* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
:root {
    --primary: #3498db;
    --primary-dark: #2980b9;
    --success: #2ecc71;
    --success-dark: #27ae60;
    --danger: #e74c3c;
    --danger-dark: #c0392b;
    --light: #f8f9fa;
    --gray: #e9ecef;
    --dark: #343a40;
    --shadow: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-hover: 0 6px 16px rgba(0,0,0,0.12);
    --radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
body {
    font-family: "Inter", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px 16px;
    text-align: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4eaf5 100%);
    color: var(--dark);
    line-height: 1.6;
    min-height: 100vh;
}
.container {
    background-color: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    padding-bottom: 32px;
    position: relative;
    z-index: 1;
}
.page-header {
    padding: 24px 0;
    background: linear-gradient(120deg, var(--primary), var(--primary-dark));
    color: white;
    margin-bottom: 0;
}
.page-header h1 {
    font-size: 28px;
    font-weight: 600;
    margin-bottom: 8px;
}
.page-header p {
    font-size: 15px;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}
.tab-container {
    display: flex;
    margin-bottom: 0;
    background-color: white;
    border-bottom: 1px solid var(--gray);
}
.tab {
    padding: 16px 24px;
    cursor: pointer;
    background-color: transparent;
    border-radius: 0;
    margin-right: 0;
    flex: 1;
    transition: var(--transition);
    font-weight: 500;
    color: #6c757d;
    border-bottom: 3px solid transparent;
    font-size: 16px;
    position: relative;
    overflow: hidden;
}
.tab::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background-color: var(--primary);
    transition: var(--transition);
}
.tab.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}
.tab.active::after {
    width: 100%;
}
.tab:hover:not(.active) {
    color: var(--primary);
    background-color: rgba(52, 152, 219, 0.05);
}
.tab-content {
    display: none;
    padding: 40px 24px;
    border: none;
    border-radius: 0;
    background-color: white;
    position: relative;
}
.tab-content.active {
    display: block;
    border: 2px dashed var(--gray);
    border-radius: 0 0 var(--radius) var(--radius);
    margin: 0 24px;
    animation: fadeIn 0.5s ease;
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}
.tab-content h2 {
    color: var(--dark);
    margin-bottom: 12px;
    font-size: 22px;
    font-weight: 600;
}
.tab-content p {
    color: #6c757d;
    margin-bottom: 32px;
    font-size: 15px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}
.media-preview {
    max-width: 100%;
    max-height: 420px;
    margin: 24px auto;
    border: 1px solid var(--gray);
    border-radius: var(--radius);
    display: block;
    box-shadow: var(--shadow);
    transition: var(--transition);
    object-fit: contain;
    background-color: var(--light);
    cursor: pointer;
}
.media-preview:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-hover);
}
.video-container {
    position: relative;
    width: 100%;
    max-width: 850px;
    margin: 24px auto;
    background-color: #000;
    border-radius: var(--radius);
    overflow: hidden;
    display: none;
    box-shadow: var(--shadow-hover);
    aspect-ratio: 16 / 9;
}
.video-container video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.file-input-label, .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    min-width: 180px;
    box-sizing: border-box;
    white-space: nowrap;
    background-color: var(--primary);
    color: white;
    border-radius: var(--radius);
    cursor: pointer;
    margin: 12px 10px;
    text-align: center;
    border: none;
    transition: var(--transition);
    font-size: 16px;
    font-weight: 500;
    box-shadow: 0 3px 8px rgba(52, 152, 219, 0.2);
    position: relative;
    overflow: hidden;
}
.file-input-label::after, .btn::after {
    content: "";
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: 0.5s;
}
.file-input-label:hover::after, .btn:hover::after {
    left: 100%;
}
.file-input-label:hover, .btn:hover {
    background-color: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 6px 14px rgba(52, 152, 219, 0.3);
    color: white;
}
.btn-success {
    background-color: var(--success);
    box-shadow: 0 3px 8px rgba(46, 204, 113, 0.2);
}
.btn-success:hover {
    background-color: var(--success-dark);
    box-shadow: 0 6px 14px rgba(46, 204, 113, 0.3);
}
.btn-danger {
    background-color: var(--danger);
    box-shadow: 0 3px 8px rgba(231, 76, 60, 0.2);
}
.btn-danger:hover {
    background-color: var(--danger-dark);
    box-shadow: 0 6px 14px rgba(231, 76, 60, 0.3);
}
.status {
    margin: 24px 0;
    min-height: 28px;
    color: #6c757d;
    font-size: 16px;
    line-height: 1.5;
    padding: 8px 0;
}
.status.success {
    color: var(--success);
    font-weight: 500;
}
.status.error {
    color: var(--danger);
}
.progress-container {
    width: 100%;
    background-color: var(--gray);
    border-radius: 20px;
    margin: 20px 0;
    display: none;
    height: 12px;
    overflow: hidden;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
}
.progress-bar {
    height: 100%;
    border-radius: 20px;
    background: linear-gradient(90deg, var(--primary), var(--primary-dark));
