:root {
    --bg-app: #f9f9f9;
    --bg-surface: #ffffff;
    --bg-muted: #f3f3f3;
    --bg-subtle: #f0f0f0;
    --bg-accent: #0588f0;
    --bg-accent-soft: #e6f4fe;
    --bg-user-bubble: rgba(5, 136, 240, 0.9);
    --text-primary: #222222;
    --text-secondary: #555555;
    --text-tertiary: #838383;
    --text-on-accent: #ffffff;
    --border-primary: #d9d9d9;
    --border-subtle: #eeeeee;
    --border-soft: #f0f0f0;
    --danger: #cf1919;
    --warning: #e9b01d;
    --success: #8fc44c;
    --shadow-soft: 0 16px 48px rgba(34, 34, 34, 0.08);
}

* {
    box-sizing: border-box;
}

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

body {
    background: var(--bg-app);
    color: var(--text-primary);
    font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button,
input,
textarea {
    font: inherit;
}

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

h1,
h2,
p {
    margin: 0;
}

.login-stage {
    align-items: center;
    background: linear-gradient(185deg, #0588f0 10%, #0d74ce 90%);
    display: flex;
    justify-content: center;
    inset: 0;
    min-height: 100vh;
    padding: 20px;
    position: fixed;
}

.login-shell {
    align-items: center;
    background: rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 40px;
    box-shadow: inset 0 0 0 1px rgba(11, 174, 255, 0.22);
    display: flex;
    flex-direction: column;
    gap: 20px;
    max-width: 400px;
    padding: 32px 20px 20px;
    width: 100%;
}

.login-logo {
    height: 64px;
    width: 64px;
}

.login-title {
    color: #ffffff;
    display: grid;
    font-size: 28px;
    font-weight: 600;
    justify-items: center;
    line-height: 1.1;
    text-align: center;
}

textarea,
input[type="text"],
input[type="password"] {
    appearance: none;
    background: var(--bg-surface);
    border: 1px solid var(--border-primary);
    border-radius: 16px;
    color: var(--text-primary);
    min-width: 0;
    padding: 13px 18px;
    width: 100%;
}

textarea:focus,
input[type="text"]:focus,
input[type="password"]:focus,
textarea:active,
input[type="text"]:active,
input[type="password"]:active {
    outline: 2px solid var(--bg-accent);
}

.login-fields {
    display: grid;
    gap: 12px;
    width: 100%;
}

.login-stage input[type="text"],
.login-stage input[type="password"] {
    background: rgba(0, 0, 0, 0.5);
    border: none;
    border-radius: 20px;
    color: #ffffff;
    font-size: 18px;
    min-height: 48px;
    padding: 13px 20px;
}

.login-stage input[type="text"]::placeholder,
.login-stage input[type="password"]::placeholder {
    color: rgba(255, 255, 255, 0.94);
}

.login-stage input[type="text"]:focus,
.login-stage input[type="password"]:focus,
.login-stage input[type="text"]:active,
.login-stage input[type="password"]:active {
    outline: 2px solid rgba(255, 255, 255, 0.7);
}

.login-button {
    background: #f4faff;
    border-radius: 20px;
    color: #0588f0;
    font-size: 18px;
    font-weight: 500;
    min-width: 107px;
    padding: 13px 26px;
}

.login-button:hover:not(:disabled) {
    background: #deefff;
}

.login-error {
    color: #ffd9d9;
    font-size: 14px;
    min-height: 17px;
    text-align: center;
}

button {
    align-items: center;
    background: transparent;
    border: none;
    border-radius: 16px;
    cursor: pointer;
    display: inline-flex;
    gap: 10px;
    height: 48px;
    justify-content: center;
    line-height: normal;
    padding: 13px 26px;
    transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease, transform 150ms ease;
}

button:disabled {
    cursor: default;
    opacity: 0.6;
}

.primary-button {
    background: var(--bg-accent);
    color: var(--text-on-accent);
}

.primary-button:hover:not(:disabled) {
    background: #0474cd;
}

.secondary-button {
    background: var(--bg-surface);
    border: 1px solid var(--border-primary);
    color: #646464;
}

.secondary-button:hover:not(:disabled) {
    background: #f7f7f7;
}

.black-button {
    box-shadow: none;
}

.container {
    align-items: stretch;
    display: flex;
    gap: 20px;
    min-height: 100vh;
    padding: 12px;
}

.workspace-rail {
    align-items: center;
    background: transparent;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 8px 0;
    width: 48px;
}

