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

:root {
    --header-height: 60px;
    --container-width: 1200px;
    --text-primary: #1d1d1f;
    --text-secondary: #6e6e73;
    --text-tertiary: #a0a0a5;
    --background: #ffffff;
    --background-light: #f5f5f7;
    --surface: #ffffff;
    --surface-hover: #ebebed;
    --border: rgba(0, 0, 0, 0.08);
    --border-mid: rgba(0, 0, 0, 0.1);
    --border-strong: rgba(0, 0, 0, 0.15);
    --header-background: rgba(255, 255, 255, 0.85);
    --input-background: #ffffff;
    --selection-background: #1d1d1f;
    --selection-color: #ffffff;
    --button-primary-background: #1d1d1f;
    --button-primary-color: #ffffff;
    --button-secondary-background: transparent;
    --shadow-sm: 0 1px 6px rgba(0, 0, 0, 0.05);
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.08);
    --shadow-image: 0 16px 56px rgba(0, 0, 0, 0.1);
    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 22px;
    --ease-apple: cubic-bezier(0.22, 1, 0.36, 1);
    color-scheme: light;
}

html[data-theme="dark"] {
    --text-primary: #f5f5f7;
    --text-secondary: #a1a1a6;
    --text-tertiary: #6e6e73;
    --background: #000000;
    --background-light: #111113;
    --surface: #1c1c1e;
    --surface-hover: #2c2c2e;
    --border: rgba(255, 255, 255, 0.09);
    --border-mid: rgba(255, 255, 255, 0.12);
    --border-strong: rgba(255, 255, 255, 0.18);
    --header-background: rgba(0, 0, 0, 0.88);
    --input-background: #1c1c1e;
    --selection-background: #f5f5f7;
    --selection-color: #000000;
    --button-primary-background: #f5f5f7;
    --button-primary-color: #000000;
    --button-secondary-background: transparent;
    --shadow-sm: 0 1px 6px rgba(0, 0, 0, 0.4);
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.5);
    --shadow-image: 0 16px 56px rgba(0, 0, 0, 0.6);
    color-scheme: dark;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
    background: var(--background);
    transition:
        background-color 0.4s var(--ease-apple),
        color 0.4s var(--ease-apple);
}

html:focus-within {
    scroll-behavior: smooth;
}

body {
    min-width: 320px;
    /*font-family:
        -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue",
        Arial, sans-serif;*/

    font-family:
        -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue",
        "Segoe UI", Ubuntu, "Liberation Sans", Arial, sans-serif;

    color: var(--text-primary);
    background: var(--background);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
    transition:
        background-color 0.4s var(--ease-apple),
        color 0.4s var(--ease-apple);
}

body.no-scroll {
    overflow: hidden;
}
a {
    color: inherit;
    text-decoration: none;
}
button,
input,
textarea {
    font: inherit;
}
button {
    border: 0;
    cursor: pointer;
}
img {
    display: block;
    max-width: 100%;
    height: auto;
}
ul {
    list-style: none;
}

::selection {
    color: var(--selection-color);
    background: var(--selection-background);
}

:focus-visible {
    outline: 2px solid var(--text-primary);
    outline-offset: 3px;
    border-radius: 4px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--text-primary);
    outline-offset: 4px;
    border-radius: 6px;
}

.skip-to-content {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--button-primary-background);
    color: var(--button-primary-color);
    padding: 8px 16px;
    border-radius: 0 0 8px 0;
    z-index: 10000;
    font-size: 14px;
    font-weight: 500;
    transition: top 0.2s ease;
}
.skip-to-content:focus {
    top: 0;
}

.container {
    width: min(calc(100% - 48px), var(--container-width));
    margin-inline: auto;
}

.header-nav {
    position: fixed;
    inset: 0 0 auto;
    width: 100%;
    height: var(--header-height);
    z-index: 1000;
    background: var(--header-background);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(28px) saturate(200%);
    -webkit-backdrop-filter: blur(28px) saturate(200%);
    transition:
        background-color 0.4s var(--ease-apple),
        border-color 0.4s var(--ease-apple);
}

.navbar {
    width: min(calc(100% - 48px), var(--container-width));
    height: 100%;
    margin-inline: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.logo {
    flex-shrink: 0;
    font-size: 17px;
    font-weight: 600;
    letter-spacing: -0.022em;
    color: var(--text-primary);
    white-space: nowrap;
    transition:
        opacity 0.2s var(--ease-apple),
        color 0.4s var(--ease-apple);
}
.logo:hover {
    opacity: 0.55;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 20px;
    flex-shrink: 0;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 20px;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
}
.nav-list::-webkit-scrollbar {
    display: none;
}

.nav-list a {
    position: relative;
    flex-shrink: 0;
    display: inline-block;
    padding: 3px 0;
    font-size: 13px;
    font-weight: 400;
    color: var(--text-secondary);
    white-space: nowrap;
    transition: color 0.2s var(--ease-apple);
}