    width: 0%;
    transition: width 0.3s ease;
    box-shadow: 0 0 10px rgba(52, 152, 219, 0.4);
    position: relative;
}
.progress-bar::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: progressFlow 1.5s infinite;
}
@keyframes progressFlow {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}
input[type="text"] {
    padding: 15px 20px;
    width: 80%;
    margin: 16px 0;
    border: 1px solid var(--gray);
    border-radius: var(--radius);
    font-size: 16px;
    transition: var(--transition);
    background-color: white;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.05);
}
input[type="text"]:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(52, 152, 219, 0.15);
}
.hidden {
    display: none !important;
}
.controls {
    margin-top: 32px;
}
#generate .file-input-label,
#generate #generateBtn {
    width: 160px !important;        
    min-width: 160px !important;    
    height: 52px !important;         
    padding: 0 !important;          
    margin: 12px 10px !important;         
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    box-sizing: border-box !important;
    line-height: 52px !important;    
    font-size: 16px !important;
    white-space: nowrap !important;
    vertical-align: middle !important;
}
.tab-content.drag-accept { 
    position: relative; 
}
.tab-content.drag-accept.dragover {
    border-color: var(--success);
    box-shadow: 0 0 0 4px rgba(46, 204, 113, 0.2) inset;
    background: rgba(46, 204, 113, 0.03);
}
.corner-links {
    position: fixed;
    right: 24px;
    bottom: 24px;
    display: flex;
    align-items: center;
    z-index: 9999;
}
.corner-link {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 18px;
    border-radius: var(--radius);
    color: var(--dark);
    text-decoration: none;
    transition: var(--transition);
    background-color: white;
    box-shadow: var(--shadow);
}
.corner-link:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    color: var(--primary);
}
.corner-link img,
.corner-link svg {
    width: 26px;
    height: 26px;
}
.corner-link .label {
    font-weight: 600;
    font-size: 16px;
}
.success-animation {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.8);
    width: 120px;
    height: 120px;
    background-color: rgba(46, 204, 113, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 0;
    transition: var(--transition);
    pointer-events: none;
}
.success-animation.active {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
}
.success-animation svg {
    width: 60px;
    height: 60px;
    fill: var(--success);
    animation: successPop 0.6s ease;
}
@keyframes successPop {
    0% { transform: scale(0); }
    70% { transform: scale(1.2); }
    100% { transform: scale(1); }
}
.success-animation::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 4px solid var(--success);
    animation: successRing 1.2s ease-out;
    opacity: 0;
}
@keyframes successRing {
    0% {
        transform: scale(0.8);
        opacity: 1;
        border-width: 4px;
    }
    100% {
        transform: scale(2);
        opacity: 0;
        border-width: 1px;
    }
}
@media (max-width: 768px) {
    .page-header h1 {
        font-size: 24px;
    }
    .tab-container {
        flex-direction: column;
    }
    .tab {
        padding: 14px 16px;
        font-size: 15px;
        text-align: left;
    }
    input[type="text"] {
        width: 95%;
        padding: 14px 18px;
        font-size: 15px;
    }
    .video-container {
        max-height: 320px;
    }
    .media-preview {
        max-height: 300px;
        margin: 20px auto;
    }
    .file-input-label, .btn {
        padding: 12px 24px;
        min-width: 160px;
        font-size: 15px;
        margin: 10px 6px;
    }
    .tab-content {
        padding: 32px 16px;
    }
    .tab-content.active {
        margin: 0 16px;
    }
    .corner-link {
        padding: 10px 14px;
    }
    .corner-link .label {
        font-size: 15px;
    }
}
@media (max-width: 480px) {
    body {
        padding: 16px 8px;
    }
    .container {
        border-radius: 8px;
        padding-bottom: 24px;
    }
    .page-header {
        padding: 20px 0;
    }
    .page-header h1 {
        font-size: 22px;
    }
    .page-header p {
        font-size: 14px;
        padding: 0 16px;
    }
    .tab {
        padding: 12px 16px;
        font-size: 14px;
    }
    .media-preview {
        max-height: 240px;
        margin: 16px auto;
    }
    .video-container {
        max-height: 280px;
    }
    .file-input-label, .btn {
        width: 90%;
        margin: 8px auto;
        display: flex;
        padding: 12px 20px;
    }
    #generate .file-input-label,
    #generate #generateBtn {
        width: 44% !important;
        margin: 8px 3% !important;
        padding: 0 !important;
        height: 48px !important;
        line-height: 48px !important;
        font-size: 14px !important;
    }
    input[type="text"] {
        padding: 12px 16px;
        font-size: 14px;
    }
    .corner-link .label {
        display: none;
    }
    .corner-link svg {
        width: 30px;
        height: 30px;
    }
    .success-animation {
        width: 100px;
        height: 100px;
    }
    .success-animation svg {
        width: 50px;
        height: 50px;
    }
}