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

/* ========== Light Theme (default) ========== */
:root,
[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fb;
    --bg-card: #ffffff;
    --bg-card-hover: #f3f4f6;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --accent: #e94560;
    --accent-hover: #d63851;
    --accent-subtle: rgba(233, 69, 96, 0.08);
    --border: #e5e7eb;
    --border-focus: #e94560;
    --success: #059669;
    --error: #dc2626;
    --radius: 12px;
    --radius-sm: 8px;
    --container: 1200px;
    --transition: 0.25s ease;
    --header-bg: rgba(255, 255, 255, 0.85);
    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-card-hover: 0 12px 40px rgba(0, 0, 0, 0.1);
    --tech-tag-bg: rgba(0, 0, 0, 0.04);
    --tech-tag-color: #6b7280;
    color-scheme: light;
}

/* ========== Dark Theme ========== */
[data-theme="dark"] {
    --bg-primary: #0a0a0a;
    --bg-secondary: #111118;
    --bg-card: #16161e;
    --bg-card-hover: #1e1e2a;
    --text-primary: #e8e8ed;
    --text-secondary: #9898a6;
    --text-muted: #6b6b7b;
    --accent: #e94560;
    --accent-hover: #ff6b81;
    --accent-subtle: rgba(233, 69, 96, 0.12);
    --border: #2a2a3a;
    --border-focus: #e94560;
    --success: #2ed573;
    --error: #ff4757;
    --header-bg: rgba(10, 10, 10, 0.85);
    --shadow-card: none;
    --shadow-card-hover: 0 12px 40px rgba(0, 0, 0, 0.3);
    --tech-tag-bg: rgba(255, 255, 255, 0.06);
    --tech-tag-color: var(--text-muted);
    color-scheme: dark;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.3s ease, color 0.3s ease;
}

main {
    flex: 1;
}

.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

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

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

/* ========== Header ========== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--header-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.2rem;
    letter-spacing: -0.5px;
}

.logo:hover {
    color: var(--text-primary);
}

.logo-icon {
    color: var(--accent);
    flex-shrink: 0;
}

.logo-text {
    font-weight: 800;
}

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

.header-right {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color var(--transition);
}

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

.cta-link {
    background: var(--accent);
    color: #fff !important;
    padding: 8px 20px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    transition: all var(--transition);
}

.cta-link:hover {
    background: var(--accent-hover);
    color: #fff !important;
}

/* ========== Theme Toggle ========== */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--bg-card);
    cursor: pointer;
    transition: all var(--transition);
    color: var(--text-secondary);
    flex-shrink: 0;
}

.theme-toggle:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.theme-toggle svg {
    width: 18px;
    height: 18px;
}

.theme-toggle .icon-sun {
    display: none;
}

.theme-toggle .icon-moon {
    display: block;
}

[data-theme="dark"] .theme-toggle .icon-sun {
    display: block;
}

[data-theme="dark"] .theme-toggle .icon-moon {
    display: none;
}

.burger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.burger span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* ========== Buttons ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all var(--transition);
    text-decoration: none;
}

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

.btn-primary:hover {
    background: var(--accent-hover);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(233, 69, 96, 0.3);
}

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

.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}

/* ========== Hero ========== */
.hero {
    padding: 100px 0 80px;
    text-align: center;
}

.hero-label {
    display: inline-block;
    background: var(--accent-subtle);
    color: var(--accent);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 24px;
    letter-spacing: 0.5px;
}

.hero-title {
    font-size: clamp(2.25rem, 5vw, 3.75rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 20px;
    letter-spacing: -1px;
}

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

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 640px;
    margin: 0 auto 40px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ========== Stats ========== */
.stats {
    padding: 60px 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 24px;
    text-align: center;
    transition: all var(--transition);
    box-shadow: var(--shadow-card);
}

.stat-card:hover {
    border-color: var(--accent);
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--accent);
    margin-bottom: 8px;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ========== Skills ========== */
.skills {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 48px;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.skill-group {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow-card);
}

.skill-group h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--accent);
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag {
    background: var(--accent-subtle);
    color: var(--accent);
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* ========== Page Hero ========== */
.page-hero {
    padding: 60px 0 40px;
    text-align: center;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 12px;
}

.page-subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* ========== Projects ========== */
.projects {
    padding: 0 0 80px;
}

.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 40px;
    justify-content: center;
}

.filter-btn {
    background: var(--bg-card);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    padding: 8px 18px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    transition: all var(--transition);
}

