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

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --bg: #f1f5f9;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --success: #16a34a;
    --accent: #0f766e;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}

.hidden {
    display: none !important;
}

/* Screens */
.screen {
    min-height: 100vh;
}

/* Landing Page */
.landing-page {
    display: block;
    background: var(--bg);
}

/* Landing Nav */
.landing-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 2rem;
    background: rgba(30, 58, 95, 0.95);
    backdrop-filter: blur(8px);
    color: white;
}

.landing-logo {
    font-weight: 700;
    font-size: 1.1rem;
}

.landing-nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.landing-nav-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.landing-nav-links a:hover {
    color: white;
}

.btn-nav {
    padding: 0.45rem 1.25rem;
    font-size: 0.85rem;
    color: white;
}

/* Hero */
.hero {
    background: linear-gradient(135deg, #1e3a5f 0%, #0f766e 100%);
    color: white;
    padding: 8rem 2rem 5rem;
    text-align: center;
}

.hero-content {
    max-width: 750px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 2.75rem;
    line-height: 1.2;
    margin-bottom: 1.25rem;
}

.hero-subtitle {
    font-size: 1.15rem;
    line-height: 1.6;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.hero-outputs {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 1.5rem 2rem;
    text-align: left;
    display: inline-block;
    margin-bottom: 2rem;
}

.hero-outputs h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    opacity: 0.8;
    margin-bottom: 0.75rem;
}

.hero-outputs ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.hero-outputs li::before {
    content: "\2713  ";
    color: #6ee7b7;
    font-weight: 700;
}

.hero-outputs li {
    font-size: 0.95rem;
}

.hero-tagline {
    font-size: 1rem;
    opacity: 0.85;
    margin-bottom: 2rem;
    font-style: italic;
}

.btn-hero {
    padding: 1rem 3rem;
    font-size: 1.15rem;
    border-radius: 10px;
}

/* Landing Sections */
.landing-section {
    padding: 5rem 2rem;
}

.landing-section.alt-bg {
    background: white;
}

.section-inner {
    max-width: 800px;
    margin: 0 auto;
}

.landing-section h2 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
    color: var(--text);
}

.section-lead {
    font-size: 1.05rem;
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 2rem;
}

/* Feature Cards */
.feature-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.feature-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.alt-bg .feature-card {
    background: var(--bg);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 0.75rem;
}

.feature-card h3 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.feature-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.5;
}

.section-note {
    font-size: 0.9rem;
    color: var(--text-muted);
    background: white;
    border-left: 3px solid var(--accent);
    padding: 1rem 1.25rem;
    border-radius: 0 8px 8px 0;
}

.alt-bg .section-note {
    background: var(--bg);
}

/* Input List */
.input-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.input-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.25rem;
    background: var(--bg);
    border-radius: 8px;
}

.input-item strong {
    font-size: 0.95rem;
}

.input-item span {
    color: var(--text-muted);
    font-size: 0.85rem;
    text-align: right;
}

.section-tip {
    font-size: 0.9rem;
    color: var(--accent);
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    padding: 1rem 1.25rem;
    border-radius: 8px;
}

/* Output Explainer */
.output-explainer {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.output-card {
    display: flex;
    gap: 1.25rem;
    padding: 1.5rem;
    background: white;
    border: 1px solid var(--border);
    border-radius: 12px;
}

.output-num {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, #1e3a5f, #0f766e);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

.output-detail h3 {
    font-size: 1.05rem;
    margin-bottom: 0.5rem;
}

.output-detail p {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.5;
    margin-bottom: 0.35rem;
}

/* Steps */
.steps {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.step {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.25rem;
    background: var(--bg);
    border-radius: 8px;
}

.step-num {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    background: var(--accent);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
}

.step p {
    font-size: 0.95rem;
}

.subsection-title {
    font-size: 1.2rem;
    margin-bottom: 1rem;
}

.usage-steps {
    padding-left: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.usage-steps li {
    font-size: 0.92rem;
    line-height: 1.5;
    color: var(--text-muted);
}

/* FAQ */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.faq-item {
    background: white;
    border: 1px solid var(--border);
    border-radius: 10px;
    overflow: hidden;
}

.faq-item summary {
    padding: 1rem 1.25rem;
    font-weight: 600;
    cursor: pointer;
    font-size: 0.95rem;
    transition: background 0.15s;
    list-style: none;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::before {
    content: "+  ";
    font-weight: 700;
    color: var(--accent);
}

.faq-item[open] summary::before {
    content: "\2212  ";
}

.faq-item summary:hover {
    background: var(--bg);
}

.faq-item p {
    padding: 0 1.25rem 1rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* Notes */
.notes-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.notes-list li {
    padding: 0.75rem 1rem;
    background: var(--bg);
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.5;
    padding-left: 2.5rem;
    position: relative;
}

