:root {
    --billing-bg: #f4f6fb;
    --billing-surface: rgba(255, 255, 255, 0.9);
    --billing-border: rgba(86, 107, 176, 0.14);
    --billing-text: #121826;
    --billing-muted: #63708b;
    --billing-primary: #315efb;
    --billing-primary-strong: #1e45cf;
    --billing-accent: #89a8ff;
    --billing-success: #0f9f77;
    --billing-danger: #d94f45;
    --billing-shadow: 0 24px 80px rgba(24, 40, 86, 0.16);
    --billing-radius: 24px;
    --billing-radius-sm: 14px;
}

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

html,
body {
    margin: 0;
    min-height: 100%;
}

body.billing-shell {
    font-family: "Inter", "Segoe UI", sans-serif;
    background:
        radial-gradient(circle at top left, rgba(73, 110, 255, 0.18), transparent 34%),
        radial-gradient(circle at bottom right, rgba(102, 201, 255, 0.14), transparent 30%),
        linear-gradient(180deg, #f8f9fd 0%, #eff2f9 100%);
    color: var(--billing-text);
}

.billing-page {
    min-height: 100vh;
    padding: 40px 20px 72px;
}

.billing-frame {
    max-width: 1080px;
    margin: 0 auto;
}

.billing-topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    margin-bottom: 28px;
}

.billing-brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    color: var(--billing-text);
    font-size: 18px;
    font-weight: 800;
    text-decoration: none;
    letter-spacing: -0.03em;
}

.billing-brand img {
    width: 34px;
    height: 34px;
}

.billing-back {
    color: var(--billing-muted);
    font-size: 14px;
    font-weight: 600;
    text-decoration: none;
}

.billing-back:hover {
    color: var(--billing-primary);
}

.billing-card {
    position: relative;
    overflow: hidden;
    background: var(--billing-surface);
    border: 1px solid var(--billing-border);
    border-radius: var(--billing-radius);
    box-shadow: var(--billing-shadow);
    backdrop-filter: blur(18px);
}

.billing-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        linear-gradient(135deg, rgba(255, 255, 255, 0.56), rgba(255, 255, 255, 0)),
        linear-gradient(180deg, rgba(49, 94, 251, 0.04), rgba(49, 94, 251, 0));
    pointer-events: none;
}

.billing-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
}

.billing-main,
.billing-side {
    position: relative;
    z-index: 1;
    padding: 36px;
}

.billing-main {
    border-right: 1px solid rgba(86, 107, 176, 0.12);
}

.billing-kicker {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    background: rgba(49, 94, 251, 0.08);
    color: var(--billing-primary);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.billing-kicker::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: currentColor;
    opacity: 0.8;
}

.billing-title {
    margin: 18px 0 12px;
    font-size: clamp(34px, 5vw, 56px);
    line-height: 0.98;
    letter-spacing: -0.05em;
}

.billing-subtitle {
    margin: 0;
    max-width: 620px;
    color: var(--billing-muted);
    font-size: 17px;
    line-height: 1.7;
}

.billing-panel {
    margin-top: 28px;
    padding: 22px;
    border-radius: calc(var(--billing-radius) - 10px);
    background: rgba(244, 247, 255, 0.92);
    border: 1px solid rgba(86, 107, 176, 0.1);
}

.billing-context {
    display: grid;
    gap: 14px;
}

.billing-context-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 10px;
    padding-bottom: 14px;
    border-bottom: 1px dashed rgba(86, 107, 176, 0.16);
}

.billing-context-row:last-child {
    padding-bottom: 0;
    border-bottom: none;
}

.billing-context-label {
    color: var(--billing-muted);
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.billing-context-value {
    color: var(--billing-text);
    font-size: 15px;
    font-weight: 700;
}

.billing-form {
    display: grid;
    gap: 18px;
    margin-top: 24px;
}

.billing-hidden {
    display: none !important;
}

.billing-field {
    display: grid;
    gap: 9px;
}

.billing-field span {
    color: var(--billing-muted);
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.billing-field input[type="email"] {
    width: 100%;
    height: 56px;
    padding: 0 18px;
    border-radius: 16px;
    border: 1px solid rgba(86, 107, 176, 0.18);
    background: #ffffff;
    color: var(--billing-text);
    font: inherit;
    font-size: 16px;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.65);
}

.billing-field input[type="email"]:focus {
    outline: none;
    border-color: rgba(49, 94, 251, 0.48);
    box-shadow: 0 0 0 4px rgba(49, 94, 251, 0.08);
}

.billing-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
}

.billing-btn,
.billing-link-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 48px;
    padding: 0 20px;
    border-radius: 14px;
    border: 1px solid transparent;
    font: inherit;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    text-decoration: none;
    transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.billing-btn:hover,
.billing-link-btn:hover {
    transform: translateY(-1px);
}

