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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    height: 100vh;
    overflow: hidden;
    background-image: url('stadium-bg.jpg');
        
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
}

.container {
    position: relative;
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.stadium-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(ellipse at center, transparent 20%, rgba(0, 0, 0, 0.2) 80%);
    pointer-events: none;
}

/* 语言选择器 */
.language-selector {
    position: absolute;
    top: 20px;
    right: 20px;
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 10px;
    background: rgba(60, 60, 60, 0.9);
    padding: 8px 16px;
    border-radius: 25px;
    color: white;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.language-selector:hover {
    background: rgba(70, 70, 70, 0.95);
    transform: translateY(-1px);
}

.lang-flag-circle {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    background: linear-gradient(135deg, #ff0000 0%, #ffff00 100%);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

.lang-flag-circle.flag-china {
    background: linear-gradient(135deg, #ff0000 0%, #ffff00 100%);
}

.lang-flag-circle.flag-uk {
    background: linear-gradient(135deg, #012169 0%, #ffffff 50%, #c8102e 100%);
}

.lang-flag-circle.flag-india {
    background: linear-gradient(135deg, #ff9933 0%, #ffffff 50%, #138808 100%);
}

.lang-flag-circle.flag-korea {
    background: linear-gradient(135deg, #ffffff 0%, #c60c30 50%, #003478 100%);
}

.lang-flag-circle.flag-vietnam {
    background: linear-gradient(135deg, #da251d 0%, #ffff00 100%);
}

.lang-flag-circle.flag-taiwan {
    background: linear-gradient(135deg, #fe0000 0%, #000095 50%, #ffffff 100%);
}

.lang-text {
    font-weight: 500;
    letter-spacing: 0.5px;
}

.lang-arrow {
    font-size: 10px;
    color: #ccc;
    transition: transform 0.3s ease;
}

.language-selector:hover .lang-arrow {
    transform: translateY(1px);
}

/* 主表单容器 */
.main-form {
    position: relative;
    z-index: 10;
    background: rgba(45, 45, 45, 0.95);
    backdrop-filter: blur(15px);
    border-radius: 20px;
    padding: 30px;
    width: 400px;
    max-width: 90vw;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

/* Logo */
.logo {
    text-align: center;
    margin-bottom: 30px;
}

.logo-image {
    max-width: 200px;
    max-height: 80px;
    width: auto;
    height: auto;
    object-fit: contain;
}

/* 赞助商标签 */
.sponsor-tabs {
    display: flex;
    justify-content: center;
    margin-bottom: 30px;
}

.sponsor-image {
    width: 100%;
    max-width: 350px;
    height: auto;
    border-radius: 12px;
    object-fit: contain;
}

/* 表单内容 */
.form-content {
    transition: all 0.3s ease;
}

.form-content.hidden {
    display: none;
}

.input-group {
    position: relative;
    margin-bottom: 16px;
}

.input-icon {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: #999;
    font-size: 16px;
    z-index: 2;
}

.form-input {
    width: 100%;
    padding: 15px 15px 15px 45px;
    background: rgba(60, 60, 60, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: white;
    font-size: 14px;
    transition: all 0.3s ease;
}

.form-input:focus {
    outline: none;
    border-color: #4285f4;
    background: rgba(60, 60, 60, 0.9);
}

.form-input::placeholder {
    color: #999;
}

.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    font-size: 12px;
}

.checkbox-container {
    display: flex;
    align-items: center;
    color: #ccc;
    cursor: pointer;
    position: relative;
}

.checkbox-container input {
    opacity: 0;
    position: absolute;
}

.checkmark {
    width: 16px;
    height: 16px;
    background: rgba(60, 60, 60, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 3px;
    margin-right: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    color: transparent;
    transition: all 0.3s ease;
}

.checkbox-container input:checked+.checkmark {
    background: #4285f4;
    border-color: #4285f4;
    color: white;
}

.forgot-password {
    color: #4285f4;
    text-decoration: none;
    font-size: 12px;
}

.forgot-password:hover {
    text-decoration: underline;
}

.action-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #4285f4 0%, #1976d2 100%);
    border: none;
    border-radius: 8px;
    color: white;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 20px;
}

.action-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 5px 15px rgba(66, 133, 244, 0.4);
}

.action-btn.disabled {
    background: rgba(60, 60, 60, 0.5);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.bottom-links {
    display: flex;
    justify-content: space-around;
    margin-bottom: 0;
}

.link {
    color: #999;
    text-decoration: none;
    font-size: 12px;
    padding: 8px;
    border-radius: 4px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.link:hover {
    color: #4285f4;
    background: rgba(66, 133, 244, 0.1);
}

.terms {
    margin-bottom: 20px;
}

.terms .checkbox-container {
    font-size: 11px;
    line-height: 1.4;
    color: #999;
    align-items: flex-start;
}

.terms-link {
    color: #4285f4;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    font-size: 11px;
}