.notes-list li::before {
    content: "!";
    position: absolute;
    left: 1rem;
    font-weight: 700;
    color: #f59e0b;
}

/* Sign In Overlay */
.sign-in-overlay {
    position: fixed;
    inset: 0;
    z-index: 300;
    display: flex;
    align-items: center;
    justify-content: center;
}

.sign-in-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

.sign-in-modal {
    position: relative;
    z-index: 1;
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-card {
    background: var(--card-bg);
    padding: 3rem;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

.login-card h2 {
    margin-bottom: 0.5rem;
}

/* Auth forms */
.auth-toggle {
    margin-top: 1rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

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

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

.form-error {
    color: #dc2626;
    font-size: 0.85rem;
    background: #fef2f2;
    border: 1px solid #fecaca;
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    margin: 0.5rem 0;
}

#signup-form, #manual-login {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

#signup-form input {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

#signup-form input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Landing Footer */
.landing-footer {
    background: var(--text);
    color: rgba(255, 255, 255, 0.7);
    text-align: center;
    padding: 2rem;
    font-size: 0.85rem;
}

.footer-note {
    margin-top: 0.5rem;
    opacity: 0.5;
    font-size: 0.75rem;
}

.login-card h1 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.subtitle {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.divider {
    display: flex;
    align-items: center;
    margin: 1.5rem 0;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    border-bottom: 1px solid var(--border);
}

.divider span {
    padding: 0 1rem;
}

#manual-login {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

#manual-login input {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

#manual-login input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

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

.btn-secondary {
    background: var(--border);
    color: var(--text);
}

.btn-secondary:hover {
    background: #cbd5e1;
}

.btn-small {
    padding: 0.4rem 0.75rem;
    font-size: 0.8rem;
    background: rgba(255, 255, 255, 0.15);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 6px;
}

.btn-small:hover {
    background: rgba(255, 255, 255, 0.25);
}

/* Profile Dropdown */
.profile-dropdown {
    position: relative;
}

.profile-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    padding: 0.35rem 0.75rem;
    color: white;
    cursor: pointer;
    transition: background 0.2s;
    font-size: 0.9rem;
}

.profile-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.dropdown-arrow {
    font-size: 0.65rem;
    opacity: 0.7;
}

.profile-menu {
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    background: white;
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    min-width: 160px;
    overflow: hidden;
    z-index: 100;
}

.profile-menu a {
    display: block;
    padding: 0.7rem 1rem;
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    transition: background 0.15s;
}

.profile-menu a:hover {
    background: var(--bg);
}

.credits-badge {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    padding: 0.35rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.credits-badge.low {
    background: rgba(239, 68, 68, 0.3);
    border-color: rgba(239, 68, 68, 0.5);
}

/* Header */
header {
    background: linear-gradient(135deg, #1e3a5f 0%, #0f766e 100%);
    color: white;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.15);
}

header h1 {
    font-size: 1.4rem;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.5);
}

#user-name {
    font-size: 0.9rem;
}

/* Main Layout */
main {
    padding: 2rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

/* Panels */
.panel {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.panel h2 {
    font-size: 1.2rem;
    margin-bottom: 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border);
    color: var(--text);
}

/* Form Grid */
.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group {
    position: relative;
}

.form-group label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 0.3rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

/* Info icon tooltip */
.info-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 13px;
    height: 13px;
    border-radius: 50%;
    background: none;
    border: 1px solid #b0b8c4;
    color: #94a3b8;
    font-size: 0.5rem;
    font-weight: 600;
    font-style: italic;
    text-transform: lowercase;
    cursor: help;
    position: relative;
    vertical-align: middle;
    margin-left: 4px;
    overflow: visible;
}

.info-icon::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 6px);
    left: 50%;
    transform: translateX(-50%);
    background: var(--text);
    color: white;
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 400;
    font-style: normal;
    text-transform: none;
    letter-spacing: normal;
    white-space: normal;
    max-width: 250px;
    line-height: 1.4;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.2s, visibility 0.2s;
    z-index: 10;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.info-icon:hover::after {
    opacity: 1;
    visibility: visible;
}

.form-group input {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.95rem;
    transition: border-color 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group .unit {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(25%);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.form-actions {
    margin-top: 1.5rem;
    display: flex;
    gap: 0.75rem;
}

.form-actions .btn {
    flex: 1;
}

/* Output Results */
.placeholder-text {
    text-align: center;
    color: var(--text-muted);
    padding: 3rem 1rem;
    font-size: 0.95rem;
    border: 2px dashed var(--border);
    border-radius: 8px;
}