.workspace-rail-top,
.workspace-rail-bottom {
    align-items: center;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.workspace-logo-wrap {
    align-items: center;
    display: flex;
    height: 48px;
    justify-content: center;
    width: 48px;
}

.workspace-logo-wrap img {
    height: 36px;
    width: 36px;
}

.rail-button {
    background: var(--bg-app);
    border: 1px solid transparent;
    color: var(--text-tertiary);
    height: 48px;
    padding: 0;
    width: 48px;
}

.rail-button i {
    font-size: 20px;
}

.rail-button:hover:not(:disabled) {
    background: #f1f1f1;
}

.rail-button.selected,
.rail-button[aria-pressed="true"] {
    background: var(--bg-accent-soft);
    color: var(--bg-accent);
}

.placeholder-button {
    color: var(--text-tertiary);
}

.workspace-main {
    display: flex;
    flex: 1;
    min-width: 0;
}

.workspace-surface {
    background: var(--bg-surface);
    border: 1px solid var(--border-primary);
    border-radius: 48px;
    display: flex;
    flex: 1;
    min-height: calc(100vh - 24px);
    min-width: 0;
    overflow: hidden;
}

.workspace-primary {
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 16px;
    min-width: 0;
    padding: 16px;
}

.status-bar {
    align-items: center;
    background: var(--bg-app);
    border-radius: 32px;
    display: flex;
    gap: 20px;
    justify-content: space-between;
    min-height: 64px;
    padding: 0 20px;
}

.status-bar > p {
    color: #333333;
    font-size: 18px;
    font-weight: 500;
    white-space: nowrap;
}

#progress-container {
    background: #f0f0f0;
    border-radius: 999px;
    flex: 1;
    max-width: 600px;
    min-width: 120px;
    overflow: hidden;
}

#progress-bar {
    background: #407cea;
    border-radius: 999px;
    height: 12px;
    width: 0;
}

#sync-status {
    color: var(--text-tertiary);
    display: none;
    font-size: 14px;
    min-height: 18px;
    padding: 0 8px;
}

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

#flashcard-section,
#word-list-section {
    display: flex;
    flex: 1;
    min-height: 0;
    min-width: 0;
}

#flashcard-section {
    align-items: stretch;
}

#flashcard {
    display: flex;
    flex: 1;
    min-width: 0;
}

.flashcard-shell {
    background: var(--bg-surface);
    border: 1px solid var(--border-primary);
    border-radius: 32px;
    display: flex;
    flex: 1;
    flex-direction: column;
    min-height: 0;
    min-width: 0;
    overflow: hidden;
}

.flashcard-stage {
    background: var(--bg-app);
    border-radius: 32px;
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 16px;
    min-height: 0;
    min-width: 0;
    padding: 16px;
}

.flashcard-top-row {
    align-items: flex-start;
    display: flex;
    gap: 16px;
    justify-content: space-between;
}

.flashcard-review-indicator {
    align-items: center;
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 16px;
    display: inline-flex;
    gap: 8px;
    min-height: 36px;
    padding: 10px 12px;
}

.flashcard-review-phase {
    align-items: center;
    display: inline-flex;
    gap: 6px;
}

.flashcard-review-divider {
    background: var(--border-soft);
    border-radius: 999px;
    height: 8px;
    width: 1px;
}

.flashcard-review-bar {
    background: var(--bg-subtle);
    border-radius: 999px;
    height: 16px;
    width: 48px;
}

.flashcard-review-bar.is-active,
.flashcard-review-bar.is-complete {
    background: var(--bg-accent);
}

.flashcard-review-dot {
    background: var(--bg-subtle);
    border-radius: 999px;
    height: 16px;
    width: 16px;
}

.flashcard-review-dot.is-active,
.flashcard-review-dot.is-complete {
    background: var(--bg-accent);
}

.flashcard-answer-chip {
    align-items: center;
    background: var(--bg-surface);
    border-radius: 999px;
    color: #407cea;
    display: inline-flex;
    gap: 6px;
    min-height: 52px;
    min-width: 214px;
    padding: 0 12px 0 22px;
}

.flashcard-answer-chip.is-hidden {
    visibility: hidden;
}

.flashcard-answer-text {
    font-size: 24px;
    font-weight: 600;
}

.flashcard-answer-chip .play-button {
    border-radius: 24px;
    color: #7d7d7d;
    height: 48px;
    padding: 0;
    width: 48px;
}

.flashcard-answer-chip .play-button:hover:not(:disabled) {
    background: #f5f5f5;
}

