:root {
    --primary-color: #10B981;
    --primary-hover: #059669;
    --secondary-color: #f9fafb;
    --accent-color: #f59e0b;
    --text-color: #1f2937;
    --heading-color: #111827;
    --border-color: #d1d5db;
    --card-bg: #ffffff;
    --shadow-light: rgba(0, 0, 0, 0.05);
    --shadow-medium: rgba(0, 0, 0, 0.1);
    --font-primary: 'Inter', sans-serif;
    --font-body: 'Inter', sans-serif;
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 16px
}

html {
    box-sizing: border-box;
    font-size: 16px;
    scroll-behavior: smooth;
    overflow: auto
}

*,
:after,
:before {
    box-sizing: inherit
}

body {
    font-family: var(--font-body);
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--secondary-color);
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-primary);
    color: var(--heading-color);
    margin-top: 1.5em;
    margin-bottom: .6em;
    line-height: 1.3;
    font-weight: 600
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color .2s ease
}

a:hover {
    color: var(--primary-hover);
    text-decoration: none
}

.navbar {
    background: linear-gradient(135deg, var(--heading-color) 0, #374151 100%);
    padding: 1rem 1.5rem;
    box-shadow: 0 4px 12px var(--shadow-medium);
    position: sticky;
    top: 0;
    z-index: 1000
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center
}

.nav-brand {
    font-size: 1.6rem;
    font-weight: 700;
    color: #fff;
    display: flex;
    align-items: center;
    transition: transform .2s ease;
    gap: 10px
}

.nav-brand:hover {
    transform: scale(1.03);
    color: #fff
}

.nav-brand .fas {
    margin-right: .6rem;
    color: var(--primary-color);
    font-size: 1.5rem
}

.nav-search .search-form {
    display: flex;
    height: 40px
}

.nav-search .search-input {
    padding: .7rem 1rem;
    border: 1px solid var(--border-color);
    border-right: none;
    border-radius: var(--border-radius-md) 0 0 var(--border-radius-md);
    font-size: .95rem;
    min-width: 300px;
    background-color: #f3f4f6;
    color: var(--text-color);
    transition: all .2s ease
}

.nav-search .search-input:focus {
    outline: 0;
    border-color: var(--primary-color);
    background-color: var(--card-bg);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, .3)
}

.nav-search .search-btn {
    padding: .7rem 1.2rem;
    background-color: var(--primary-color);
    color: #fff;
    border: 1px solid var(--primary-color);
    border-radius: 0 var(--border-radius-md) var(--border-radius-md) 0;
    cursor: pointer;
    transition: background-color .2s ease, transform .1s ease
}

.nav-search .search-btn:hover {
    background-color: var(--primary-hover);
    transform: scale(1.05)
}

.nav-search .search-btn:active {
    transform: scale(.98)
}

.main-content {
    flex-grow: 1;
    padding: 2.5rem 1.5rem
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem
}

.character-title-main {
    font-family: var(--font-headings);
    font-size: 3rem;
    color: var(--primary-color-dark);
    margin: 0;
    line-height: 1.1;
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: var(--spacing-md, 1rem);
    margin-bottom: var(--spacing-sm, .5rem)
}

.character-header {
    display: flex;
    flex-wrap: wrap;
    gap: 2.5rem;
    padding: 2.5rem;
    background-color: var(--card-bg);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 10px 30px -10px var(--shadow-medium);
    margin-bottom: 3rem;
    align-items: center
}

.character-display {
    flex: 1 1 320px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 320px;
    padding: 1rem
}

.character-title {
    font-size: 3.5rem;
    margin-top: 0;
    margin-bottom: .75rem;
    color: var(--heading-color);
    font-weight: 700;
    line-height: 1.2
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 0;
    margin-bottom: 1.25rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: .75rem;
    display: flex;
    align-items: center;
    color: var(--heading-color)
}

.card-title .fas {
    margin-right: .85rem;
    color: var(--primary-color);
    font-size: 1.3rem;
    width: 24px;
    text-align: center
}

.word-characters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.25rem
}

.search-header {
    text-align: center;
    margin-bottom: 3rem
}

.search-title {
    font-size: 2.5rem;
    color: var(--heading-color);
    margin-bottom: .5rem
}

.search-query {
    color: var(--primary-color)
}

.result-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 4px 6px var(--shadow-light);
    padding: 1.5rem 2rem;
    transition: transform .3s ease, box-shadow .3s ease, border-color .3s ease;
    display: flex;
    flex-direction: column
}