.nav-list a::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: -3px;
    width: 0;
    height: 1.5px;
    border-radius: 999px;
    background: var(--text-primary);
    transform: translateX(-50%);
    transition: width 0.25s var(--ease-apple);
}

.nav-list a:hover {
    color: var(--text-primary);
}
.nav-list a.active {
    color: var(--text-primary);
    font-weight: 500;
}
.nav-list a.active::after {
    width: 14px;
}

.theme-switcher {
    flex-shrink: 0;
}

.theme-icon-button {
    width: 34px;
    height: 34px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    color: var(--text-primary);
    background: transparent;
    border-radius: 50%;
    -webkit-tap-highlight-color: transparent;
    transition:
        background-color 0.2s var(--ease-apple),
        transform 0.25s var(--ease-apple),
        color 0.4s var(--ease-apple);
}
.theme-icon-button:hover {
    background: var(--background-light);
    transform: translateY(-1px);
}
.theme-icon-button:active {
    transform: scale(0.9);
}

.theme-icon-button .theme-icon {
    font-size: 17px;
    line-height: 1;
    pointer-events: none;
    transition:
        transform 0.35s var(--ease-apple),
        color 0.4s var(--ease-apple);
}
.theme-icon-button:hover .theme-icon {
    transform: rotate(14deg);
}
html[data-theme="dark"] .theme-icon-button:hover .theme-icon {
    transform: rotate(-14deg);
}

.section {
    min-height: 100vh;
    padding: 112px 0;
    background: var(--background);
    transition: background-color 0.4s var(--ease-apple);
}

.section-header {
    max-width: 680px;
    margin-bottom: 56px;
}

.section-label {
    display: inline-block;
    margin-bottom: 8px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-tertiary);
    transition: color 0.4s var(--ease-apple);
}

.section-header h2,
.about-header h2 {
    font-size: clamp(34px, 4.5vw, 60px);
    font-weight: 600;
    line-height: 1.02;
    letter-spacing: -0.045em;
    color: var(--text-primary);
    transition: color 0.4s var(--ease-apple);
}

.hero {
    min-height: 100vh;
    padding-top: var(--header-height);
    display: flex;
    align-items: center;
    background: var(--background);
    transition: background-color 0.4s var(--ease-apple);
}

.hero-content {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 360px;
    align-items: center;
    gap: clamp(48px, 7vw, 96px);
    padding: 64px 0;
}

.hero-text {
    max-width: 640px;
}

.hero-greeting {
    margin-bottom: 6px;
    font-size: 17px;
    color: var(--text-secondary);
    transition: color 0.4s var(--ease-apple);
}

.hero-text h1 {
    margin-bottom: 8px;
    font-size: clamp(52px, 7.5vw, 96px);
    font-weight: 700;
    line-height: 0.93;
    letter-spacing: -0.065em;
    color: var(--text-primary);
    transition: color 0.4s var(--ease-apple);
}

.hero-highlight {
    display: block;
    color: var(--text-secondary);
    transition: color 0.4s var(--ease-apple);
}

.hero-text h2 {
    margin-bottom: 16px;
    font-size: clamp(19px, 2.5vw, 32px);
    font-weight: 500;
    line-height: 1.15;
    letter-spacing: -0.03em;
    color: var(--text-primary);
    transition: color 0.4s var(--ease-apple);
}

.hero-description {
    max-width: 500px;
    margin-bottom: 28px;
    font-size: 17px;
    line-height: 1.6;
    color: var(--text-secondary);
    transition: color 0.4s var(--ease-apple);
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.button {
    min-height: 42px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0 18px;
    border-radius: 999px;
    font-size: 14px;
    font-weight: 500;
    white-space: nowrap;
    cursor: pointer;
    transition:
        transform 0.25s var(--ease-apple),
        background-color 0.25s var(--ease-apple),
        color 0.25s var(--ease-apple),
        border-color 0.25s var(--ease-apple),
        box-shadow 0.25s var(--ease-apple),
        opacity 0.25s var(--ease-apple);
}

.button:hover:not(:disabled):not([aria-busy="true"]) {
    transform: translateY(-2px);
}

.button-primary {
    color: var(--button-primary-color);
    background: var(--button-primary-background);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.14);
}
.button-primary:hover:not(:disabled) {
    box-shadow: 0 6px 22px rgba(0, 0, 0, 0.2);
}
html[data-theme="dark"] .button-primary {
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.45);
}
html[data-theme="dark"] .button-primary:hover:not(:disabled) {
    box-shadow: 0 6px 22px rgba(0, 0, 0, 0.55);
}

.button-secondary {
    color: var(--text-primary);
    border: 1px solid var(--border-strong);
    background: var(--button-secondary-background);
}
.button-secondary:hover:not(:disabled) {
    background: var(--background-light);
}

.button:disabled,
.button[aria-busy="true"] {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

