:root {
    --page-bg: #eef3f8;
    --surface: rgba(255, 255, 255, 0.92);
    --surface-strong: #ffffff;
    --text-main: #172033;
    --text-muted: #5a6678;
    --accent: #1267b7;
    --accent-strong: #0a4f8d;
    --accent-soft: #dfefff;
    --border: #c6d2df;
    --input-bg: #ffffff;
    --input-text: #101828;
    --danger: #b42318;
    --success: #147d4f;
    --shadow: 0 18px 40px rgba(22, 32, 51, 0.16);
    --hero-overlay: linear-gradient(90deg, rgba(238, 243, 248, 0.9), rgba(238, 243, 248, 0.7));
}

body.dark-mode {
    --page-bg: #080b14;
    --surface: rgba(14, 20, 38, 0.9);
    --surface-strong: #10182b;
    --text-main: #f6f8fb;
    --text-muted: #b8c5d8;
    --accent: #ffd166;
    --accent-strong: #f5b83f;
    --accent-soft: rgba(255, 209, 102, 0.15);
    --border: #263754;
    --input-bg: #111a2f;
    --input-text: #ffffff;
    --danger: #ff7a7a;
    --success: #5bd69f;
    --shadow: 0 18px 40px rgba(0, 0, 0, 0.35);
    --hero-overlay: linear-gradient(90deg, rgba(8, 11, 20, 0.92), rgba(8, 11, 20, 0.64));
}

* {
    box-sizing: border-box;
}

html {
    min-height: 100%;
}

body {
    min-height: 100vh;
    margin: 0;
    background: var(--page-bg);
    color: var(--text-main);
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.5;
}

body.auth-page {
    background-color: var(--page-bg);
    background-image: var(--hero-overlay), url("../images/frontPageEarth.jpg");
    background-position: center;
    background-size: cover;
    background-attachment: fixed;
}

a {
    color: var(--accent);
    font-weight: 700;
    text-decoration: none;
}

a:hover {
    color: var(--accent-strong);
    text-decoration: underline;
}

button,
input {
    font: inherit;
}

.site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    width: 100%;
    padding: 18px clamp(18px, 5vw, 64px);
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.brand {
    color: var(--text-main);
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: 0;
}

.brand:hover {
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 14px;
}

.nav-links a {
    color: var(--text-main);
    font-size: 0.96rem;
}

.theme-toggle-btn,
.primary-button,
.secondary-button,
.text-button,
.icon-button {
    min-height: 42px;
    border: 0;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 800;
}

.theme-toggle-btn {
    padding: 8px 14px;
    background: var(--accent-soft);
    color: var(--text-main);
    border: 1px solid var(--border);
}

.primary-button {
    width: 100%;
    padding: 11px 18px;
    background: var(--accent);
    color: #101828;
}

body:not(.dark-mode) .primary-button {
    color: #ffffff;
}

.primary-button:hover,
.theme-toggle-btn:hover {
    filter: brightness(0.96);
}

.secondary-button {
    padding: 10px 16px;
    background: var(--surface-strong);
    color: var(--text-main);
    border: 1px solid var(--border);
}

.text-button {
    padding: 8px 4px;
    background: transparent;
    color: var(--text-main);
}

.danger-text {
    color: var(--danger);
}

.compact-button {
    width: auto;
}

.landing-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(320px, 410px);
    gap: clamp(28px, 6vw, 80px);
    align-items: center;
    min-height: calc(100vh - 146px);
    width: min(1180px, calc(100% - 36px));
    margin: 0 auto;
    padding: 48px 0;
}

.center-layout {
    display: grid;
    place-items: center;
    min-height: calc(100vh - 80px);
    width: min(100%, 520px);
    margin: 0 auto;
    padding: 42px 18px;
}

.hero-copy {
    max-width: 650px;
}

.eyebrow {
    margin: 0 0 10px;
    color: var(--accent);
    font-size: 0.78rem;
    font-weight: 900;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.hero-copy h1,
.dashboard-heading h1,
.auth-card h1,
.auth-card h2 {
    margin: 0;
    color: var(--text-main);
    line-height: 1.05;
    letter-spacing: 0;
}

.hero-copy h1 {
    font-size: clamp(3rem, 8vw, 5.6rem);
}

.hero-subtitle {
    margin: 12px 0 0;
    color: var(--text-muted);
    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
    font-weight: 700;
}

.hero-text {
    max-width: 560px;
    margin: 22px 0 0;
    color: var(--text-main);
    font-size: 1.08rem;
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
    margin-top: 30px;
}