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

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 24px;
}

.project-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-card);
}

.project-card:hover {
    border-color: var(--accent);
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
}

.project-card.hidden {
    display: none;
}

.project-header {
    margin-bottom: 16px;
}

.project-category {
    display: inline-block;
    background: var(--accent-subtle);
    color: var(--accent);
    padding: 4px 12px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.project-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 12px;
    line-height: 1.3;
}

.project-desc {
    color: var(--text-secondary);
    font-size: 0.925rem;
    margin-bottom: 16px;
    line-height: 1.6;
    flex: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 16px;
}

.tech-tag {
    background: var(--tech-tag-bg);
    color: var(--tech-tag-color);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.78rem;
    font-weight: 500;
}

.project-features h4 {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.project-features ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.project-features li {
    color: var(--text-muted);
    font-size: 0.85rem;
    padding-left: 16px;
    position: relative;
}

.project-features li::before {
    content: "\2022";
    color: var(--accent);
    position: absolute;
    left: 0;
}

/* ========== Contact ========== */
.contact {
    padding: 0 0 80px;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
}

.contact-info h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 24px;
}

.info-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.info-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 20px;
    box-shadow: var(--shadow-card);
}

.info-icon {
    font-size: 1.5rem;
    margin-bottom: 8px;
}

.info-card h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.info-card p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ========== Form ========== */
.contact-form {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow-card);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 14px 16px;
    font-size: 0.95rem;
    color: var(--text-primary);
    font-family: inherit;
    transition: border-color var(--transition), box-shadow var(--transition);
    outline: none;
}

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

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

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

.form-group input.invalid,
.form-group textarea.invalid {
    border-color: var(--error);
}

.field-error {
    display: block;
    color: var(--error);
    font-size: 0.8rem;
    margin-top: 4px;
    min-height: 1.2em;
}

.alert {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    font-size: 0.9rem;
}

.alert-error {
    background: rgba(220, 38, 38, 0.08);
    color: var(--error);
    border: 1px solid rgba(220, 38, 38, 0.2);
}

/* ========== Success Page ========== */
.success-page {
    padding: 120px 0;
    text-align: center;
}

.success-card {
    max-width: 500px;
    margin: 0 auto;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 48px;
    box-shadow: var(--shadow-card);
}

.success-icon {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: rgba(5, 150, 105, 0.1);
    color: var(--success);
    font-size: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
}

.success-card h1 {
    font-size: 1.75rem;
    margin-bottom: 12px;
}

.success-card p {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.success-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
}

/* ========== CTA Section ========== */
.cta-section {
    padding: 80px 0;
}

.cta-card {
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(233, 69, 96, 0.06) 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 56px;
    text-align: center;
}

.cta-card h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.cta-card p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 28px;
}

/* ========== Contact Direct ========== */
.contact-direct {
    margin-top: 32px;
}

.contact-direct h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.contact-link-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    transition: color var(--transition);
}

.contact-link-item:hover {
    color: var(--accent);
}

.contact-link-item svg {
    flex-shrink: 0;
    color: var(--accent);
}

/* ========== Footer ========== */
.footer {
    border-top: 1px solid var(--border);
    padding: 48px 0 24px;
    margin-top: auto;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 32px;
    align-items: start;
    margin-bottom: 32px;
}

.footer-brand .logo {
    font-size: 1.1rem;
}

.footer-desc {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 8px;
    max-width: 360px;
}

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

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

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

.footer-contacts {
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: flex-end;
}

.footer-contact-link {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    font-size: 0.875rem;
    transition: color var(--transition);
}

.footer-contact-link:hover {
    color: var(--accent);
}

.footer-contact-link svg {
    flex-shrink: 0;
    color: var(--accent);
}

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 20px;
    text-align: center;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.825rem;
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
    .nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
    }

    .nav.open {
        display: flex;
    }

    .burger {
        display: flex;
    }

    .header-right {
        gap: 12px;
    }

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

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

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

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

    .info-cards {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .footer-contacts {
        align-items: flex-start;
    }

    .hero {
        padding: 60px 0 40px;
    }

    .cta-card {
        padding: 32px 24px;
    }

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

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }

    .stat-card {
        padding: 20px 16px;
    }

    .stat-number {
        font-size: 2rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .filter-bar {
        justify-content: flex-start;
        overflow-x: auto;
        flex-wrap: nowrap;
        -webkit-overflow-scrolling: touch;
        padding-bottom: 8px;
    }

    .filter-btn {
        white-space: nowrap;
    }
}