:root {
    --cinnabar: #B5453A;
    --cinnabar-light: #F5E6E4;
    --cinnabar-glow: rgba(181, 69, 58, 0.08);
    --oxford: #2B4C6F;
    --oxford-light: #E4EAF1;
    --oxford-glow: rgba(43, 76, 111, 0.08);
    --amber: #C4703F;
    --amber-light: #F5EBE0;
    --amber-glow: rgba(196, 112, 63, 0.12);
    --parchment: #FAF7F2;
    --parchment-deep: #F0EBE2;
    --ivory: #FFFDF9;
    --ink: #2D2926;
    --ink-soft: #4A4440;
    --stone: #8A7F72;
    --stone-light: #A99E90;
    --sand: #E0D8CC;
    --sand-light: #EDE7DD;
    --font-size-result: 28px;
    --radius: 14px;
    --radius-sm: 10px;
    --radius-xs: 6px;
    --shadow-sm: 0 1px 2px rgba(45,41,38,0.04);
    --shadow-md: 0 2px 8px rgba(45,41,38,0.06), 0 1px 2px rgba(45,41,38,0.04);
    --shadow-lg: 0 8px 24px rgba(45,41,38,0.08), 0 2px 6px rgba(45,41,38,0.04);
    --shadow-xl: 0 16px 48px rgba(45,41,38,0.1), 0 4px 12px rgba(45,41,38,0.05);
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.svg-defs {
    position: absolute;
    width: 0;
    height: 0;
    overflow: hidden;
}

body {
    font-family: 'DM Sans', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: var(--parchment);
    color: var(--ink);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 20% 10%, var(--cinnabar-glow), transparent),
        radial-gradient(ellipse 60% 50% at 80% 90%, var(--oxford-glow), transparent);
    pointer-events: none;
    z-index: 0;
}

.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 20px;
    background: rgba(250, 247, 242, 0.85);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--sand-light);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.brand-icon {
    color: var(--amber);
    display: flex;
    align-items: center;
}

.brand-text {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.brand-text h1 {
    font-family: 'Noto Serif SC', serif;
    font-size: 17px;
    font-weight: 700;
    color: var(--ink);
    letter-spacing: 2px;
}

.brand-sub {
    font-family: 'Playfair Display', serif;
    font-size: 11px;
    font-weight: 400;
    color: var(--stone);
    letter-spacing: 1.5px;
    text-transform: uppercase;
}

.header-controls {
    display: flex;
    gap: 6px;
}

.btn-icon {
    background: transparent;
    border: 1.5px solid var(--sand);
    color: var(--stone);
    width: 38px;
    height: 38px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.25s var(--ease-out);
}

.btn-icon:hover {
    border-color: var(--amber);
    color: var(--amber);
    background: var(--amber-glow);
}

#appMain {
    padding: 16px;
    gap: 16px;
    position: relative;
    z-index: 1;
}

#appMain.dual-panel {
    display: flex;
    flex-direction: column;
}

#appMain.single-panel {
    display: flex;
    flex-direction: column;
}

#appMain.single-panel .panel {
    display: none;
}

#appMain.single-panel .panel.active {
    display: flex;
    animation: panelFadeIn 0.4s var(--ease-out);
}

@keyframes panelFadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.panel {
    background: var(--ivory);
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: box-shadow 0.3s var(--ease-out), transform 0.3s var(--ease-out);
    position: relative;
    overflow: hidden;
    animation: panelEnter 0.5s var(--ease-out) backwards;
}

.panel:nth-child(2) {
    animation-delay: 0.08s;
}

@keyframes panelEnter {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

.panel::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
}

.panel-zh::before {
    background: linear-gradient(90deg, var(--cinnabar), var(--cinnabar-light));
}

.panel-en::before {
    background: linear-gradient(90deg, var(--oxford), var(--oxford-light));
}

.panel-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    font-weight: 600;
}

.lang-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.lang-badge-zh {
    background: var(--cinnabar-light);
    color: var(--cinnabar);
}

