:root {
    --bg-color: #f4f7fb;
    --bg-gradient: radial-gradient(circle at top left, #ffffff 0%, #edf3ff 45%, #f4f7fb 100%);
    --container-bg: #ffffff;
    --text-color: #1f2937;
    --muted-color: #64748b;
    --border-color: #d7deeb;
    --chat-bg: #f8faff;
    --assistant-bg: #edf2ff;
    --assistant-text: #1e293b;
    --user-bg: #2563eb;
    --user-text: #ffffff;
    --input-bg: #ffffff;
    --shadow: 0 24px 60px rgba(15, 23, 42, 0.12);
    --ring-color: rgba(37, 99, 235, 0.3);
    --success-color: #16a34a;
    --warning-color: #d97706;
    --error-color: #dc2626;
}

[data-theme="dark"] {
    --bg-color: #0b1220;
    --bg-gradient: radial-gradient(circle at top left, #1c2840 0%, #0f172a 48%, #0b1220 100%);
    --container-bg: #121a2b;
    --text-color: #e5e7eb;
    --muted-color: #94a3b8;
    --border-color: #27344d;
    --chat-bg: #0f1828;
    --assistant-bg: #1a2841;
    --assistant-text: #dbeafe;
    --user-bg: #3b82f6;
    --user-text: #f8fafc;
    --input-bg: #0f172a;
    --shadow: 0 24px 60px rgba(2, 6, 23, 0.52);
    --ring-color: rgba(59, 130, 246, 0.35);
    --success-color: #22c55e;
    --warning-color: #f59e0b;
    --error-color: #f87171;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg-gradient);
    color: var(--text-color);
    margin: 0;
    padding: 10px 0 18px;
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.container {
    width: min(92vw, 760px);
    background: var(--container-bg);
    min-height: calc(100vh - 20px);
    min-height: calc(100dvh - 20px);
    height: calc(100vh - 20px);
    height: calc(100dvh - 20px);
    padding: 18px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    backdrop-filter: blur(6px);
    display: flex;
    flex-direction: column;
    gap: 12px;
    overflow: hidden;
    min-width: 0;
    min-height: 0;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
}

.title-group {
    display: flex;
    align-items: baseline;
    gap: 10px;
    flex-wrap: wrap;
}

.title-group h1 {
    margin: 0;
    font-size: clamp(1.3rem, 2.2vw, 1.8rem);
    letter-spacing: 0.3px;
}

.subtitle {
    margin: 0;
    font-size: 0.9rem;
    color: var(--muted-color);
}

.settings {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.setting-item {
    display: grid;
    grid-template-columns: minmax(30px, 60px) minmax(0, 1fr) auto;
    align-items: center;
    column-gap: 10px;
    row-gap: 6px;
    padding: 3px 7px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: color-mix(in srgb, var(--chat-bg) 72%, transparent);
}

.setting-heading {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 8px;
    min-width: 0;
}

.setting-item label {
    color: var(--muted-color);
    font-size: 0.8rem;
    font-weight: 600;
    line-height: 1.2;
}

.setting-control {
    grid-column: 2 / 4;
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 0;
}

.setting-item input,
.setting-item select,
textarea {
    width: 100%;
    padding: 7px 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--input-bg);
    color: var(--text-color);
    line-height: 1.2;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.setting-control input {
    flex: 1 1 auto;
    min-width: 0;
}

.setting-item input:focus,
.setting-item select:focus,
textarea:focus,
button:focus-visible,
a:focus-visible {
    outline: none;
    border-color: var(--user-bg);
    box-shadow: 0 0 0 4px var(--ring-color);
}

.get-api-link {
    font-size: 0.85em;
    color: var(--user-bg);
    text-decoration: none;
    white-space: nowrap;
    font-weight: 600;
}

.get-api-link:hover {
    text-decoration: underline;
}

.file-name {
    font-size: 0.78rem;
    color: var(--muted-color);
    display: inline-block;
    min-width: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
}

@media (min-width: 681px) {
    .setting-heading {
        grid-column: 1;
    }

    .setting-item input,
    .setting-item select {
        grid-column: 2;
    }

    .setting-control {
        grid-column: 2 / 4;
    }

    .setting-item .file-name {
        grid-column: 3;
        text-align: right;
        max-width: 220px;
    }
}

.status-bar {
    padding: 8px 10px;
    border-radius: 10px;
    border: 1px dashed var(--border-color);
    color: var(--muted-color);
    font-size: 0.88rem;
    background: color-mix(in srgb, var(--chat-bg) 70%, transparent);
}

.status-bar[data-type="success"] {
    color: var(--success-color);
    border-color: color-mix(in srgb, var(--success-color) 30%, var(--border-color));
}

.status-bar[data-type="warning"],
.status-bar[data-type="pending"] {
    color: var(--warning-color);
}

.status-bar[data-type="error"] {
    color: var(--error-color);
    border-color: color-mix(in srgb, var(--error-color) 36%, var(--border-color));
}

