:root {
    /* BACKGROUND COLORS */
    --bg-window: hsl(0, 0%, 80%);
    --tab-selected: hsl(0, 0%, 70%);
    --bg-content: hsl(0, 0%, 95%);

    /* BORDER COLORS */
    --border-light: hsl(0, 0%, 100%);
    --border-mid: hsl(0, 0%, 60%);
    --border-dark: hsl(0, 0%, 0%);
    --hover-border-light: hsl(0, 0%, 85%);
    --hover-border-dark: hsl(0, 0%, 25%);

    /* TEXT & ACCENT COLORS */
    --text-color: hsl(0, 0%, 0%);
    --accent: hsl(0, 0%, 0%);
    --heading-shadow: hsl(0, 0%, 100%);
    --heading-color: hsl(0, 0%, 15%);
    --paragraph-color: hsl(0, 0%, 10%);

    /* TITLE BAR COLORS */
    --titlebar-gradient-top: hsl(219, 100%, 47%);
    --titlebar-gradient-bottom: hsl(222, 88%, 56%);
    --titlebar-border-light: hsl(0, 0%, 100%);
    --titlebar-border-dark: hsl(0, 0%, 0%);
    --titlebar-text-shadow: hsl(0, 0%, 0%);
    --titlebar-text-color: hsl(0, 0%, 100%);

    /* WINDOW BUTTON COLORS */
    --window-button-bg: hsl(30, 10%, 80%);
    --window-button-hover-bg: hsl(45, 18%, 89%);
    --window-button-close-hover-bg: hsl(0, 100%, 50%);
    --window-button-close-hover-text: hsl(0, 0%, 100%);
    --window-button-border: hsl(0, 0%, 0%);
    --window-button-shadow: hsl(0, 0%, 100%);

    /* ARROW COLORS */
    --arrow-bg: hsl(0, 0%, 80%);
    --arrow-hover-bg: hsl(0, 0%, 70%);

    /* FONT */
    --font-main: "MS Sans Serif", Arial, sans-serif;
}

/* RESET */

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

html,
body {
    height: 100%;
    font-family: var(--font-main);
}

body {
    background-image: url("https://www.visitfinland.com/dam/jcr:e2a969ed-9f21-4e84-a944-3096a0d52059/Finland_Repovesi_np_sunset_optimized.jpg");
    background-repeat: no-repeat;
    background-size: cover;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

/* WINDOW */

.browser {
    width: 100%;
    max-width: 900px;
    height: 80vh;
    max-height: 700px;

    background: var(--bg-window);
    border-top: 3px solid var(--border-light);
    border-left: 3px solid var(--border-light);
    border-right: 3px solid var(--border-dark);
    border-bottom: 3px solid var(--border-dark);

    overflow: hidden;
    display: flex;
    flex-direction: column;
}

/* TITLE BAR */

.title-bar {
    background: linear-gradient(to bottom, var(--titlebar-gradient-top) 0%, var(--titlebar-gradient-bottom) 100%);
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 8px;
    color: var(--titlebar-text-color);
    font-weight: bold;
    font-size: 16px;
    border-top: 2px solid var(--titlebar-border-light);
    border-left: 2px solid var(--titlebar-border-light);
    border-right: 2px solid var(--titlebar-border-dark);
    border-bottom: 2px solid var(--titlebar-border-dark);
    user-select: none;
}

.title-text {
    text-shadow: 1px 1px 0 var(--titlebar-text-shadow);
    font-family: var(--font-main);
}

.window-buttons {
    display: flex;
    gap: 2px;
}

.win-btn {
    width: 32px;
    height: 24px;
    border: 1px solid var(--window-button-border);
    background: var(--window-button-bg);
    font-weight: bold;
    font-size: 12px;
    cursor: pointer;
    padding: 0;
    line-height: 1;
    box-shadow: inset 1px 1px 0 var(--window-button-shadow);
}

.win-btn:hover {
    background: var(--window-button-hover-bg);
}

.win-btn.close:hover {
    background: var(--window-button-close-hover-bg);
    color: var(--window-button-close-hover-text);
}

/* TAB */

.tab-bar {
    height: 48px;
    background: var(--bg-window);
    display: flex;
    align-items: center;
    padding: 0 12px;
    gap: 6px;
}

.tab {
    min-width: 110px;
    height: 34px;
    background: var(--bg-window);
    color: var(--text-color);
    display: flex;
    align-items: center;
    text-align: center;
    justify-content: center;
    font-size: 13px;
    font-weight: bold;
    cursor: pointer;
    padding: 0 16px;
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
    border-right: 2px solid var(--border-mid);
    border-bottom: 2px solid var(--border-mid);
}

.tab:hover {
    border-top: 2px solid var(--hover-border-light);
    border-left: 2px solid var(--hover-border-light);
    border-right: 2px solid var(--hover-border-dark);
    border-bottom: 2px solid var(--hover-border-dark);
}

.tab.active {
    background-color: var(--tab-selected);
    color: var(--text-color);
    border-top: 2px solid var(--border-mid);
    border-left: 2px solid var(--border-mid);
    border-right: 2px solid var(--border-light);
    border-bottom: 2px solid var(--border-light);
    text-transform: uppercase;
    padding-top: 1px;
}

.tab.active::after {
    content: "";
    height: 3px;
    background: var(--accent);
}

/* BAR */

.address-bar {
    display: flex;
    align-items: center;
    padding: 4px 12px;
    background: var(--bg-window);
    gap: 6px;
}

