/* ===== 基础样式 ===== */
:root {
    --primary-color: #1cc088;
    --primary-hover: #14a77e;
    --card-bg: #fff;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --border-color: #e0e6ed;
    --light-bg: #f5f7fa;
    --success-bg: #e8f5e9;
    --error-bg: #ffebee;
    --loading-bg: #e3f9f2;
    --nav-height: 70px;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-color: var(--light-bg);
    color: var(--text-dark);
    background-image: linear-gradient(135deg, #f5f7fa 0%, #e8f9f2 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ===== 布局样式 ===== */
.container {
    max-width: 1200px;
    margin: 30px auto;
    padding: 0 20px;
    width: 100% !important;
}

.card-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 25px;
    margin-bottom: 30px;
}

@media (min-width: 992px) {
    .card-grid {
        grid-template-columns: 1fr 1fr;
    }
}

/* ===== 导航栏样式 ===== */
.navbar {
    background-color: var(--card-bg);
    height: var(--nav-height);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-dark);
    text-decoration: none;
}

.logo i {
    color: var(--primary-color);
    font-size: 1.6rem;
}

.hamburger {
    display: none;
    cursor: pointer;
    padding: 10px;
    font-size: 1.5rem;
    color: var(--text-dark);
    background: none;
    border: none;
}

.nav-links {
    display: flex;
    gap: 25px;
}

.nav-link {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links .nav-link.active {
    font-weight: bold;
    color: #1CBE86;
}

.nav-link:hover {
    color: var(--primary-color);
}

.mobile-nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background-color: var(--card-bg);
    box-shadow: 0 10px 10px rgba(0,0,0,0.1);
    z-index: 99;
}

.mobile-nav-links.active {
    display: flex;
}

.mobile-nav-link {
    padding: 15px 20px;
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.3s;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.mobile-nav-link:hover {
    background-color: #f7f9fc;
    color: var(--primary-color);
}

/* ===== 标题样式 ===== */
.page-title {
    font-size: 2.2rem;
    margin-bottom: 8px;
    color: var(--text-dark);
    text-align: center;
}

.page-subtitle {
    font-size: 1.1rem;
    color: var(--text-light);
    text-align: center;
    margin-bottom: 40px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* ===== 卡片组件样式 ===== */
.card {
    background-color: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    padding: 25px;
    transition: all 0.3s ease;
    position: relative;
}

.card:hover {
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.card-icon {
    background-color: rgba(28, 192, 136, 0.15);
    width: 42px;
    height: 42px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 18px;
}

.card-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-dark);
}

/* ===== 上传区域样式 ===== */
.upload-area {
    border: 3px dashed var(--primary-color);
    border-radius: 12px;
    padding: 40px 20px;
    text-align: center;
    background-color: #f8f9fa;
    transition: all 0.3s;
    cursor: pointer;
    min-height: 240px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.upload-area:hover, .upload-area.drag-over {
    background-color: #e8f9f2;
    border-color: var(--primary-hover);
}

.upload-icon {
    font-size: 3.2rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.upload-text {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--text-dark);
    text-align: center;
    max-width: 90%;
}

.file-input {
    display: none;
}

.preview-container {
    text-align: center;
    margin: 25px 0 15px;
    display: none;
}

.preview-image {
    max-width: 100px;
    max-height: 100px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    object-fit: contain;
}

/* ===== 尺寸选择样式 ===== */
.sizes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
    gap: 15px;
    margin-bottom: 15px;
}

.size-option {
    padding: 16px 8px;
    text-align: center;
    background: #f1f5f9;
    border: 2px solid #dbe4f0;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: 500;
}

.size-option:hover {
    background: #e8f9f2;
    border-color: var(--primary-color);
}

.size-option.selected {
    background: #d6f7eb;
    border-color: var(--primary-color);
    color: var(--primary-color);
    font-weight: 600;
}

.size-option i {
    font-size: 0.8rem;
    margin-right: 5px;
}

.size-hint {
    background: #f3faf7;
    padding: 15px;
    border-radius: 8px;
    margin-top: 10px;
    border-left: 4px solid var(--primary-color);
    color: var(--text-light);
    font-size: 0.95rem;
}

.note {
    font-size: 14px;
    color: var(--text-light);
    margin-top: 8px;
    font-style: italic;
    text-align: center;
}

/* ===== 按钮样式 ===== */
.convert-btn {
    display: block;
    width: 100%;
    padding: 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}

.convert-btn:hover {
    background: var(--primary-hover);
    box-shadow: 0 5px 15px rgba(0,0,0,0.12);
}

.convert-btn:disabled {
    background: #bdc3c7;
    cursor: not-allowed;
    box-shadow: none;
}

.download-btn {
    display: inline-block;
    padding: 12px 25px;
    background: var(--primary-color);
    color: white;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: background 0.3s;
}

.download-btn:hover {
    background: var(--primary-hover);
}

/* ===== 结果区域样式 ===== */
.result-container {
    margin-top: 25px;
    display: none;
}

.result-box {
    padding: 25px;
    border-radius: 8px;
    margin-top: 10px;
    font-size: 1rem;
}

.success {
    background-color: var(--success-bg);
    border: 1px solid #66bb6a;
    color: #2e7d32;
}

.error {
    background-color: var(--error-bg);
    border: 1px solid #ef5350;
    color: #c62828;
}

.loading {
    background-color: var(--loading-bg);
    border: 1px solid var(--primary-color);
    color: #0d704f;
}

.filename {
    font-weight: 600;
    color: var(--text-dark);
    margin-top: 8px;
}

.download-container {
    margin-top: 20px;
    text-align: center;
    display: none;
}

/* ===== 页脚样式 ===== */
.footer {
    background-color: var(--card-bg);
    color: white;
    text-align: center;
    padding: 1rem 1rem;
    font-size: 0.95em;
    margin-top: auto;
}

.footer p {
    line-height: 1.6;
    color: var(--text-light);
}

.footer a {
    text-decoration: none;
    color: var(--text-dark);
}

.footer a:hover {
    color: #1cc088;
    text-decoration: none;
}

/* ===== 计数器样式 ===== */
.counter {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
    background-color: rgba(28, 192, 136, 0.1);
    padding: 8px 16px;
    border-radius: 50px;
    margin-top: 6px;
    margin-bottom: 10px;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

/* ===== 响应式设计 ===== */
@media (max-width: 991px) {
    .nav-links {
        display: none;
    }
    
    .hamburger {
        display: block;
    }
    
    .card-grid {
        gap: 20px;
    }
    
    .sizes-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    }
}

@media (max-width: 767px) {
    .page-title {
        font-size: 1.8rem;
    }
    
    .page-subtitle {
        font-size: 0.95rem;
    }
    
    .card {
        padding: 20px;
    }
    
    .upload-area {
        min-height: 200px;
    }
}