:root {
    --primary: #4f46e5;
    --primary-dark: #4338ca;
    --dark: #1e293b;
    --muted: #64748b;
    --light: #f8fafc;
    --border: #e2e8f0;
    --white: #ffffff;
    --radius: 12px;
    --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}

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

body {
    font-family: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
    color: var(--dark);
    background: var(--white);
    line-height: 1.7;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    width: 100%;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: 0.5px;
}

.nav-links {
    display: flex;
    gap: 28px;
    list-style: none;
}

.nav-links a {
    font-weight: 500;
    color: var(--dark);
    transition: color 0.2s;
}

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

/* Hero */
.hero {
    background: linear-gradient(135deg, #eef2ff 0%, #f8fafc 100%);
    padding: 100px 0 90px;
    text-align: center;
}

.hero h1 {
    font-size: 2.8rem;
    line-height: 1.2;
    margin-bottom: 18px;
}

.hero h1 span {
    color: var(--primary);
}

.hero p {
    font-size: 1.15rem;
    color: var(--muted);
    max-width: 620px;
    margin: 0 auto 32px;
}

.btn {
    display: inline-block;
    background: var(--primary);
    color: var(--white);
    padding: 13px 30px;
    border-radius: 50px;
    font-weight: 600;
    transition: background 0.2s, transform 0.2s;
}

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

/* Sections */
.section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 12px;
}

.section-subtitle {
    text-align: center;
    color: var(--muted);
    margin-bottom: 48px;
}

/* About */
.about {
    background: var(--light);
}

.about-content {
    max-width: 720px;
    margin: 0 auto;
    text-align: center;
    font-size: 1.1rem;
    color: var(--muted);
}

/* Services */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 28px;
}

.card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 26px;
    box-shadow: var(--shadow);
    transition: transform 0.2s;
}

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

.card .icon {
    font-size: 2rem;
    margin-bottom: 14px;
}

.card h3 {
    font-size: 1.25rem;
    margin-bottom: 10px;
}

.card p {
    color: var(--muted);
    font-size: 0.98rem;
}

/* Portfolio */
.portfolio {
    background: var(--light);
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 22px;
}

.work {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.work .thumb {
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.4rem;
    color: var(--white);
}

.work:nth-child(1) .thumb { background: linear-gradient(135deg, #6366f1, #8b5cf6); }
.work:nth-child(2) .thumb { background: linear-gradient(135deg, #06b6d4, #3b82f6); }
.work:nth-child(3) .thumb { background: linear-gradient(135deg, #f59e0b, #ef4444); }
.work:nth-child(4) .thumb { background: linear-gradient(135deg, #10b981, #059669); }

.work h3 {
    padding: 18px 20px 4px;
    font-size: 1.1rem;
}

.work p {
    padding: 0 20px 20px;
    color: var(--muted);
    font-size: 0.95rem;
}

/* Contact */
.contact-form {
    max-width: 560px;
    margin: 0 auto;
    display: grid;
    gap: 16px;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 13px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 1rem;
    font-family: inherit;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

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

.alert {
    max-width: 560px;
    margin: 0 auto 20px;
    padding: 14px 18px;
    border-radius: var(--radius);
    font-weight: 500;
}

.alert-success {
    background: #dcfce7;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

/* Footer */
.site-footer {
    background: var(--dark);
    color: #cbd5e1;
    text-align: center;
    padding: 32px 0;
    font-size: 0.95rem;
}

@media (max-width: 640px) {
    .nav-links { gap: 16px; font-size: 0.9rem; }
    .hero h1 { font-size: 2rem; }
    .section { padding: 56px 0; }
}