/* ============================================
   BTS Danışmanlık - Corporate Website Styles
   High-tech, traditional, professional
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #0a1628;
    --primary-light: #132240;
    --accent: #00b4d8;
    --accent-dark: #0096b7;
    --accent-glow: rgba(0, 180, 216, 0.15);
    --text: #e0e6ed;
    --text-muted: #8892a4;
    --white: #ffffff;
    --bg-card: rgba(19, 34, 64, 0.7);
    --border: rgba(0, 180, 216, 0.2);
    --gradient-hero: linear-gradient(135deg, #0a1628 0%, #132240 50%, #0d1f3c 100%);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(0, 180, 216, 0.1);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    background: var(--primary);
    color: var(--text);
    line-height: 1.7;
    overflow-x: hidden;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition);
}

a:hover {
    color: var(--white);
}

img {
    max-width: 100%;
    height: auto;
}

/* --- Grid Background Animation --- */
.grid-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    opacity: 0.03;
    background-image:
        linear-gradient(var(--accent) 1px, transparent 1px),
        linear-gradient(90deg, var(--accent) 1px, transparent 1px);
    background-size: 60px 60px;
}

/* --- Navbar --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 22, 40, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: all var(--transition);
}

.navbar.scrolled {
    background: rgba(10, 22, 40, 0.98);
    box-shadow: 0 2px 30px rgba(0, 0, 0, 0.5);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--white);
    letter-spacing: -0.02em;
}

.nav-logo .logo-icon {
    width: 38px;
    height: 38px;
    background: linear-gradient(135deg, var(--accent), var(--accent-dark));
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    font-weight: 800;
    color: var(--white);
    letter-spacing: 0.05em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 0.25rem;
}

.nav-links a {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all var(--transition);
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--white);
    background: var(--accent-glow);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background: var(--accent);
    border-radius: 1px;
}

/* Mobile menu */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
    background: none;
    border: none;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: all var(--transition);
}

/* --- Hero Section --- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background: var(--gradient-hero);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -30%;
    width: 80%;
    height: 200%;
    background: radial-gradient(ellipse, rgba(0, 180, 216, 0.06) 0%, transparent 60%);
    pointer-events: none;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 8rem 2rem 4rem;
    position: relative;
    z-index: 1;
    width: 100%;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--accent-glow);
    border: 1px solid var(--border);
    padding: 0.4rem 1rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 1.5rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.hero-badge::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
    animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
}

.hero h1 {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    color: var(--white);
    margin-bottom: 1.5rem;
    letter-spacing: -0.03em;
}

.hero h1 .highlight {
    background: linear-gradient(135deg, var(--accent), #48cae4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.15rem;
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 2.5rem;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.85rem 1.75rem;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), var(--accent-dark));
    color: var(--white);
    box-shadow: 0 4px 20px rgba(0, 180, 216, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(0, 180, 216, 0.4);
    color: var(--white);
}

.btn-outline {
    background: transparent;
    color: var(--text);
    border: 1px solid var(--border);
}

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

/* Hero Stats */
.hero-stats {
    display: flex;
    gap: 3rem;
    margin-top: 4rem;
    padding-top: 3rem;
    border-top: 1px solid var(--border);
}

.hero-stat .stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--white);
    letter-spacing: -0.02em;
}

.hero-stat .stat-number span {
    color: var(--accent);
}

.hero-stat .stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-top: 0.25rem;
}

/* --- Section Base --- */
.section {
    padding: 6rem 2rem;
    position: relative;
    z-index: 1;
}

.section-container {
    max-width: 1200px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--accent);
    margin-bottom: 1rem;
}

.section-header h2 {
    font-family: var(--font-heading);
    font-size: clamp(1.75rem, 3vw, 2.5rem);
    font-weight: 800;
    color: var(--white);
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.05rem;
    max-width: 600px;
    margin: 0 auto;
}

/* --- About / Expertise Section --- */
.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.expertise-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.expertise-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    opacity: 0;
    transition: opacity var(--transition);
}

.expertise-card:hover {
    border-color: rgba(0, 180, 216, 0.4);
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
}

.expertise-card:hover::before {
    opacity: 1;
}

.expertise-icon {
    width: 48px;
    height: 48px;
    background: var(--accent-glow);
    border: 1px solid var(--border);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    margin-bottom: 1.25rem;
}

.expertise-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 0.75rem;
}

.expertise-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.7;
}

/* --- Technologies Section --- */
.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 1rem;
}

.tech-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1.25rem;
    text-align: center;
    transition: all var(--transition);
}