.lang-badge-en {
    background: var(--oxford-light);
    color: var(--oxford);
}

.panel-label {
    color: var(--ink-soft);
    font-size: 13px;
    font-weight: 500;
}

.panel-arrow {
    color: var(--sand);
    display: flex;
    align-items: center;
    margin: 0 2px;
}

.btn-switch-dir {
    display: none;
    margin-left: auto;
    background: transparent;
    border: 1.5px solid var(--sand);
    color: var(--stone);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    transition: all 0.25s var(--ease-out);
    flex-shrink: 0;
}

.btn-switch-dir:hover {
    border-color: var(--amber);
    color: var(--amber);
    background: var(--amber-glow);
}

.btn-switch-dir:active {
    transform: scale(0.92);
}

#appMain.single-panel .btn-switch-dir {
    display: inline-flex;
}

.input-area {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.text-input {
    width: 100%;
    padding: 14px 16px;
    border: 1.5px solid var(--sand);
    border-radius: var(--radius-sm);
    font-size: 16px;
    font-family: inherit;
    resize: none;
    transition: all 0.25s var(--ease-out);
    outline: none;
    line-height: 1.6;
    background: var(--ivory);
    color: var(--ink);
}

.text-input::placeholder {
    color: var(--stone-light);
}

.text-input:focus {
    border-color: var(--amber);
    box-shadow: 0 0 0 3px var(--amber-glow);
}

.panel-zh .text-input:focus {
    border-color: var(--cinnabar);
    box-shadow: 0 0 0 3px var(--cinnabar-glow);
}

.panel-en .text-input:focus {
    border-color: var(--oxford);
    box-shadow: 0 0 0 3px var(--oxford-glow);
}

.input-actions {
    display: flex;
    gap: 10px;
}

.btn-voice {
    width: 48px;
    height: 48px;
    border: 1.5px solid var(--sand);
    background: var(--ivory);
    border-radius: var(--radius-sm);
    cursor: pointer;
    color: var(--stone);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.25s var(--ease-out);
    flex-shrink: 0;
}

.btn-voice:hover {
    border-color: var(--amber);
    color: var(--amber);
    background: var(--amber-glow);
}

.btn-voice.listening {
    border-color: var(--cinnabar);
    color: var(--cinnabar);
    background: var(--cinnabar-light);
    animation: voicePulse 2s ease-in-out infinite;
}

@keyframes voicePulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(181, 69, 58, 0.2); }
    50% { box-shadow: 0 0 0 10px rgba(181, 69, 58, 0); }
}

.btn-send {
    flex: 1;
    height: 48px;
    background: var(--ink);
    color: var(--ivory);
    border: none;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.25s var(--ease-out);
    letter-spacing: 0.5px;
}

.btn-send:hover {
    background: var(--ink-soft);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-send:active {
    transform: translateY(0);
}

.panel-zh .btn-send {
    background: var(--cinnabar);
}

.panel-zh .btn-send:hover {
    background: #9E3B31;
}

.panel-en .btn-send {
    background: var(--oxford);
}

.panel-en .btn-send:hover {
    background: #1F3A56;
}

.result-area {
    background: var(--parchment);
    border: 1.5px solid var(--sand-light);
    border-radius: var(--radius);
    padding: 24px 20px;
    min-height: 120px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    transition: all 0.35s var(--ease-out);
}

.result-area.has-result {
    background: var(--ivory);
    border-color: var(--sand);
    box-shadow: var(--shadow-sm);
}

.result-placeholder {
    color: var(--stone-light);
    font-size: 14px;
    font-style: italic;
}

.result-area.has-result .result-placeholder {
    display: none;
}

.result-translation {
    font-family: 'Playfair Display', 'Noto Serif SC', serif;
    font-size: var(--font-size-result);
    font-weight: 700;
    line-height: 1.35;
    word-break: break-word;
    color: var(--ink);
    animation: resultReveal 0.5s var(--ease-out);
}

