/* ==========================================================================
   RESET & SYSTEM VARIABLES
   ========================================================================== */
:root {
    --bg-base: #f8fafc;
    --bg-surface: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --accent-color: #1d4ed8;
    --accent-hover: #1e40af;
    --border-light: #e2e8f0;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --font-stack: 'Inter', sans-serif;
    --max-width: 1200px;
}

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

body {
    background:
        radial-gradient(circle at top left, rgba(29, 78, 216, 0.08), transparent 32%),
        radial-gradient(circle at top right, rgba(14, 165, 233, 0.08), transparent 24%),
        var(--bg-base);
    color: var(--text-main);
    font-family: var(--font-stack);
    line-height: 1.5;
    overflow-x: hidden;
}

.container {
    width: 90%;
    max-width: var(--max-width);
    margin: 0 auto;
}

/* ==========================================================================
   TOP BAR & ANNOUNCEMENT
   ========================================================================== */
.top-bar {
    background: linear-gradient(90deg, #0f172a, #1e293b);
    color: #ffffff;
    text-align: center;
    padding: 10px 0;
    font-size: 0.88rem;
    font-weight: 500;
    letter-spacing: 0.2px;
}

/* ==========================================================================
   HEADER NAVIGATION
   ========================================================================== */
.navbar {
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-light);
    min-height: 80px;
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    display: flex;
    align-items: center;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 24px;
    padding: 14px 0;
}

.logo {
    text-decoration: none;
    flex-shrink: 0;
}

.logo h2 {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.5px;
}

.logo h2 span {
    color: var(--accent-color);
}

/* Central Search Engine Box */
.search-box {
    flex-grow: 1;
    max-width: 450px;
    position: relative;
}

.search-box form {
    width: 100%;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 16px;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.search-box input {
    width: 100%;
    padding: 12px 16px 12px 44px;
    border: 1px solid var(--border-light);
    background-color: #f1f5f9;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    outline: none;
    color: var(--text-main);
    transition: all 0.2s ease;
}

.search-box input:focus {
    border-color: var(--accent-color);
    background-color: var(--bg-surface);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.search-box button {
    display: none; /* Removed traditional button layout since search filters live */
}

/* Auth Actions */
.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.btn-login {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 600;
    font-size: 0.9rem;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    transition: background 0.2s;
}

.btn-login:hover {
    background-color: #f1f5f9;
}

.btn-signup {
    text-decoration: none;
    background-color: var(--accent-color);
    color: #ffffff;
    font-weight: 600;
    font-size: 0.9rem;
    padding: 10px 22px;
    border-radius: var(--radius-sm);
    box-shadow: 0 4px 10px rgba(37, 99, 235, 0.15);
    transition: background 0.2s;
}

.btn-signup:hover {
    background-color: var(--accent-hover);
}

/* ==========================================================================
   HERO CONSOLE SECTION
   ========================================================================== */
.hero {
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.88), rgba(248, 250, 252, 0.96)),
        var(--bg-surface);
    padding: 86px 0 72px 0;
    border-bottom: 1px solid var(--border-light);
}

.hero-wrapper {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 50px;
    align-items: center;
}

.hero-left {
    position: relative;
}

.hero-card h1 {
    font-size: clamp(2.6rem, 5vw, 4.2rem);
    font-weight: 900;
    line-height: 1.15;
    letter-spacing: -1.5px;
    margin-bottom: 20px;
    color: #0f172a;
}

.hero-card p {
    font-size: 1.1rem;
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 32px;
    max-width: 520px;
}

.hero-kicker {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 18px;
}

.hero-kicker-pill {
    display: inline-flex;
    align-items: center;
    background: rgba(29, 78, 216, 0.1);
    color: var(--accent-color);
    border: 1px solid rgba(29, 78, 216, 0.14);
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.35px;
    text-transform: uppercase;
    padding: 8px 12px;
    border-radius: 999px;
}

.hero-kicker-note {
    display: inline-flex;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.92rem;
    font-weight: 500;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 28px;
}

.btn-primary {
    text-decoration: none;
    background-color: var(--accent-color);
    color: #ffffff;
    font-weight: 700;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    transition: background 0.2s;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
}

.btn-secondary {
    text-decoration: none;
    background-color: transparent;
    border: 1px solid var(--border-light);
    color: var(--text-main);
    font-weight: 600;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    transition: background 0.2s;
}

.btn-secondary:hover {
    background-color: #f8fafc;
}

.hero-right {
    display: flex;
    justify-content: center;
}

.hero-image-box {
    position: relative;
    width: 100%;
    max-width: 480px;
    min-height: 420px;
    border-radius: var(--radius-lg);
    overflow: hidden;
    background:
        linear-gradient(180deg, rgba(15, 23, 42, 0.08), rgba(15, 23, 42, 0.02)),
        #e2e8f0;
    box-shadow: 0 20px 40px -12px rgba(15, 23, 42, 0.24);
}

.hero-image-box img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-image-overlay {
    position: absolute;
    left: 20px;
    right: 20px;
    bottom: 20px;
    background: rgba(15, 23, 42, 0.8);
    color: #ffffff;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 14px;
    padding: 16px 18px;
    backdrop-filter: blur(12px);
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.hero-image-overlay strong {
    font-size: 1rem;
    display: block;
}

