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

:root {
    --bg: #f6f6f3;
    --surface: #ffffff;
    --surface-soft: #fbfbf9;
    --text: #000000;
    --text-soft: #2f2f2f;
    --text-muted: #4f4f4f;
    --border: #e5e5e5;
    --border-soft: #e1e1e1;
    --hover: #f4f4ef;
    --hover-border: #cfcfcf;
    --line: #d9d9d9;
    --toggle-hover: #eeeeee;
}

html[data-theme='dark'] {
    --bg: #000000;
    --surface: #1a1d21;
    --surface-soft: #20252a;
    --text: #f4f6f8;
    --text-soft: #d5dae0;
    --text-muted: #b2bac4;
    --border: #2d353f;
    --border-soft: #35404b;
    --hover: #26303a;
    --hover-border: #475767;
    --line: #35404b;
    --toggle-hover: #2a2a2a;
}

body {
    font-family: 'Geist', sans-serif;
    background: var(--bg);
    color: var(--text);
    padding: 1.1rem 1.1rem 2rem;
    line-height: 1.5;
    transition: background-color 200ms ease, color 200ms ease;
}

.page-wrap {
    width: 100%;
    max-width: 820px;
    margin: 0 auto;
}

.page-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.8rem;
}

.back-home {
    display: inline-flex;
    align-items: center;
    gap: 0.42rem;
    text-decoration: none;
    color: var(--text-soft);
    font-size: 0.88rem;
    line-height: 1;
    margin-top: 0.25rem;
    margin-bottom: 1rem;
    transition: color 180ms ease, transform 180ms ease;
}

.back-home-arrow {
    display: inline-block;
    transition: transform 180ms ease;
}

.back-home-arrow svg {
    width: 0.98rem;
    height: 0.98rem;
    stroke: currentColor;
    stroke-width: 2;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.back-home:hover {
    color: var(--text);
    transform: translateX(-2px);
}

.back-home:hover .back-home-arrow {
    transform: translateX(-3px);
}

.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: var(--surface);
    color: var(--text);
    border-radius: 50%;
    width: 2.1rem;
    height: 2.1rem;
    padding: 0;
    margin: 0;
    cursor: pointer;
    transition: background-color 0.6s cubic-bezier(0.4, 0, 0.2, 1), transform 0.3s ease;
    touch-action: manipulation;
}

@media (hover: hover) {
    .theme-toggle:hover {
        background: var(--toggle-hover);
        transform: translateY(-1px);
    }
}

.theme-toggle-icon {
    width: 1rem;
    height: 1rem;
    display: inline-block;
    position: relative;
}

.theme-toggle-icon svg {
    width: 100%;
    height: 100%;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
    position: absolute;
    top: 0;
    left: 0;
    transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1), transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.theme-icon-sun {
    opacity: 1;
    transform: rotate(0deg);
}

.theme-icon-moon {
    opacity: 0;
    transform: rotate(-90deg);
}

html[data-theme='dark'] .theme-icon-sun {
    opacity: 0;
    transform: rotate(90deg);
}

html[data-theme='dark'] .theme-icon-moon {
    opacity: 1;
    transform: rotate(0deg);
}

.certs-page-title {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text);
}

.certs-page-subtitle {
    margin-top: 0.28rem;
    font-size: 0.86rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.cert-filters {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1.25rem;
    flex-wrap: wrap;
}

.cert-filter-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.38rem 0.75rem;
    border-radius: 999px;
    background: var(--surface);
    border: 1px solid var(--border-soft);
    color: var(--text-muted);
    font-family: 'Geist', sans-serif;
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease, transform 160ms ease;
    touch-action: manipulation;
}

.cert-filter-btn:hover {
    background: var(--hover);
    border-color: var(--hover-border);
    color: var(--text);
    transform: translateY(-1px);
}

.cert-filter-btn.is-active {
    background: var(--text);
    border-color: var(--text);
    color: var(--bg);
}

.cert-filter-btn .filter-count {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.72rem;
    opacity: 0.8;
}

.cert-category-section {
    margin-top: 2rem;
    transition: opacity 200ms ease;
}

.cert-category-head {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 0.85rem;
    padding-bottom: 0.4rem;
    border-bottom: 1px solid var(--border-soft);
}

.cert-category-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.01em;
    margin: 0;
}

.cert-category-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--text-muted);
    background: var(--surface-soft);
    border: 1px solid var(--border-soft);
    border-radius: 999px;
    padding: 0.15rem 0.52rem;
    line-height: 1;
}

.certs-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.85rem;
}

@media (max-width: 700px) {
    .certs-grid {
        grid-template-columns: 1fr;
    }
}