.flashcard-sentence-panel {
    align-items: center;
    display: flex;
    flex: 1;
    justify-content: center;
    min-height: 260px;
    min-width: 0;
    padding: 12px 32px;
}

.flashcard-sentence-wrap {
    align-content: center;
    align-items: center;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    width: 100%;
}

#sentence-container {
    align-items: center;
    display: flex;
    flex-wrap: wrap;
    font-size: 24px;
    font-weight: 500;
    gap: 10px;
    justify-content: center;
    line-height: 1.4;
    width: 100%;
}

#user-input {
    background: var(--bg-surface);
    border: 1px solid var(--border-primary);
    border-radius: 16px;
    color: var(--text-primary);
    font-size: 24px;
    font-weight: 400;
    max-width: 320px;
    min-height: 56px;
    min-width: 240px;
    padding: 13px 18px;
}

#user-input.correct,
#user-input.correct:focus {
    color: var(--success);
    outline: 2px solid var(--success);
}

#user-input.partial-correct,
#user-input.partial-correct:focus {
    color: var(--warning);
    outline: 2px solid var(--warning);
}

#user-input.incorrect,
#user-input.incorrect:focus {
    color: var(--danger);
    outline: 2px solid var(--danger);
}

.flashcard-toolbar {
    align-items: center;
    display: flex;
    gap: 16px;
    justify-content: space-between;
}

.memorize-section {
    align-items: center;
    display: flex;
    gap: 12px;
}

#special-characters {
    align-items: center;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: flex-end;
}

#special-characters .secondary-button {
    min-width: 40px;
    padding: 13px 18px;
}

.flashcard-footer {
    align-items: flex-end;
    border-top: 1px solid var(--border-soft);
    display: flex;
    gap: 20px;
    justify-content: space-between;
    padding: 24px 32px 32px;
}

#flashcard-en-cn {
    color: var(--text-secondary);
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 6px;
}

#flashcard-en-cn > p {
    color: var(--text-secondary);
    font-size: 18px;
}

#flashcard-actions {
    align-items: center;
    display: flex;
    gap: 12px;
    justify-content: flex-end;
}

.empty-state {
    align-items: center;
    color: var(--text-tertiary);
    display: flex;
    flex: 1;
    font-size: 18px;
    justify-content: center;
    padding: 40px;
    text-align: center;
}

.coach-panel {
    background: var(--bg-app);
    border-left: 1px solid var(--border-primary);
    display: flex;
    flex-direction: column;
    gap: 12px;
    min-width: 320px;
    padding: 16px;
    width: 360px;
}

.coach-thread {
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 12px;
    min-height: 0;
    overflow-y: auto;
    padding-right: 4px;
}

.coach-message {
    display: flex;
    width: 100%;
}

.coach-message.assistant,
.coach-message.system {
    justify-content: flex-start;
}

.coach-message.user {
    justify-content: flex-end;
}

.coach-bubble {
    border-radius: 20px;
    color: #4d4f52;
    font-family: "SF Pro Text", "Inter", sans-serif;
    font-size: 17px;
    line-height: 22px;
    max-width: 85%;
    padding: 10px 14px;
    white-space: pre-wrap;
    word-break: break-word;
}

.coach-message.assistant .coach-bubble {
    background: rgba(0, 0, 0, 0.02);
}

.coach-message.user .coach-bubble {
    background: var(--bg-user-bubble);
    color: var(--text-on-accent);
}

.coach-message.system .coach-bubble {
    background: #fff7e7;
    color: #6a4f18;
}

.coach-bubble.is-loading {
    color: var(--text-tertiary);
}

#flashcard-recording-indicator {
    display: none;
}

.recording-banner {
    align-items: center;
    background: #fff4f4;
    border: 1px solid #f2c8c8;
    border-radius: 16px;
    display: flex;
    gap: 12px;
    justify-content: space-between;
    padding: 10px 12px;
}

.recording-label {
    align-items: center;
    color: #8a1c1c;
    display: flex;
    font-size: 16px;
    font-weight: 510;
    gap: 8px;
}

.recording-dot {
    background: var(--danger);
    border-radius: 999px;
    height: 10px;
    width: 10px;
}

.coach-prompt-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.coach-chip {
    background: var(--bg-surface);
    border: 1px solid var(--border-primary);
    border-radius: 999px;
    color: #646464;
    font-size: 14px;
    font-weight: 500;
    height: 40px;
    padding: 0 14px;
}

.coach-chip:hover:not(:disabled) {
    background: #f7f7f7;
}

.coach-composer {
    align-items: flex-end;
    background: var(--bg-surface);
    border: 1px solid var(--border-soft);
    border-radius: 32px;
    display: flex;
    gap: 12px;
    padding: 16px;
}

