:root {
    color-scheme: light;
    --background: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #4a4a4a;
    --border: #d9d9d9;
    --accent: #e6e6e6;
    --font-family: "Helvetica", "Arial", sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: var(--font-family);
    background-color: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
}

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

a:hover,
a:focus {
    text-decoration: underline;
}

img {
    display: block;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.site-header {
    border-bottom: 1px solid var(--border);
    background-color: var(--background);
}

.header-inner {
    margin: 0 auto;
    max-width: 960px;
    padding: 16px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    letter-spacing: 0.4px;
}

.site-logo img {
    border: 1px solid var(--border);
    padding: 4px;
    background-color: #f9f9f9;
}

.site-nav {
    display: flex;
    gap: 16px;
    font-size: 0.95rem;
}

.nav-link {
    padding: 6px 0;
    border-bottom: 2px solid transparent;
}

.nav-link:focus,
.nav-link:hover,
.nav-link.is-active {
    border-color: var(--text-primary);
}

.nav-link:focus,
.nav-link:hover {
    text-decoration: none;
}

.main-content {
    margin: 0 auto;
    max-width: 960px;
    padding: 0 20px 80px;
}

.section {
    padding: 56px 0;
    border-bottom: 1px solid var(--border);
}

.section:last-of-type {
    border-bottom: none;
}

.section-inner {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.hero {
    position: relative;
    text-align: center;
    overflow: hidden;
    padding: 96px 0 120px;
    border-bottom: none;
    background: var(--background);
}

.hero .section-inner {
    position: relative;
    z-index: 2;
    gap: 0;
    max-width: 1024px;
    padding: 0 32px;
    align-items: center;
}

.hero-layout {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.hero-content {
    max-width: 640px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    align-items: center;
}

.hero-heading {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
    row-gap: 12px;
    justify-content: center;
}

.arrow-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 8px;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.2s ease;
    border: 1px solid var(--border);
    background-color: rgba(255, 255, 255, 0.8);
}

.arrow-link:hover,
.arrow-link:focus {
    background-color: var(--accent);
    border-color: var(--text-primary);
    transform: translateY(-1px);
    text-decoration: none;
}

@media (max-width: 768px) {
    .hero {
        padding: 80px 0 96px;
    }

    .hero-content {
        gap: 24px;
    }

    .arrow-link {
        width: 32px;
        height: 32px;
    }

    .hero-heading {
        align-items: flex-start;
    }

    .hero-figure {
        opacity: 0.45;
    }

    .hero-figure--diamond {
        top: 12%;
        left: 6%;
        width: 48px;
        height: 48px;
    }

    .hero-figure--circle {
        top: 66%;
        right: 6%;
        width: 38px;
        height: 38px;
    }

    .hero-figure--hex {
        bottom: 12%;
        left: 12%;
        width: 44px;
        height: 44px;
    }

    .hero-figure--triangle {
        top: 32%;
        right: 16%;
        width: 36px;
        height: 36px;
    }
}

.hero-title {
    margin: 0;
    font-size: clamp(3.5rem, 6vw, 4.5rem);
    letter-spacing: -0.01em;
    font-weight: 700;
}

.hero-subtitle {
    margin: 0;
    max-width: 54ch;
    color: var(--text-secondary);
    font-size: clamp(1.15rem, 2.8vw, 1.4rem);
    text-align: center;
}

.hero-principles {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    justify-content: center;
    margin-top: 8px;
}

.principles-display {
    display: inline-flex;
    align-items: center;
    justify-content: flex-start;
    gap: 10px;
    padding: 0;
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: none;
    color: var(--text-primary);
    transition:
        opacity 0.2s ease,
        color 0.25s ease,
        border-color 0.25s ease;
}

.principles-display::before {
    content: "";
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: currentColor;
    opacity: 0.55;
}

.principles-display.fade-out {
    opacity: 0;
}

.principles-display.fade-in {
    opacity: 1;
}

.principle-text {
    letter-spacing: inherit;
}

.principles-display.is-blue {
    color: #304c89;
}

.principles-display.is-green {
    color: #2f5233;
}

.principles-display.is-purple {
    color: #4b3f72;
}

.principles-display.is-orange {
    color: #8c4b25;
}

.principles-display.is-red {
    color: #7a1f1f;
}

@media (max-width: 768px) {
    .principles-display {
        font-size: 1rem;
    }
}

@media (max-width: 640px) {
    .hero-heading {
        flex-direction: row;
        align-items: center;
        flex-wrap: nowrap;
        justify-content: flex-start;
        gap: 12px;
    }

    .hero-principles {
        width: 100%;
    }

    .arrow-link {
        align-self: center;
        margin-top: 0;
    }
}

.hero-figures {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 1;
}

.hero-figure {
    position: absolute;
    display: block;
    border: 1px solid rgba(48, 76, 137, 0.18);
    background: rgba(48, 76, 137, 0.08);
    backdrop-filter: blur(2px);
    animation: heroFloat 12s ease-in-out infinite;
    opacity: 0.6;
    --hero-rotation: 0deg;
    transform: translateY(0) rotate(var(--hero-rotation));
}

.hero-figure--diamond {
    width: 60px;
    height: 60px;
    top: 16%;
    left: 12%;
    --hero-rotation: 45deg;
    animation-delay: -2s;
}

.hero-figure--circle {
    width: 46px;
    height: 46px;
    top: 62%;
    right: 14%;
    border-radius: 999px;
    animation-delay: -6s;
}

.hero-figure--hex {
    width: 54px;
    height: 54px;
    bottom: 22%;
    left: 24%;
    clip-path: polygon(25% 6%, 75% 6%, 100% 50%, 75% 94%, 25% 94%, 0% 50%);
    --hero-rotation: 12deg;
    animation-delay: -8s;
}