.chat-window {
    flex: 1;
    min-height: 320px;
    min-width: 0;
    min-height: 0;
    border: 1px solid var(--border-color);
    border-radius: 14px;
    overflow-y: auto;
    overflow-x: hidden;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
    padding: 12px;
    background: var(--chat-bg);
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.message {
    padding: 9px 12px;
    border-radius: 12px;
    max-width: min(88%, 560px);
    white-space: pre-wrap;
    word-break: break-word;
    display: flex;
    flex-direction: column;
    line-height: 1.45;
}

.has-audio .message-content {
    cursor: pointer;
}

.has-audio .message-content:hover {
    opacity: 0.9;
}

.message-actions {
    margin-top: 6px;
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    font-size: 0.78rem;
}

.download-link,
.delete-link {
    color: inherit;
    text-decoration: underline;
    opacity: 0.78;
    cursor: pointer;
}

.download-link:hover,
.delete-link:hover {
    opacity: 1;
}

.delete-link {
    color: var(--error-color);
}

.assistant .download-link {
    color: var(--user-bg);
}

.user {
    background-color: var(--user-bg);
    color: var(--user-text);
    align-self: flex-end;
    margin-left: auto;
}

.assistant {
    background-color: var(--assistant-bg);
    color: var(--assistant-text);
}

.system {
    align-self: center;
    text-align: center;
    font-size: 0.85rem;
    color: var(--muted-color);
    background: transparent;
    padding: 2px;
}

.input-area {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 10px;
    align-items: end;
}

textarea {
    resize: none;
    min-height: 52px;
    max-height: 120px;
    line-height: 1.5;
}

button {
    border: 1px solid transparent;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    transition: transform 0.15s ease, opacity 0.2s ease, background-color 0.2s ease;
}

button:hover:not(:disabled) {
    transform: translateY(-1px);
}

button:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

#themeToggle {
    width: 40px;
    height: 40px;
    padding: 0;
    background: transparent;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    line-height: 1;
}

#themeToggle:hover:not(:disabled) {
    background: color-mix(in srgb, var(--user-bg) 8%, transparent);
}

#themeToggle:active:not(:disabled) {
    transform: scale(0.96);
}

#sendBtn {
    padding: 0 18px;
    background-color: var(--user-bg);
    color: #fff;
    min-width: 140px;
    min-height: 52px;
}

.audio-player {
    text-align: center;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: color-mix(in srgb, var(--chat-bg) 74%, transparent);
}

audio {
    width: 100%;
    border-radius: 8px;
}

.footer {
    margin-top: auto;
    padding-top: 8px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.8rem;
    color: var(--muted-color);
}

.footer p {
    margin: 4px 0;
}

.footer a {
    color: var(--user-bg);
    text-decoration: none;
    font-weight: 600;
}

.footer a:hover {
    text-decoration: underline;
}

@media (max-width: 680px) {
    body {
        padding: 3px 0;
        align-items: flex-start;
    }

    .container {
        width: calc(100vw - 14px);
        margin: 3px 7px;
        padding: 10px;
        border-radius: 14px;
        min-height: calc(100dvh - 6px);
        height: calc(100dvh - 6px);
        gap: 8px;
        overflow: hidden;
    }

    .header {
        flex-direction: row;
        align-items: center;
        gap: 8px;
    }

    .title-group {
        flex: 1;
        align-items: center;
        gap: 4px 8px;
    }

    .title-group h1 {
        font-size: 1.15rem;
    }

    .subtitle {
        font-size: 0.78rem;
    }

    #themeToggle {
        width: 34px;
        height: 34px;
        font-size: 0.92rem;
    }

    .settings {
        gap: 4px;
    }

    .setting-item {
        column-gap: 7px;
        row-gap: 3px;
        padding: 1px 5px;
        border-radius: 8px;
    }

    .setting-item label {
        font-size: 0.72rem;
    }

    .file-name {
        max-width: min(42vw, 60px);
        font-size: 0.7rem;
    }

    .setting-control {
        gap: 4px;
    }

    .setting-item input,
    .setting-item select,
    textarea {
        padding: 4px 7px;
        border-radius: 7px;
        font-size: 0.84rem;
    }

    .get-api-link {
        flex: 0 0 auto;
        font-size: 0.78rem;
    }

    .status-bar {
        padding: 6px 8px;
        font-size: 0.8rem;
    }

    .chat-window {
        flex: 1;
        min-height: 0;
        max-height: none;
        padding: 8px;
        gap: 6px;
        border-radius: 12px;
    }

    .message {
        max-width: 94%;
        padding: 7px 9px;
        font-size: 0.92rem;
    }

    .message-actions {
        margin-top: 4px;
        gap: 8px;
        font-size: 0.72rem;
    }

    .input-area {
        grid-template-columns: 1fr;
        gap: 6px;
    }

    textarea {
        min-height: 46px;
        max-height: 88px;
        line-height: 1.4;
    }

    #sendBtn {
        min-height: 38px;
        width: 100%;
        padding: 0 14px;
        font-size: 0.92rem;
    }

    .audio-player {
        margin-top: 0;
        border-radius: 10px;
    }

    .footer {
        padding-top: 6px;
        font-size: 0.72rem;
    }

    .footer p {
        margin: 2px 0;
    }
}