/* --- Global Variables --- */
:root {
    --primary-blue: #007AFF;
    --accent-green: #34C759;
    --background-gradient-start: #FFFFFF;
    --background-gradient-end: #F5F5F7;
    --text-primary: #1D1D1F;
    --text-secondary: #6E6E73;
    --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --card-border-radius: 16px;
    --card-background: #FFFFFF;
    --input-border-color: #D1D1D6;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: linear-gradient(180deg, var(--background-gradient-start), var(--background-gradient-end));
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.main-header, main, .main-footer {
    width: 100%;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* --- Header & Navigation Styles --- */
.main-header {
    padding: 20px 0;
    border-bottom: 1px solid #EAEAEA;
    background-color: var(--background-gradient-start);
}

.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 20px;
    font-weight: 700;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    margin-right: 10px;
    font-size: 24px;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 30px;
}

.main-nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s ease;
}

.main-nav a:hover {
    color: var(--primary-blue);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* --- Button Styles --- */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
    width: 100%;
    text-align: center;
    border: 1px solid transparent;
    cursor: pointer;
    font-size: 16px;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background-color: var(--primary-blue);
    color: #FFF;
}

.btn-primary:hover:not(:disabled) {
    opacity: 0.9;
}

.btn-large {
    padding: 15px 30px;
    font-size: 16px;
    width: auto;
}

.btn-secondary {
    background-color: #fff;
    color: var(--text-primary);
    border: 1px solid var(--input-border-color);
}

.btn-secondary:hover:not(:disabled) {
    background-color: #f5f5f5;
}

/* --- Hero Section Styles --- */
.hero-section {
    text-align: center;
    padding: 100px 0;
}

.hero-section h1 {
    font-size: 56px;
    font-weight: 700;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.2;
}

.hero-section .subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    max-width: 650px;
    margin: 20px auto 40px;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
}

/* --- Features Section Styles --- */
.features-section {
    padding: 80px 0;
}

.section-title {
    font-size: 42px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 60px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    background-color: var(--card-background);
    border-radius: var(--card-border-radius);
    padding: 30px;
    box-shadow: var(--card-shadow);
    border: 1px solid #EAEAEA;
    position: relative;
}

.feature-card h3 {
    font-size: 22px;
    margin-bottom: 15px;
}

.feature-card p {
    color: var(--text-secondary);
}

.badge {
    position: absolute;
    top: 15px;
    background-color: var(--accent-green);
    color: #fff;
    padding: 4px 8px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 700;
}

.feature-badge {
    right: 15px;
}

/* --- Pricing Section Styles --- */
.pricing-section {
    padding: 80px 0;
    background-color: #FAFAFC;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    align-items: center;
}

.pricing-card {
    background-color: var(--card-background);
    border-radius: var(--card-border-radius);
    padding: 40px 30px;
    box-shadow: var(--card-shadow);
    border: 2px solid #EAEAEA;
    text-align: left;
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.2s ease;
}

.pricing-card.selected-plan {
    border-color: var(--primary-blue);
    transform: scale(1.05);
}

.pricing-card .badge {
    right: -40px;
    transform: rotate(45deg);
    padding: 5px 40px;
    top: 15px;
}

.pricing-card h3 {
    font-size: 24px;
    margin-bottom: 10px;
}

.pricing-card .price {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.pricing-card .price span {
    font-size: 48px;
    font-weight: 700;
    color: var(--text-primary);
}

.plan-features {
    list-style: none;
    margin-bottom: 40px;
    flex-grow: 1;
}

.plan-features li {
    margin-bottom: 15px;
    padding-left: 25px;
    position: relative;
}

.plan-features li::before {
    content: '✓';
    color: var(--accent-green);
    position: absolute;
    left: 0;
    font-weight: 700;
}

/* --- Generator and Form Styles --- */
.generator-section {
    padding: 80px 0;
}

.generator-container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--card-background);
    padding: 40px;
    border-radius: var(--card-border-radius);
    box-shadow: var(--card-shadow);
    border: 1px solid #EAEAEA;
}

.form-group {
    margin-bottom: 25px;
}

.form-group:last-child {
    margin-bottom: 0;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 8px;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.action-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

input[type="text"],
input[type="email"],
input[type="password"],
textarea,
select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--input-border-color);
    border-radius: 8px;
    font-size: 16px;
    font-family: 'Inter', sans-serif;
    background-color: #fff;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="password"]:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.1);
}

textarea {
    resize: vertical;
}

.result-box {
    width: 100%;
    min-height: 150px;
    background-color: #F5F5F7;
    border: 1px solid var(--input-border-color);
    border-radius: 8px;
    padding: 15px;
    color: var(--text-secondary);
    white-space: pre-wrap;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* --- Contact Section Styles --- */
.contact-section {
    padding: 80px 0;
    background-color: #FAFAFC;
}