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

.hero-image img {
    width: 100%;
    max-width: 340px;
    aspect-ratio: 1;
    object-fit: cover;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-image);
    transition:
        transform 0.6s var(--ease-apple),
        box-shadow 0.6s var(--ease-apple);
}

@media (hover: hover) and (pointer: fine) {
    .hero-image:hover img {
        transform: translateY(-7px) scale(1.012);
        box-shadow: 0 28px 72px rgba(0, 0, 0, 0.15);
    }
}
html[data-theme="dark"] .hero-image img {
    box-shadow: 0 12px 48px rgba(0, 0, 0, 0.5);
}

.about {
    position: relative;
    background: var(--background);
    transition: background-color 0.4s var(--ease-apple);
}

.about-sticky {
    position: sticky;
    top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
    display: flex;
    align-items: center;
    overflow: hidden;
}

.about-content {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: clamp(40px, 7vw, 88px);
    align-items: center;
    padding: 56px 0;
}

.about-header {
    max-width: 460px;
}

.about-body {
    display: flex;
    flex-direction: column;
    gap: 14px;
    max-height: calc(100vh - var(--header-height) - 80px);
    overflow: hidden;
}

.about-body p {
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-primary);
    opacity: 0.22;
    transform: translate3d(0, 6px, 0) scale(0.99);
    transform-origin: left center;
    filter: blur(0.3px);
    transition:
        opacity 0.5s var(--ease-apple),
        transform 0.5s var(--ease-apple),
        filter 0.5s var(--ease-apple),
        color 0.4s var(--ease-apple);
    will-change: opacity, transform;
}

.about-body p.active {
    opacity: 1;
    font-weight: 500;
    transform: translate3d(3px, 0, 0) scale(1);
    filter: blur(0);
}

.projects {
    background: var(--background-light);
    transition: background-color 0.4s var(--ease-apple);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
    min-height: 200px;
}

.project-card {
    position: relative;
    display: flex;
    flex-direction: column;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition:
        transform 0.3s var(--ease-apple),
        box-shadow 0.3s var(--ease-apple),
        border-color 0.3s var(--ease-apple),
        background-color 0.4s var(--ease-apple);
}
.project-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-mid);
    box-shadow: var(--shadow-card);
}

.project-demo-img {
    width: 100%;
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background: var(--background-light);
    flex-shrink: 0;
    transition: background-color 0.4s var(--ease-apple);
}
.project-demo-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.55s var(--ease-apple);
}
.project-card:hover .project-demo-img img {
    transform: scale(1.04);
}

.project-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 22px;
}

.project-number {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.07em;
    color: var(--text-tertiary);
    margin-bottom: auto;
    padding-bottom: 14px;
    transition: color 0.4s var(--ease-apple);
}

.project-content h3 {
    font-size: clamp(15px, 1.6vw, 19px);
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    margin-bottom: 7px;
    overflow-wrap: anywhere;
    transition:
        color 0.4s var(--ease-apple),
        transform 0.25s var(--ease-apple);
}
.project-card:hover .project-content h3 {
    transform: translateY(-1px);
}

.project-content p {
    font-size: 13px;
    line-height: 1.55;
    color: var(--text-secondary);
    margin-bottom: 12px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    transition: color 0.4s var(--ease-apple);
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    margin-bottom: 14px;
}
.project-tech span {
    padding: 3px 8px;
    font-size: 11px;
    color: var(--text-tertiary);
    background: var(--background-light);
    border-radius: 999px;
    white-space: nowrap;
    transition:
        background-color 0.25s var(--ease-apple),
        color 0.25s var(--ease-apple);
}
.project-card:hover .project-tech span {
    color: var(--text-secondary);
}

.project-links {
    margin-top: auto;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 14px;
}

.project-link {
    font-size: 12px;
    font-weight: 500;
    transition:
        opacity 0.2s var(--ease-apple),
        transform 0.2s var(--ease-apple),
        color 0.4s var(--ease-apple);
}
.project-link:hover {
    opacity: 0.5;
    transform: translateX(2px);
}
.project-link-live {
    color: var(--text-primary);
    font-weight: 600;
}
.project-link-github {
    color: var(--text-tertiary);
    font-weight: 400;
}

.github-loading {
    pointer-events: none;
    opacity: 1 !important;
    transform: none !important;
}
.github-loading .project-number {
    opacity: 0.3;
}
.github-loading .project-content h3 {
    color: var(--text-secondary);
}
.github-loading .project-content p {
    color: var(--text-tertiary);
}

.education {
    background: var(--background);
    min-height: auto;
    transition: background-color 0.4s var(--ease-apple);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
}

.education-card {
    display: flex;
    flex-direction: column;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition:
        transform 0.3s var(--ease-apple),
        box-shadow 0.3s var(--ease-apple),
        border-color 0.3s var(--ease-apple),
        background-color 0.4s var(--ease-apple);
}
.education-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-mid);
    box-shadow: var(--shadow-card);
}