.feature-card,
.auth-card,
.controls-panel,
.contact-card,
.empty-state,
.modal-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.feature-card {
    min-height: 128px;
    padding: 16px;
}

.feature-card h2 {
    margin: 0 0 8px;
    color: var(--accent);
    font-size: 1.05rem;
}

.feature-card p,
.card-subtitle,
.auth-switch,
.empty-state p,
.welcome-text,
.contact-meta {
    color: var(--text-muted);
}

.feature-card p {
    margin: 0;
    font-size: 0.92rem;
}

.auth-card {
    width: 100%;
    padding: clamp(22px, 4vw, 34px);
}

.narrow-card {
    max-width: 440px;
}

.auth-card h1,
.auth-card h2 {
    font-size: 2rem;
}

.card-subtitle {
    margin: 10px 0 24px;
}

.form-field {
    display: grid;
    gap: 7px;
    margin-bottom: 16px;
}

.form-field label {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 800;
}

.form-field input,
.search-form input {
    width: 100%;
    min-height: 44px;
    padding: 10px 12px;
    background: var(--input-bg);
    color: var(--input-text);
    border: 1px solid var(--border);
    border-radius: 8px;
    outline: none;
}

.form-field input:focus,
.search-form input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.form-row {
    display: flex;
    align-items: center;
    gap: 14px;
}

.split-row {
    justify-content: space-between;
    margin: 4px 0 14px;
}

.check-label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-weight: 700;
}

.status-message {
    min-height: 22px;
    margin: 10px 0 14px;
    color: var(--text-muted);
    font-size: 0.94rem;
}

.status-message.error {
    color: var(--danger);
}

.status-message.success {
    color: var(--success);
}

.auth-switch {
    margin: 22px 0 0;
    text-align: center;
}

.site-footer {
    padding: 16px 18px;
    color: var(--text-muted);
    text-align: center;
}

.site-footer p {
    margin: 0;
    font-size: 0.9rem;
}

.dashboard-page {
    display: flex;
    flex-direction: column;
}

.dashboard-container {
    flex: 1;
    width: min(1180px, calc(100% - 36px));
    margin: 0 auto;
    padding: 34px 0 44px;
}

.dashboard-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 18px;
    margin-bottom: 20px;
}

.dashboard-heading h1 {
    font-size: clamp(2rem, 5vw, 3.2rem);
}

.controls-panel {
    padding: 16px;
    margin-bottom: 12px;
}

.search-form {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 12px;
}

.dashboard-status {
    margin-bottom: 18px;
}

.contacts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 18px;
}

.contact-card {
    display: grid;
    gap: 14px;
    padding: 18px;
}

.contact-card-header {
    display: flex;
    align-items: start;
    justify-content: space-between;
    gap: 12px;
}

.contact-name {
    margin: 0;
    color: var(--text-main);
    font-size: 1.2rem;
    line-height: 1.25;
}

.contact-meta {
    margin: 0;
    font-size: 0.88rem;
}

.contact-date-label,
.contact-date-value {
    display: block;
}

.contact-date-label {
    white-space: nowrap;
}

.contact-date-value {
    margin-top: 2px;
}

.delete-card-btn {
    min-height: 34px;
    padding: 7px 10px;
    background: transparent;
    color: var(--danger);
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    font-weight: 800;
}

.update-card-btn {
    min-height: 34px;
    padding: 7px 10px;
    background: transparent;
    color: var(--accent);
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    font-weight: 800;
}

.empty-state {
    padding: 34px;
    text-align: center;
}

.empty-state h2 {
    margin: 0 0 8px;
}

.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 20;
    display: grid;
    place-items: center;
    padding: 18px;
    background: rgba(0, 0, 0, 0.62);
}

.modal-card {
    position: relative;
    width: min(100%, 460px);
    padding: 26px;
}

.modal-card h2 {
    margin: 0 0 20px;
}

.icon-button {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 36px;
    min-height: 36px;
    background: transparent;
    color: var(--text-muted);
    border: 1px solid var(--border);
}

.form-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

[hidden] {
    display: none !important;
}

@media (max-width: 900px) {
    .landing-layout {
        grid-template-columns: 1fr;
        min-height: auto;
        padding: 36px 0;
    }

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

    .dashboard-heading {
        align-items: stretch;
        flex-direction: column;
    }

    .compact-button {
        width: 100%;
    }
}

@media (max-width: 640px) {
    .site-header {
        align-items: flex-start;
        flex-direction: column;
    }

    .nav-links {
        justify-content: flex-start;
        width: 100%;
    }

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

    .split-row {
        align-items: flex-start;
        flex-direction: column;
        gap: 8px;
    }
}