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

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --default-background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-radius: 16px;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 15px 40px rgba(0, 0, 0, 0.15);
}

html {
    min-height: 100vh;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    min-height: 100vh;
    padding: 20px;
    color: var(--text-primary);
    background: transparent;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 40px;
    padding: 20px;
}

header h1 {
    font-size: 3rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.95;
}

main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 40px;
}

section {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

section:hover {
    box-shadow: var(--shadow-hover);
}

h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.8rem;
}

h3 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

/* 输入组 */
.input-group {
    margin-bottom: 25px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-secondary);
}

input[type="date"] {
    width: 100%;
    padding: 12px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

input[type="date"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* 心情选择器 */
.mood-selector {
    margin-bottom: 25px;
}

.mood-options {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    margin-top: 15px;
}

.mood-btn {
    background: #f9fafb;
    border: 3px solid transparent;
    border-radius: 12px;
    padding: 20px 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.mood-btn:hover {
    background: #f3f4f6;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.mood-btn.selected {
    border-color: var(--primary-color);
    background: #eef2ff;
    transform: scale(1.05);
}

.mood-btn .emoji {
    font-size: 2.5rem;
}

.mood-btn .label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* 笔记输入 */
.note-group {
    margin-bottom: 25px;
}

textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.3s ease;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* 保存按钮 */
.save-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.save-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

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

/* 日历 */
.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.nav-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: var(--secondary-color);
    transform: scale(1.1);
}

.calendar {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 10px;
}

.calendar-day {
    aspect-ratio: 1;
    background: #f9fafb;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.calendar-day:hover {
    background: #f3f4f6;
    transform: scale(1.05);
}

.calendar-day.empty {
    background: transparent;
    cursor: default;
}

.calendar-day.empty:hover {
    transform: none;
}

.calendar-day.today {
    border: 2px solid var(--primary-color);
    font-weight: 700;
}

.calendar-day.has-mood {
    background: #eef2ff;
    border: 2px solid var(--primary-color);
}

.calendar-day .day-number {
    font-size: 0.9rem;
    color: var(--text-primary);
    margin-bottom: 5px;
}

.calendar-day .mood-emoji {
    font-size: 1.5rem;
}

/* 弹窗 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    background: white;
    margin: 10% auto;
    padding: 40px;
    border-radius: var(--border-radius);
    max-width: 500px;
    position: relative;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    position: absolute;
    right: 20px;
    top: 20px;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

.close:hover {
    color: var(--text-primary);
}

.modal-mood {
    text-align: center;
    margin: 20px 0;
    font-size: 4rem;
}

.modal-note {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
}

.delete-btn {
    width: 100%;
    padding: 12px;
    background: #ef4444;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.delete-btn:hover {
    background: #dc2626;
    transform: translateY(-2px);
}

/* 底部 */
footer {
    text-align: center;
    color: white;
    padding: 20px;
    font-size: 1.1rem;
}

/* 背景设置按钮 */
.bg-settings-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    border-radius: 50%;
    font-size: 2rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    z-index: 999;
}

.bg-settings-btn:hover {
    transform: scale(1.1) rotate(15deg);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* 背景设置弹窗 */
.bg-modal-content {
    max-width: 700px;
    max-height: 80vh;
    overflow-y: auto;
}

.bg-section {
    margin-bottom: 30px;
}

.bg-section h4 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.bg-options {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.bg-option {
    aspect-ratio: 16/9;
    border-radius: 12px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    border: 3px solid transparent;
    transition: all 0.3s ease;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: 10px;
}

.bg-option:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.bg-option.selected {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.bg-label {
    background: rgba(255, 255, 255, 0.9);
    padding: 5px 12px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* 上传部分 */
.upload-section {
    text-align: center;
}

.upload-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 10px;
}

.upload-btn:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
}

.upload-hint {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-top: 10px;
}

.preview-container {
    margin-top: 20px;
    position: relative;
}

.bg-preview {
    max-width: 100%;
    max-height: 300px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.remove-bg-btn {
    margin-top: 10px;
    background: #ef4444;
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.remove-bg-btn:hover {
    background: #dc2626;
}

/* 响应式设计 */
@media (max-width: 768px) {
    main {
        grid-template-columns: 1fr;
    }

    header h1 {
        font-size: 2rem;
    }

    .mood-options {
        grid-template-columns: repeat(2, 1fr);
    }

    .calendar {
        gap: 5px;
    }

    .calendar-day .mood-emoji {
        font-size: 1.2rem;
    }

    .modal-content {
        margin: 20% auto;
        padding: 30px 20px;
    }

    .bg-settings-btn {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
        top: 15px;
        right: 15px;
    }

    .bg-options {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .bg-modal-content {
        max-height: 90vh;
    }
}

/* 登录认证样式 */
.auth-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10000;
}

.auth-container {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 400px;
    width: 90%;
    animation: slideIn 0.5s ease;
}

.auth-header {
    text-align: center;
    margin-bottom: 30px;
}

.auth-header h2 {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 10px;
}

.auth-subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.auth-form h3 {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.auth-form .input-group {
    margin-bottom: 20px;
}

.auth-form .input-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-weight: 600;
}

.auth-form .input-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.auth-form .input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.auth-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.auth-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

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

.auth-switch {
    text-align: center;
    margin-top: 20px;
    color: var(--text-secondary);
}

.auth-switch a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.auth-switch a:hover {
    text-decoration: underline;
}

/* 用户信息显示 */
.user-info {
    position: fixed;
    top: 20px;
    left: 20px;
    background: rgba(255, 255, 255, 0.95);
    padding: 12px 20px;
    border-radius: 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    display: flex;
    align-items: center;
    gap: 15px;
    z-index: 998;
}

.user-info span {
    color: var(--primary-color);
    font-weight: 600;
}

.logout-btn {
    background: #ef4444;
    color: white;
    border: none;
    padding: 6px 15px;
    border-radius: 15px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.logout-btn:hover {
    background: #dc2626;
    transform: scale(1.05);
}