.education-img-wrap {
    width: 100%;
    aspect-ratio: 16 / 6;
    overflow: hidden;
    background: var(--background-light);
    flex-shrink: 0;
    transition: background-color 0.4s var(--ease-apple);
}
.education-img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.55s var(--ease-apple);
}
.education-card:hover .education-img-wrap img {
    transform: scale(1.04);
}

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

.education-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
}

.education-badge {
    display: inline-flex;
    align-items: center;
    padding: 2px 8px;
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.07em;
    text-transform: uppercase;
    color: var(--button-primary-color);
    background: var(--button-primary-background);
    border-radius: 999px;
    transition:
        background-color 0.4s var(--ease-apple),
        color 0.4s var(--ease-apple);
}

.education-date {
    font-size: 12px;
    color: var(--text-tertiary);
    transition: color 0.4s var(--ease-apple);
}

.education-card h3 {
    margin-bottom: 4px;
    font-size: clamp(15px, 1.5vw, 18px);
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    transition: color 0.4s var(--ease-apple);
}

.education-field {
    margin-bottom: 10px;
    font-size: 13px;
    color: var(--text-secondary);
    transition: color 0.4s var(--ease-apple);
}

.education-desc {
    margin-bottom: 14px;
    font-size: 13px;
    line-height: 1.6;
    color: var(--text-secondary);
    transition: color 0.4s var(--ease-apple);
}

.education-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    margin-bottom: 14px;
}
.education-tech span {
    padding: 3px 8px;
    font-size: 11px;
    color: var(--text-tertiary);
    background: var(--background-light);
    border-radius: 999px;
    transition:
        color 0.25s var(--ease-apple),
        background-color 0.25s var(--ease-apple);
}

.education-link {
    display: inline-flex;
    align-items: center;
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-top: auto;
    transition:
        color 0.2s var(--ease-apple),
        transform 0.2s var(--ease-apple);
}
.education-link:hover {
    color: var(--text-primary);
    transform: translateX(2px);
}

.skills {
    background: var(--background-light);
    min-height: auto;
    transition: background-color 0.4s var(--ease-apple);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    column-gap: 48px;
    row-gap: 36px;
}

.skill-group {
    display: flex;
    flex-direction: column;
}

.skill-group h3 {
    margin-bottom: 14px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-tertiary);
    transition: color 0.4s var(--ease-apple);
}

.skill-group ul {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.skill-group li {
    display: inline-flex;
    padding: 5px 11px;
    font-size: 12px;
    font-weight: 400;
    color: var(--text-secondary);
    border: 1px solid var(--border-mid);
    border-radius: 999px;
    cursor: default;
    transition:
        color 0.2s var(--ease-apple),
        background-color 0.2s var(--ease-apple),
        border-color 0.2s var(--ease-apple),
        transform 0.2s var(--ease-apple);
}
.skill-group li:hover {
    color: var(--button-primary-color);
    background: var(--button-primary-background);
    border-color: var(--button-primary-background);
    transform: translateY(-1px);
}

.certificates {
    background: var(--background);
    min-height: auto;
    transition: background-color 0.4s var(--ease-apple);
}

.cert-showcase {
    max-width: 740px;
    margin-inline: auto;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition:
        background-color 0.4s var(--ease-apple),
        border-color 0.4s var(--ease-apple),
        box-shadow 0.4s var(--ease-apple);
}

.cert-main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: stretch;
}

.cert-image-wrap {
    aspect-ratio: 4 / 3;
    overflow: hidden;
    background: var(--background-light);
    border-right: 1px solid var(--border);
    flex-shrink: 0;
    transition:
        border-color 0.4s var(--ease-apple),
        background-color 0.4s var(--ease-apple);
}
.cert-image-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition:
        transform 0.55s var(--ease-apple),
        opacity 0.3s var(--ease-apple);
}
.cert-showcase:hover .cert-image-wrap img {
    transform: scale(1.03);
}

.cert-info {
    padding: 28px;
    display: flex;
    flex-direction: column;
}

.cert-meta {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 8px;
    flex-wrap: wrap;
}

.cert-issuer {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.4s var(--ease-apple);
}

.cert-date {
    font-size: 11px;
    color: var(--text-tertiary);
    white-space: nowrap;
    transition: color 0.4s var(--ease-apple);
}

.cert-title {
    font-size: clamp(16px, 2vw, 22px);
    font-weight: 600;
    line-height: 1.25;
    letter-spacing: -0.025em;
    color: var(--text-primary);
    margin-bottom: 10px;
    transition: color 0.4s var(--ease-apple);
}

.cert-desc {
    font-size: 13px;
    line-height: 1.6;
    color: var(--text-secondary);
    margin-bottom: 20px;
    flex: 1;
    transition: color 0.4s var(--ease-apple);
}