.cert-item {
    border: 1px solid var(--border-soft);
    background: var(--surface-soft);
    border-radius: 0.6rem;
    padding: 0.85rem 1rem;
    transition: border-color 180ms ease, background-color 180ms ease, transform 180ms ease, box-shadow 180ms ease;
    text-decoration: none;
    color: inherit;
    display: flex;
    align-items: center;
    gap: 0.85rem;
    cursor: pointer;
}

.cert-item:hover {
    border-color: var(--hover-border);
    background: var(--hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04);
}

html[data-theme='dark'] .cert-item:hover {
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.22);
}

.cert-logo-wrap {
    width: 2.85rem;
    height: 2.85rem;
    min-width: 2.85rem;
    border-radius: 0.45rem;
    background: #ffffff;
    border: 1px solid var(--border-soft);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 0.25rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    flex-shrink: 0;
    transition: transform 180ms ease, border-color 180ms ease;
}

.cert-item:hover .cert-logo-wrap {
    transform: scale(1.05);
    border-color: var(--hover-border);
}

.cert-logo {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
}

.cert-info {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.cert-title {
    margin: 0;
    font-size: 0.88rem;
    font-weight: 700;
    color: var(--text);
    line-height: 1.35;
}

.cert-meta {
    margin: 0.25rem 0 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.74rem;
    color: var(--text-muted);
    line-height: 1.25;
}

.cert-arrow {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    opacity: 0.5;
    flex-shrink: 0;
    margin-left: 0.2rem;
    transition: transform 180ms ease, opacity 180ms ease, color 180ms ease;
}

.cert-item:hover .cert-arrow {
    opacity: 1;
    color: var(--text);
    transform: translateX(3px);
}

/* Modal styles */
.cert-modal {
    position: fixed;
    inset: 0;
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.25rem;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 220ms ease, visibility 220ms ease;
}

.cert-modal.is-active {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.cert-modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.cert-modal-dialog {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 820px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0.65rem;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: 0 12px 36px rgba(0, 0, 0, 0.35);
    max-height: 90vh;
}

.cert-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.85rem 1.1rem;
    border-bottom: 1px solid var(--border-soft);
    background: var(--surface);
}

.cert-modal-title {
    margin: 0;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text);
}

.cert-modal-meta {
    margin: 0.2rem 0 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.74rem;
    color: var(--text-muted);
}

.cert-modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.35rem;
    border-radius: 0.35rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: color 150ms ease, background-color 150ms ease;
}

.cert-modal-close:hover {
    color: var(--text);
    background: var(--hover);
}

.cert-modal-body {
    position: relative;
    padding: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: auto;
    background: var(--surface-soft);
    min-height: 250px;
}

.cert-modal-loader {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 180ms ease, visibility 180ms ease;
    z-index: 2;
}

.cert-modal-body.is-loading .cert-modal-loader {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.cert-spinner {
    width: 38px;
    height: 38px;
    border: 3px solid var(--border);
    border-top-color: var(--text);
    border-radius: 50%;
    animation: cert-spinner-spin 0.75s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

@keyframes cert-spinner-spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

.cert-modal-img {
    max-width: 100%;
    max-height: 70vh;
    object-fit: contain;
    border-radius: 0.35rem;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
    opacity: 0;
    transform: scale(0.985);
    transition: opacity 220ms ease, transform 220ms ease;
}

.cert-modal-img.is-loaded {
    opacity: 1;
    transform: scale(1);
}

.cert-modal-body.is-loading .cert-modal-img {
    opacity: 0;
    pointer-events: none;
}

/* Freeze transitions while theme overlay is active */
html.theme-no-transition,
html.theme-no-transition * {
    transition: none !important;
    animation: none !important;
}

/* Kill default cross-fade */
::view-transition-old(root),
::view-transition-new(root) {
    animation: none;
    mix-blend-mode: normal;
}

/* Suppress all element transitions during the sweep so nothing bleeds */
html[data-theme-sweep="on"] *,
html[data-theme-sweep="on"] *::before,
html[data-theme-sweep="on"] *::after {
    transition: none !important;
    animation: none !important;
}

/* New theme expands in as a circle from the toggle button */
html[data-theme-sweep="on"]::view-transition-new(root) {
    clip-path: circle(0px at var(--sweep-x, 50%) var(--sweep-y, 50%));
    animation: theme-sweep 800ms cubic-bezier(0.4, 0, 0.2, 1) forwards;
    z-index: 9999;
}

html[data-theme-sweep="on"]::view-transition-old(root) {
    z-index: 1;
    animation: none;
}

@keyframes theme-sweep {
    to {
        clip-path: circle(var(--sweep-r, 100vmax) at var(--sweep-x, 50%) var(--sweep-y, 50%));
    }
}