.address-bar input {
    flex: 1;
    height: 26px;
    font-size: 12px;
    padding: 0 6px;
    background: var(--bg-content);
    border-top: 2px solid var(--border-dark);
    border-left: 2px solid var(--border-dark);
    border-right: 2px solid var(--border-light);
    border-bottom: 2px solid var(--border-light);
    color: var(--text-color);
}

/* CONTENT BOX */

.content {
    flex: 1;
    padding: 22px;
    margin: 14px;
    overflow: hidden;
    background: var(--bg-content);
    border-top: 2px solid var(--border-mid);
    border-left: 3px solid var(--border-dark);
    border-right: 2.4px solid var(--border-light);
    border-bottom: 2.4px solid var(--border-light);
    position: relative;
    background-clip: padding-box;
}

.page {
    display: none;
}

.page.visible {
    display: block;
}

/* PAGE 1 */

#page1 {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--paragraph-color);
    height: 100%;
    padding: 24px;
    padding-top: 0;
    padding-bottom: 0;
    gap: 16px;
}

#page1 h1 {
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 18px;
    text-shadow: 1px 1px 0 var(--heading-shadow);
    color: var(--heading-color);
}

#page1 p {
    font-size: 16px;
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto;
}

#page1 img {
    width: 100%;
    max-width: 520px;
    height: auto;
    margin-top: 10px;
    border: 2px solid var(--border-dark);
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
}

.carousel {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    max-width: 510px;
    margin-top: 10px;
    margin: 0 auto;
}

.carousel img {
    width: 100%;
    height: auto;
    border: 2px solid var(--border-dark);
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
    transition: opacity 0.3s ease;
}

.arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 32px;
    height: 32px;
    background: var(--arrow-bg);
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
    border-right: 2px solid var(--border-dark);
    border-bottom: 2px solid var(--border-dark);
    cursor: pointer;
    font-weight: bold;
    font-size: 16px;
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s ease;
}

.arrow:hover {
    background: var(--arrow-hover-bg);
}

.arrow.left {
    left: -46px;
}

.arrow.right {
    right: -46px;
}

/* PAGE 2 */

#page2 {
    flex-direction: row;
    align-items: flex-start;
    gap: 32px;
    padding: 16px 24px;
    padding-top: 0;
    font-size: 15px;
    line-height: 1.6;
    color: var(--paragraph-color);
}

#page2.visible {
    display: flex;
}

.text-content {
    flex: 1;
    min-width: 0;
    padding-right: 16px;
}

#page2 h1 {
    font-size: 32px;
    font-weight: bold;
    text-shadow: 1px 1px 0 var(--heading-shadow);
    color: var(--heading-color);
}

#page2 p {
    margin-bottom: 16px;
    font-size: 15px;
}

#page2 ul {
    list-style-type: square;
    margin-left: 24px;
    margin-bottom: 20px;
}

#page2 li {
    margin-bottom: 8px;
}

.image-collage {
    margin-left: auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-self: flex-start;
}

.img-main {
    width: 260px;
    height: auto;
    object-fit: cover;
}

.bottom-row {
    display: flex;
    gap: 16px;
}

.img-small {
    width: 120px;
    height: 114px;
    object-fit: cover;
}

/* PAGE 3 */

#page3 {
    flex-direction: row;
    align-items: flex-start;
    justify-content: space-between;
    gap: 24px;
    padding-left: 20px;
    font-size: 16px;
    line-height: 1.6;
    color: var(--paragraph-color);
}

#page3.visible {
    display: flex;
}

#page3 .text-content {
    flex: 1;
    min-width: 0;
}

#page3 h1 {
    font-size: 32px;
    font-weight: bold;
    text-shadow: 1px 1px 0 var(--heading-shadow);
    color: var(--heading-color);
}

#page3 p {
    font-size: 16px;
    padding-bottom: 12px;
}

#page3 ul {
    list-style-type: square;
    margin-left: 24px;
}

#page3 li {
    margin-bottom: 10px;
    font-size: 14px;
}

#page3 a {
    text-decoration: none;
}

#page3 img {
    width: 275px;
    height: auto;
    object-fit: cover;
    margin-right: 12px;
    border: 2px solid var(--border-dark);
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
}

#page3 button {
    background: var(--bg-window);
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
    border-right: 2px solid var(--border-dark);
    border-bottom: 2px solid var(--border-dark);
    padding: 10px 20px;
    font-weight: bold;
    font-size: 14px;
    transition: all 0.2s ease;
    margin-top: 12px;
}

#page3 button:hover {
    background: var(--tab-selected);
}

/* PAGE 4 */

#page4 {
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    text-align: center;
    gap: 12px;
    height: 100%;
    color: var(--paragraph-color);
}

#page4.visible {
    display: flex;
}

#page4 .text-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 10px;
}

#page4 h1 {
    font-size: 32px;
    font-weight: bold;
    text-shadow: 1px 1px 0 var(--heading-shadow);
    color: var(--heading-color);
}

#page4 p {
    font-size: 16px;
    line-height: 1.6;
}

#page4 button {
    background: var(--bg-window);
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
    border-right: 2px solid var(--border-dark);
    border-bottom: 2px solid var(--border-dark);
    padding: 8px 16px;
    font-weight: bold;
    font-size: 14px;
    transition: all 0.2s ease;
}

#page4 button:hover {
    background: var(--tab-selected);
}

#page4 img {
    width: 100%;
    margin-top: -16px;
    max-width: 400px;
    height: auto;
    border: 2px solid var(--border-dark);
    border-top: 2px solid var(--border-light);
    border-left: 2px solid var(--border-light);
    align-self: center;
}