.tech-item:hover {
    border-color: rgba(0, 180, 216, 0.4);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.tech-item .tech-name {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--white);
    margin-bottom: 0.25rem;
}

.tech-item .tech-cat {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

/* --- Projects Page --- */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
}

.project-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.project-card:hover {
    border-color: rgba(0, 180, 216, 0.4);
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
}

.project-category {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    background: var(--accent-glow);
    padding: 0.3rem 0.75rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.project-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.project-card p {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.project-tag {
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.08);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
}

/* Filter buttons */
.filter-bar {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 3rem;
}

.filter-btn {
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text-muted);
    padding: 0.5rem 1.25rem;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--accent-glow);
    border-color: var(--accent);
    color: var(--white);
}

/* --- Contact Section / Page --- */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 3rem;
    align-items: start;
}

.contact-info {
    padding: 2rem 0;
}

.contact-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 1rem;
}

.contact-info p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.contact-details {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.contact-details li {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: var(--text);
    font-size: 0.9rem;
}

.contact-details .detail-icon {
    width: 42px;
    height: 42px;
    background: var(--accent-glow);
    border: 1px solid var(--border);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 1rem;
}

.contact-form-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2.5rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.85rem 1rem;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--white);
    font-family: var(--font-main);
    font-size: 0.9rem;
    transition: border-color var(--transition);
    outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-group textarea {
    min-height: 130px;
    resize: vertical;
}

.form-group select option {
    background: var(--primary);
    color: var(--text);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.25rem;
}

.form-submit {
    margin-top: 0.5rem;
}

.form-submit .btn {
    width: 100%;
    justify-content: center;
    padding: 1rem;
    font-size: 1rem;
}

.form-message {
    display: none;
    padding: 1rem;
    border-radius: 8px;
    margin-top: 1rem;
    font-size: 0.9rem;
    text-align: center;
}

.form-message.success {
    display: block;
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: #10b981;
}

.form-message.error {
    display: block;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: #ef4444;
}

/* --- Footer --- */
.footer {
    background: rgba(5, 10, 20, 0.8);
    border-top: 1px solid var(--border);
    padding: 3rem 2rem;
    position: relative;
    z-index: 1;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    color: var(--white);
    font-size: 1rem;
}

.footer-brand .logo-icon {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--accent), var(--accent-dark));
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 800;
    color: var(--white);
}

.footer-copy {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.footer-links a {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
}

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

/* --- Page Header --- */
.page-header {
    padding: 8rem 2rem 3rem;
    background: var(--gradient-hero);
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -30%;
    width: 60%;
    height: 200%;
    background: radial-gradient(ellipse, rgba(0, 180, 216, 0.04) 0%, transparent 60%);
    pointer-events: none;
}

.page-header-content {
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.page-header h1 {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    color: var(--white);
    letter-spacing: -0.02em;
    margin-bottom: 0.75rem;
}

.page-header p {
    color: var(--text-muted);
    font-size: 1.05rem;
    max-width: 600px;
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--primary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-dark);
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(10, 22, 40, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 1rem;
        gap: 0;
        border-bottom: 1px solid var(--border);
        transform: translateY(-120%);
        transition: transform var(--transition);
    }

    .nav-links.open {
        transform: translateY(0);
    }

    .nav-links a {
        padding: 0.75rem 1rem;
        font-size: 1rem;
    }

    .hero-container {
        padding: 7rem 1.5rem 3rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 1.5rem;
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .footer-container {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }

    .hero-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .expertise-grid {
        grid-template-columns: 1fr;
    }

    .tech-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

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

.animate-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.animate-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Stagger children */
.stagger > * {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.stagger.visible > *:nth-child(1) { transition-delay: 0.05s; }
.stagger.visible > *:nth-child(2) { transition-delay: 0.1s; }
.stagger.visible > *:nth-child(3) { transition-delay: 0.15s; }
.stagger.visible > *:nth-child(4) { transition-delay: 0.2s; }
.stagger.visible > *:nth-child(5) { transition-delay: 0.25s; }
.stagger.visible > *:nth-child(6) { transition-delay: 0.3s; }
.stagger.visible > *:nth-child(7) { transition-delay: 0.35s; }
.stagger.visible > *:nth-child(8) { transition-delay: 0.4s; }
.stagger.visible > *:nth-child(9) { transition-delay: 0.45s; }
.stagger.visible > *:nth-child(10) { transition-delay: 0.5s; }
.stagger.visible > *:nth-child(11) { transition-delay: 0.55s; }
.stagger.visible > *:nth-child(12) { transition-delay: 0.6s; }

.stagger.visible > * {
    opacity: 1;
    transform: translateY(0);
}