:root {
    --bg: #08111f;
    --bg-strong: #0d1829;
    --paper-strong: rgba(17, 28, 45, 0.95);
    --ink: #f5f7fb;
    --ink-soft: #9eabc0;
    --line: rgba(176, 196, 222, 0.16);
    --accent: #7bb0ff;
    --accent-strong: #497ee4;
    --accent-soft: rgba(123, 176, 255, 0.16);
    --success: #39b980;
    --warning: #f2a65a;
    --danger: #ff6b81;
    --shadow: 0 24px 72px rgba(0, 0, 0, 0.42);
    --radius-xl: 28px;
    --radius-lg: 18px;
}

*, *::before, *::after {
    box-sizing: border-box;
}

html {
    font-size: 16px;
}

body {
    margin: 0;
    min-height: 100vh;
    min-height: 100svh;
    color: var(--ink);
    font-family: "Space Grotesk", "Avenir Next", "Segoe UI", sans-serif;
    background:
        radial-gradient(circle at top left, rgba(123, 176, 255, 0.16), transparent 30%),
        radial-gradient(circle at right center, rgba(255, 255, 255, 0.06), transparent 24%),
        radial-gradient(circle at bottom left, rgba(80, 130, 220, 0.12), transparent 28%),
        linear-gradient(180deg, var(--bg), var(--bg-strong));
}

body::before,
body::after {
    content: "";
    position: fixed;
    inset: auto;
    border-radius: 999px;
    pointer-events: none;
    z-index: 0;
    filter: blur(12px);
}

body::before {
    width: 18rem;
    height: 18rem;
    top: -4rem;
    right: -4rem;
    background: rgba(123, 176, 255, 0.12);
}

body::after {
    width: 15rem;
    height: 15rem;
    bottom: -4rem;
    left: -4rem;
    background: rgba(255, 255, 255, 0.06);
}

a {
    color: inherit;
}

button,
input,
textarea {
    font: inherit;
}

.page-shell {
    position: relative;
    z-index: 1;
    width: min(100%, 1100px);
    margin: 0 auto;
    padding: 20px 20px 32px;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 20px;
    flex-wrap: nowrap;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    min-width: 0;
    text-decoration: none;
    flex: 1 1 auto;
}

.brand > div {
    min-width: 0;
}

.brand img {
    display: block;
    border-radius: 12px;
    box-shadow: 0 14px 32px rgba(0, 0, 0, 0.28);
}

.brand strong,
.topbar-links a,
.eyebrow,
label,
.primary-btn,
.secondary-btn,
summary,
.step-index {
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
}

.brand strong {
    display: block;
    font-size: 1rem;
    letter-spacing: 0.02em;
}

.brand span {
    display: block;
    color: var(--ink-soft);
    font-size: 0.88rem;
    line-height: 1.35;
}

.topbar-links {
    display: flex;
    flex-wrap: nowrap;
    justify-content: flex-end;
    gap: 12px;
    flex: 0 0 auto;
}

.topbar-links a {
    text-decoration: none;
    font-size: 0.92rem;
    color: var(--ink-soft);
}

.topbar-links a:hover {
    color: var(--ink);
}

.layout-single {
    display: grid;
    align-items: start;
    gap: 18px;
}

.quick-start {
    display: grid;
    gap: 14px;
    padding: 18px 22px;
    border: 1px solid var(--line);
    border-radius: 22px;
    background: rgba(17, 28, 45, 0.7);
}

.quick-start-head {
    display: grid;
    gap: 10px;
}

.quick-start-head .eyebrow {
    margin: 0;
}

.quick-start-head h2 {
    margin: 0;
    font-size: clamp(1.05rem, 1.8vw, 1.35rem);
    line-height: 1.2;
    letter-spacing: -0.02em;
    text-wrap: balance;
}

.quick-start-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
    margin: 0;
    padding: 0;
    list-style: none;
    counter-reset: quick-start-step;
}