.result-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px var(--shadow-medium);
    border-color: var(--primary-color)
}

.result-link {
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    flex-grow: 1
}

.result-chinese {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1.2;
    margin-bottom: .75rem
}

@media (max-width:992px) {
    .character-header {
        flex-direction: column;
        align-items: center;
        text-align: center
    }
}

@media (max-width:768px) {
    .nav-container {
        flex-direction: column;
        align-items: stretch;
        gap: .75rem
    }

    .nav-search {
        width: 100%
    }

    .nav-search .search-input {
        min-width: 0;
        width: calc(100% - 70px)
    }

    .character-title {
        font-size: 2.8rem
    }

    .main-content {
        padding: 2rem 1rem
    }

    .container {
        padding: 0 1rem
    }
}

@media (max-width:480px) {
    html {
        font-size: 15px
    }

    .nav-brand {
        font-size: 1.4rem
    }

    .nav-brand .fas {
        font-size: 1.3rem;
        margin-right: .6rem
    }

    .nav-search .search-input {
        font-size: .9rem;
        padding: .6rem .8rem
    }

    .nav-search .search-btn {
        padding: .6rem 1rem
    }

    .character-header {
        padding: 1.5rem
    }

    .character-title {
        font-size: 2.2rem
    }

    .card-title {
        font-size: 1.3rem
    }
}

:root {
    --primary-color: #10B981;
    --primary-hover: #059669;
    --secondary-color: #f9fafb;
    --accent-color: #f59e0b;
    --text-color: #1f2937;
    --heading-color: #111827;
    --border-color: #d1d5db;
    --card-bg: #ffffff;
    --shadow-light: rgba(0, 0, 0, 0.05);
    --shadow-medium: rgba(0, 0, 0, 0.1);
    --font-primary: 'Inter', sans-serif;
    --font-body: 'Inter', sans-serif;
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 16px
}

.words-container {
    margin: 2rem auto;
    padding: 2rem;
    margin-left: 5rem;
    margin-right: 5rem;
    background-color: var(--card-bg);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 10px 30px -10px var(--shadow-medium)
}

.words-header {
    text-align: center;
    margin-bottom: 2.5rem
}

.words-header h1 {
    font-size: 2.5rem;
    color: var(--heading-color);
    margin-bottom: .5rem
}

.words-header p {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 1.5rem
}

.data-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap
}

.action-btn {
    padding: .7rem 1.2rem;
    font-size: .95rem;
    font-weight: 600;
    border-radius: var(--border-radius-md);
    border: 1px solid var(--border-color);
    background-color: var(--card-bg);
    color: var(--text-color);
    cursor: pointer;
    transition: all .2s ease;
    display: inline-flex;
    align-items: center;
    gap: .5rem;
    min-width: 140px;
    justify-content: center
}

.action-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px var(--shadow-light)
}

.action-btn .fas {
    font-size: 1rem
}

.word-card-container {
    position: relative
}

.learn-toggle-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background-color: #e5e7eb;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    width: 30px;
    height: 30px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: .9rem;
    transition: background-color .2s, color .2s, border-color .2s;
    z-index: 2
}

.learn-toggle-btn:hover {
    background-color: #cff4d8;
    border-color: var(--primary-color)
}

.word-card.learned+.learn-toggle-btn:hover {
    background-color: #fed7d7;
    border-color: #e53e3e;
    color: #c53030
}

.learn-toggle-btn .icon-times {
    display: none
}

.learn-toggle-btn .icon-check {
    display: inline-block
}

.word-card.learned+.learn-toggle-btn:hover .icon-check {
    display: none
}

.word-card.learned+.learn-toggle-btn:hover .icon-times {
    display: inline-block
}

.word-card.learned+.learn-toggle-btn {
    background-color: var(--primary-color);
    color: #fff;
    opacity: 1;
    visibility: visible
}

.word-card.learned {
    opacity: .7;
    background-color: #f0fdf4;
    border-color: var(--primary-color)
}

.words-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 1.5rem;
    padding: .5rem
}

.word-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 1.5rem 1rem;
    background-color: var(--secondary-color);
    border-radius: var(--border-radius-md);
    border: 1px solid var(--border-color);
    text-decoration: none;
    transition: box-shadow .2s ease, border-color .2s ease, transform .2s ease;
    min-height: 120px
}

.word-card:hover {
    box-shadow: 0 8px 20px -5px var(--shadow-medium);
    border-color: var(--primary-color);
    transform: translateY(-2px)
}

