:root {
    color-scheme: light;
    --bg: #eef4ef;
    --surface: #ffffff;
    --surface-soft: #f8fbf9;
    --text: #17211c;
    --muted: #607066;
    --line: #d8e3dc;
    --line-strong: #bfd2c8;
    --accent: #07b53b;
    --accent-dark: #069231;
    --danger-bg: #fff0ed;
    --danger-text: #a23425;
    --danger-line: #efb3aa;
    --notice-bg: #ecf8f0;
    --notice-text: #11642e;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    color: var(--text);
    font-family: "Yu Gothic", "Meiryo", system-ui, sans-serif;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.78), rgba(255, 255, 255, 0)),
        var(--bg);
}

a {
    color: inherit;
}

.topbar {
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    z-index: 10;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    gap: 20px;
    min-height: 68px;
    padding: 0 28px;
    border-bottom: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    box-shadow: 0 12px 24px rgba(23, 33, 28, 0.08);
    transform: translateY(calc(-100% + 8px));
    transition: transform 180ms ease;
}

.topbar:hover,
.topbar:focus-within {
    transform: translateY(0);
}

.brand,
nav {
    display: flex;
    align-items: center;
    gap: 14px;
}

.brand {
    font-weight: 800;
    text-decoration: none;
}

.brand-mark {
    display: grid;
    place-items: center;
    width: 34px;
    height: 34px;
    border-radius: 8px;
    color: #ffffff;
    background: var(--accent);
}

nav {
    color: var(--muted);
    font-size: 0.94rem;
}

nav a,
.guest-box a {
    text-decoration: none;
}

.nav-button,
.guest-box a,
button {
    border: 0;
    border-radius: 8px;
    color: #ffffff;
    background: var(--accent);
    font: inherit;
    font-weight: 700;
    cursor: pointer;
}

.nav-button {
    padding: 9px 14px;
}

.layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 24px;
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    padding: 12px 0 24px;
}

.timeline-shell,
.side-panel {
    border: 1px solid var(--line);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 18px 40px rgba(23, 33, 28, 0.08);
}

.timeline-shell {
    display: flex;
    flex-direction: column;
    min-height: min(840px, calc(100vh - 48px));
    max-height: calc(100vh - 36px);
    overflow: hidden;
}

.eyebrow,
.message-meta time,
.feature-list {
    color: var(--muted);
}

.eyebrow {
    margin: 0 0 6px;
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

h1,
h2,
p {
    margin-top: 0;
}

h1 {
    margin-bottom: 0;
    font-size: 1.55rem;
}

h2 {
    margin-bottom: 18px;
    font-size: 1.15rem;
}

.notice,
.alert,
.dev-link,
.guest-box {
    margin: 20px 24px 0;
    border-radius: 8px;
}

.notice {
    padding: 13px 15px;
    color: var(--notice-text);
    background: var(--notice-bg);
    border: 1px solid #bde8c8;
}

.alert {
    padding: 13px 15px;
    color: var(--danger-text);
    background: var(--danger-bg);
    border: 1px solid #efb3aa;
}

.alert p,
.dev-link p,
.guest-box p {
    margin-bottom: 0;
}

.dev-link {
    padding: 14px 15px;
    border: 1px dashed var(--line-strong);
    background: #fbfdfb;
}

.dev-link a {
    display: block;
    margin-top: 8px;
    overflow-wrap: anywhere;
    color: var(--accent-dark);
}

.post-box {
    margin: 0;
    padding: 14px;
    border-top: 1px solid var(--line);
    border-radius: 0;
    background: var(--surface-soft);
}

.post-row {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    gap: 10px;
    align-items: center;
}

.post-text-input {
    height: 46px;
}

textarea,
input {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 12px 13px;
    color: var(--text);
    background: #ffffff;
    font: inherit;
}

textarea {
    resize: vertical;
}

textarea:focus,
input:focus {
    border-color: var(--accent);
    outline: 3px solid rgba(7, 181, 59, 0.14);
}

.image-picker {
    display: block;
}

.image-picker label {
    display: inline-flex;
    flex: 0 0 auto;
    border: 1px solid var(--line-strong);
    border-radius: 8px;
    padding: 9px 12px;
    color: var(--text);
    background: #ffffff;
    cursor: pointer;
    white-space: nowrap;
}

.image-picker input {
    position: absolute;
    inline-size: 1px;
    block-size: 1px;
    opacity: 0;
    pointer-events: none;
}

.post-row button {
    height: 46px;
    white-space: nowrap;
}

.image-preview {
    margin-top: 12px;
}

.image-preview[hidden] {
    display: none;
}

.image-preview img {
    display: block;
    width: min(180px, 100%);
    aspect-ratio: 1 / 1;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #ffffff;
    object-fit: cover;
}

button {
    padding: 11px 20px;
}

button:hover,
.nav-button:hover,
.guest-box a:hover {
    background: var(--accent-dark);
}

.danger-light {
    border: 1px solid var(--danger-line);
    padding: 7px 10px;
    color: var(--danger-text);
    background: var(--danger-bg);
    font-size: 0.84rem;
}