.hero-figure--triangle {
    width: 44px;
    height: 44px;
    top: 28%;
    right: 26%;
    clip-path: polygon(50% 0%, 0% 100%, 100% 100%);
    --hero-rotation: -8deg;
    animation-delay: -4s;
}

@keyframes heroFloat {
    0%,
    100% {
        transform: translateY(0) rotate(var(--hero-rotation));
        opacity: 0.55;
    }
    40% {
        transform: translateY(-18px) rotate(calc(var(--hero-rotation) + 6deg));
        opacity: 0.75;
    }
    70% {
        transform: translateY(12px) rotate(calc(var(--hero-rotation) - 5deg));
        opacity: 0.65;
    }
}

.text-block h3,
.text-block h4 {
    margin-top: 0;
    margin-bottom: 8px;
}

.text-block p {
    margin: 0;
    color: var(--text-primary);
}

.principles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
}

.principle-item {
    border: 1px solid var(--border);
    padding: 16px;
    background-color: #fafafa;
}

.apps-header p {
    margin: 0;
    color: var(--text-secondary);
}

.filters {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    padding: 16px;
    background-color: #fafafa;
    border: 1px solid var(--border);
    border-radius: 0;
    align-items: center;
}

.filter-field {
    display: flex;
    flex-direction: column;
    gap: 6px;
    min-width: 160px;
    flex: 1 1 220px;
}

.filter-field--search {
    flex: 2 1 320px;
}

.filter-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-secondary);
}

.filters input,
.filters select {
    width: 100%;
    padding: 10px 12px;
    border-radius: 0;
    border: 1px solid var(--border);
    background-color: #fafafa;
    font: inherit;
    color: var(--text-primary);
    transition: border-color 0.2s ease;
}

.filters input:focus,
.filters select:focus {
    outline: none;
    border-color: var(--text-primary);
}

.filters select {
    appearance: none;
    padding-right: 36px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16' fill='none' stroke='%23656D7B' stroke-width='1.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='3.5 6 8 10.5 12.5 6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    background-size: 14px;
}

.filter-actions {
    display: flex;
    align-items: flex-end;
}

.clear-button {
    padding: 10px 16px;
    border-radius: 8px;
    border: 1px solid var(--border);
    background-color: #fff;
    font: inherit;
    color: var(--text-primary);
    cursor: pointer;
    transition:
        background-color 0.2s ease,
        border-color 0.2s ease;
}

.clear-button:hover,
.clear-button:focus {
    background-color: var(--accent);
    border-color: var(--text-primary);
}

@media (max-width: 640px) {
    .filter-field,
    .filter-field--search {
        flex-basis: 100%;
    }

    .filter-actions {
        width: 100%;
        justify-content: flex-start;
    }

    .clear-button {
        width: 100%;
    }
}

.apps-grid {
    display: grid;
    gap: 16px;
    margin-top: 24px;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.apps-grid.is-empty {
    min-height: 32px;
}

.app-card {
    border: 1px solid var(--border);
    border-radius: 0;
    padding: 20px;
    background-color: #fafafa;
    display: flex;
    flex-direction: column;
    gap: 12px;
    transition: border-color 0.2s ease;
}

.app-card:hover,
.app-card:focus-within {
    border-color: rgba(48, 76, 137, 0.4);
}

.app-title-link {
    color: inherit;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.15rem;
}

.app-title-link:hover,
.app-title-link:focus {
    text-decoration: underline;
}

.app-card h3 {
    margin: 0;
}

.app-card p {
    margin: 0;
    color: var(--text-secondary);
}

.app-meta {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
}

.app-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 4px;
}

.app-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 12px;
    border-radius: 6px;
    border: 1px solid var(--border);
    background-color: #ffffff;
    font-weight: 600;
    color: var(--text-primary);
    transition:
        background-color 0.2s ease,
        border-color 0.2s ease;
}

.app-link:hover,
.app-link:focus {
    background-color: var(--accent);
    border-color: rgba(48, 76, 137, 0.45);
}

.contact-grid {
    display: grid;
    gap: 16px;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.contact-item {
    border: 1px solid var(--border);
    background-color: #fafafa;
    padding: 16px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
}

.contact-item p {
    margin: 0;
    font-weight: 600;
}

.contact-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-secondary);
}

.contact-item a {
    color: var(--text-primary);
    font-weight: 600;
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s ease, color 0.2s ease;
}

.contact-item a:hover,
.contact-item a:focus {
    border-color: var(--text-primary);
}

.contact-grid + .contact-grid {
    margin-top: 16px;
}

.contact-grid--social {
    grid-template-columns: minmax(220px, 1fr);
    max-width: 320px;
}

.donation-list {
    display: grid;
    gap: 16px;
}

.donation-card {
    border: 1px solid var(--border);
    padding: 16px;
    background-color: #fafafa;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.donation-header {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    align-items: center;
}

.donation-header h4 {
    margin: 0;
}

.donation-card code {
    word-break: break-all;
    font-family: "Courier New", Courier, monospace;
    background-color: #f0f0f0;
    padding: 8px;
    border: 1px solid var(--border);
}

.copy-button {
    padding: 8px 12px;
    border: 1px solid var(--border);
    background-color: #f5f5f5;
    font: inherit;
    color: var(--text-primary);
    cursor: pointer;
}

.copy-button:hover,
.copy-button:focus {
    background-color: var(--accent);
}

.copy-message {
    min-height: 24px;
    color: var(--text-secondary);
}

@media (max-width: 640px) {
    .header-inner {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .site-nav {
        flex-wrap: wrap;
    }

    .section {
        padding: 40px 0;
    }
}