/* =========================================================
   CSS Custom Properties – Light & Dark Themes
   ========================================================= */
:root {
    --bg:           #f8f9fb;
    --bg-alt:       #eef0f5;
    --surface:      #ffffff;
    --border:       #e2e5eb;
    --text:         #1a1d23;
    --text-muted:   #6b7280;
    --accent:       #6366f1;
    --accent-dark:  #4f46e5;
    --accent-rgb:   99, 102, 241;
    --success:      #22c55e;
    --error:        #ef4444;

    --nav-h:        64px;
    --radius:       12px;
    --radius-sm:    8px;
    --shadow:       0 4px 24px rgba(0,0,0,.07);
    --shadow-lg:    0 8px 40px rgba(0,0,0,.12);
    --transition:   200ms ease;
    --font-mono:    'JetBrains Mono', 'Courier New', monospace;
}

[data-theme="dark"] {
    --bg:           #0f1117;
    --bg-alt:       #161b27;
    --surface:      #1e2330;
    --border:       #2a3042;
    --text:         #e8eaf0;
    --text-muted:   #8892a4;
    --accent:       #818cf8;
    --accent-dark:  #6366f1;
    --shadow:       0 4px 24px rgba(0,0,0,.3);
    --shadow-lg:    0 8px 40px rgba(0,0,0,.5);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-h);
    font-size: 16px;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.7;
    transition: background-color var(--transition), color var(--transition);
    -webkit-font-smoothing: antialiased;
}

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

ul { list-style: none; }

img { display: block; max-width: 100%; }

/* =========================================================
   Utility
   ========================================================= */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.container-narrow {
    max-width: 720px;
    margin: 0 auto;
    padding: 0 24px;
}

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

/* =========================================================
   Navigation
   ========================================================= */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-h);
    z-index: 1000;
    background: transparent;
    transition: background-color var(--transition), box-shadow var(--transition);
}

.navbar.scrolled {
    background: var(--surface);
    box-shadow: var(--shadow);
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--text);
    transition: color var(--transition);
}

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

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-muted);
    transition: color var(--transition), background-color var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
    background-color: rgba(var(--accent-rgb), 0.08);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Theme toggle */
.theme-toggle {
    width: 40px;
    height: 40px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    transition: border-color var(--transition), background-color var(--transition), transform var(--transition);
    color: var(--text);
}

.theme-toggle:hover {
    border-color: var(--accent);
    transform: rotate(15deg);
}

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

/* Hamburger */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    cursor: pointer;
    padding: 0 10px;
    transition: border-color var(--transition), background-color var(--transition);
}

.hamburger span {
    display: block;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile overlay */
.nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.4);
    z-index: 999;
    backdrop-filter: blur(2px);
}

.nav-overlay.active { display: block; }

/* =========================================================
   Sections
   ========================================================= */
.section {
    padding: 100px 0;
}

.section-alt {
    background-color: var(--bg-alt);
}

.section-header {
    margin-bottom: 48px;
}

.section-label {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    display: block;
    margin-bottom: 8px;
}

.section-title {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--text);
}

/* =========================================================
   Hero
   ========================================================= */
.hero {
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: calc(var(--nav-h) + 40px) 24px 80px;
    position: relative;
}

.hero-content { max-width: 680px; }

.hero-greeting {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--accent);
    font-weight: 500;
    letter-spacing: 0.05em;
    margin-bottom: 12px;
}

.hero-name {
    font-size: clamp(2.8rem, 7vw, 5rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.1;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--text) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-title {
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.hero-description {
    font-size: 1.05rem;
    color: var(--text-muted);
    max-width: 520px;
    margin: 0 auto 36px;
}

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

.hero-scroll-hint {
    position: absolute;
    bottom: 36px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-size: 0.75rem;
    font-family: var(--font-mono);
    letter-spacing: 0.05em;
    animation: fadeInUp 1s ease 1s both;
}

.scroll-line {
    width: 1px;
    height: 48px;
    background: linear-gradient(to bottom, var(--text-muted), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

/* =========================================================
   Buttons
   ========================================================= */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform var(--transition), box-shadow var(--transition),
                background-color var(--transition), color var(--transition),
                border-color var(--transition);
    text-decoration: none;
}

.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    box-shadow: 0 4px 16px rgba(var(--accent-rgb), .35);
}

.btn-primary:hover {
    background: var(--accent-dark);
    border-color: var(--accent-dark);
    box-shadow: 0 6px 24px rgba(var(--accent-rgb), .5);
}

.btn-outline {
    background: transparent;
    color: var(--accent);
    border-color: var(--accent);
}

.btn-outline:hover {
    background: rgba(var(--accent-rgb), .08);
}

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

/* =========================================================
   About
   ========================================================= */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 64px;
    align-items: start;
}

.about-text p {
    color: var(--text-muted);
    margin-bottom: 20px;
    font-size: 1.05rem;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 32px;
}

