:root {
    --bg: #eef3fb;
    --surface: #ffffff;
    --surface-soft: #dce8fb;
    --text: #172033;
    --muted: #667085;
    --primary: #315fae;
    --primary-dark: #244a8d;
    --primary-soft: #cbdcf6;
    --accent: #6241b5;
    --border: #cfdaea;
    --success: #2f855a;
    --shadow: 0 18px 50px rgba(35, 52, 88, 0.14);
    --radius-lg: 28px;
    --radius-md: 20px;
    --radius-sm: 14px;
    --container: 1180px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

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

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

.container {
    width: min(calc(100% - 40px), var(--container));
    margin: 0 auto;
}

.narrow {
    max-width: 820px;
}

.hero {
    position: relative;
    overflow: hidden;
    min-height: 740px;
    background:
        radial-gradient(circle at 15% 20%, rgba(98, 65, 181, 0.17), transparent 34%),
        radial-gradient(circle at 80% 25%, rgba(49, 95, 174, 0.28), transparent 31%),
        linear-gradient(145deg, #e4ecf9 0%, #d8e4f7 52%, #e8e3f7 100%);
}

.hero::after {
    content: "";
    position: absolute;
    inset: auto -180px -220px auto;
    width: 520px;
    height: 520px;
    border-radius: 50%;
    background: rgba(49, 95, 174, 0.11);
}

.nav {
    position: relative;
    z-index: 3;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 92px;
}

.brand {
    font-size: 1.38rem;
    font-weight: 850;
    letter-spacing: -0.035em;
}

.nav-link {
    font-size: 0.94rem;
    font-weight: 800;
    color: var(--primary);
}

.nav-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 0 17px;
    border-radius: 12px;
    background: var(--primary);
    color: #ffffff;
    box-shadow: 0 9px 22px rgba(49, 95, 174, 0.24);
    transition: transform 0.2s ease, background 0.2s ease;
}

.nav-button:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.hero-content {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.7fr);
    gap: 70px;
    align-items: center;
    padding: 58px 0 96px;
}

.hero-copy {
    max-width: 690px;
}

.eyebrow,
.section-label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
    color: var(--primary);
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.11em;
    text-transform: uppercase;
}

.hero h1 {
    margin: 0;
    max-width: 720px;
    font-size: clamp(2.7rem, 5vw, 4.75rem);
    line-height: 1.02;
    letter-spacing: -0.05em;
}

.hero-description {
    max-width: 650px;
    margin: 28px 0 0;
    font-size: 1.14rem;
    color: #59657a;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 32px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 50px;
    padding: 0 20px;
    border-radius: 13px;
    font-weight: 800;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.button:hover {
    transform: translateY(-2px);
}

.button-primary {
    background: var(--primary);
    color: #ffffff;
    box-shadow: 0 12px 26px rgba(49, 95, 174, 0.28);
}

.button-primary:hover {
    background: var(--primary-dark);
}

.button-secondary {
    background: rgba(255, 255, 255, 0.82);
    color: var(--text);
    border: 1px solid rgba(195, 208, 228, 0.95);
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 28px;
}

.hero-tags span {
    padding: 7px 11px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.78);
    border: 1px solid rgba(193, 207, 229, 0.9);
    color: #46546d;
    font-size: 0.82rem;
    font-weight: 700;
}

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

.phone-frame {
    position: relative;
    width: min(340px, 100%);
    padding: 13px;
    border-radius: 42px;
    background: #111827;
    box-shadow: 0 35px 80px rgba(34, 50, 84, 0.3);
    transform: none;
}

.phone-frame::before {
    content: "";
    position: absolute;
    top: 10px;
    left: 50%;
    width: 92px;
    height: 20px;
    transform: translateX(-50%);
    border-radius: 999px;
    background: #0b1020;
    z-index: 2;
}

.phone-frame img {
    width: 100%;
    border-radius: 31px;
}

.section {
    padding: 104px 0;
}

.intro {
    background: var(--surface);
}

.intro h2,
.section-heading h2,
.tech-layout h2,
.privacy-card h2,
.final-cta h2 {
    margin: 0;
    font-size: clamp(2rem, 3.5vw, 3.2rem);
    line-height: 1.1;
    letter-spacing: -0.04em;
}

.intro p {
    margin: 22px 0 0;
    color: var(--muted);
    font-size: 1.08rem;
}

.features-section {
    background: #e7eef8;
}

.section-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 44px;
    margin-bottom: 42px;
}

.section-heading > div {
    min-width: 0;
    flex: 1;
}

.section-heading h2 {
    max-width: 650px;
}

.section-heading > p {
    max-width: 430px;
    margin: 0;
    color: var(--muted);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.feature-card {
    min-height: 250px;
    padding: 28px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: 0 12px 32px rgba(36, 52, 84, 0.06);
}

.feature-number {
    display: inline-block;
    color: var(--primary);
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.1em;
}

.feature-card h3 {
    margin: 34px 0 8px;
    font-size: 1.3rem;
    letter-spacing: -0.02em;
}

.feature-card p {
    margin: 0;
    color: var(--muted);
}

.showcase {
    background: var(--surface);
}

.screens-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
    align-items: stretch;
}

.screen-card,
.screen-card.featured {
    overflow: hidden;
    display: flex;
    flex-direction: column;
    background: #eef3fb;
    border: 1px solid var(--border);
    border-radius: 26px;
    transform: none;
    box-shadow: none;
}