#coach-input {
    background: transparent;
    border: none;
    color: var(--text-primary);
    line-height: 22px;
    max-height: 128px;
    min-height: 22px;
    overflow-y: auto;
    padding: 10px 0;
    resize: none;
}

#coach-input:focus,
#coach-input:active {
    outline: none;
}

.coach-send-button {
    border-radius: 16px;
    flex-shrink: 0;
    height: 48px;
    padding: 0;
    width: 48px;
}

#word-list-section {
    background: var(--bg-app);
    border: 1px solid var(--border-primary);
    border-radius: 32px;
    flex-direction: column;
    min-height: 0;
    overflow: hidden;
}

#word-list-toolbar {
    display: flex;
    justify-content: flex-end;
    padding: 16px 20px 8px;
}

#add-new-word-section {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

#import-file-input {
    display: none;
}

#word-list {
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 16px;
    min-height: 0;
    overflow-y: auto;
    padding: 8px 20px 24px;
}

.word-item {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.word-item-content {
    align-items: center;
    display: flex;
    gap: 24px;
    justify-content: space-between;
    padding: 20px 24px;
}

.word-item-text-content {
    display: flex;
    flex: 1;
    flex-direction: column;
    gap: 10px;
    min-width: 0;
}

.word-item-row-1,
.word-item-row-2,
.word-item-german,
.word-item-info-action {
    align-items: center;
    display: flex;
    gap: 12px;
}

.word-item-row-1,
.word-item-row-2 {
    justify-content: space-between;
}

.word-item-row-2 {
    align-items: flex-start;
}

.word-item-german {
    flex-wrap: wrap;
}

.word-item-word {
    font-size: 20px;
    font-weight: 600;
}

.word-item-sentence,
.word-item-meanings,
.word-item-translations {
    color: var(--text-tertiary);
    font-size: 16px;
}

.word-item-info-action {
    flex-wrap: wrap;
    justify-content: flex-end;
    min-width: 240px;
}

.memorize-info {
    align-items: center;
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 16px;
    color: var(--text-tertiary);
    display: inline-flex;
    font-size: 15px;
    font-weight: 500;
    gap: 4px;
    height: 48px;
    justify-content: center;
    min-width: 78px;
    padding: 0 14px;
}

.divider {
    background: var(--border-subtle);
    height: 1px;
    width: 100%;
}

.overlay-open {
    overflow: hidden;
}

.overlay-backdrop {
    align-items: center;
    background: rgba(0, 0, 0, 0.34);
    display: flex;
    inset: 0;
    justify-content: center;
    padding: 24px;
    position: fixed;
    z-index: 1200;
}

.overlay-backdrop[hidden] {
    display: none;
}

.add-words-overlay-panel {
    background: var(--bg-surface);
    border-radius: 28px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.22);
    display: flex;
    flex-direction: column;
    gap: 14px;
    max-width: 980px;
    padding: 24px;
    width: 100%;
}

.add-words-overlay-panel > h2 {
    margin: 0;
}

#overlay-limit-text {
    color: var(--text-tertiary);
    font-size: 15px;
}

#overlay-word-input {
    min-height: 180px;
    resize: vertical;
}

.overlay-actions-row {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
}

.overlay-actions-row > button {
    min-width: 160px;
}

#add-words-result-view {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.generated-actions-top {
    display: flex;
    justify-content: flex-end;
}

.generated-preview-scroll {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 20px;
    max-height: 420px;
    overflow-y: auto;
    padding: 14px 0;
}

.generated-word-item .word-item-content {
    align-items: flex-start;
}

.generated-word-actions {
    min-width: unset;
    width: auto;
}

.generated-regenerate-button.is-loading {
    opacity: 0.75;
}

.generated-regenerate-button.is-loading i {
    animation: spin 0.8s linear infinite;
}

.button-loading {
    pointer-events: none;
}

.button-spinner {
    animation: spin 0.9s linear infinite;
    border: 2px solid rgba(255, 255, 255, 0.45);
    border-radius: 50%;
    border-top-color: var(--text-on-accent);
    display: inline-block;
    height: 14px;
    width: 14px;
}

.generated-skeleton-row {
    padding: 12px 24px;
}

.skeleton-line {
    animation: shimmer 1.35s ease-in-out infinite;
    background: linear-gradient(90deg, #efefef 0%, #f8f8f8 45%, #efefef 100%);
    background-size: 280px 100%;
    border-radius: 999px;
    height: 14px;
    margin-bottom: 10px;
}