.skill-category h4 {
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    font-family: var(--font-mono);
    margin-bottom: 12px;
}

.skill-category li {
    font-size: 0.9rem;
    color: var(--text-muted);
    padding: 4px 0;
    border-bottom: 1px solid var(--border);
}

.skill-category li:last-child { border-bottom: none; }

.about-image-wrapper {
    position: sticky;
    top: calc(var(--nav-h) + 24px);
}

.about-image-frame {
    border-radius: var(--radius);
    overflow: hidden;
    border: 2px solid var(--border);
    box-shadow: var(--shadow-lg);
    transition: border-color var(--transition);
    aspect-ratio: 3/4;
    position: relative;
}

.about-image-frame:hover { border-color: var(--accent); }

.about-image-placeholder {
    width: 100%;
    height: 100%;
    background: var(--bg-alt);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    font-family: var(--font-mono);
    position: absolute;
    inset: 0;
}

/* =========================================================
   Projects
   ========================================================= */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
}

.project-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
    box-shadow: var(--shadow);
}

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

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

.project-icon {
    font-size: 1.5rem;
    color: var(--accent);
    opacity: 0.7;
}

.project-links {
    display: flex;
    gap: 12px;
}

.project-link {
    color: var(--text-muted);
    transition: color var(--transition);
    display: flex;
    align-items: center;
}

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

.project-title {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text);
    letter-spacing: -0.01em;
}

.project-description {
    font-size: 0.92rem;
    color: var(--text-muted);
    line-height: 1.65;
    flex: 1;
}

.project-description p { margin: 0; }
.project-description strong { font-weight: 600; color: var(--text); }
.project-description a { color: var(--accent); text-decoration: underline; }

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: auto;
}

.tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--accent);
    background: rgba(var(--accent-rgb), 0.1);
    border-radius: 4px;
    padding: 3px 10px;
    letter-spacing: 0.02em;
}

/* =========================================================
   Project card – clickable footer hint
   ========================================================= */
.project-card {
    cursor: pointer;
}

.project-card-footer {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 4px;
    margin-top: 8px;
    padding-top: 12px;
    border-top: 1px solid var(--border);
}

.card-details-hint {
    font-size: 0.78rem;
    font-family: var(--font-mono);
    color: var(--accent);
    opacity: 0.7;
    transition: opacity var(--transition);
}

.card-details-arrow {
    color: var(--accent);
    opacity: 0.7;
    transition: opacity var(--transition), transform var(--transition);
    flex-shrink: 0;
}

.project-card:hover .card-details-hint,
.project-card:hover .card-details-arrow {
    opacity: 1;
}

.project-card:hover .card-details-arrow {
    transform: translateX(3px);
}

/* =========================================================
   Project Modal
   ========================================================= */
.modal-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    animation: fadeIn 0.2s ease;
}

.modal-backdrop[hidden] { display: none; }

.modal {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 780px;
    max-height: 90dvh;
    overflow-y: auto;
    position: relative;
    animation: slideUp 0.25s ease;
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
}

.modal-close {
    position: sticky;
    top: 0;
    float: right;
    margin: 16px 16px 0 0;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text-muted);
    font-size: 1.4rem;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition), border-color var(--transition), background-color var(--transition);
    z-index: 10;
}

.modal-close:hover {
    color: var(--text);
    border-color: var(--accent);
    background: rgba(var(--accent-rgb), .08);
}

.modal-header {
    padding: 20px 28px 0;
    clear: both;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text);
    margin-bottom: 12px;
}

.modal-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 24px;
}

.modal-body {
    padding: 0 28px 28px;
    display: flex;
    flex-direction: column;
    gap: 28px;
}

/* Screenshot gallery */
.gallery { display: flex; flex-direction: column; gap: 12px; }

.gallery-main {
    display: flex;
    align-items: center;
    gap: 8px;
}

.gallery-main-img-wrap {
    flex: 1;
    aspect-ratio: 16/9;
    border-radius: var(--radius-sm);
    overflow: hidden;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.gallery-main-img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    cursor: zoom-in;
    transition: opacity 0.2s ease;
}

.gallery-main-placeholder {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: center;
    padding: 16px;
}

.gallery-nav {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text-muted);
    font-size: 1.4rem;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition), border-color var(--transition);
}

.gallery-nav:hover:not(:disabled) {
    color: var(--accent);
    border-color: var(--accent);
}

.gallery-nav:disabled { opacity: 0.3; cursor: default; }

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

.gallery-thumb {
    width: 72px;
    height: 48px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    border: 2px solid var(--border);
    cursor: pointer;
    flex-shrink: 0;
    transition: border-color var(--transition);
    background: var(--bg-alt);
}

.gallery-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    pointer-events: none;
}

.gallery-thumb.active,
.gallery-thumb:hover { border-color: var(--accent); }

/* Fullscreen image overlay */
.img-zoom-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.9);
    z-index: 3000;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: zoom-out;
    animation: fadeIn 0.15s ease;
    padding: 24px;
}