.panel-en .result-translation {
    font-family: 'Noto Serif SC', serif;
}

@keyframes resultReveal {
    from { opacity: 0; transform: translateY(6px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-original {
    font-size: 14px;
    color: var(--stone);
    line-height: 1.5;
    word-break: break-word;
    border-top: 1px solid var(--sand-light);
    padding-top: 10px;
    width: 100%;
    font-style: italic;
}

.btn-speak {
    align-self: flex-end;
    background: transparent;
    border: 1.5px solid var(--sand);
    border-radius: 20px;
    padding: 6px 14px;
    cursor: pointer;
    font-size: 13px;
    font-family: inherit;
    font-weight: 500;
    color: var(--stone);
    transition: all 0.25s var(--ease-out);
    display: none;
    align-items: center;
    gap: 5px;
}

.result-area.has-result .btn-speak {
    display: inline-flex;
}

.btn-speak:hover {
    border-color: var(--amber);
    color: var(--amber);
    background: var(--amber-glow);
}

.btn-speak.speaking {
    border-color: var(--amber);
    color: var(--amber);
    background: var(--amber-light);
}

.history-section {
    padding: 0 16px 24px;
    position: relative;
    z-index: 1;
}

.history-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--sand-light);
}

.history-header h2 {
    font-family: 'Noto Serif SC', serif;
    font-size: 15px;
    font-weight: 600;
    color: var(--ink-soft);
    letter-spacing: 1px;
}

.btn-text-danger {
    background: none;
    border: none;
    font-size: 12px;
    font-family: inherit;
    color: var(--stone-light);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius-xs);
    transition: all 0.2s var(--ease-out);
}

.btn-text-danger:hover {
    color: var(--cinnabar);
    background: var(--cinnabar-glow);
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 320px;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--sand) transparent;
}

.history-list::-webkit-scrollbar {
    width: 4px;
}

.history-list::-webkit-scrollbar-track {
    background: transparent;
}

.history-list::-webkit-scrollbar-thumb {
    background: var(--sand);
    border-radius: 2px;
}

.history-item {
    background: var(--ivory);
    border-radius: var(--radius-sm);
    padding: 12px 16px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--sand-light);
    display: flex;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    transition: all 0.25s var(--ease-out);
}

.history-item:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--sand);
    transform: translateY(-1px);
}

.history-item .h-direction {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.history-item .h-direction:contains('中') {
    color: var(--cinnabar);
}

.history-item .h-original {
    font-size: 13px;
    color: var(--stone);
    font-style: italic;
}

.history-item .h-translation {
    font-size: 15px;
    font-weight: 600;
    color: var(--ink);
}

.modal {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
    padding: 20px;
}

.modal.hidden {
    display: none;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(45, 41, 38, 0.3);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.modal-content {
    background: var(--ivory);
    border-radius: var(--radius);
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow-xl);
    position: relative;
    animation: modalEnter 0.35s var(--ease-spring);
    border: 1px solid var(--sand-light);
}

@keyframes modalEnter {
    from { opacity: 0; transform: scale(0.95) translateY(8px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 22px;
    border-bottom: 1px solid var(--sand-light);
}

.modal-header h2 {
    font-family: 'Noto Serif SC', serif;
    font-size: 16px;
    font-weight: 600;
    color: var(--ink);
    letter-spacing: 1px;
}

.btn-close {
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--stone);
    padding: 4px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s var(--ease-out);
}

.btn-close:hover {
    color: var(--ink);
    background: var(--parchment-deep);
}

.modal-body {
    padding: 22px;
    display: flex;
    flex-direction: column;
    gap: 18px;
}

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

.setting-group label {
    font-size: 12px;
    font-weight: 600;
    color: var(--stone);
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.setting-group select,
.setting-group input[type="url"],
.setting-group input[type="password"],
.setting-group input[type="text"] {
    padding: 10px 14px;
    border: 1.5px solid var(--sand);
    border-radius: var(--radius-xs);
    font-size: 14px;
    font-family: inherit;
    outline: none;
    background: var(--ivory);
    color: var(--ink);
    transition: all 0.25s var(--ease-out);
}