.line-title {
    height: 18px;
    width: 32%;
}

.line-subtitle {
    width: 72%;
}

.line-detail {
    width: 58%;
}

@keyframes shimmer {
    0% {
        background-position: -280px 0;
    }

    100% {
        background-position: 280px 0;
    }
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

body.view-wordlist .coach-panel {
    display: none;
}

body.view-wordlist .workspace-primary {
    flex: 1;
}

@media screen and (max-width: 1180px) {
    .container {
        padding: 10px;
    }

    .workspace-surface {
        border-radius: 36px;
        flex-direction: column;
        min-height: calc(100vh - 20px);
    }

    .coach-panel {
        border-left: none;
        border-top: 1px solid var(--border-primary);
        min-width: 0;
        width: 100%;
    }

    .flashcard-footer {
        flex-direction: column;
        gap: 16px;
    }

    #flashcard-actions {
        width: 100%;
    }

    #flashcard-actions > button {
        flex: 1;
    }
}

@media screen and (max-width: 860px) {
    .container {
        flex-direction: column;
        gap: 12px;
    }

    .workspace-rail {
        flex-direction: row;
        justify-content: space-between;
        padding: 0;
        width: 100%;
    }

    .workspace-rail-top,
    .workspace-rail-bottom {
        flex-direction: row;
    }

    .workspace-main {
        min-height: 0;
    }

    .workspace-surface {
        border-radius: 32px;
        min-height: auto;
    }

    .workspace-primary {
        padding: 12px;
    }

    .status-bar {
        gap: 12px;
        min-height: 56px;
        padding: 0 16px;
    }

    .status-bar > p {
        font-size: 15px;
    }

    #flashcard-en-cn > p,
    .word-item-sentence,
    .word-item-meanings,
    .word-item-translations {
        font-size: 15px;
    }

    .flashcard-stage {
        padding: 12px;
    }

    .flashcard-sentence-panel {
        min-height: 220px;
        padding: 12px 20px;
    }

    #sentence-container,
    #user-input,
    .flashcard-answer-text {
        font-size: 20px;
    }

    #user-input {
        max-width: 100%;
        min-width: 180px;
    }

    .flashcard-top-row,
    .flashcard-toolbar,
    .word-item-content,
    .word-item-row-1,
    .word-item-row-2,
    .word-item-info-action {
        flex-direction: column;
        align-items: flex-start;
    }

    .flashcard-top-row,
    .flashcard-toolbar {
        gap: 12px;
    }

    .flashcard-answer-chip {
        justify-content: space-between;
        width: 100%;
    }

    .memorize-section,
    #special-characters,
    #flashcard-actions,
    #add-new-word-section {
        width: 100%;
    }

    #special-characters,
    #flashcard-actions {
        justify-content: flex-start;
    }

    .word-item-info-action {
        min-width: 0;
        width: 100%;
    }
}

@media screen and (max-width: 560px) {
    .login-stage {
        padding: 14px;
    }

    .login-shell {
        border-radius: 32px;
        max-width: 100%;
        padding: 26px 16px 16px;
    }

    .login-title {
        font-size: 24px;
    }

    .login-logo {
        height: 56px;
        width: 56px;
    }

    .login-stage input[type="text"],
    .login-stage input[type="password"] {
        border-radius: 18px;
        font-size: 16px;
        min-height: 44px;
        padding: 11px 16px;
    }

    .login-button {
        border-radius: 18px;
        font-size: 16px;
        min-height: 44px;
    }

    .container {
        padding: 8px;
    }

    .workspace-surface {
        border-radius: 24px;
    }

    .workspace-primary,
    .coach-panel {
        padding: 10px;
    }

    .status-bar {
        flex-wrap: wrap;
        justify-content: flex-start;
        padding: 14px;
    }

    #progress-container {
        max-width: none;
        width: 100%;
    }

    .flashcard-stage {
        padding: 10px;
    }

    .flashcard-footer {
        padding: 18px 20px 20px;
    }

    #sentence-container,
    #user-input {
        font-size: 18px;
    }

    .flashcard-review-indicator {
        width: 100%;
    }

    .flashcard-review-phase {
        flex: 1;
        justify-content: center;
    }

    .flashcard-review-bar {
        width: 100%;
    }

    .coach-bubble {
        max-width: 100%;
    }

    .overlay-actions-row {
        flex-direction: column-reverse;
    }

    .overlay-actions-row > button {
        width: 100%;
    }
}