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

.cert-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    padding: 14px 28px;
    border-top: 1px solid var(--border);
    transition: border-color 0.4s var(--ease-apple);
}

.cert-btn {
    width: 30px;
    height: 30px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    line-height: 1;
    color: var(--text-secondary);
    background: transparent;
    border-radius: 50%;
    -webkit-tap-highlight-color: transparent;
    transition:
        background-color 0.2s var(--ease-apple),
        transform 0.2s var(--ease-apple),
        opacity 0.2s var(--ease-apple),
        color 0.4s var(--ease-apple);
}
.cert-btn:hover:not(:disabled) {
    background: var(--background-light);
    color: var(--text-primary);
    transform: scale(1.1);
}
.cert-btn:disabled {
    opacity: 0.2;
    cursor: not-allowed;
    transform: none;
}

.cert-indicator {
    min-width: 40px;
    text-align: center;
    font-size: 11px;
    letter-spacing: 0.05em;
    color: var(--text-tertiary);
    transition: color 0.4s var(--ease-apple);
}

.contact {
    background: var(--background-light);
    transition: background-color 0.4s var(--ease-apple);
}

.contact-content {
    display: grid;
    grid-template-columns: minmax(220px, 0.7fr) minmax(0, 1.3fr);
    gap: 64px;
    align-items: start;
}

.contact-info {
    margin: 0;
    font-style: normal;
}

.contact-info ul {
    display: flex;
    flex-direction: column;
    gap: 18px;
    margin: 0;
    padding: 0;
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
    transition: border-color 0.4s var(--ease-apple);
}

.contact-item span {
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-tertiary);
    transition: color 0.4s var(--ease-apple);
}

.contact-item a {
    position: relative;
    width: fit-content;
    display: inline-flex;
    align-items: center;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-primary);
    overflow-wrap: anywhere;
    transition:
        opacity 0.2s var(--ease-apple),
        transform 0.2s var(--ease-apple),
        color 0.4s var(--ease-apple);
}

.contact-item a::after {
    content: "\2197";
    margin-left: 4px;
    font-size: 11px;
    opacity: 0;
    transform: translate3d(-2px, 1px, 0);
    transition:
        opacity 0.2s var(--ease-apple),
        transform 0.2s var(--ease-apple);
}
.contact-item a:hover {
    opacity: 0.6;
    transform: translateX(2px);
}
.contact-item a:hover::after {
    opacity: 0.8;
    transform: translate3d(0, 0, 0);
}
.contact-item a[download]::after {
    content: "\2193";
}
.contact-item a[download]:hover::after {
    transform: translate3d(0, 2px, 0);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 18px;
    padding: 28px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition:
        background-color 0.4s var(--ease-apple),
        border-color 0.4s var(--ease-apple);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.4s var(--ease-apple);
}

.form-group input,
.form-group textarea {
    width: 100%;
    color: var(--text-primary);
    background: var(--input-background);
    border: 1px solid var(--border-mid);
    border-radius: var(--radius-sm);
    outline: none;
    transition:
        border-color 0.2s var(--ease-apple),
        box-shadow 0.2s var(--ease-apple),
        background-color 0.4s var(--ease-apple),
        color 0.4s var(--ease-apple);
}

.form-group input {
    height: 46px;
    padding: 0 14px;
}
.form-group textarea {
    min-height: 120px;
    padding: 12px 14px;
    resize: vertical;
}
.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-tertiary);
}
.form-group input:hover,
.form-group textarea:hover {
    border-color: var(--border-strong);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--text-primary);
    box-shadow: 0 0 0 3px rgba(128, 128, 128, 0.12);
}

html[data-theme="dark"] .form-group input:focus,
html[data-theme="dark"] .form-group textarea:focus {
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.1);
}

.form-group input:user-invalid,
.form-group textarea:user-invalid {
    border-color: #dc2626;
}
.form-group input:user-invalid:focus,
.form-group textarea:user-invalid:focus {
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.1);
}

.contact-button {
    align-self: flex-start;
    min-height: 42px;
    padding: 0 20px;
    color: var(--button-primary-color);
    background: var(--button-primary-background);
    border-radius: 999px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition:
        transform 0.25s var(--ease-apple),
        opacity 0.25s var(--ease-apple),
        box-shadow 0.25s var(--ease-apple),
        background-color 0.4s var(--ease-apple);
}
.contact-button:hover:not(:disabled):not([aria-busy="true"]) {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.14);
}
html[data-theme="dark"] .contact-button:hover:not(:disabled) {
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.45);
}

.contact-button:disabled,
.contact-button[aria-busy="true"] {
    cursor: not-allowed;
    opacity: 0.5;
    transform: none !important;
    box-shadow: none;
}

.form-status {
    min-height: 16px;
    font-size: 13px;
    color: var(--text-secondary);
    transition: color 0.3s var(--ease-apple);
}
.form-status[data-state="success"] {
    color: #16a34a;
}
.form-status[data-state="error"] {
    color: #dc2626;
}