.quick-start-list li {
    min-width: 0;
    padding: 12px 14px 12px 42px;
    border: 1px solid rgba(123, 176, 255, 0.14);
    border-radius: 18px;
    background: rgba(6, 14, 26, 0.48);
    color: var(--ink-soft);
    line-height: 1.45;
    position: relative;
}

.quick-start-list li::before {
    counter-increment: quick-start-step;
    content: counter(quick-start-step);
    position: absolute;
    left: 14px;
    top: 12px;
    width: 18px;
    height: 18px;
    border-radius: 999px;
    display: grid;
    place-items: center;
    background: var(--accent-soft);
    color: var(--accent);
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 0.72rem;
    font-weight: 700;
}

.quick-start-note {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.92rem;
    line-height: 1.4;
}

.panel {
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.03));
    box-shadow: var(--shadow);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
}

.panel::before {
    content: "";
    position: absolute;
    inset: auto auto 0 -10%;
    width: 240px;
    height: 240px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(123, 176, 255, 0.16), transparent 72%);
    pointer-events: none;
}

.panel::after {
    content: "";
    position: absolute;
    inset: -14% -8% auto auto;
    width: 220px;
    height: 220px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.08), transparent 72%);
    pointer-events: none;
}

.panel-primary {
    padding: 28px;
}

.panel-intro {
    margin-bottom: 20px;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    width: fit-content;
    margin: 0 0 16px;
    padding: 8px 14px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.03);
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-size: 0.72rem;
    font-weight: 700;
}

.panel-intro h1,
.decryption-copy h2 {
    margin: 0;
    font-size: clamp(1.9rem, 3vw, 3.5rem);
    line-height: 0.98;
    letter-spacing: -0.04em;
    text-wrap: balance;
}

.lede {
    margin: 10px 0 0;
    max-width: 42rem;
    color: var(--ink-soft);
    font-size: 1rem;
    line-height: 1.65;
}

.footer-version span {
    position: relative;
    display: block;
    margin-bottom: 8px;
    color: var(--ink-soft);
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 0.76rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.stack {
    display: grid;
    gap: 16px;
}

.stack.stack-decryption-active > :not(.decryption-card) {
    display: none;
}

.field-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.field-group {
    display: grid;
    gap: 8px;
}

.field-group-main {
    gap: 10px;
}

label {
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

textarea,
input[type="text"],
input[type="password"] {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: rgba(6, 14, 26, 0.66);
    color: var(--ink);
    padding: 14px 16px;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
    transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

textarea {
    min-height: clamp(196px, 36vh, 330px);
    resize: vertical;
    line-height: 1.45;
}

input:focus,
textarea:focus {
    outline: none;
    border-color: rgba(123, 176, 255, 0.55);
    box-shadow: 0 0 0 4px rgba(123, 176, 255, 0.14);
    background: rgba(10, 20, 36, 0.92);
}

textarea[readonly] {
    background: rgba(8, 16, 28, 0.9);
}

textarea.textarea-locked {
    cursor: progress;
    opacity: 0.86;
}

textarea.receive-state-info,
textarea.receive-state-error {
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 0.98rem;
    line-height: 1.5;
}

textarea.receive-state-info {
    color: var(--ink-soft);
}

textarea.receive-state-error {
    color: var(--danger);
    background: rgba(48, 12, 20, 0.7);
    border-color: rgba(255, 107, 129, 0.28);
}

.field-note {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.9rem;
    line-height: 1.45;
}

.action-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
}

.primary-btn,
.secondary-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    min-height: 52px;
    padding: 0 18px;
    border-radius: 999px;
    border: 1px solid transparent;
    text-decoration: none;
    font-size: 0.97rem;
    font-weight: 700;
    letter-spacing: 0.01em;
    cursor: pointer;
    transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}