.screen-card.featured {
    border-color: #b8cbea;
    box-shadow: 0 16px 38px rgba(49, 95, 174, 0.13);
}

.screen-card img {
    width: 100%;
    background: #dce6f5;
}

.screen-card > div {
    flex: 1;
    padding: 20px 20px 22px;
    background: #eef3fb;
}

.screen-card span {
    color: var(--primary);
    font-size: 0.75rem;
    font-weight: 800;
}

.screen-card h3 {
    margin: 4px 0;
    font-size: 1.12rem;
}

.screen-card p {
    margin: 0;
    color: var(--muted);
    font-size: 0.92rem;
}

.workflow-section {
    background: #111827;
    color: #ffffff;
}

.workflow-section .section-label {
    color: #a8c1ff;
}

.workflow {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
}

.workflow-step {
    padding: 24px;
    border: 1px solid rgba(255, 255, 255, 0.11);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.05);
}

.workflow-step span {
    color: #a8c1ff;
    font-size: 0.78rem;
    font-weight: 800;
}

.workflow-step h3 {
    margin: 34px 0 8px;
    font-size: 1.16rem;
}

.workflow-step p {
    margin: 0;
    color: #b9c3d5;
}

.tech-section {
    background: var(--surface);
}

.tech-layout {
    display: grid;
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1fr);
    gap: 80px;
    align-items: start;
}

.tech-layout > div:first-child p {
    max-width: 570px;
    margin-top: 20px;
    color: var(--muted);
}

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

.tech-list > div {
    display: flex;
    flex-direction: column;
    gap: 6px;
    min-height: 112px;
    padding: 20px;
    border: 1px solid #cbd8ea;
    border-radius: 16px;
    background: linear-gradient(145deg, #f7faff, #e8f0fb);
    box-shadow: 0 8px 24px rgba(49, 95, 174, 0.08);
}

.tech-list strong {
    color: var(--primary-dark);
    font-size: 1.04rem;
}

.tech-list span {
    color: var(--muted);
    text-align: left;
    font-size: 0.92rem;
}

.privacy-section {
    background: #dde7f5;
}

.privacy-card {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(300px, 0.85fr);
    gap: 70px;
    align-items: center;
    padding-top: 58px;
    padding-bottom: 58px;
    border: 1px solid #b8c9e5;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, #c5d7f2 0%, #d2d8f1 48%, #d6cdef 100%);
    box-shadow: 0 22px 54px rgba(49, 70, 118, 0.16);
}

.privacy-card > * {
    margin-left: 46px;
    margin-right: 46px;
}

.privacy-card p {
    color: #43516a;
    font-size: 1.05rem;
}

.final-cta {
    padding-top: 130px;
    padding-bottom: 130px;
    text-align: center;
    background:
        radial-gradient(circle at 50% 0%, rgba(49, 95, 174, 0.2), transparent 34%),
        #ffffff;
}

.final-cta p {
    max-width: 720px;
    margin: 20px auto 28px;
    color: var(--muted);
}

.author-link {
    color: var(--primary);
    font-weight: 800;
}

.author-link:hover {
    text-decoration: underline;
}

footer {
    padding: 52px 0;
    background: #111827;
    color: #c9d2e3;
}

.footer-content {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}

.footer-project {
    color: #ffffff;
    font-size: 1.02rem;
    font-weight: 800;
}

.footer-github {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: #dce5f5;
    font-size: 0.95rem;
    font-weight: 750;
    transition: color 0.2s ease;
}

.footer-github:hover {
    color: #ffffff;
}

.footer-github svg {
    width: 21px;
    height: 21px;
}

@media (max-width: 980px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-copy {
        margin: 0 auto;
    }

    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-actions,
    .hero-tags {
        justify-content: center;
    }

    .hero-phone {
        margin-top: 10px;
    }

    .features-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .screens-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .workflow {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .tech-layout,
    .privacy-card {
        grid-template-columns: 1fr;
    }

    .privacy-card {
        gap: 18px;
    }
}

@media (max-width: 680px) {
    .container {
        width: min(calc(100% - 28px), var(--container));
    }

    .nav {
        min-height: 76px;
    }

    .brand {
        font-size: 1.15rem;
    }

    .nav-button {
        min-height: 40px;
        padding: 0 13px;
        font-size: 0.84rem;
    }

    .hero {
        min-height: auto;
    }

    .hero-content {
        gap: 38px;
        padding: 46px 0 74px;
    }

    .hero h1 {
        font-size: clamp(2.45rem, 12vw, 3.8rem);
    }

    .hero-description {
        font-size: 1rem;
    }

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

    .button {
        width: 100%;
    }

    .section {
        padding: 76px 0;
    }

    .section-heading {
        display: block;
        margin-bottom: 30px;
    }

    .section-heading > p {
        margin-top: 14px;
    }

    .features-grid,
    .screens-grid,
    .workflow,
    .tech-list {
        grid-template-columns: 1fr;
    }

    .feature-card {
        min-height: auto;
    }

    .phone-frame {
        width: min(310px, 86vw);
    }

    .privacy-card {
        padding-top: 38px;
        padding-bottom: 38px;
    }

    .privacy-card > * {
        margin-left: 24px;
        margin-right: 24px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}