.results {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.result-card {
    display: flex;
    align-items: center;
    padding: 1.25rem;
    background: linear-gradient(135deg, #f0fdf4 0%, #ecfdf5 100%);
    border: 1px solid #bbf7d0;
    border-radius: 10px;
    transition: transform 0.2s;
}

.result-card:hover {
    transform: translateX(4px);
}

.result-label {
    flex: 1;
    font-weight: 600;
    color: var(--text);
    font-size: 0.95rem;
}

.result-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent);
    margin: 0 0.5rem;
    min-width: 80px;
    text-align: right;
}

/* Loading spinner */
.btn.loading {
    pointer-events: none;
    opacity: 0.7;
    position: relative;
}

.btn.loading::after {
    content: '';
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: translateY(-50%) rotate(360deg); }
}

/* Toast messages */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    z-index: 500;
    animation: slideIn 0.3s ease;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.toast.error {
    background: #dc2626;
    color: white;
}

.toast.success {
    background: #16a34a;
    color: white;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-50%) translateY(20px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

.btn-download {
    width: 100%;
    margin-top: 1rem;
}

.result-unit {
    font-size: 0.8rem;
    color: var(--text-muted);
    min-width: 30px;
}

/* Account Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
}

.account-modal {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    max-width: 420px;
    width: 90%;
    position: relative;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.25);
}

.modal-close {
    position: absolute;
    top: 0.75rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-muted);
    cursor: pointer;
    line-height: 1;
}

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

.account-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding-bottom: 1.25rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1.25rem;
}

.account-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid var(--border);
}

.account-header h3 {
    font-size: 1.1rem;
    margin-bottom: 0.15rem;
}

.account-email {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.account-section {
    margin-bottom: 1.25rem;
}

.account-section h4 {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.account-stats {
    display: flex;
    gap: 0.75rem;
}

.account-stat {
    flex: 1;
    text-align: center;
    padding: 0.75rem;
    background: var(--bg);
    border-radius: 8px;
}

.account-stat.highlight {
    background: linear-gradient(135deg, #f0fdf4 0%, #ecfdf5 100%);
    border: 1px solid #bbf7d0;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
}

.account-stat.highlight .stat-value {
    color: var(--accent);
}

.stat-label {
    display: block;
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.2rem;
    text-transform: uppercase;
}

.account-next-price {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

/* Mill Tabs */
.mill-tabs {
    display: flex;
    gap: 0.5rem;
    max-width: 1200px;
    margin: 0 auto 1.5rem;
    padding: 0 0;
}

.mill-tab {
    flex: 1;
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--border);
    border-radius: 10px;
    background: white;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
}

.mill-tab:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.mill-tab.active {
    background: linear-gradient(135deg, #1e3a5f 0%, #0f766e 100%);
    color: white;
    border-color: transparent;
}

.mill-label {
    font-size: 0.85rem;
    font-weight: 400;
    color: var(--accent);
}

/* No Credits Gate */
#no-credits-gate {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 70px);
    padding: 2rem;
}

.gate-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 3rem;
    text-align: center;
    max-width: 450px;
    width: 100%;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.gate-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.gate-card h2 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text);
}

.gate-card p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

.gate-price {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 1.5rem;
}

.gate-credits {
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-muted);
    display: block;
    margin-top: 0.25rem;
}

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
}

/* Mock Payment Modal */
.mock-payment-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.mock-payment-modal {
    background: white;
    border-radius: 16px;
    padding: 2.5rem;
    text-align: center;
    max-width: 360px;
    width: 90%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.mock-payment-modal h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--text);
}

.mock-amount {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent);
    margin: 0.5rem 0;
}

.mock-desc {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.mock-actions {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.mock-actions .btn {
    flex: 1;
}

.mock-note {
    font-size: 0.75rem;
    color: var(--text-muted);
    line-height: 1.4;
}

/* Responsive */
@media (max-width: 900px) {
    .container {
        grid-template-columns: 1fr;
    }

    .form-grid {
        grid-template-columns: 1fr;
    }

    header {
        flex-direction: column;
        gap: 0.75rem;
        text-align: center;
    }

    .feature-cards {
        grid-template-columns: 1fr;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .landing-nav-links a:not(.btn-nav) {
        display: none;
    }

    .input-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.25rem;
    }

    .input-item span {
        text-align: left;
    }

    .output-card {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .login-card {
        margin: 1rem;
        padding: 2rem 1.5rem;
    }

    main {
        padding: 1rem;
    }

    .panel {
        padding: 1rem;
    }

    .hero {
        padding: 6rem 1rem 3rem;
    }

    .hero h1 {
        font-size: 1.6rem;
    }

    .landing-section {
        padding: 3rem 1rem;
    }
}