.primary-btn:hover,
.secondary-btn:hover {
    transform: translateY(-1px);
}

.primary-btn {
    color: #f7fbff;
    background: linear-gradient(135deg, var(--accent), var(--accent-strong));
    box-shadow: 0 14px 30px rgba(73, 126, 228, 0.28);
}

.primary-btn.is-busy {
    background: linear-gradient(135deg, #46638f, #33507d);
}

.primary-btn.is-ready {
    background: linear-gradient(135deg, #3362c3, #194fba);
}

.primary-btn.is-success {
    background: linear-gradient(135deg, #238857, #176a42);
    box-shadow: 0 14px 30px rgba(31, 143, 78, 0.22);
}

.secondary-btn {
    color: var(--ink);
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--line);
}

.primary-btn:disabled,
.secondary-btn:disabled {
    cursor: not-allowed;
    transform: none;
    opacity: 0.55;
    box-shadow: none;
}

.primary-btn-link {
    min-width: fit-content;
}

.icon {
    width: 20px;
    height: 20px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.generated-output,
.qr-output {
    display: grid;
    gap: 8px;
}

.generated-output[hidden],
.qr-output[hidden],
.decryption-card:not(.is-visible),
[hidden] {
    display: none !important;
}

.generated-output input {
    font-family: "Courier New", monospace;
    font-size: 0.92rem;
}

.info-section {
    display: grid;
    gap: 18px;
    content-visibility: auto;
    contain-intrinsic-size: 900px;
}

.info-hero {
    max-width: 760px;
}

.info-hero h2 {
    margin: 0 0 16px;
    font-size: clamp(2rem, 4vw, 3.8rem);
    line-height: 1.02;
    letter-spacing: -0.04em;
}

.info-hero p {
    margin: 0;
    color: var(--ink-soft);
    font-size: 1.04rem;
    line-height: 1.7;
}

.feature-grid,
.step-grid {
    display: grid;
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 18px;
}

.feature-card,
.step-card,
.info-panel {
    position: relative;
    overflow: hidden;
    padding: 26px;
    border-radius: 22px;
    border: 1px solid var(--line);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.03));
    box-shadow: var(--shadow);
}

.feature-card::before,
.step-card::before,
.info-panel::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(123, 176, 255, 0.08), transparent 45%);
    pointer-events: none;
}

.feature-card {
    grid-column: span 4;
    min-height: 230px;
}

.feature-card-wide {
    grid-column: span 6;
    min-height: 0;
}

.feature-icon {
    width: 48px;
    height: 48px;
    display: inline-grid;
    place-items: center;
    margin-bottom: 18px;
    border-radius: 14px;
    background: var(--accent-soft);
    border: 1px solid rgba(123, 176, 255, 0.18);
}

.feature-icon svg {
    width: 22px;
    height: 22px;
    stroke: var(--accent);
}

.feature-card h3,
.step-card h3,
.info-panel h3 {
    position: relative;
    margin: 0 0 10px;
    font-size: 1.1rem;
    line-height: 1.25;
    letter-spacing: -0.02em;
}

.feature-card p,
.step-card p,
.info-panel p,
.info-panel span,
.info-list {
    position: relative;
}

.feature-card p,
.step-card p,
.info-panel p,
.info-panel span {
    margin: 0;
    max-width: 46ch;
    color: var(--ink-soft);
    line-height: 1.7;
}

.info-band {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.8fr);
    gap: 18px;
}

.info-list {
    display: grid;
    gap: 12px;
    margin: 0;
    padding: 0;
    list-style: none;
    color: var(--ink-soft);
}

.info-list li {
    position: relative;
    padding-left: 20px;
    line-height: 1.6;
}

.info-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.68em;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 0 6px rgba(123, 176, 255, 0.1);
}

.info-panel-stat {
    display: grid;
    gap: 10px;
    align-content: start;
}

.info-panel-stat strong {
    position: relative;
    font-size: clamp(2rem, 4vw, 3rem);
    line-height: 1;
    letter-spacing: -0.05em;
}