.contact-section .subtitle {
    text-align: center;
    margin-top: -40px;
    margin-bottom: 40px;
    color: var(--text-secondary);
}

.contact-form {
    max-width: 700px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    position: relative;
}

.contact-form .input-wrapper {
    position: relative;
}

.contact-form .full-width {
    grid-column: 1 / -1;
}

.contact-form button {
    width: auto;
    padding-left: 40px;
    padding-right: 40px;
    justify-self: center;
    grid-column: 1 / -1;
}

#form-status {
    grid-column: 1 / -1;
    text-align: center;
    margin-top: 15px;
    font-weight: 500;
}
#form-status.success {
    color: var(--accent-green);
}
#form-status.error {
    color: red;
}

.error-message {
    color: red;
    font-size: 14px;
    height: 1em;
    margin-top: 4px;
}

/* --- Export Options Styles --- */
.export-options {
    display: flex;
    gap: 15px;
}

.export-btn {
    flex-grow: 1;
    padding: 10px;
    font-size: 16px;
    font-weight: 500;
    border: 1px solid var(--input-border-color);
    background-color: #fff;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
}

.export-btn:hover {
    border-color: var(--primary-blue);
    color: var(--primary-blue);
}

.export-btn.premium-feature {
    color: var(--text-secondary);
}

.export-btn.premium-feature span {
    background-color: var(--primary-blue);
    color: #fff;
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 4px;
    margin-left: 8px;
    font-weight: 700;
}

/* --- Footer Styles --- */
.main-footer {
    padding: 40px 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 14px;
    border-top: 1px solid #EAEAEA;
}

/* --- Loading Animation --- */
.loader {
    font-size: 10px;
    margin: 50px auto;
    text-indent: -9999em;
    width: 3em;
    height: 3em;
    border-radius: 50%;
    background: var(--primary-blue);
    background: linear-gradient(to right, var(--primary-blue) 10%, rgba(0, 122, 255, 0) 42%);
    position: relative;
    animation: load 1.4s infinite linear;
    transform: translateZ(0);
}
@keyframes load {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* --- 登录/注册弹窗样式 --- */
#auth-modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 1;
    transition: opacity 0.3s ease;
}

#auth-modal-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

#auth-modal {
    background: var(--card-background);
    padding: 40px;
    border-radius: var(--card-border-radius);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 420px;
    position: relative;
    transform: scale(1);
    transition: transform 0.3s ease;
}

#auth-modal-overlay.hidden #auth-modal {
    transform: scale(0.95);
}

#close-modal-btn {
    position: absolute;
    top: 15px;
    right: 15px;
    background: none;
    border: none;
    font-size: 28px;
    color: var(--text-secondary);
    cursor: pointer;
}

.auth-tabs {
    display: flex;
    border-bottom: 1px solid var(--input-border-color);
    margin-bottom: 30px;
}

.auth-tabs .tab-link {
    flex: 1;
    padding: 15px;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 18px;
    font-weight: 500;
    color: var(--text-secondary);
    border-bottom: 3px solid transparent;
}

.auth-tabs .tab-link.active {
    color: var(--text-primary);
    border-bottom-color: var(--primary-blue);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.tab-content h2 {
    font-size: 24px;
    text-align: center;
    margin-bottom: 20px;
}

.tab-content .input-wrapper {
    margin-bottom: 20px;
}

.btn.full-width {
    width: 100%;
}

.social-login {
    text-align: center;
    margin-top: 25px;
}

.social-login span {
    display: block;
    color: var(--text-secondary);
    margin-bottom: 15px;
    position: relative;
}
.social-login span::before, .social-login span::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 38%;
    height: 1px;
    background: var(--input-border-color);
}
.social-login span::before {
    left: 0;
}
.social-login span::after {
    right: 0;
}

.btn-social-google {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--input-border-color);
    background: #fff;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    border-radius: 8px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
}
.btn-social-google::before {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    background-image: url('https://upload.wikimedia.org/wikipedia/commons/c/c1/Google_%22G%22_logo.svg');
    background-size: contain;
    background-repeat: no-repeat;
}