.footer {
    padding: 24px 0;
    background: var(--background);
    border-top: 1px solid var(--border);
    transition:
        background-color 0.4s var(--ease-apple),
        border-color 0.4s var(--ease-apple);
}

.footer .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.footer p {
    font-size: 12px;
    color: var(--text-tertiary);
    transition: color 0.4s var(--ease-apple);
}

.footer-socials {
    display: flex;
    align-items: center;
    gap: 2px;
    flex-shrink: 0;
}

.footer-socials a {
    width: 34px;
    height: 34px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--text-tertiary);
    border-radius: 50%;
    transition:
        color 0.2s var(--ease-apple),
        background-color 0.2s var(--ease-apple),
        transform 0.2s var(--ease-apple);
}
.footer-socials a:hover {
    color: var(--text-primary);
    background: var(--background-light);
    transform: translateY(-2px);
}
.footer-socials a:active {
    transform: scale(0.9);
}
.footer-socials a:focus-visible {
    outline: 2px solid var(--text-primary);
    outline-offset: 2px;
}
.footer-socials svg {
    display: block;
    flex-shrink: 0;
}

.reveal {
    opacity: 0;
    transform: translate3d(0, 20px, 0);
    will-change: opacity, transform;
    transition:
        opacity 0.65s var(--ease-apple),
        transform 0.65s var(--ease-apple);
}
.reveal.visible {
    opacity: 1;
    transform: translate3d(0, 0, 0);
}

.github-loading.reveal,
.github-loading.reveal.visible {
    opacity: 1 !important;
    transform: none !important;
    transition-delay: 0s !important;
}

.about-body p.reveal {
    opacity: 1;
    transform: none;
    transition: none;
}

@media (max-width: 1100px) {
    .hero-content {
        grid-template-columns: minmax(0, 1fr) 300px;
    }
    .projects-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    .skills-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        column-gap: 40px;
    }
    .contact-content {
        gap: 48px;
    }
}

@media (max-width: 1024px) {
    .about {
        min-height: auto;
    }
    .about-sticky {
        position: relative;
        top: auto;
        min-height: auto;
        overflow: visible;
        padding: 80px 0;
    }
    .about-body {
        max-height: none;
        overflow: visible;
    }
    .about-body p {
        opacity: 0.7;
        transform: none;
        filter: none;
        transition:
            opacity 0.3s var(--ease-apple),
            color 0.4s var(--ease-apple);
    }
    .about-body p.active {
        opacity: 1;
        transform: none;
        font-weight: 500;
    }
}

@media (max-width: 900px) {
    .education-grid {
        grid-template-columns: 1fr;
    }
    .about-content {
        gap: 36px;
    }
}

@media (max-width: 800px) {
    :root {
        --header-height: 56px;
    }

    .container {
        width: min(calc(100% - 32px), 720px);
    }
    .navbar {
        width: min(calc(100% - 32px), 720px);
        gap: 12px;
    }

    .nav-right {
        flex: 1;
        min-width: 0;
        overflow: hidden;
    }
    .nav-list {
        flex: 1;
        min-width: 0;
        overflow-x: auto;
        gap: 16px;
    }
    .nav-list a {
        font-size: 13px;
    }

    .hero {
        min-height: auto;
    }
    .hero-content {
        grid-template-columns: 1fr;
        padding: 72px 0 52px;
        gap: 0;
    }
    .hero-image {
        display: none;
    }

    .about-sticky {
        padding: 80px 0;
    }
    .about-content {
        grid-template-columns: 1fr;
        gap: 28px;
        padding: 0;
    }
    .about-body p {
        font-size: 15px;
        opacity: 1;
    }

    .section {
        min-height: auto;
        padding: 88px 0;
    }
    .section-header {
        margin-bottom: 40px;
    }

    .projects-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 12px;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 36px;
    }

    .cert-main {
        grid-template-columns: 1fr;
    }
    .cert-image-wrap {
        aspect-ratio: 16 / 7;
        border-right: none;
        border-bottom: 1px solid var(--border);
        max-height: 200px;
    }
}

@media (max-width: 600px) {
    :root {
        --header-height: 52px;
    }

    .container {
        width: calc(100% - 32px);
    }
    .navbar {
        width: calc(100% - 32px);
        gap: 8px;
    }

    .logo {
        font-size: 15px;
    }
    .nav-list {
        gap: 12px;
    }
    .nav-list a {
        font-size: 12px;
    }
    .theme-icon-button {
        width: 32px;
        height: 32px;
    }
    .theme-icon-button .theme-icon {
        font-size: 16px;
    }

    .hero-content {
        padding: 60px 0 44px;
    }
    .hero-greeting {
        font-size: 15px;
    }
    .hero-text h1 {
        font-size: clamp(44px, 13vw, 64px);
    }
    .hero-text h2 {
        font-size: clamp(17px, 5vw, 22px);
    }
    .hero-description {
        font-size: 15px;
    }
    .hero-buttons {
        gap: 8px;
    }
    .button {
        min-height: 40px;
        padding: 0 16px;
        font-size: 13px;
    }