.setting-group select:focus,
.setting-group input:focus {
    border-color: var(--amber);
    box-shadow: 0 0 0 3px var(--amber-glow);
}

.range-row {
    display: flex;
    align-items: center;
    gap: 12px;
}

.setting-group input[type="range"] {
    flex: 1;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--sand);
    border-radius: 2px;
    outline: none;
}

.setting-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--amber);
    cursor: pointer;
    border: 2px solid var(--ivory);
    box-shadow: var(--shadow-sm);
}

.range-value {
    font-size: 13px;
    font-weight: 600;
    color: var(--amber);
    min-width: 36px;
    text-align: right;
}

.llm-settings.hidden {
    display: none;
}

.btn-primary {
    background: var(--ink);
    color: var(--ivory);
    border: none;
    border-radius: var(--radius-sm);
    padding: 13px;
    font-size: 14px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.25s var(--ease-out);
    letter-spacing: 0.5px;
}

.btn-primary:hover {
    background: var(--ink-soft);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.voice-indicator {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--ink);
    color: var(--ivory);
    padding: 12px 24px;
    border-radius: 28px;
    font-size: 14px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 12px;
    box-shadow: var(--shadow-xl);
    z-index: 300;
    animation: voiceIndicatorEnter 0.35s var(--ease-spring);
}

.voice-indicator.hidden {
    display: none;
}

@keyframes voiceIndicatorEnter {
    from { opacity: 0; transform: translateX(-50%) translateY(12px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

.voice-waves {
    display: flex;
    align-items: center;
    gap: 3px;
    height: 20px;
}

.voice-waves span {
    display: block;
    width: 3px;
    background: var(--cinnabar);
    border-radius: 2px;
    animation: wave 1.2s ease-in-out infinite;
}

.voice-waves span:nth-child(1) { height: 6px; animation-delay: 0s; }
.voice-waves span:nth-child(2) { height: 12px; animation-delay: 0.1s; }
.voice-waves span:nth-child(3) { height: 18px; animation-delay: 0.2s; }
.voice-waves span:nth-child(4) { height: 12px; animation-delay: 0.3s; }
.voice-waves span:nth-child(5) { height: 6px; animation-delay: 0.4s; }

@keyframes wave {
    0%, 100% { transform: scaleY(0.5); }
    50% { transform: scaleY(1); }
}

.voice-text {
    font-family: 'Noto Serif SC', serif;
    letter-spacing: 1px;
}

.loading .result-translation {
    color: var(--stone-light);
    font-style: italic;
    font-weight: 400;
    font-family: inherit;
    animation: loadingPulse 1.5s ease-in-out infinite;
}

@keyframes loadingPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.error .result-translation {
    color: var(--cinnabar);
    font-size: 15px;
    font-weight: 500;
    font-family: inherit;
    font-style: normal;
}

@media (min-width: 768px) {
    #appMain.dual-panel {
        flex-direction: row;
    }

    #appMain.dual-panel .panel {
        flex: 1;
    }

    .brand-text h1 {
        font-size: 19px;
    }

    .brand-sub {
        font-size: 12px;
    }

    :root {
        --font-size-result: 32px;
    }

    #appMain {
        padding: 20px;
        gap: 20px;
    }

    .history-section {
        padding: 0 20px 32px;
    }
}

@media (min-width: 1024px) {
    #appMain {
        max-width: 1040px;
        margin: 0 auto;
        padding: 24px;
    }

    .history-section {
        max-width: 1040px;
        margin: 0 auto;
        padding: 0 24px 40px;
    }

    :root {
        --font-size-result: 36px;
    }

    .panel {
        padding: 24px;
    }

    .result-area {
        padding: 32px 24px;
        min-height: 140px;
    }
}