.terms-link:hover {
    color: #5a9bff;
    text-decoration: underline;
}

/* 密码找回页面 */
.forgot-password-page,
.verification-page {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(45, 45, 45, 0.95);
    backdrop-filter: blur(15px);
    border-radius: 20px;
    padding: 0;
    z-index: 20;
}

.forgot-password-page.hidden,
.verification-page.hidden {
    display: none;
}

.page-header {
    display: flex;
    align-items: center;
    padding: 20px 30px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    position: relative;
}

.back-btn {
    background: none;
    border: none;
    color: white;
    font-size: 18px;
    cursor: pointer;
    padding: 5px;
    margin-right: 15px;
}

.page-header h2 {
    color: white;
    font-size: 16px;
    font-weight: 500;
    flex: 1;
    text-align: center;
    margin-right: 30px;
}

.progress-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
}

.progress-step {
    flex: 1;
    background: rgba(255, 255, 255, 0.2);
    margin-right: 1px;
}

.progress-step.active {
    background: #4285f4;
}

.progress-step:last-child {
    margin-right: 0;
}

.forgot-content,
.verification-content {
    padding: 40px 30px;
    text-align: center;
}

.forgot-content h3,
.verification-content h3 {
    color: white;
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 15px;
}

.forgot-desc,
.verification-desc {
    color: #999;
    font-size: 14px;
    line-height: 1.5;
    margin-bottom: 30px;
}

/* 验证方式选择 */
.verification-options {
    margin-bottom: 30px;
}

.verification-option {
    display: flex;
    align-items: center;
    padding: 20px;
    background: rgba(60, 60, 60, 0.3);
    border-radius: 12px;
    margin-bottom: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.verification-option:hover {
    background: rgba(60, 60, 60, 0.5);
}

.option-icon {
    font-size: 24px;
    margin-right: 15px;
}

.option-content {
    flex: 1;
    text-align: left;
}

.option-title {
    color: white;
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 5px;
}

.option-desc {
    color: #999;
    font-size: 12px;
}

.option-arrow {
    color: #999;
    font-size: 18px;
}

.help-text {
    color: #999;
    font-size: 12px;
    line-height: 1.4;
}

.help-link {
    color: #4285f4;
    text-decoration: none;
}

.help-link:hover {
    text-decoration: underline;
}

/* 语言设置弹窗 */
.language-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    display: flex;
    align-items: flex-end;
    justify-content: center;
}

.language-modal.hidden {
    display: none;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
}

.modal-content {
    position: relative;
    background: white;
    border-radius: 20px 20px 0 0;
    width: 100%;
    max-width: 500px;
    max-height: 70vh;
    overflow: hidden;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px;
    border-bottom: 1px solid #eee;
}

.modal-header h3 {
    color: #333;
    font-size: 18px;
    font-weight: 500;
}

.close-btn {
    background: none;
    border: none;
    font-size: 24px;
    color: #999;
    cursor: pointer;
    padding: 5px;
}

.language-list {
    max-height: 400px;
    overflow-y: auto;
}

.language-item {
    display: flex;
    align-items: center;
    padding: 15px 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.language-item:hover {
    background: #f5f5f5;
}

.language-item.active {
    background: #f0f8ff;
}

.language-item .lang-flag {
    font-size: 20px;
    margin-right: 15px;
}

.language-item .lang-name {
    flex: 1;
    color: #333;
    font-size: 16px;
}

.check-mark {
    color: #4285f4;
    font-size: 18px;
    font-weight: bold;
}

/* 响应式设计 */
@media (max-width: 480px) {
    body {
        background-image: url('bg2.png');
    }
    
    .main-form {
        width: 95vw;
        padding: 20px;
        margin: 10px;
    }

    .sponsor-tabs {
        flex-direction: column;
        gap: 8px;
    }

    .sponsor-tab {
        flex-direction: row;
        text-align: left;
        padding: 12px;
    }

    .sponsor-tab img,
    .sponsor-logo {
        margin-right: 12px;
        margin-bottom: 0;
    }

    .sponsor-info {
        align-items: flex-start;
    }

    .bottom-links {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }

    .language-selector {
        top: 10px;
        right: 10px;
        padding: 6px 12px;
        font-size: 11px;
    }

    .page-header {
        padding: 15px 20px;
    }

    .forgot-content,
    .verification-content {
        padding: 30px 20px;
    }
}

@media (max-width: 360px) {
    .main-form {
        padding: 15px;
    }

    .form-input {
        padding: 12px 12px 12px 40px;
    }

    .action-btn {
        padding: 12px;
    }

    .sponsor-image {
        max-width: 100%;
        border-radius: 8px;
    }
}

/* 平板响应式 */
@media (min-width: 481px) and (max-width: 768px) {
    .main-form {
        width: 450px;
    }

    .modal-content {
        border-radius: 20px;
        margin: 20px;
        max-height: 80vh;
    }
}

/* 大屏幕优化 */
@media (min-width: 1200px) {
    .main-form {
        width: 420px;
    }
}