.step-card {
    grid-column: span 4;
}

.step-index {
    position: relative;
    display: inline-block;
    margin-bottom: 18px;
    color: var(--accent);
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.18em;
}

.info-panel-inline {
    padding-top: 24px;
    padding-bottom: 24px;
}

.site-footer {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    margin-top: 18px;
    padding: 14px 2px 4px;
    color: var(--ink-soft);
    content-visibility: auto;
    contain-intrinsic-size: 180px;
}

.footer-block strong {
    display: block;
    margin-bottom: 4px;
    color: var(--ink);
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 0.92rem;
}

.footer-block p {
    margin: 0;
    font-size: 0.9rem;
    line-height: 1.4;
}

.footer-version {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 0;
}

.footer-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 12px;
    margin-top: 14px;
}

.footer-version span {
    margin: 0;
}

.footer-version code {
    padding: 7px 10px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.04);
    color: var(--accent);
    font-size: 0.82rem;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 10px 14px;
}

.footer-links a {
    color: var(--ink-soft);
    text-decoration: none;
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: var(--ink);
}

.qr-card {
    display: grid;
    justify-items: center;
    gap: 12px;
    padding: 18px;
    border: 1px solid var(--line);
    border-radius: 24px;
    background: rgba(255, 255, 255, 0.04);
}

#qrCode {
    width: min(100%, 220px);
}

#qrCode canvas,
#qrCode img {
    display: block;
    width: 100% !important;
    height: auto !important;
    border-radius: 16px;
}

.limit-indicator {
    display: grid;
    gap: 8px;
    margin-top: 2px;
}

.limit-indicator-bar {
    height: 8px;
    overflow: hidden;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.08);
}

.limit-indicator-fill {
    display: block;
    width: 0;
    height: 100%;
    border-radius: inherit;
    background: var(--warning);
    transition: width 0.18s ease;
}

.limit-indicator-label {
    color: var(--warning);
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 0.88rem;
    font-weight: 700;
}

.limit-indicator.danger .limit-indicator-fill {
    background: var(--danger);
}

.limit-indicator.danger .limit-indicator-label {
    color: var(--danger);
}

.decryption-card {
    display: grid;
    gap: 14px;
    padding: 18px;
    border: 1px solid rgba(123, 176, 255, 0.22);
    border-radius: 22px;
    background: rgba(123, 176, 255, 0.08);
}

.decryption-copy h2 {
    font-size: clamp(1.3rem, 1.6vw, 1.7rem);
    line-height: 1.05;
}

.inline-action {
    display: flex;
    align-items: end;
}

.app-popup {
    width: min(100% - 24px, 480px);
    padding: 0;
    border: 0;
    background: transparent;
    color: var(--ink);
}

.app-popup::backdrop {
    background: rgba(3, 9, 17, 0.46);
    backdrop-filter: blur(6px);
}

.app-popup-card {
    display: grid;
    gap: 16px;
    margin: 0;
    padding: 20px;
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 24px;
    background: var(--paper-strong);
    box-shadow: var(--shadow);
}

.app-popup-head {
    display: block;
}

.app-popup-head h2 {
    margin: 0;
    font-size: 1.35rem;
    line-height: 1.1;
    letter-spacing: -0.02em;
}

.app-popup-body {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.98rem;
    line-height: 1.5;
}

.app-popup-actions {
    display: flex;
    justify-content: flex-end;
}

@media (max-width: 900px) {
    .page-shell {
        padding: 16px;
    }

    .quick-start-list {
        grid-template-columns: 1fr;
    }

    .panel-primary {
        padding: 22px;
    }

    .field-grid {
        grid-template-columns: 1fr;
    }

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

    .feature-card,
    .feature-card-wide,
    .step-card {
        grid-column: auto;
    }