.img-zoom-overlay img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: var(--radius-sm);
    box-shadow: 0 0 80px rgba(0,0,0,.8);
}

.modal-detail {
    font-size: 0.97rem;
    color: var(--text-muted);
    line-height: 1.75;
}

.modal-detail p + p { margin-top: .75em; }
.modal-detail h2 { font-size: 1.15rem; font-weight: 700; color: var(--text); margin: 1.25em 0 .4em; }
.modal-detail h3 { font-size: 1rem; font-weight: 600; color: var(--text); margin: 1em 0 .35em; }
.modal-detail ul, .modal-detail ol { padding-left: 1.4em; margin: .6em 0; }
.modal-detail li + li { margin-top: .3em; }
.modal-detail blockquote { border-left: 3px solid var(--accent); padding-left: .85em; margin: .75em 0; }
.modal-detail code { background: rgba(0,0,0,.07); padding: 2px 5px; border-radius: 4px; font-size: .85em; font-family: monospace; }
.modal-detail pre { background: #1E293B; color: #E2E8F0; padding: .9em 1em; border-radius: 8px; overflow-x: auto; margin: .75em 0; font-size: .85em; }
.modal-detail pre code { background: none; padding: 0; }
.modal-detail a { color: var(--accent); text-decoration: underline; }
.modal-detail strong { color: var(--text); }

.modal-links {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

@keyframes fadeIn  { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }

/* Modal responsive */
@media (max-width: 680px) {
    .modal-backdrop { padding: 0; align-items: flex-end; }
    .modal { max-height: 92dvh; border-bottom-left-radius: 0; border-bottom-right-radius: 0; }
    .modal-header { padding: 16px 20px 0; }
    .modal-body { padding: 0 20px 24px; }
    .gallery-thumb { width: 56px; height: 38px; }
}

/* =========================================================
   Contact
   ========================================================= */
.contact-intro {
    font-size: 1.05rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    text-align: center;
}

.contact-form {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 40px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text);
    letter-spacing: 0.02em;
}

.form-group input,
.form-group textarea {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 12px 16px;
    font-size: 0.95rem;
    color: var(--text);
    font-family: inherit;
    transition: border-color var(--transition), box-shadow var(--transition), background-color var(--transition);
    outline: none;
    resize: vertical;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
    opacity: 0.6;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(var(--accent-rgb), .15);
}

.form-group input.invalid,
.form-group textarea.invalid {
    border-color: var(--error);
    box-shadow: 0 0 0 3px rgba(239,68,68,.15);
}

.field-error {
    font-size: 0.8rem;
    color: var(--error);
    min-height: 1em;
    font-family: var(--font-mono);
}

.form-actions { margin-top: 4px; }

.form-status {
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    text-align: center;
}

.form-status.success {
    background: rgba(34,197,94,.1);
    border: 1px solid rgba(34,197,94,.3);
    color: var(--success);
}

.form-status.error {
    background: rgba(239,68,68,.1);
    border: 1px solid rgba(239,68,68,.3);
    color: var(--error);
}

.contact-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
}

.contact-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 0.875rem;
    color: var(--text-muted);
    background: var(--surface);
    transition: border-color var(--transition), color var(--transition), transform var(--transition);
}

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

/* =========================================================
   Footer
   ========================================================= */
.footer {
    padding: 32px 0;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
    background: var(--surface);
}

/* =========================================================
   Animations
   ========================================================= */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes scrollPulse {
    0%, 100% { opacity: 1; }
    50%       { opacity: 0.3; }
}

.reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* =========================================================
   Responsive – Tablet (≤ 900px)
   ========================================================= */
@media (max-width: 900px) {
    .about-grid {
        grid-template-columns: 1fr;
    }

    .about-image-wrapper {
        position: static;
        max-width: 320px;
        margin: 0 auto;
    }

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

/* =========================================================
   Responsive – Mobile (≤ 680px)
   ========================================================= */
@media (max-width: 680px) {
    .section { padding: 72px 0; }

    /* Nav mobile */
    .hamburger { display: flex; }

    .nav-links {
        position: fixed;
        top: var(--nav-h);
        right: 0;
        bottom: 0;
        width: 260px;
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
        background: var(--surface);
        border-left: 1px solid var(--border);
        padding: 24px 16px;
        transform: translateX(100%);
        transition: transform 0.3s ease;
        z-index: 1001;
        box-shadow: var(--shadow-lg);
    }

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

    .nav-link {
        width: 100%;
        padding: 12px 16px;
        font-size: 1rem;
    }

    /* Hero */
    .hero-actions { flex-direction: column; align-items: center; }
    .btn { width: 100%; max-width: 280px; justify-content: center; }

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

    /* Contact form */
    .contact-form { padding: 24px 20px; }
    .form-row { grid-template-columns: 1fr; }
}