
    padding: 4rem 0;
}

.section-header h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.section-header p {
    color: var(--text-secondary);
    margin-bottom: 3rem;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    transition: transform 0.3s;
}

.project-card:hover {
    transform: translateY(-6px);
}

.project-image {
    height: 240px;
    position: relative;
    padding: 1rem;
}

.project-tag {
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(8px);
    color: #fff;
    font-size: 0.75rem;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
}

.project-info {
    padding: 1.5rem;
}

.project-info h3 {
    margin-bottom: 0.5rem;
}

.project-info p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Footer */
.footer {
    border-top: 1px solid var(--border-color);
    margin-top: -1rem;
    padding: 4rem 0 2rem;
}

.email-link {
    color: var(--accent-color);
    font-size: 1.9rem;
    text-decoration: none;
    font-weight: 900;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
    color: var(--text-secondary);
    font-size: 1rem;
}
/* Social Media Tooltip Tag */
.socials {
    display: flex;
    gap: 1.2rem;
    align-items: center;
}

.socials a {
    position: relative;
    color: var(--text-secondary);
    font-size: 1.25rem;
    text-decoration: none;
    transition: color 0.3s ease, transform 0.3s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

/* Hover Effect on Icon */
.socials a:hover {
    color: var(--text-primary);
    transform: translateY(-3px);
}

/* Tooltip Tag Box (Pseudo-element) */
.socials a::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 135%;
    left: 50%;
    transform: translateX(-50%) translateY(6px);
    background-color: var(--surface-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.3rem 0.6rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 6px;
    white-space: nowrap;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.socials a::before {
    content: '';
    position: absolute;
    bottom: 110%;
    left: 50%;
    transform: translateX(-50%) translateY(6px);
    border-width: 5px;
    border-style: solid;
    border-color: var(--border-color) transparent transparent transparent;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.socials a:hover::after,
.socials a:hover::before {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.4rem;
    }
    .nav-links {
        display: none;
    }
}

/* Contact Section Styles */
.contact-section {
    padding: 6rem 0 4rem;
    max-width: 720px;
    margin: 0 auto;
}

.contact-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-tag {
    color: var(--accent-color);
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.contact-header h2 {
    font-size: 2.2rem;
    margin: 0.5rem 0;
    font-weight: 700;
}

.contact-header p {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Form Styles */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    background: var(--surface-color);
    padding: 2.5rem;
    border-radius: 20px;
    border: 1px solid var(--border-color);
}

.form-group-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

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

.form-group label {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.85rem 1rem;
    border-radius: 10px;
    font-family: var(--font-main);
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.3s, box-shadow 0.3s;
}

/* Interactive Focus State (UX Feature) */
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: #6b7280;
}

/* Customizing Dropdown Option Styles */
.form-group select option {
    background-color: var(--surface-color);
    color: var(--text-primary);
}

.btn-submit {
    background: var(--text-primary);
    color: var(--bg-color);
    border: none;
    padding: 1rem 1.8rem;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: transform 0.2s, opacity 0.2s;
    margin-top: 0.5rem;
}

.btn-submit:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

/* Responsiveness for Mobile */
@media (max-width: 600px) {
    .form-group-row {
        grid-template-columns: 1fr;
    }
    .contact-form {
        padding: 1.5rem;
    }
}



#floating-button {
    position: fixed;
    bottom: 90px;
    right: 20px;
    padding: 15px 25px;
    background: #22303d;
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(100px);
    transition: all 0.3s ease;
    z-index: 9999;
}

#floating-button:hover {
    background: linear-gradient(47deg, #0f172a, #6366f1, #38bdf8);
    box-shadow: 0 4px 8px #9b8585;
}

#floating-button.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
/* Floating Chat Button (Smooth Transition Settings) */
#chat-toggle-btn {
  position: fixed;
  bottom: 25px;
  right: 25px;
  padding: 14px 22px;
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: #ffffff;
  border: none;
  border-radius: 50px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.4);
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 8px;
  