    .about-sticky {
        padding: 64px 0;
    }
    .about-body p {
        font-size: 15px;
        line-height: 1.65;
    }

    .section {
        padding: 72px 0;
    }
    .section-header {
        margin-bottom: 32px;
    }
    .section-header h2,
    .about-header h2 {
        font-size: clamp(28px, 9vw, 40px);
    }

    .projects-grid {
        grid-template-columns: 1fr;
        gap: 10px;
        min-height: auto;
    }
    .education-grid {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    .skills-grid {
        grid-template-columns: 1fr;
        column-gap: 0;
        row-gap: 24px;
    }

    .contact-form {
        padding: 22px;
        gap: 16px;
    }
    .contact-button {
        width: 100%;
        justify-content: center;
    }

    .footer {
        padding: 20px 0;
    }
    .footer .container {
        flex-direction: column;
        gap: 12px;
    }
    .footer p {
        order: 2;
    }
    .footer-socials {
        order: 1;
        justify-content: center;
    }

    .cert-info {
        padding: 20px;
    }
    .cert-controls {
        padding: 12px 20px;
    }
}

@media (max-width: 480px) {
    .projects-grid {
        gap: 8px;
    }
    .education-grid {
        gap: 8px;
    }
    .section-header {
        margin-bottom: 28px;
    }
    .about-sticky {
        padding: 56px 0;
    }
}

@media (max-width: 430px) {
    .navbar {
        gap: 6px;
    }
    .logo {
        font-size: 14px;
    }
    .nav-list {
        gap: 10px;
    }
    .nav-list a {
        font-size: 11px;
    }
    .theme-icon-button {
        width: 30px;
        height: 30px;
    }
    .theme-icon-button .theme-icon {
        font-size: 15px;
    }
    .cert-actions {
        flex-direction: column;
    }
    .cert-actions .button {
        width: 100%;
    }
}

@media (max-width: 360px) {
    .navbar {
        gap: 4px;
    }
    .logo {
        font-size: 13px;
    }
    .nav-list {
        gap: 8px;
    }
    .nav-list a {
        font-size: 10.5px;
    }
    .hero-text h1 {
        font-size: clamp(38px, 13vw, 52px);
    }
    .button {
        min-height: 38px;
        padding: 0 14px;
        font-size: 12px;
    }
    .about-sticky {
        padding: 48px 0;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .reveal,
    .reveal.visible {
        opacity: 1 !important;
        transform: none !important;
    }

    .about-body p,
    .about-body p.active {
        opacity: 1 !important;
        transform: none !important;
        filter: none !important;
    }

    .project-card,
    .project-demo-img img,
    .project-link,
    .education-card,
    .education-img-wrap img,
    .education-link,
    .cert-showcase,
    .cert-image-wrap img,
    .cert-btn,
    .skill-group li,
    .contact-item a,
    .footer-socials a,
    .hero-image img,
    .button,
    .contact-button,
    .theme-icon-button,
    .theme-icon-button .theme-icon,
    .logo {
        transform: none !important;
        transition:
            color 0.01ms,
            background-color 0.01ms,
            border-color 0.01ms,
            opacity 0.01ms !important;
    }
}
/* MOBILE HAMBURGER NAVIGATION */

.menu-toggle {
    display: none;
    width: 34px;
    height: 34px;
    flex-shrink: 0;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 4px;
    padding: 0;
    color: var(--text-primary);
    background: transparent;
    border-radius: 50%;
    -webkit-tap-highlight-color: transparent;
    transition:
        background-color 0.2s var(--ease-apple),
        transform 0.25s var(--ease-apple),
        color 0.4s var(--ease-apple);
}

.menu-toggle:hover {
    background: var(--background-light);
    transform: translateY(-1px);
}

.menu-toggle:active {
    transform: scale(0.9);
}

.menu-toggle span {
    display: block;
    width: 18px;
    height: 1.5px;
    border-radius: 999px;
    background: currentColor;
    transform-origin: center;
    transition:
        transform 0.25s var(--ease-apple),
        opacity 0.2s var(--ease-apple);
}

.menu-toggle.is-open span:nth-child(1) {
    transform: translateY(5.5px) rotate(45deg);
}

.menu-toggle.is-open span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.is-open span:nth-child(3) {
    transform: translateY(-5.5px) rotate(-45deg);
}

@media (max-width: 800px) {
    .nav-right {
        position: relative;
        gap: 8px;
    }