.word-text {
    font-size: 2rem;
    font-weight: 600;
    color: var(--heading-color);
    margin-bottom: .5rem;
    text-align: center
}

.word-freq {
    font-size: .9rem;
    color: var(--text-color);
    background-color: #e5e7eb;
    padding: .2rem .6rem;
    border-radius: var(--border-radius-sm);
    text-align: center;
    white-space: nowrap
}

@media (max-width:1200px) {
    .words-container {
        margin-left: 3rem;
        margin-right: 3rem
    }

    .words-grid {
        grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
        gap: 1.25rem
    }
}

@media (max-width:992px) {
    .words-container {
        margin: 1.5rem auto;
        margin-left: 2rem;
        margin-right: 2rem;
        padding: 1.5rem
    }

    .words-header h1 {
        font-size: 2.2rem
    }

    .words-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
        gap: 1rem
    }

    .word-text {
        font-size: 1.8rem
    }

    .word-card {
        padding: 1.25rem .75rem;
        min-height: 110px
    }
}

@media (max-width:768px) {
    .words-container {
        margin: 1rem auto;
        margin-left: 1rem;
        margin-right: 1rem;
        padding: 1.25rem;
        border-radius: var(--border-radius-md)
    }

    .words-header {
        margin-bottom: 2rem
    }

    .words-header h1 {
        font-size: 2rem
    }

    .words-header p {
        font-size: 1rem;
        margin-bottom: 1.25rem
    }

    .data-actions {
        gap: .75rem;
        margin-bottom: 1.5rem
    }

    .action-btn {
        padding: .6rem 1rem;
        font-size: .9rem;
        min-width: 120px
    }

    .words-grid {
        grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
        gap: .875rem
    }

    .word-card {
        padding: 1rem .5rem;
        min-height: 100px
    }

    .word-text {
        font-size: 1.6rem;
        margin-bottom: .375rem
    }

    .word-freq {
        font-size: .8rem;
        padding: .15rem .5rem
    }

    .learn-toggle-btn {
        width: 28px;
        height: 28px;
        top: 8px;
        right: 8px;
        font-size: .8rem
    }
}

@media (max-width:480px) {
    html {
        font-size: 15px
    }

    .words-container {
        margin: .75rem auto;
        margin-left: .75rem;
        margin-right: .75rem;
        padding: 1rem;
        border-radius: var(--border-radius-md)
    }

    .words-header h1 {
        font-size: 1.8rem;
        margin-bottom: .375rem
    }

    .words-header p {
        font-size: .95rem;
        margin-bottom: 1rem;
        line-height: 1.5
    }

    .data-actions {
        flex-direction: column;
        align-items: center;
        gap: .5rem;
        margin-bottom: 1.25rem
    }

    .action-btn {
        padding: .6rem 1.5rem;
        font-size: .9rem;
        width: 100%;
        max-width: 200px
    }

    .words-grid {
        grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
        gap: .75rem;
        padding: .25rem
    }

    .word-card {
        padding: .875rem .375rem;
        min-height: 90px
    }

    .word-text {
        font-size: 1.4rem;
        margin-bottom: .25rem
    }

    .word-freq {
        font-size: .75rem;
        padding: .125rem .375rem
    }

    .learn-toggle-btn {
        width: 26px;
        height: 26px;
        top: 6px;
        right: 6px;
        font-size: .75rem
    }
}

@media (max-width:360px) {
    .words-container {
        margin: .5rem auto;
        margin-left: .5rem;
        margin-right: .5rem;
        padding: .875rem
    }

    .words-header h1 {
        font-size: 1.6rem
    }

    .words-grid {
        grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
        gap: .625rem
    }

    .word-card {
        padding: .75rem .25rem;
        min-height: 80px
    }

    .word-text {
        font-size: 1.25rem
    }

    .word-freq {
        font-size: .7rem
    }

    .learn-toggle-btn {
        width: 24px;
        height: 24px;
        top: 4px;
        right: 4px;
        font-size: .7rem
    }
}

@media (prefers-contrast:high) {
    .word-card {
        border-width: 2px
    }

    .action-btn {
        border-width: 2px
    }

    .learn-toggle-btn {
        border-width: 2px
    }
}

@media (prefers-reduced-motion:reduce) {

    .action-btn,
    .learn-toggle-btn,
    .word-card {
        transition: none
    }

    .word-card:hover {
        transform: none
    }

    .action-btn:hover {
        transform: none
    }
}