  /* --- IMPORTANT: Separate, Long, and Smooth Transition --- */
  transition-property: opacity, visibility, transform, box-shadow;
  transition-duration: 0.6s, 0.6s, 0.6s, 0.3s; /* Hide hobar somoy 0.6 second lagbe */
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1); /* Direct Ease er bodole smooth curve */

  /* Normal Show Style */
  opacity: 1;
  visibility: visible;
  transform: translateY(0px) scale(1);
}

/* Float Animation normal interaction setup */
#chat-toggle-btn:hover {
  transform: translateY(-5px) scale(1.05) !important;
  box-shadow: 0 12px 25px rgba(37, 99, 235, 0.6);
}

/* Chat Window/Container Smooth Transition */
#chat-container {
  position: fixed;
  bottom: 85px;
  right: 25px;
  width: 340px;
  height: 450px;
  background-color: #ffffff;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  z-index: 1000;
  
  /* --- Same Smooth Transition for Container --- */
  transition-property: opacity, visibility, transform;
  transition-duration: 0.5s;
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
  transform-origin: bottom right;

  /* Normal Show Style for Chat Window */
  opacity: 1;
  visibility: visible;
  transform: translateY(0px) scale(1);
}

/* Hide Functionality (ai class JavaScript control kore) */
.chat-hidden {
  opacity: 0 !important;
  visibility: hidden !important;
  pointer-events: none !important;
  /* Window hide hobar somoy scale down ebong fade hobe */
  transform: translateY(30px) scale(0.8) !important;
}

/* Scroll Hide Logic (For Contact Form detection) */
.chat-scroll-hidden {
  opacity: 0 !important;
  visibility: hidden !important;
  pointer-events: none !important;
  /* Button hidden hobar somoy halka scale-down (0.85) hoye vanish hobe */
  transform: translateY(30px) scale(0.85) !important;
}

#chat-container {
  display: flex;
  flex-direction: column; 
  overflow: hidden; 
  background-color: #ffffff;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.chat-header {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: white;
  padding: 15px 20px;
  font-weight: bold;
  font-size: 16px;
  display: flex;
  justify-content: space-between; 
  align-items: center;
  border-bottom: 1px solid rgba(0,0,0,0.1);
  flex-shrink: 0; 
}

.chat-header button {
  background: none;
  border: none;
  color: white;
  font-size: 20px;
  cursor: pointer;
  opacity: 0.8;
  transition: opacity 0.2s;
  padding: 0;
  line-height: 1;
}

.chat-header button:hover {
  opacity: 1;
}

#chat-box {
  flex: 1; 
  padding: 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 15px; 
  background-color: #f9fafb;
}

.message {
  max-width: 80%;
  padding: 12px 16px;
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.5;
  position: relative;
  word-wrap: break-word; 
}


.bot-message {
  align-self: flex-start;
  background-color: #ffffff;
  color: #1f2937;
  border-radius: 0px 12px 12px 12px; 
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}


.user-message {
  align-self: flex-end; 
  background-color: #2563eb;
  color: white;
  border-radius: 12px 12px 0px 12px;
}


.chat-input-area {
  padding: 15px;
  background-color: #ffffff;
  border-top: 1px solid #e5e7eb;
  display: flex;
  gap: 10px;
  flex-shrink: 0;
}

.chat-input-area input {
  flex: 1; 
  padding: 10px 15px;
  border: 1px solid #d1d5db;
  border-radius: 25px;
  outline: none;
  font-size: 14px;
  transition: border-color 0.2s;
}

.chat-input-area input:focus {
  border-color: #2563eb;
}

.chat-input-area button {
  padding: 10px 20px;
  background-color: #2563eb;
  color: white;
  border: none;
  border-radius: 25px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s;
}

.chat-input-area button:hover {
  background-color: #1d4ed8;
}

/* Scroll To Top Button Placement Fix */
#floating-button {
    position: fixed;
    bottom: 25px;
    left: 25px; /* চ্যাটবট ডানে (Right), এটি বামে (Left) রাখলে ক্লিন দেখাবে */
    width: 48px;
    height: 48px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    font-size: 16px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 999;
}

#floating-button:hover {
    background: var(--text-primary);
    color: var(--bg-color);
}

#floating-button.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}