.hero-image-overlay p {
    color: #cbd5e1;
    margin: 4px 0 0 0;
    font-size: 0.9rem;
    line-height: 1.45;
}

.overlay-chip {
    display: inline-flex;
    width: fit-content;
    padding: 6px 10px;
    border-radius: 999px;
    background: rgba(59, 130, 246, 0.16);
    color: #dbeafe;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.3px;
    text-transform: uppercase;
}

.highlights-strip {
    padding: 24px 0 6px 0;
}

.highlights-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.highlight-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 22px 20px;
    display: flex;
    gap: 14px;
    align-items: flex-start;
    box-shadow: 0 10px 24px -18px rgba(15, 23, 42, 0.24);
}

.highlight-card i {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    background: rgba(29, 78, 216, 0.1);
    color: var(--accent-color);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.highlight-card h3 {
    font-size: 1rem;
    margin-bottom: 4px;
}

.highlight-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.5;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
}

.hero-stat {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 16px 18px;
    box-shadow: 0 10px 24px -18px rgba(15, 23, 42, 0.25);
}

.hero-stat strong {
    display: block;
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 4px;
}

.hero-stat span {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ==========================================================================
   DYNAMIC CATEGORIES INTERFACE
   ========================================================================== */
.categories-section {
    padding: 48px 0 26px 0;
}

.section-header-inline {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 30px;
    gap: 20px;
}

.sh-left h2, .section-header h2 {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    margin-bottom: 8px;
}

.sh-left p, .section-header p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

/* Standard Dropdown Custom Shell */
.filter-select-shell select {
    padding: 10px 16px;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    background-color: var(--bg-surface);
    font-size: 0.9rem;
    color: var(--text-main);
    outline: none;
    cursor: pointer;
    font-weight: 500;
}

/* Category Filter Button Layout Rows */
.categories-pill-box {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.cat-filter-btn {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-light);
    color: var(--text-main);
    padding: 10px 20px;
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s ease;
}

.cat-filter-btn:hover {
    border-color: var(--text-muted);
}

.cat-filter-btn.active {
    background-color: var(--accent-color);
    border-color: var(--accent-color);
    color: #ffffff;
}

/* ==========================================================================
   COURSE CONTENT STANDARD GRID ARCHITECTURE
   ========================================================================== */
.courses-section {
    padding: 42px 0 80px 0;
}

.courses-section .section-header {
    margin-bottom: 40px;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}

.course-card-node {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.course-card-node:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 20px -5px rgba(0,0,0,0.05);
}

.course-image-frame {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* Fixed 16:9 Aspect Frame */
    background-color: #cbd5e1;
}

.course-image-frame img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.badge-status {
    position: absolute;
    top: 12px;
    right: 12px;
    background-color: rgba(15, 23, 42, 0.85);
    color: #ffffff;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    backdrop-filter: blur(4px);
}

.course-body {
    padding: 24px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.course-category-tag {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 700;
    color: var(--accent-color);
    letter-spacing: 0.5px;
    margin-bottom: 8px;
    display: block;
}

.course-body h3 {
    font-size: 1.15rem;
    font-weight: 700;
    line-height: 1.4;
    color: var(--text-main);
    margin-bottom: 10px;
}

.course-description {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.5;
    margin-bottom: 24px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-footer-row {
    margin-top: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 16px;
    border-top: 1px solid #f1f5f9;
}

.price-indicator {
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--text-main);
}

.view-btn {
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent-color);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: color 0.2s;
}

.view-btn:hover {
    color: var(--accent-hover);
}

.empty-data-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 60px 0;
    color: var(--text-muted);
}

.empty-data-state i {
    font-size: 2.5rem;
    margin-bottom: 12px;
}

/* ==========================================================================
   WHY TSBD ARCHITECTURE STRATEGY
   ========================================================================== */
.why-us {
    background-color: var(--bg-surface);
    padding: 84px 0;
    border-top: 1px solid var(--border-light);
    border-bottom: 1px solid var(--border-light);
}

.text-center {
    text-align: center;
}

.why-us .section-header {
    margin-bottom: 50px;
}

.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
}

.why-card {
    background-color: var(--bg-base);
    border: 1px solid var(--border-light);
    padding: 32px 24px;
    border-radius: var(--radius-lg);
    transition: transform 0.2s;
}

.why-card:hover {
    transform: translateY(-2px);
}

.icon-shell {
    width: 48px;
    height: 48px;
    background-color: rgba(37, 99, 235, 0.1);
    color: var(--accent-color);
    border-radius: var(--radius-md);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.25rem;
    margin-bottom: 20px;
}

.why-card h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.why-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* ==========================================================================
   POPULAR SKILLS ELEMENT ROW
   ========================================================================== */
.skills-section {
    padding: 68px 0;
}

.skills-section .section-header {
    margin-bottom: 30px;
}

.skills-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
}

.skills-grid span {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-light);
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-main);
}