.billing-btn.primary,
.billing-link-btn.primary {
    background: linear-gradient(135deg, var(--billing-primary), var(--billing-primary-strong));
    color: #ffffff;
    box-shadow: 0 12px 28px rgba(49, 94, 251, 0.22);
}

.billing-btn.secondary,
.billing-link-btn.secondary {
    background: rgba(49, 94, 251, 0.06);
    color: var(--billing-primary);
    border-color: rgba(49, 94, 251, 0.14);
}

.billing-btn.ghost,
.billing-link-btn.ghost {
    background: transparent;
    color: var(--billing-muted);
    border-color: rgba(86, 107, 176, 0.16);
}

.billing-status {
    min-height: 24px;
    color: var(--billing-muted);
    font-size: 14px;
    line-height: 1.6;
}

.billing-status.success {
    color: var(--billing-success);
}

.billing-status.error {
    color: var(--billing-danger);
}

.billing-session-card,
.billing-mailbox-card {
    margin-top: 24px;
    padding: 18px 18px 20px;
    border-radius: 18px;
    border: 1px solid rgba(49, 94, 251, 0.14);
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(240, 245, 255, 0.96));
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

.billing-session-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
}

.billing-session-label,
.billing-mailbox-label {
    color: var(--billing-primary);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.billing-session-email {
    margin-top: 6px;
    font-size: 20px;
    font-weight: 800;
    letter-spacing: -0.03em;
    color: var(--billing-text);
    word-break: break-word;
}

.billing-session-badge {
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(15, 159, 119, 0.12);
    color: var(--billing-success);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.billing-session-copy,
.billing-mailbox-copy {
    margin: 12px 0 0;
    color: var(--billing-muted);
    font-size: 14px;
    line-height: 1.7;
}

.billing-mailbox-title {
    margin: 8px 0 0;
    font-size: 22px;
    letter-spacing: -0.03em;
}

.billing-notes {
    display: grid;
    gap: 16px;
}

.billing-note-card {
    padding: 18px;
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.78);
    border: 1px solid rgba(86, 107, 176, 0.12);
}

.billing-note-card h3 {
    margin: 0 0 8px;
    font-size: 17px;
    letter-spacing: -0.03em;
}

.billing-note-card p,
.billing-note-card li {
    color: var(--billing-muted);
    font-size: 14px;
    line-height: 1.7;
}

.billing-note-card ul {
    margin: 0;
    padding-left: 18px;
}

.billing-side-accent {
    margin-bottom: 18px;
    color: var(--billing-primary);
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.billing-side-title {
    margin: 0 0 10px;
    font-size: 26px;
    letter-spacing: -0.04em;
}

.billing-side-copy {
    margin: 0 0 24px;
    color: var(--billing-muted);
    font-size: 15px;
    line-height: 1.7;
}

.billing-bullets {
    display: grid;
    gap: 14px;
}

.billing-bullet {
    display: grid;
    grid-template-columns: 18px 1fr;
    gap: 12px;
    align-items: start;
    color: var(--billing-text);
}

.billing-bullet-dot {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, rgba(49, 94, 251, 0.18), rgba(49, 94, 251, 0.04));
    border: 1px solid rgba(49, 94, 251, 0.18);
    position: relative;
}

.billing-bullet-dot::before {
    content: "";
    position: absolute;
    inset: 5px;
    border-radius: 50%;
    background: var(--billing-primary);
}

.billing-bullet strong {
    display: block;
    margin-bottom: 4px;
    font-size: 14px;
}

.billing-bullet span {
    color: var(--billing-muted);
    font-size: 14px;
    line-height: 1.6;
}

.billing-mini-card {
    margin-top: 24px;
    padding: 18px;
    border-radius: 20px;
    background: linear-gradient(180deg, rgba(49, 94, 251, 0.06), rgba(255, 255, 255, 0.9));
    border: 1px solid rgba(49, 94, 251, 0.12);
}

.billing-mini-card h4 {
    margin: 0 0 8px;
    font-size: 15px;
    letter-spacing: -0.02em;
}

.billing-mini-card p {
    margin: 0;
    color: var(--billing-muted);
    font-size: 13px;
    line-height: 1.6;
}

@media (max-width: 920px) {
    .billing-grid {
        grid-template-columns: 1fr;
    }

    .billing-main {
        border-right: none;
        border-bottom: 1px solid rgba(86, 107, 176, 0.12);
    }

    .billing-main,
    .billing-side {
        padding: 28px 22px;
    }
}

@media (max-width: 640px) {
    .billing-page {
        padding: 20px 14px 48px;
    }

    .billing-topbar {
        align-items: flex-start;
        flex-direction: column;
        margin-bottom: 18px;
    }

    .billing-title {
        font-size: 34px;
    }

    .billing-actions {
        flex-direction: column;
        align-items: stretch;
    }

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