    .menu-toggle {
        display: inline-flex;
    }

    .nav-list {
        position: absolute;
        top: calc(100% + 8px);
        right: 0;
        z-index: 1001;
        display: none;
        width: min(200px, calc(100vw - 32px));
        max-height: calc(100vh - var(--header-height) - 24px);
        flex-direction: column;
        align-items: stretch;
        gap: 2px;
        padding: 8px;
        overflow-x: hidden;
        overflow-y: auto;
        background: var(--surface);
        border: 1px solid var(--border);
        border-radius: var(--radius-md);
        box-shadow: var(--shadow-card);
    }

    .nav-list.is-open {
        display: flex;
    }

    .nav-list li {
        width: 100%;
    }

    .nav-list a {
        display: block;
        width: 100%;
        padding: 10px 12px;
        border-radius: var(--radius-sm);
    }

    .nav-list a::after {
        display: none;
    }
}

@media (max-width: 430px) {
    .menu-toggle {
        width: 30px;
        height: 30px;
    }

    .menu-toggle span {
        width: 17px;
    }
}

/* RESPONSIVE NAVIGATION FINAL FIX */

.nav-right {
    margin-left: auto;
    flex-shrink: 1;
    min-width: 0;
}

.nav-list {
    flex-shrink: 1;
    min-width: 0;
    justify-content: flex-end;
}

@media (max-width: 1100px) and (min-width: 801px) {
    .navbar {
        gap: 16px;
    }

    .nav-right {
        gap: 12px;
        margin-left: auto;
        overflow: visible;
    }

    .nav-list {
        display: flex;
        align-items: center;
        justify-content: flex-end;
        gap: 12px;
        overflow-x: auto;
        overflow-y: hidden;
        white-space: nowrap;
        scrollbar-width: none;
    }

    .nav-list::-webkit-scrollbar {
        display: none;
    }

    .nav-list a {
        font-size: 12px;
    }

    .theme-switcher {
        flex-shrink: 0;
    }
}

@media (max-width: 800px) {
    .nav-right {
        position: relative;
        margin-left: auto;
        flex: 0 1 auto;
        width: auto;
        overflow: visible;
        gap: 6px;
    }

    .menu-toggle {
        display: inline-flex;
        position: relative;
        z-index: 1002;
        flex-shrink: 0;
    }

    .nav-list {
        position: absolute;
        top: calc(100% + 8px);
        right: 0;
        z-index: 1001;
        display: none;
        flex: none;
        width: min(220px, calc(100vw - 32px));
        max-height: calc(100vh - var(--header-height) - 24px);
        flex-direction: column;
        align-items: stretch;
        justify-content: flex-start;
        gap: 2px;
        padding: 8px;
        overflow-x: hidden;
        overflow-y: auto;
        background: var(--surface);
        border: 1px solid var(--border);
        border-radius: var(--radius-md);
        box-shadow: var(--shadow-card);
    }

    .nav-list.is-open {
        display: flex;
    }

    .nav-list li {
        width: 100%;
    }

    .nav-list a {
        display: block;
        width: 100%;
        padding: 10px 12px;
        font-size: 13px;
        border-radius: var(--radius-sm);
    }

    .nav-list a::after {
        display: none;
    }

    .theme-switcher {
        flex-shrink: 0;
    }
}

@media (max-width: 600px) {
    .nav-right {
        gap: 4px;
    }

    .menu-toggle {
        width: 32px;
        height: 32px;
    }
}

@media (max-width: 430px) {
    .nav-right {
        gap: 2px;
    }

    .menu-toggle {
        width: 30px;
        height: 30px;
    }

    .hero-buttons {
        display: flex;
        flex-direction: column;
        width: 100%;
        gap: 10px;
    }

    .hero-buttons .buttons {
        width: 100%;
        max-width: 100%;
        justify-content: center;
    }
}
/* CERTIFICATES: extra fields (credential id, skills) */

.cert-id {
    margin-bottom: 12px;
    font-size: 11px;
    letter-spacing: 0.02em;
    color: var(--text-tertiary);
    overflow-wrap: anywhere;
    transition: color 0.4s var(--ease-apple);
}
.cert-id:empty {
    display: none;
}

.cert-skills {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    margin-bottom: 18px;
}
.cert-skills:empty {
    display: none;
}
.cert-skills li {
    padding: 3px 8px;
    font-size: 11px;
    color: var(--text-tertiary);
    background: var(--background-light);
    border-radius: 999px;
    white-space: nowrap;
    transition:
        background-color 0.25s var(--ease-apple),
        color 0.25s var(--ease-apple);
}
.cert-showcase:hover .cert-skills li {
    color: var(--text-secondary);
}

/* When the certificate image is missing, script.js adds this class */
.cert-main.no-image {
    grid-template-columns: 1fr;
}
.cert-main.no-image .cert-image-wrap {
    display: none;
}
/* Theme icon alignment fix */
.theme-switcher {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  height: 100%;
}

.theme-icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  padding: 0;
  line-height: 1;
}

.theme-icon-button .theme-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 0;
}

.theme-icon-button .theme-icon svg {
  display: block;
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}