/* ==========================================================================
   TESTIMONIALS MODULAR ROW
   ========================================================================== */
.testimonials {
    padding: 68px 0 84px 0;
}

.testimonials .section-header {
    margin-bottom: 50px;
}

.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.testimonial-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-light);
    padding: 32px;
    border-radius: var(--radius-lg);
    position: relative;
}

.quote-mark {
    font-size: 1.5rem;
    color: #cbd5e1;
    margin-bottom: 16px;
}

.testimonial-card p {
    font-size: 0.95rem;
    color: #334155;
    line-height: 1.6;
    margin-bottom: 20px;
    font-style: italic;
}

.testimonial-card h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-main);
}

/* ==========================================================================
   CALL TO ACTION SHELL
   ========================================================================== */
.cta {
    padding-bottom: 60px;
}

.cta-box {
    background: linear-gradient(135deg, #0f172a, #1e293b 70%);
    color: #ffffff;
    padding: 60px 40px;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1);
}

.cta-box h2 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}

.cta-box p {
    color: #94a3b8;
    font-size: 1.05rem;
    margin-bottom: 30px;
}

.cta-btn {
    text-decoration: none;
    background-color: var(--accent-color);
    color: #ffffff;
    font-weight: 700;
    padding: 14px 32px;
    border-radius: var(--radius-md);
    display: inline-block;
    transition: background 0.2s;
}

.cta-btn:hover {
    background-color: var(--accent-hover);
}

/* ==========================================================================
   FOOTER CONSOLE CORE STYLES
   ========================================================================== */
.footer {
    background-color: #0f172a;
    color: #94a3b8;
    padding: 80px 0 40px 0;
    border-top: 1px solid #1e293b;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.2fr repeat(3, 0.8fr);
    gap: 40px;
    margin-bottom: 60px;
}

.footer-brand-info h3 {
    color: #ffffff;
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 16px;
}

.footer-brand-info p {
    font-size: 0.9rem;
    line-height: 1.6;
    max-width: 260px;
}

.footer h4 {
    color: #ffffff;
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer a {
    display: block;
    color: #94a3b8;
    text-decoration: none;
    font-size: 0.9rem;
    margin-bottom: 12px;
    transition: color 0.2s;
}

.footer a:hover {
    color: #ffffff;
}

.footer .social-anchor i {
    margin-right: 6px;
    width: 16px;
}

.copyright {
    border-top: 1px solid #1e293b;
    padding-top: 30px;
    text-align: center;
    font-size: 0.85rem;
    color: #64748b;
}

/* ==========================================================================
   RESPONSIVE DESIGN SYSTEM OVERRIDES
   ========================================================================== */
@media screen and (max-width: 1024px) {
    .hero-wrapper {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    .hero-card p {
        margin: 0 auto 32px auto;
    }
    .hero-buttons {
        justify-content: center;
    }
    .hero-stats {
        max-width: 620px;
        margin: 0 auto;
    }
    .highlights-grid {
        grid-template-columns: 1fr;
    }
    .section-header-inline {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media screen and (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        height: auto;
        padding: 15px 0;
        gap: 15px;
    }
    .navbar {
        height: auto;
    }
    body {
        padding-top: 0;
    }
    .search-box {
        width: 100%;
        max-width: none;
    }
    .hero-card h1 {
        font-size: 2.2rem;
    }
    .hero-stats {
        grid-template-columns: 1fr;
    }
    .hero-image-box {
        min-height: 320px;
    }
    .hero-image-overlay {
        left: 14px;
        right: 14px;
        bottom: 14px;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    .footer h4 {
        margin-bottom: 12px;
    }
}


/* ==========================================================================
   Header Navigation Actions & Auth Buttons
   ========================================================================== */

   .nav-actions {
    display: flex;
    align-items: center;
    gap: 15px; /* বাটনগুলোর ভেতরের গ্যাপ */
}

/* ড্যাশবোর্ড লিঙ্ক টেক্সট */
.nav-actions a.text-decoration-none {
    color: #16466B !important;
    font-size: 15px;
    font-weight: 600;
    text-decoration: none !important;
    display: inline-flex;
    align-items: center;
    transition: color 0.2s ease;
}

.nav-actions a.text-decoration-none:hover {
    color: #0f3550 !important;
}

.nav-actions a.text-decoration-none i {
    margin-right: 6px;
}

/* ডিফল্ট লগইন ও সাইন-আপ বাটন */
.nav-actions .btn-login {
    border: 1px solid #16466B;
    color: #16466B;
    padding: 8px 18px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 14px;
    text-decoration: none;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
}

.nav-actions .btn-login:hover {
    background: #16466B;
    color: #ffffff !important;
}

.nav-actions .btn-signup {
    background: #16466B;
    color: #ffffff !important;
    border: 1px solid #16466B;
    padding: 8px 18px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 14px;
    text-decoration: none;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
}

.nav-actions .btn-signup:hover {
    background: #0f3550;
    border-color: #0f3550;
}

/* বুটস্ট্র্যাপের me-3 মার্জিনের অল্টারনেটিভ (যদি বুটস্ট্র্যাপ না থাকে) */
.me-3 {
    margin-right: 1rem !important;
}