    .info-band {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 680px) {
    body {
        min-height: 100dvh;
        background: linear-gradient(180deg, var(--bg), var(--bg-strong));
    }

    body::before,
    body::after {
        display: none;
    }

    .page-shell {
        padding: 12px;
    }

    .topbar {
        align-items: center;
        margin-bottom: 12px;
        gap: 10px;
    }

    .topbar-links {
        justify-content: flex-end;
        gap: 10px;
    }

    .panel-primary {
        padding: 16px;
        border-radius: 22px;
    }

    .quick-start {
        gap: 12px;
        padding: 14px 16px;
        border-radius: 20px;
    }

    .quick-start-head {
        gap: 8px;
    }

    .quick-start-head h2 {
        font-size: 1rem;
        line-height: 1.25;
    }

    .quick-start-list {
        gap: 8px;
    }

    .quick-start-list li {
        padding: 10px 12px 10px 40px;
        border-radius: 16px;
        font-size: 0.94rem;
        line-height: 1.35;
    }

    .quick-start-list li::before {
        top: 10px;
        left: 12px;
    }

    .quick-start-note {
        font-size: 0.88rem;
        line-height: 1.35;
    }

    .panel {
        background: rgba(17, 28, 45, 0.92);
        box-shadow: 0 14px 30px rgba(0, 0, 0, 0.26);
        backdrop-filter: none;
        -webkit-backdrop-filter: none;
    }

    .panel::before,
    .panel::after,
    .feature-card::before,
    .step-card::before,
    .info-panel::before {
        display: none;
    }

    .panel-intro {
        margin-bottom: 14px;
    }

    .panel-intro h1 {
        font-size: 1.7rem;
    }

    .lede {
        font-size: 0.94rem;
        line-height: 1.4;
    }

    .action-row {
        flex-direction: column;
        align-items: stretch;
    }

    .primary-btn,
    .secondary-btn,
    .primary-btn-link {
        width: 100%;
    }

    textarea {
        min-height: min(34dvh, 240px);
    }

    .brand span,
    .lede {
        max-width: 32ch;
    }

    .info-hero h2 {
        font-size: 1.8rem;
    }

    .info-hero p {
        font-size: 0.98rem;
    }

    .feature-grid,
    .step-grid {
        grid-template-columns: 1fr;
    }

    .feature-card,
    .step-card,
    .info-panel {
        min-height: 0;
        box-shadow: 0 12px 24px rgba(0, 0, 0, 0.2);
    }

    .feature-card,
    .step-card,
    .info-panel,
    .qr-card,
    .app-popup-card {
        background: rgba(17, 28, 45, 0.92);
    }

    .site-footer {
        flex-direction: column;
        gap: 10px;
        margin-top: 14px;
    }

    .footer-links {
        justify-content: flex-start;
    }

    .app-popup::backdrop {
        backdrop-filter: none;
    }
}

@media (max-width: 480px) {
    .topbar {
        gap: 8px;
    }

    .topbar-links a {
        font-size: 0.82rem;
    }

    .topbar-links {
        gap: 8px;
    }

    .brand {
        gap: 10px;
    }

    .brand strong {
        font-size: 0.95rem;
    }

    .brand span {
        font-size: 0.82rem;
    }

    .panel-intro h1 {
        font-size: 1.5rem;
    }

    .lede {
        font-size: 0.9rem;
    }

    .footer-version {
        flex-direction: column;
        align-items: flex-start;
        gap: 6px;
    }

    .footer-meta {
        gap: 8px;
    }

    .feature-card,
    .step-card,
    .info-panel {
        padding: 22px 18px;
    }

    .brand img {
        width: 36px;
        height: 36px;
    }
}

@media (max-width: 680px) and (max-height: 760px) {
    .page-send .lede {
        display: none;
    }

    .page-send textarea {
        min-height: min(28dvh, 180px);
    }

    .page-send .panel-intro {
        margin-bottom: 10px;
    }
}