.danger-light:hover {
    color: #ffffff;
    background: var(--danger-text);
}

.guest-box {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px;
    border: 1px solid var(--line);
    background: var(--surface-soft);
}

.guest-box p {
    flex: 1;
    color: var(--muted);
}

.guest-box a {
    flex: 0 0 auto;
    padding: 10px 13px;
    font-size: 0.92rem;
}

.timeline {
    display: grid;
    flex: 1;
    min-height: 0;
    align-content: start;
    gap: 18px;
    padding: 24px;
    overflow-y: auto;
    overscroll-behavior: contain;
    scrollbar-color: var(--line-strong) transparent;
    scrollbar-width: thin;
}

.timeline::-webkit-scrollbar {
    width: 10px;
}

.timeline::-webkit-scrollbar-thumb {
    border: 3px solid transparent;
    border-radius: 999px;
    background: var(--line-strong);
    background-clip: content-box;
}

.timeline::-webkit-scrollbar-track {
    background: transparent;
}

.message {
    display: grid;
    grid-template-columns: 42px minmax(0, 1fr);
    gap: 12px;
    align-items: start;
}

.avatar {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    color: #ffffff;
    background: #256d85;
    font-weight: 800;
}

.bubble {
    position: relative;
    width: fit-content;
    max-width: min(680px, 100%);
    padding: 13px 15px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #ffffff;
}

.bubble::before {
    content: "";
    position: absolute;
    top: 15px;
    left: -7px;
    width: 12px;
    height: 12px;
    border-left: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    background: #ffffff;
    transform: rotate(45deg);
}

.message-meta {
    display: flex;
    align-items: baseline;
    gap: 10px;
    margin-bottom: 6px;
}

.message-meta time {
    font-size: 0.82rem;
}

.bubble p {
    margin-bottom: 0;
    line-height: 1.75;
    overflow-wrap: anywhere;
}

.posted-image {
    display: block;
    margin-top: 10px;
}

.posted-image img {
    display: block;
    width: min(420px, 100%);
    max-height: 420px;
    border: 1px solid var(--line);
    border-radius: 8px;
    object-fit: cover;
}

.admin-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px solid var(--line);
}

.admin-actions form {
    margin: 0;
}

.empty {
    padding: 28px;
    border: 1px dashed var(--line-strong);
    border-radius: 8px;
    color: var(--muted);
    background: var(--surface-soft);
}

.empty h2 {
    color: var(--text);
}

.side-panel {
    align-self: start;
    position: sticky;
    top: 16px;
    padding: 22px;
}

.auth-form {
    display: grid;
    gap: 15px;
}

label {
    display: grid;
    gap: 8px;
    color: var(--muted);
    font-weight: 700;
}

.password-control {
    position: relative;
    display: block;
}

.password-control input {
    padding-right: 48px;
}

.password-toggle {
    position: absolute;
    top: 50%;
    right: 6px;
    display: grid;
    place-items: center;
    width: 36px;
    height: 36px;
    padding: 0;
    color: var(--muted);
    background: transparent;
    transform: translateY(-50%);
}

.password-toggle:hover,
.password-toggle[aria-pressed="true"] {
    color: var(--accent-dark);
    background: transparent;
}

.password-toggle svg {
    width: 21px;
    height: 21px;
    fill: none;
    stroke: currentColor;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-width: 2;
}

.auth-form > button {
    width: 100%;
}

.admin-note,
.auth-note {
    margin: 16px 0;
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 12px;
    color: var(--muted);
    background: var(--surface-soft);
    font-size: 0.9rem;
    line-height: 1.7;
}

.admin-note p,
.auth-note p {
    margin-bottom: 0;
}

.member-list {
    display: grid;
    gap: 10px;
}

.member-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 10px;
    align-items: center;
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 12px;
    background: #ffffff;
}

.member-row div {
    display: grid;
    gap: 3px;
    min-width: 0;
}

.member-row span,
.member-row small,
.self-label {
    color: var(--muted);
}

.member-row span {
    overflow: hidden;
    font-size: 0.86rem;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.member-row small,
.self-label {
    font-size: 0.8rem;
}

.feature-list {
    display: grid;
    gap: 10px;
    margin: 0;
    padding-left: 1.2em;
    line-height: 1.7;
}

@media (max-width: 860px) {
    .topbar {
        align-items: center;
        flex-wrap: wrap;
        padding: 14px 16px;
    }

    nav {
        flex-wrap: wrap;
    }

    .layout {
        grid-template-columns: 1fr;
        width: min(100% - 24px, 1120px);
        padding-top: 18px;
    }

    .side-panel {
        position: static;
        order: -1;
    }

    .timeline,
    .side-panel {
        padding: 18px;
    }

    .notice,
    .alert,
    .dev-link,
    .guest-box {
        margin-right: 18px;
        margin-left: 18px;
    }

    .guest-box {
        align-items: stretch;
        flex-direction: column;
    }

    .member-row {
        grid-template-columns: 1fr;
    }

    .post-row {
        grid-template-columns: auto minmax(0, 1fr) auto;
        gap: 8px;
    }

    .image-picker label {
        justify-content: center;
    }

    .guest-box a,
    button {
        text-align: center;
    }
}